Merge remote-tracking branch 'origin/master' into feat/web-cards-toolrow

# Conflicts:
#	packages/client/connection/src/client/fixture.ts
#	packages/client/ui-conversation/README.i18n.yaml
#	packages/client/ui-conversation/src/client/apply.ts
#	packages/client/ui-conversation/src/client/chat/GenericToolCard.tsx
#	packages/client/ui-conversation/src/client/skeleton/DetailsPanel.tsx
#	packages/client/ui-conversation/src/client/toolviews/file-mutation-row.tsx
#	packages/client/ui-conversation/src/client/toolviews/search-row.tsx
#	packages/client/ui-conversation/tests/chat-apply.spec.tsx
#	packages/client/ui-primitives/src/index.ts

packages/client/connection/src/client/fixture.ts

@@ -15,6 +15,7 @@ import type {
   AssistantMessage,
   ContentBlock,
   MessageSource,
+  TokenUsage,
   ToolResultMessage,
   UserMessage,
 } from '@deepseek-ai/dsh-llm'
@@ -138,34 +139,7 @@ const TERMINAL_EXIT_STATUS: Record<string, { exitCode: number } | { signal: stri
 }
 
 /**
- * Read-card sample for the read turn: a WINDOW past an offset, so the line
- * numbers start above 1 (the card's gutter keeps the file's own numbering) and
- * `totalLines` exceeds the window (the card shows a "showing N of M" note). The
- * fixture is client-side and cannot import the read tool, so the structured
- * window is authored inline exactly as the tool would project it through
- * `presentationMeta`. `lang` is a `ts` hint so the shiki path highlights it.
- */
-const READ_SAMPLE_FIRST_LINE = 41
-const READ_SAMPLE_SOURCE = [
-  'export interface ReadBlockProps {',
-  '  label?: string | undefined',
-  '  lines: readonly ReadBlockLine[]',
-  '  totalLines: number',
-  '  lang?: string | undefined',
-  '  maxLines?: number | undefined',
-  '  className?: string | undefined',
-  '}',
-  '',
-  '// A windowed read keeps the file line numbers in the gutter.',
-  'const marker = "fixture read sample"',
-]
-const READ_SAMPLE_LINES = READ_SAMPLE_SOURCE.map((text, index) => ({ number: READ_SAMPLE_FIRST_LINE + index, text }))
-const READ_SAMPLE_PATH = 'packages/client/ui-primitives/src/ReadBlock.tsx'
-const READ_SAMPLE_TOTAL = 180
-const READ_SAMPLE_TEXT = READ_SAMPLE_SOURCE.map((text, index) => `${READ_SAMPLE_FIRST_LINE + index}: ${text}`).join('\n')
-
-/**
- * Structured grep result for the search sample (turn 68): matches grouped by
+ * Structured grep result for the search sample (turn 66): matches grouped by
  * file, authored inline because the client-side fixture cannot import the tool
  * that produces the canonical value. `truncated` with a larger `total` than the
  * retained match count exercises the search card's capped indicator; the file
@@ -211,11 +185,11 @@ const SEARCH_MATCHES_TEXT = [
   ...SEARCH_MATCHES_FIXTURE.map(file =>
     [file.path, ...file.matches.map(m => `Line ${m.lineNumber}: ${m.line}`)].join('\n')),
   '',
-  '(Full grep result stored at: fixture://spill/grep-68. Read it to see every match.)',
+  '(Full grep result stored at: fixture://spill/grep-66. Read it to see every match.)',
 ].join('\n')
 
 /**
- * Structured glob result for the search sample (turn 69): a flat path list,
+ * Structured glob result for the search sample (turn 67): a flat path list,
  * truncated with a larger `total` so the path card shows its capped indicator.
  */
 const SEARCH_PATHS_FIXTURE = [
@@ -234,11 +208,38 @@ const SEARCH_PATHS_FIXTURE = [
 const SEARCH_PATHS_TEXT = [
   ...SEARCH_PATHS_FIXTURE,
   '',
-  '(Showing 5 of 23 paths. Full sorted result stored at: fixture://spill/glob-69. Read it to see every path.)',
+  '(Showing 5 of 23 paths. Full sorted result stored at: fixture://spill/glob-67. Read it to see every path.)',
 ].join('\n')
 
 /**
- * The structured `web_search` result view for fixture turn 70, authored inline
+ * Read-card sample for the read turn: a WINDOW past an offset, so the line
+ * numbers start above 1 (the card's gutter keeps the file's own numbering) and
+ * `totalLines` exceeds the window (the card shows a "showing N of M" note). The
+ * fixture is client-side and cannot import the read tool, so the structured
+ * window is authored inline exactly as the tool would project it through
+ * `presentationMeta`. `lang` is a `ts` hint so the shiki path highlights it.
+ */
+const READ_SAMPLE_FIRST_LINE = 41
+const READ_SAMPLE_SOURCE = [
+  'export interface ReadBlockProps {',
+  '  label?: string | undefined',
+  '  lines: readonly ReadBlockLine[]',
+  '  totalLines: number',
+  '  lang?: string | undefined',
+  '  maxLines?: number | undefined',
+  '  className?: string | undefined',
+  '}',
+  '',
+  '// A windowed read keeps the file line numbers in the gutter.',
+  'const marker = "fixture read sample"',
+]
+const READ_SAMPLE_LINES = READ_SAMPLE_SOURCE.map((text, index) => ({ number: READ_SAMPLE_FIRST_LINE + index, text }))
+const READ_SAMPLE_PATH = 'packages/client/ui-primitives/src/ReadBlock.tsx'
+const READ_SAMPLE_TOTAL = 180
+const READ_SAMPLE_TEXT = READ_SAMPLE_SOURCE.map((text, index) => `${READ_SAMPLE_FIRST_LINE + index}: ${text}`).join('\n')
+
+/**
+ * The structured `web_search` result view for the web-search turn, authored inline
  * because this client-side fixture cannot import the web tool that projects it.
  * The sources exercise the citation list's features: a titled source with a
  * snippet and a date, a source with no title (its hostname labels the link) and
@@ -268,7 +269,7 @@ const WEB_SEARCH_RESULT: Omit<Extract<ToolResultView, { card: 'web'; kind: 'sear
   truncated: true,
 }
 
-/** The `web_fetch` result view for fixture turn 71, authored inline for the same reason. */
+/** The `web_fetch` result view for the web-fetch turn, authored inline for the same reason. */
 const WEB_FETCH_RESULT: Omit<Extract<ToolResultView, { card: 'web'; kind: 'fetch' }>, 'card' | 'kind'> = {
   url: 'https://www.deepseek.com/blog/harness-architecture',
   statusCode: 200,
@@ -327,6 +328,16 @@ function sid(id: string): SessionId {
   return id as SessionId
 }
 
+/** Deterministic provider billing attached to fixture assistant messages. */
+function fixtureUsage(turn: number, step: number): TokenUsage {
+  return {
+    inputTokens: 20 + turn % 5,
+    outputTokens: 8 + step,
+    cacheReadTokens: turn === 0 ? 0 : 80,
+    cacheWriteTokens: turn % 10 === 0 ? 4 : 0,
+  }
+}
+
 /** fx-alpha history script: 60 turns (~130+ messages -> 3 pages at PAGE_MESSAGES=50),
  *  mixing reasoning blocks / tool call+result / steering / context. */
 function buildAlphaLog(): SessionEvent[] {
@@ -334,7 +345,17 @@ function buildAlphaLog(): SessionEvent[] {
   let time = Date.now() - 3_600_000
   const push = (e: Record<string, unknown>): number => {
     const seq = events.length
-    events.push({ seq, time: (time += 800), ...e })
+    const data = e['data'] as Record<string, unknown> | undefined
+    const authored = e['type'] === 'assistant/message' && data !== undefined
+      ? {
+        ...e,
+        data: {
+          ...data,
+          usage: fixtureUsage(data['turn'] as number, data['step'] as number),
+        },
+      }
+      : e
+    events.push({ seq, time: (time += 800), ...authored })
     return seq
   }
   for (let turn = 0; turn < 60; turn++) {
@@ -471,7 +492,17 @@ function buildAlphaLog(): SessionEvent[] {
   // strip empty and take the todo surfaces' own coverage with it.
   toolTurn(65, 'bash', '{"command":"pnpm run check","cwd":"/tmp/fixture/deep/nested"}', TERMINAL_OUTPUT_FIXTURE)
 
-  // Turn 66: the read sample — a WINDOW past an offset so the card draws file
+  // Turns 66-67: the search card's two shapes. `grep` emits a `card: 'search'`
+  // `shape: 'matches'` result view (grouped-by-file matches, truncated with a
+  // larger `total`), `glob` emits `shape: 'paths'` (a flat path list, likewise
+  // truncated). Both ride the keyed SearchRow registration under their own
+  // names; the render-site fallback row is covered by the model derivation
+  // tests, since every fixture search tool has a keyed row. Ordered before the
+  // todo turn for the same standing-plan reason the bash turn is.
+  toolTurn(66, 'grep', '{"pattern":"SEARCH_MAX_LINES","path":"packages/client"}', SEARCH_MATCHES_TEXT)
+  toolTurn(67, 'glob', '{"pattern":"**/SearchBlock*","path":"packages/client"}', SEARCH_PATHS_TEXT)
+
+  // Turn 68: the read sample — a WINDOW past an offset so the card draws file
   // line numbers starting above 1 and a "showing N of M" note (the window is
   // shorter than READ_SAMPLE_TOTAL), with a `ts` language hint the shiki path
   // highlights. Named `read`, so it exercises the keyed ReadRow registration.
@@ -482,19 +513,9 @@ function buildAlphaLog(): SessionEvent[] {
   // this fixture. The read render intent is result-side only, so its pending
   // call stays a generic `kind: 'read'` card; presentResult carries the
   // structured window.
-  toolTurn(66, 'read', `{"file_path":${JSON.stringify(READ_SAMPLE_PATH)},"offset":${READ_SAMPLE_FIRST_LINE}}`, READ_SAMPLE_TEXT)
+  toolTurn(68, 'read', `{"file_path":${JSON.stringify(READ_SAMPLE_PATH)},"offset":${READ_SAMPLE_FIRST_LINE}}`, READ_SAMPLE_TEXT)
 
-  // Turns 68-69: the search card's two shapes. `grep` emits a `card: 'search'`
-  // `shape: 'matches'` result view (grouped-by-file matches, truncated with a
-  // larger `total`), `glob` emits `shape: 'paths'` (a flat path list, likewise
-  // truncated). Both ride the keyed SearchRow registration under their own
-  // names; the render-site fallback row is covered by the model derivation
-  // tests, since every fixture search tool has a keyed row. Ordered before the
-  // todo turn for the same standing-plan reason the bash turn is.
-  toolTurn(68, 'grep', '{"pattern":"SEARCH_MAX_LINES","path":"packages/client"}', SEARCH_MATCHES_TEXT)
-  toolTurn(69, 'glob', '{"pattern":"**/SearchBlock*","path":"packages/client"}', SEARCH_PATHS_TEXT)
-
-  // Turns 70-71: the web render intent — a web_search whose result view carries
+  // Turns 69-70: the web render intent — a web_search whose result view carries
   // structured sources plus an answer (the citation list, one source lacking a
   // title so its hostname labels the link, the capped indicator on), and a
   // web_fetch whose result view carries the fetched URL and its HTTP status.
@@ -503,11 +524,11 @@ function buildAlphaLog(): SessionEvent[] {
   // the real tools so they hit the keyed WebRow registration. Ordered BEFORE
   // the todo turn for the same reason turn 65 is: the standing plan retires at
   // the next turn/start, so a turn after it would empty the dock's plan strip.
-  toolTurn(70, 'web_search', '{"query":"deepseek harness architecture"}', 'Search results for deepseek harness architecture.')
-  toolTurn(71, 'web_fetch', '{"url":"https://www.deepseek.com/blog/harness-architecture"}', '# Harness architecture\n\nEverything is a plugin.')
+  toolTurn(69, 'web_search', '{"query":"deepseek harness architecture"}', 'Search results for deepseek harness architecture.')
+  toolTurn(70, 'web_fetch', '{"url":"https://www.deepseek.com/blog/harness-architecture"}', '# Harness architecture\n\nEverything is a plugin.')
 
   const todoArgs = JSON.stringify({ todos: fixtureTodos })
-  toolTurn(72, 'todo_write', todoArgs, 'Updated todo list: 1 pending, 1 in progress, 1 completed.')
+  toolTurn(71, 'todo_write', todoArgs, 'Updated todo list: 1 pending, 1 in progress, 1 completed.')
   // The real tool appends the snapshot mid-execution — between tool/call and
   // tool/result — so the fixture reproduces that exact ordering (the last
   // toolTurn events run ... tool/call, tool/result, step/end, turn/end).
@@ -591,16 +612,6 @@ function presentCall(name: string, argsRaw: string): ToolCallView | undefined {
 function presentResult(name: string, argsRaw: string, resultText: string): ToolResultView | undefined {
   const call = presentCall(name, argsRaw)
   if (call === undefined) return undefined
-  // The read result is the structured window the tool projects through
-  // `presentationMeta`; the fixture authors it inline (it cannot import the
-  // tool). Keyed on the name because the read pending call is a generic card,
-  // so `call.card` alone does not distinguish it from edit/write.
-  if (name === 'read') {
-    return {
-      card: 'read', path: READ_SAMPLE_PATH, offset: READ_SAMPLE_FIRST_LINE, lines: READ_SAMPLE_LINES,
-      totalLines: READ_SAMPLE_TOTAL, lang: 'ts', content: text(resultText),
-    }
-  }
   // Search is result-time only: the call stays a generic search card, and the
   // result view carries the structured shape the card renders. The view holds no
   // result text — a UI without a search card falls back to the raw tool/result
@@ -613,6 +624,16 @@ function presentResult(name: string, argsRaw: string, resultText: string): ToolR
   if (name === 'glob') {
     return { card: 'search', shape: 'paths', paths: SEARCH_PATHS_FIXTURE, truncated: true, total: 23 }
   }
+  // The read result is the structured window the tool projects through
+  // `presentationMeta`; the fixture authors it inline (it cannot import the
+  // tool). Keyed on the name because the read pending call is a generic card,
+  // so `call.card` alone does not distinguish it from edit/write.
+  if (name === 'read') {
+    return {
+      card: 'read', path: READ_SAMPLE_PATH, offset: READ_SAMPLE_FIRST_LINE, lines: READ_SAMPLE_LINES,
+      totalLines: READ_SAMPLE_TOTAL, lang: 'ts', content: text(resultText),
+    }
+  }
   // The web tools keep a generic pending card, so their result card is chosen
   // by tool name rather than by the pending card tag: the structured `web` card
   // the frontend consumes. The view carries no `content` copy (per the contract
@@ -727,6 +748,113 @@ function permissionSelectOf(
   }
 }
 
+interface FixtureTokenUsageProjection {
+  uncachedInputTokens: number
+  outputTokens: number
+  cacheReadTokens: number
+  cacheWriteTokens: number
+}
+
+interface FixtureUsageSample {
+  turn: number
+  step: number
+  usage: TokenUsage
+}
+
+/** Read one provider usage sample from either durable carrier. */
+function usageSampleOf(event: SessionEvent): FixtureUsageSample | undefined {
+  const item = event as unknown as {
+    type: string
+    data: {
+      turn?: number
+      step?: number
+      usage?: TokenUsage
+      chunk?: { type?: string; usage?: TokenUsage }
+    }
+  }
+  const usage = item.type === 'assistant/chunk' && item.data.chunk?.type === 'usage'
+    ? item.data.chunk.usage
+    : item.type === 'assistant/message'
+      ? item.data.usage
+      : undefined
+  return usage === undefined || item.data.turn === undefined || item.data.step === undefined
+    ? undefined
+    : { turn: item.data.turn, step: item.data.step, usage }
+}
+
+/** Fixture parallel of token-meter's last-sample-replacing usage projection. */
+function tokenUsageOf(log: readonly SessionEvent[]): FixtureTokenUsageProjection {
+  const totals: FixtureTokenUsageProjection = {
+    uncachedInputTokens: 0,
+    outputTokens: 0,
+    cacheReadTokens: 0,
+    cacheWriteTokens: 0,
+  }
+  let last: {
+    turn: number
+    step: number
+    buckets: FixtureTokenUsageProjection
+  } | null = null
+  for (const event of log) {
+    const sample = usageSampleOf(event)
+    if (sample === undefined) continue
+    const buckets: FixtureTokenUsageProjection = {
+      uncachedInputTokens: sample.usage.inputTokens,
+      outputTokens: sample.usage.outputTokens,
+      cacheReadTokens: sample.usage.cacheReadTokens ?? 0,
+      cacheWriteTokens: sample.usage.cacheWriteTokens ?? 0,
+    }
+    const previous = last?.turn === sample.turn && last.step === sample.step
+      ? last.buckets
+      : undefined
+    totals.uncachedInputTokens += buckets.uncachedInputTokens - (previous?.uncachedInputTokens ?? 0)
+    totals.outputTokens += buckets.outputTokens - (previous?.outputTokens ?? 0)
+    totals.cacheReadTokens += buckets.cacheReadTokens - (previous?.cacheReadTokens ?? 0)
+    totals.cacheWriteTokens += buckets.cacheWriteTokens - (previous?.cacheWriteTokens ?? 0)
+    last = { turn: sample.turn, step: sample.step, buckets }
+  }
+  return totals
+}
+
+interface FixtureRequestContext {
+  provider: string
+  model: string
+  contextWindow?: number
+}
+
+/** Latest log-only route context, or undefined before any request ran. */
+function lastRequestContext(
+  log: readonly SessionEvent[],
+): FixtureRequestContext | undefined {
+  const event = log.findLast(item => (item as { type: string }).type === 'request/context')
+  return event === undefined
+    ? undefined
+    : (event as unknown as { data: FixtureRequestContext }).data
+}
+
+/**
+ * Fixture parallel of token-meter's request-pressure projection: the last
+ * provider-reported prompt size paired with the last recorded capacity. The
+ * two need not come from one request — see the token-meter README.
+ */
+function contextPressureOf(
+  log: readonly SessionEvent[],
+): { pressureTokens?: number; contextWindow?: number } {
+  let pressureTokens: number | undefined
+  for (const event of log) {
+    const sample = usageSampleOf(event)
+    if (sample === undefined) continue
+    pressureTokens = sample.usage.inputTokens
+      + (sample.usage.cacheReadTokens ?? 0)
+      + (sample.usage.cacheWriteTokens ?? 0)
+  }
+  const contextWindow = lastRequestContext(log)?.contextWindow
+  return {
+    ...pressureTokens === undefined ? {} : { pressureTokens },
+    ...contextWindow === undefined ? {} : { contextWindow },
+  }
+}
+
 function projectionValuesOf(log: readonly SessionEvent[]): Record<string, unknown> {
   const values: Record<string, unknown> = {}
   const titleEvent = log.findLast(item => (item as { type: string }).type === 'session/title')
@@ -741,12 +869,32 @@ function projectionValuesOf(log: readonly SessionEvent[]): Record<string, unknow
   values['plan'] = planViewOf(log)
   // Always present (GoalService unit composed): null before create / after clear.
   values['goal'] = backscanGoal(log)
+  // Always present (token-meter composed): full-log provider billing.
+  values['tokenUsage'] = tokenUsageOf(log)
+  // Always present (token-meter composed): last request pressure and capacity.
+  values['contextPressure'] = contextPressureOf(log)
   return values
 }
 
 /** Host push-frame parallel: emit one session/projection frame per key the given event advanced. */
 function projectionFramesOf(id: SessionId, log: readonly SessionEvent[], event: SessionEvent): Extract<MuxFrame, { type: 'session/projection' }>[] {
   const type = (event as { type: string }).type
+  // One usage sample advances both token-meter units.
+  if (usageSampleOf(event) !== undefined) {
+    return [
+      { type: 'session/projection', sessionId: id, key: 'tokenUsage', value: tokenUsageOf(log), seq: event.seq },
+      { type: 'session/projection', sessionId: id, key: 'contextPressure', value: contextPressureOf(log), seq: event.seq },
+    ]
+  }
+  if (type === 'request/context') {
+    return [{
+      type: 'session/projection',
+      sessionId: id,
+      key: 'contextPressure',
+      value: contextPressureOf(log),
+      seq: event.seq,
+    }]
+  }
   if (type === 'session/title') {
     const values = projectionValuesOf(log)
     /* v8 ignore next -- the advancing title event is in the log, so the key is present. */
@@ -1443,7 +1591,16 @@ export function createFixtureApi(options: FixtureOptions = {}): ApiProxy {
       replays.delete(id)
       const done = pieces.slice(0, i).join('')
       append(id, { type: 'assistant/chunk', data: { turn, step, chunk: { type: 'block-end', index: 0, block: { type: 'text', text: done } } } })
-      append(id, { type: 'assistant/message', surfaceOp: 'append', data: { turn, step, message: assistantMessage(text(aborted ? `${done}（已中断）` : done)) } })
+      append(id, {
+        type: 'assistant/message',
+        surfaceOp: 'append',
+        data: {
+          turn,
+          step,
+          message: assistantMessage(text(aborted ? `${done}（已中断）` : done)),
+          usage: fixtureUsage(turn, step),
+        },
+      })
       append(id, { type: 'step/end', data: { turn, step } })
       append(id, { type: 'turn/end', data: { turn, reason: { kind: aborted ? 'cancelled' : 'completed' } } })
       setRunning(id, false)
@@ -1712,6 +1869,16 @@ export function createFixtureApi(options: FixtureOptions = {}): ApiProxy {
           append(id, { type: 'plan/mode', data: { active: plan.wanted } })
         }
         append(id, { type: 'user/message', surfaceOp: 'append', data: userMessage(content) })
+        // Capacity parallel of the host token-meter's request/context record:
+        // log-only, appended inside the open turn, and deduplicated against the
+        // route already recorded (the fixture never varies contextWindow).
+        const target = modelTargets.get(id) ?? { provider: 'deepseek', model: 'deepseek-v4-flash' }
+        if (lastRequestContext(logOf(id))?.model !== target.model) {
+          append(id, {
+            type: 'request/context',
+            data: { provider: target.provider, model: target.model, contextWindow: 128_000 },
+          })
+        }
         startReply(
           id,
           turn,

packages/client/connection/tests/fixture.spec.ts

@@ -141,6 +141,14 @@ describe('createFixtureApi', () => {
         },
         plan: { active: false, pending: false },
         goal: null,
+        tokenUsage: {
+          uncachedInputTokens: 0,
+          outputTokens: 0,
+          cacheReadTokens: 0,
+          cacheWriteTokens: 0,
+        },
+        // No request ran, so neither pressure nor capacity is known yet.
+        contextPressure: {},
       } },
     })
   })
@@ -275,6 +283,17 @@ describe('createFixtureApi', () => {
     expect(types).toContain('assistant/chunk')
     expect(types).toContain('assistant/message')
     expect(types.at(-1)).toBe('turn/end')
+    // Capacity is durable log state, not a transient frame: the prompt path
+    // records request/context and the projection carries it to the client.
+    expect(types).toContain('request/context')
+    expect(frames.some(frame =>
+      frame.type === 'session/projection'
+      && frame.key === 'tokenUsage'
+      && (frame.value as { outputTokens?: number }).outputTokens === 8)).toBe(true)
+    expect(frames.some(frame =>
+      frame.type === 'session/projection'
+      && frame.key === 'contextPressure'
+      && (frame.value as { contextWindow?: number }).contextWindow === 128_000)).toBe(true)
     const finalize = frames.find((f): f is Extract<MuxFrame, { type: 'session/event' }> => f.type === 'session/event' && f.event.type === 'assistant/message')
     expect(JSON.stringify(finalize?.event.data)).toContain('（已中断）')
     // Idle cancel: no replay in flight, must not explode; running flips false.
@@ -306,7 +325,7 @@ describe('createFixtureApi', () => {
       const envelopes: RpcRequest<MuxFrame>[] = []
       for await (const envelope of api.events.mux(req({}), abort.signal)) {
         envelopes.push(envelope)
-        if (envelopes.length >= 8) abort.abort()
+        if (envelopes.length >= 10) abort.abort()
       }
       return envelopes
     }
@@ -314,16 +333,18 @@ describe('createFixtureApi', () => {
     const second = await openOnce()
     expect(first[0]?.payload).toMatchObject({ type: 'session/subscribed', sessionId: 'fx-alpha' })
     expect((first[0]?.payload as { lastSeq: number }).lastSeq).toBeGreaterThan(0)
-    // Projection baseline frames follow the subscribed frame (title + todos + permissions + plan + goal units).
+    // Projection baseline frames follow subscribed (domain units + token usage).
     expect(first[1]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'title', value: 'Fixture 历史会话' })
     expect(first[2]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'todos' })
     expect(first[3]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'permissions' })
     expect(first[4]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'plan', value: { active: false, pending: false } })
     expect(first[5]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'goal', value: null })
-    expect(first[6]?.payload).toMatchObject({ type: 'approval/requested', toolName: 'dangerous_tool' })
-    expect(second[6]?.rpcId).toBe(first[6]?.rpcId) // stable rpcId across replays (host replay semantics)
-    expect(first[7]?.payload).toMatchObject({ type: 'question/requested', sessionId: 'fx-alpha' })
-    expect(second[7]?.rpcId).toBe(first[7]?.rpcId)
+    expect(first[6]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'tokenUsage' })
+    expect(first[7]?.payload).toMatchObject({ type: 'session/projection', sessionId: 'fx-alpha', key: 'contextPressure' })
+    expect(first[8]?.payload).toMatchObject({ type: 'approval/requested', toolName: 'dangerous_tool' })
+    expect(second[8]?.rpcId).toBe(first[8]?.rpcId) // stable rpcId across replays (host replay semantics)
+    expect(first[9]?.payload).toMatchObject({ type: 'question/requested', sessionId: 'fx-alpha' })
+    expect(second[9]?.rpcId).toBe(first[9]?.rpcId)
   })
 
   it('steer with no replay in flight falls through to a fresh queued turn; non-text blocks stringify empty', async () => {

packages/client/connection/tests/node-half.spec.ts

@@ -61,23 +61,9 @@ describe('connection node half', () => {
     const ctx = new Context()
     ctx.provide('httpServer', fakeHttpServer(routes) as HttpServerService)
     ctx.provide('apiProxy', {} as unknown as ApiProxy)
-    // The apply throw also escapes cordis as a late rejection — the shape the
-    // boot's installFailLoud is contracted to catch. Capture it so the run
-    // stays clean, same pattern as the webserver bind-failure test.
-    const rejections: unknown[] = []
-    const onUnhandled = (err: unknown): void => { rejections.push(err) }
-    process.on('unhandledRejection', onUnhandled)
-    try {
-      const fiber = ctx.plugin({ inject: [...inject], apply }, { trustedHosts: ['harness.internal/path'] })
-      await expect(fiber.await()).rejects.toThrow(/not a bare host\[:port\] authority/)
-      expect(routes).toHaveLength(0)
-      for (let i = 0; i < 100 && rejections.length === 0; i++) {
-        await new Promise(resolve => setTimeout(resolve, 10))
-      }
-      expect(rejections.map(String).join('\n')).toContain('not a bare host[:port] authority')
-    } finally {
-      process.off('unhandledRejection', onUnhandled)
-    }
+    const fiber = ctx.plugin({ inject: [...inject], apply }, { trustedHosts: ['harness.internal/path'] })
+    await expect(fiber).rejects.toThrow(/not a bare host\[:port\] authority/)
+    expect(routes).toHaveLength(0)
   })
 
   it('registers the /api prefix route and removes it with the fiber', async () => {

packages/client/runtime/tests/slots-service.spec.ts

@@ -41,8 +41,8 @@ interface Bench {
 
 async function boot(): Promise<Bench> {
   const ctx = new Context()
-  ctx.plugin(SlotsService)
-  await ctx.fiber.await()
+  const fiber = ctx.plugin(SlotsService)
+  await fiber
   // Service accessor (ctx.get reads the reflect store, which Service-class
   // plugins do not write; the accessor is the product path).
   const svc = ctx.slots

packages/client/ui-conversation/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/client/ui-conversation/README.md
-README.md: 37a5c216d0e70def7c4884b710b2802e60a4c32a
-README.zh.md: f364714a0dd2ed15d7696e3eb408d347cafc0900
+README.md: 6f78fb3ccf5c407b8f493bef61bae6b8e06f7b77
+README.zh.md: 6949ad65cb8894bec91a5d13a5fd2be45dfa8370

packages/client/ui-conversation/README.md

@@ -36,6 +36,8 @@ Per-session UI state for selection and the active view lives in the declared cha
 
 The composer bar declares session-scoped single seats for `'conversation.input.plan'` (right of the local access-mode control) and `'conversation.input.model'` (immediately before the pending indicator and send/stop button), plus list slots for overlay, dock, left, and right input extensions. Feature packages own each control and its state; ui-conversation supplies placement, the `locked` owner prop, and the standard slot shares. The leading plus button is a Command launcher, not an attachment surface: it asks the session's `SlashController` to open only the `/` trigger's `command` source over the current textarea selection, while ui-slash's existing `MenuView` remains the sole floating menu and pick path. No file row, file input, upload protocol, or second menu component is introduced. While the `plan` projection's effective target is plan mode, InputBar swaps its textarea placeholder to the plan-task wording, localized through the `conversation` locale namespace this package registers (the `placeholder.plan` / `hint.plan` keys) and shared verbatim with the claimed `/plan` command hint (a host-folded value read through the standard-kit `useProjection`; owner-supplied placeholders win). A pending composer takeover remains mounted when another conversation view is active so the blocked agent can still receive its answer; without a pending interaction, the active-session composer belongs to Chat. The composer-bar slot itself is `session-maybe`: with no current session the same bar renders inert (machine faces absent, `disabled` owner prop) instead of swapping in a parallel disabled tree, so the textarea DOM survives the workspace pick; the strict-session control seats simply stay empty until a session exists.
 
+The chat stats line takes its token accounting from two generic token-meter projections read through the standard-kit `useProjection`: `tokenUsage` for full-log billing (billed input is uncached input plus cache reads and writes; cache hit divides cache reads by that total) and `contextPressure` for context occupancy. Visible nodes supply only the turn and step counts plus the LLM and tool wall times, which are window-scoped facts about what is on screen rather than accounting; durable token and context groups remain visible when compaction leaves no assistant node in the loaded window. A deployment without token-meter drops the token groups, and occupancy stays hidden until both provider pressure and route capacity are known. Occupancy is deliberately an approximation — its numerator and capacity are independent last-wins projection fields, not one atomic request observation ([rationale](../../llm/token-meter/README.md)). The inline stats row remains the sole context UI; the model selector has no circle or accessory.
+
 `src/client/` is organized for the future package split: `contract/` is the sole inter-domain shared face (`slots.ts` slot declarations + composed slot props including the tool-row contract, `views.ts` shared primitives, `tool-call-model.ts`); the `skeleton/`, `chat/`, and `toolviews/` (sample registrants) domain directories import contract files and never each other; `apply.ts` is the only assembly point allowed to import all three domains. The `/client` export surface is the contract only — `apply`/`inject`, the two service classes, and the `contract/` type families; implementation components (skeleton, chat rows) and the store factory stay internal and reach the page exclusively through apply's slot registrations (tests take them via the `./src/*` subpath).
 
 ## Model Experience
@@ -51,6 +53,7 @@ None; this package neither assembles nor sends a provider request.
 - **Stats-line durations cover the in-window flow only** — LLM and tool wall times fold the snapshot's assistant `timing` and tool call/result pairs, so nodes outside the loaded event window (older history) are not counted.
 - **Details panel is the minimal form and currently has no entry point** — selected call args/result raw display; the Input/Output/Metadata switch, Prev/Next stepping, and See-in-trajectory deep link are deferred. Tool rows stopped being details-panel click targets and nothing replaced that gesture, so `ChatViewInjected.openDetails` is implemented but uncalled and the panel (including its terminal card) is unreachable in the assembled application; its rendering stays covered by mounting it with a selection directly.
 - **Assistant per-message paging is a reserved slot** — drawn in the design, not implemented. The finalized content IconActions row (copy / branch / clock) ships under the last content-text assistant of each turn only; mid-turn narration and Think-only nodes stay chrome-free. Branch forks through the turn containing that message, increments the inherited title on the client, and then opens the child, while a fork or rename failure leaves the source selected.
+- **Sent user messages cannot be edited** — the user bubble's IconActions row carries clock / copy / branch only, and branching from the message is the nearest gesture. The control returns with the capability behind it: a client mutation over a settled user message, plus the host behavior for the turn that already consumed it ([decision](../../../.agents/notes/implemented/simplification/2026-07-31-drop-user-message-edit-stub.md)).
 - **The sparkle icon for the others tool row is a hand-drawn approximation** — the design glyph's vector geometry is not exportable locally; promotion into ui-primitives waits on an exact export.
 - **The approval panel's "Always allow this type" is deferred** — durable grants need a grant-storage design; only allow-once/reject answer today.
 - **TodoPanel truncates long item text to one ellipsized line** — the figma strip has no wrap or expand affordance; full text is not readable inline.

packages/client/ui-conversation/README.zh.md

@@ -36,6 +36,8 @@ todo 两个面就是在该形状上的两个注册项，都是普通注册方插
 
 输入栏为 `'conversation.input.plan'`（位于本地 access 模式控件右侧）和 `'conversation.input.model'`（渲染在 pending 指示器与发送／停止按钮之前）声明会话作用域的单实例 seat，并为 overlay、dock、left 和 right 输入扩展声明列表 slot。各功能包拥有相应控件及其状态；ui-conversation 提供放置位置、`locked` owner prop 和标准 slot share。前置加号按钮是 Command launcher，而非附件入口：它要求当前会话的 `SlashController` 基于 textarea 当前 selection，只打开 `/` trigger 的 `command` source，同时 ui-slash 既有的 `MenuView` 仍是唯一的浮层菜单与 pick 路径。不引入 File 行、file input、上传协议或第二套菜单组件。当 `plan` 投影的有效目标为 plan mode 时，InputBar 将文本框 placeholder 切换为 plan 任务措辞，经本包注册的 `conversation` locale 命名空间（`placeholder.plan` / `hint.plan` 键）本地化，并与已认领 `/plan` 命令的提示逐字共用同一份文案（经标准套件 `useProjection` 读取的 host 折叠值；owner 提供的 placeholder 优先）。另一个会话视图活跃时，待处理的 composer 接管仍保持挂载，使被阻塞的 agent（智能体）仍能收到回答；没有待处理交互时，活跃会话的 composer 归 Chat 所有。composer bar slot 本身为 `session-maybe`：没有当前会话时，同一个 bar 以不可交互状态渲染（machine face 均缺席、`disabled` owner prop），而不是换入一棵平行的 disabled 树，因此选择 workspace 时 textarea DOM 不会被销毁；严格会话作用域的控件 seat 在会话存在之前保持为空。
 
+聊天统计行的 token 账目来自经标准套件 `useProjection` 读取的两个通用 token-meter 投影：`tokenUsage` 提供完整日志计费用量（计费输入为未缓存输入、缓存读取与缓存写入之和；缓存命中率以缓存读取除以该总量），`contextPressure` 提供上下文占用率。可见节点只提供轮次与步骤计数，以及 LLM（大语言模型）和工具的墙钟时间：这些是关于「屏幕上有什么」的窗口作用域事实，而非账目；压缩（compaction）使已加载窗口不再包含 assistant 节点时，持久 token 与上下文分组仍保持可见。未组合 token-meter 的部署会整组省略 token 分组；只有提供方压力与路由容量都已知时才显示占用率。占用率是刻意为之的近似值：它的分子与容量是两个相互独立的「后写覆盖」投影字段，并非同一次请求的原子观测（[原理](../../llm/token-meter/README.md)）。行内统计行仍是唯一的上下文 UI；模型选择器不增加圆环或附属控件。
+
 `src/client/` 按未来的包拆分组织：`contract/` 是唯一的跨领域共享表层（`slots.ts` slot 声明 + 组合后的 slot props，包括工具行契约、`views.ts` 共享原语、`tool-call-model.ts`）；`skeleton/`、`chat/` 和 `toolviews/`（示例注册方）领域目录只导入 contract 文件，彼此绝不导入；`apply.ts` 是唯一允许导入全部三个领域的组装点。`/client` 导出表层只包含契约：`apply`／`inject`、两个服务类和 `contract/` 类型家族；实现组件（骨架、聊天行）与 store factory 保持内部状态，只能通过 apply 的 slot 注册到达页面（测试通过 `./src/*` 子路径获取它们）。
 
 ## 模型体验
@@ -48,9 +50,10 @@ todo 两个面就是在该形状上的两个注册项，都是普通注册方插
 
 ## 已知限制与暂缓事项
 
-- **统计行的耗时只覆盖窗口内消息流**：LLM（大语言模型）与工具墙钟时间由快照的 assistant `timing` 与工具 call/result 配对折算，落在已加载事件窗口之外的节点（更早的历史）不计入。
+- **统计行的耗时只覆盖窗口内消息流**：LLM 与工具墙钟时间由快照的 assistant `timing` 与工具 call/result 配对折算，落在已加载事件窗口之外的节点（更早的历史）不计入。
 - **详情面板是最小形态，且当前没有入口**：以原始形式显示已选择调用的参数／结果；Input/Output/Metadata 切换、Prev/Next 步进与 See-in-trajectory 深链接暂缓实现。工具行已不再是详情面板的点击目标，且没有任何手势接替它，因此 `ChatViewInjected.openDetails` 虽已实现却无人调用，该面板（含其终端卡片）在组装后的应用中不可达；其渲染仍由直接以选中态挂载它来覆盖。
 - **assistant 逐消息分页是预留 slot**：设计中已有图稿，尚未实现。已定稿的内容 IconActions 行（复制／分支／时钟）只挂在每个轮次中最后一条带 text 内容的 assistant 下；轮次中间的叙述与纯 Think 节点不带 chrome。分支会 fork 到包含该消息的轮次末尾，在 client 端递增继承标题后打开子会话，而 fork 或改名失败时源会话保持选中。
+- **已发送的 user 消息无法编辑**：user 气泡的 IconActions 行只有时钟／复制／分支，从该消息分支是最接近的手势。该控件要与其背后的能力一起回归：既需要针对已定稿 user 消息的 client 变更，也需要 host 侧对已经消费过它的轮次给出行为（[决策](../../../.agents/notes/implemented/simplification/2026-07-31-drop-user-message-edit-stub.md)）。
 - **others 工具行的闪光图标是手绘近似版本**：无法在本地导出设计字形的矢量几何；等到存在精确导出后再将其提升到 ui-primitives。
 - **审批面板的「始终允许此类」暂缓**：持久授权需要授权存储设计；今天只能回答允许一次／拒绝。
 - **TodoPanel 将过长条目截成单行省略号**：figma 条没有换行或展开入口，完整文本无法在行内读完。

packages/client/ui-conversation/package.json

@@ -45,6 +45,7 @@
     "@deepseek-ai/dsh-client-ui-slash": "^0.0.1",
     "@deepseek-ai/dsh-client-ui-slots": "^0.0.1",
     "@deepseek-ai/dsh-invariants": "^0.0.1",
+    "@deepseek-ai/dsh-token-meter": "^0.0.1",
     "cordis": "^4.0.0-rc.7",
     "react": "^18.2.0"
   },
@@ -60,6 +61,7 @@
     "@deepseek-ai/dsh-invariants": "workspace:^",
     "@deepseek-ai/dsh-permission": "workspace:^",
     "@deepseek-ai/dsh-session-projection": "workspace:^",
+    "@deepseek-ai/dsh-token-meter": "workspace:^",
     "@deepseek-ai/dsh-tool-todo": "workspace:^",
     "@types/react": "~18.3.1",
     "cordis": "^4.0.0-rc.7",

packages/client/ui-conversation/src/client/chat/MessageIconActions.tsx

@@ -1,10 +1,9 @@
 // Shared IconActions chrome for user and assistant messages: copy live,
-// branch wired through onBranch, date-aware clock,
-// optional edit stub.
+// branch wired through onBranch, date-aware clock.
 
 import { useCallback } from 'react'
 import {
-  IconBranchOutline16, IconCopyOutline16, IconEditOutline16, Tooltip,
+  IconBranchOutline16, IconCopyOutline16, Tooltip,
 } from '@deepseek-ai/dsh-client-ui-primitives'
 import type { ChatViewSlotProps } from '../contract/slots.ts'
 import { formatMessageClock, writeClipboard } from './message-chrome.ts'
@@ -18,8 +17,6 @@ export interface MessageIconActionsProps {
   time: number
   /** Clock before icons (user) or after (assistant). */
   clock: 'start' | 'end'
-  /** When true, append the stub edit control (user bubble). */
-  edit?: boolean | undefined
   /** Fork the session at this message. */
   onBranch?: (() => void) | undefined
   /** Parent layout class composed onto the actions row. */
@@ -30,11 +27,11 @@ export interface MessageIconActionsProps {
 
 /**
  * Copy / branch (/ clock) IconActions row shared by user and assistant chrome.
- * @param props - Copy text, event time, clock side, optional edit, branch callback, className.
+ * @param props - Copy text, event time, clock side, branch callback, className.
  * @returns The actions row element.
  */
 export function MessageIconActions({
-  text, time, clock, edit, onBranch, className, t,
+  text, time, clock, onBranch, className, t,
 }: MessageIconActionsProps) {
   const day = useCalendarDay()
   const onCopy = useCallback(() => {
@@ -58,13 +55,6 @@ export function MessageIconActions({
           <IconBranchOutline16 />
         </button>
       </Tooltip>
-      {edit === true && (
-        <Tooltip label={t('edit')} side="bottom">
-          <button type="button" className={css.action} aria-label={t('edit')}>
-            <IconEditOutline16 />
-          </button>
-        </Tooltip>
-      )}
       {clock === 'end' ? clockEl : null}
     </div>
   )

packages/client/ui-conversation/src/client/chat/MessageItem.tsx

@@ -1,5 +1,5 @@
 // MessageItem: simple chat nodes — user bubble (right-aligned, with
-// clock + copy / branch / edit IconActions), steering (badged bubble), context
+// clock + copy / branch IconActions), steering (badged bubble), context
 // injection, retry disclosure, and unknown-surface JSON rows.
 
 import { memo, useEffect, useMemo, useState } from 'react'
@@ -156,7 +156,6 @@ export const MessageItem = memo(function MessageItem({
             text={text}
             time={node.time}
             clock="start"
-            edit
             onBranch={onFork === undefined ? undefined : () => { onFork(node.seq) }}
             className={css.actions}
             t={t}

packages/client/ui-conversation/src/client/chat/StatsLine.tsx

@@ -3,43 +3,35 @@
 // active conversation scrollport (see ConversationRoot data-conversation-scroll).
 
 import { Fragment, memo, useMemo } from 'react'
-import type { ConversationSnapshot } from '@deepseek-ai/dsh-client-runtime/client'
+import type { ConversationSnapshot, UseProjection } from '@deepseek-ai/dsh-client-runtime/client'
 import type { SnapshotSelectorHook } from '@deepseek-ai/dsh-client-ui-slots'
+import type { ContextPressureProjection, TokenUsageProjection } from '@deepseek-ai/dsh-token-meter/client'
 import css from './StatsLine.module.css'
 
-interface UsageTotals {
+interface WindowStats {
   turns: number
   steps: number
   /** Summed request wall time (step/start → assistant/message); 0 when no node carries timing. */
   llmMs: number
   /** Summed tool wall time (tool/call → tool/result); 0 when no pair is in-window. */
   toolMs: number
-  /** Prompt-side tokens: inputTokens + cacheReadTokens. */
-  inputTokens: number
-  outputTokens: number
-  cacheHitPct: number | null
-}
-
-/** Token accounting slice of assistant `usage` (typed upstream as unknown). */
-interface UsageLike {
-  inputTokens?: number
-  outputTokens?: number
-  cacheReadTokens?: number
 }
 
 /**
- * Fold assistant and tool-result nodes into display totals.
+ * Fold assistant and tool-result nodes into the window-scoped display totals.
+ *
+ * Counts and wall times describe the loaded window on purpose — they answer
+ * "what is on screen". Token accounting deliberately does NOT come from here:
+ * the window is paged and compaction rewrites it, so billing rides the durable
+ * `tokenUsage` projection instead.
  * @param nodes - snapshot nodes.
- * @returns totals; cacheHitPct null until any cache accounting arrives.
+ * @returns visible counts and summed wall times.
  */
-export function deriveStats(nodes: ConversationSnapshot['nodes']): UsageTotals {
+export function deriveStats(nodes: ConversationSnapshot['nodes']): WindowStats {
   const turns = new Set<number>()
   let steps = 0
   let llmMs = 0
   let toolMs = 0
-  let input = 0
-  let output = 0
-  let cacheRead = 0
   for (const node of nodes) {
     if (node.kind === 'tool-result') {
       if (node.callTime !== null) toolMs += Math.max(0, node.time - node.callTime)
@@ -51,22 +43,8 @@ export function deriveStats(nodes: ConversationSnapshot['nodes']): UsageTotals {
     if (node.timing !== undefined && node.timing.stepStartTime !== null) {
       llmMs += Math.max(0, node.timing.completedTime - node.timing.stepStartTime)
     }
-    const usage = node.usage as UsageLike | undefined
-    if (usage === undefined) continue
-    input += usage.inputTokens ?? 0
-    output += usage.outputTokens ?? 0
-    cacheRead += usage.cacheReadTokens ?? 0
-  }
-  const denom = input + cacheRead
-  return {
-    turns: turns.size,
-    steps,
-    llmMs,
-    toolMs,
-    inputTokens: input + cacheRead,
-    outputTokens: output,
-    cacheHitPct: denom === 0 ? null : Math.round((cacheRead / denom) * 100),
   }
+  return { turns: turns.size, steps, llmMs, toolMs }
 }
 
 /**
@@ -94,21 +72,82 @@ export function formatDuration(ms: number): string {
   return `${Math.floor(whole / 60)}m${whole % 60}s`
 }
 
-/** Props: the conversation-snapshot selector (dock registration or unit mount). */
-export interface StatsLineProps { useSession: SnapshotSelectorHook<ConversationSnapshot> }
+/**
+ * Cache-hit share of prompt-side input over the whole durable log.
+ * @param usage - the session's token-usage projection value.
+ * @returns rounded integer percent, or null when no input was billed.
+ */
+export function cacheHitPercent(usage: TokenUsageProjection): number | null {
+  const denominator = billedInputTokens(usage)
+  return denominator === 0
+    ? null
+    : Math.round(usage.cacheReadTokens / denominator * 100)
+}
 
-export const StatsLine = memo(function StatsLine({ useSession }: StatsLineProps) {
+/** Sum the three disjoint prompt-side billing buckets. */
+function billedInputTokens(usage: TokenUsageProjection): number {
+  return usage.uncachedInputTokens + usage.cacheReadTokens + usage.cacheWriteTokens
+}
+
+interface ContextOccupancy {
+  percent: number
+  contextWindow: number
+}
+
+/**
+ * Approximate context occupancy, using the TUI's integer rounding and upper
+ * clamp. The numerator and capacity are independent last-wins projection
+ * fields, so this is a reference figure rather than an exact measurement of one
+ * request (see the token-meter README).
+ * @param pressure - the session's context-pressure projection value.
+ * @returns occupancy and its denominator, or null until both values are known.
+ */
+export function contextOccupancy(
+  pressure: ContextPressureProjection | undefined,
+): ContextOccupancy | null {
+  if (pressure?.pressureTokens === undefined || pressure.contextWindow === undefined) return null
+  return {
+    percent: Math.min(100, Math.round(pressure.pressureTokens / pressure.contextWindow * 100)),
+    contextWindow: pressure.contextWindow,
+  }
+}
+
+/** Props: the conversation-snapshot selector plus the projection read seat. */
+export interface StatsLineProps {
+  useSession: SnapshotSelectorHook<ConversationSnapshot>
+  useProjection: UseProjection
+}
+
+export const StatsLine = memo(function StatsLine({ useSession, useProjection }: StatsLineProps) {
   const nodes = useSession(s => s.nodes)
+  const usage = useProjection('tokenUsage')
+  const pressure = useProjection('contextPressure')
   const stats = useMemo(() => deriveStats(nodes), [nodes])
-  if (stats.steps === 0) return null
   // Pipe-separated groups (figma stats strip); a group with no data drops out whole.
-  const groups: string[] = [`${stats.turns} turns · ${stats.steps} steps`]
-  const durations: string[] = []
-  if (stats.llmMs > 0) durations.push(`LLM ${formatDuration(stats.llmMs)}`)
-  if (stats.toolMs > 0) durations.push(`Tool call ${formatDuration(stats.toolMs)}`)
-  if (durations.length > 0) groups.push(durations.join(' · '))
-  if (stats.cacheHitPct !== null) groups.push(`Cache hit ${stats.cacheHitPct}%`)
-  groups.push(`Input ${formatTokens(stats.inputTokens)} tok · Output ${formatTokens(stats.outputTokens)} tok`)
+  const groups: string[] = []
+  if (stats.steps > 0) {
+    groups.push(`${stats.turns} turns · ${stats.steps} steps`)
+    const durations: string[] = []
+    if (stats.llmMs > 0) durations.push(`LLM ${formatDuration(stats.llmMs)}`)
+    if (stats.toolMs > 0) durations.push(`Tool call ${formatDuration(stats.toolMs)}`)
+    if (durations.length > 0) groups.push(durations.join(' · '))
+  }
+  const context = contextOccupancy(pressure)
+  if (context !== null) {
+    groups.push(`Context ${context.percent}% of ${formatTokens(context.contextWindow)}`)
+  }
+  // Billing rides the durable projection, so these survive paging and
+  // compaction. Suppress the empty projection on a brand-new session.
+  if (usage !== undefined
+    && (stats.steps > 0 || billedInputTokens(usage) > 0 || usage.outputTokens > 0)) {
+    const cacheHit = cacheHitPercent(usage)
+    if (cacheHit !== null) groups.push(`Cache hit ${cacheHit}%`)
+    groups.push(
+      `Input ${formatTokens(billedInputTokens(usage))} tok`
+      + ` · Output ${formatTokens(usage.outputTokens)} tok`,
+    )
+  }
+  if (groups.length === 0) return null
   return (
     <div className={css.root}>
       {groups.map((group, i) => (

packages/client/ui-conversation/tests/chat-branch-tails.spec.tsx

@@ -27,7 +27,7 @@ afterEach(() => {
 const t: MessageItemProps['t'] = makeTranslate(zh, commonZh)
 
 describe('MessageItem arms', () => {
-  it('user bubbles expose clock / copy / branch / edit; copy writes the text', () => {
+  it('user bubbles expose clock / copy / branch and no edit; copy writes the text', () => {
     const writeText = vi.fn().mockResolvedValue(undefined)
     Object.defineProperty(navigator, 'clipboard', {
       configurable: true,
@@ -47,7 +47,7 @@ describe('MessageItem arms', () => {
     expect(screen.getByText('14:24')).toBeTruthy()
     expect(screen.getByRole('button', { name: '复制' })).toBeTruthy()
     expect(screen.getByRole('button', { name: '在新对话中分支' })).toBeTruthy()
-    expect(screen.getByRole('button', { name: '编辑' })).toBeTruthy()
+    expect(screen.queryByRole('button', { name: '编辑' })).toBeNull()
     fireEvent.click(screen.getByRole('button', { name: '复制' }))
     expect(writeText).toHaveBeenCalledWith('hello bubble')
   })
@@ -417,14 +417,19 @@ describe('small branch tails', () => {
   })
 
   it('StatsLine omits the cache-hit segment when no input accounting exists at all', () => {
-    // cacheHitPct is null only when input+cacheRead are both zero (pure
-    // output accounting) — any input makes it a real 0%.
+    // Cache hit is null only when all three prompt buckets are zero (pure
+    // output accounting) — any billed input makes it a real 0%.
     const snap = {
       nodes: [{ kind: 'assistant', seq: 1, turn: 1, step: 1, blocks: [], usage: { outputTokens: 10 } }],
     }
     const source = { getSnapshot: () => snap, subscribe: () => () => {} }
     const view = render(
-      <StatsLine useSession={bindSnapshotSelector(source) as unknown as StatsLineProps['useSession']} />,
+      <StatsLine
+        useSession={bindSnapshotSelector(source) as unknown as StatsLineProps['useSession']}
+        useProjection={(key: string) => key === 'tokenUsage'
+          ? { uncachedInputTokens: 0, outputTokens: 10, cacheReadTokens: 0, cacheWriteTokens: 0 }
+          : undefined}
+      />,
     )
     expect(view.container.textContent).toBe('1 turns · 1 steps|Input 0 tok · Output 10 tok')
   })

packages/client/ui-conversation/tests/chat-stats-bash-sample.spec.tsx

@@ -58,7 +58,7 @@ function makeSource(init?: Partial<ConversationSnapshot>) {
 }
 
 describe('deriveStats', () => {
-  it('folds turns/steps/token split and cache hit percentage', () => {
+  it('counts turns and steps and never folds node usage into accounting', () => {
     const stats = deriveStats([
       assistant(1, 1, { inputTokens: 100, outputTokens: 50, cacheReadTokens: 900 }),
       assistant(2, 1, { inputTokens: 100, outputTokens: 50 }),
@@ -66,12 +66,12 @@ describe('deriveStats', () => {
     ])
     expect(stats.turns).toBe(2)
     expect(stats.steps).toBe(3)
-    expect(stats.inputTokens).toBe(1100)
-    expect(stats.outputTokens).toBe(100)
-    expect(stats.cacheHitPct).toBe(82)
+    // Window-scoped by design: the paged window is not an accounting source, so
+    // the fold exposes no token fields at all (billing rides the projection).
+    expect(Object.keys(stats).sort()).toEqual(['llmMs', 'steps', 'toolMs', 'turns'])
   })
 
-  it('cache hit stays null with no cache accounting; out-of-window tool results ignored', () => {
+  it('ignores tool results with no call time', () => {
     const tool: ToolResultNode = {
       kind: 'tool-result', seq: 5, time: 5_000, callId: 'c', call: null, callTime: null, content: [],
       isError: false, callView: null, resultView: null,
@@ -79,7 +79,6 @@ describe('deriveStats', () => {
     const stats = deriveStats([tool, assistant(1, 1)])
     expect(stats.steps).toBe(1)
     expect(stats.toolMs).toBe(0)
-    expect(stats.cacheHitPct).toBeNull()
   })
 
   it('sums LLM wall time from assistant timing and tool wall time from call/result pairs', () => {
@@ -116,22 +115,105 @@ describe('formatters', () => {
 })
 
 describe('StatsLine', () => {
-  function props(source: { getSnapshot(): ConversationSnapshot; subscribe(fn: () => void): () => void }): StatsLineProps {
-    return { useSession: bindSnapshotSelector(source) }
+  const USAGE = { uncachedInputTokens: 10, outputTokens: 5, cacheReadTokens: 90, cacheWriteTokens: 0 }
+
+  /** Stub the projection seat: a key-addressed table of whole values. */
+  function projections(values: Record<string, unknown>): StatsLineProps['useProjection'] {
+    return (key: string) => values[key]
   }
 
-  it('renders the grouped stats row and hides with zero steps', () => {
-    const { source } = makeSource({
-      nodes: [assistant(1, 1, { inputTokens: 10, outputTokens: 5, cacheReadTokens: 90 })],
-    })
+  function props(
+    source: { getSnapshot(): ConversationSnapshot; subscribe(fn: () => void): () => void },
+    values: Record<string, unknown> = { tokenUsage: USAGE },
+  ): StatsLineProps {
+    return { useSession: bindSnapshotSelector(source), useProjection: projections(values) }
+  }
+
+  it('renders the grouped stats row and hides a brand-new empty session', () => {
+    const { source } = makeSource({ nodes: [assistant(1, 1)] })
     const view = render(<StatsLine {...props(source)} />)
-    // No timing on the fixture: the duration group drops out whole.
+    // No timing on the fixture: the duration group drops out whole. Tokens come
+    // from the projection, so paging the window cannot change them.
     expect(view.container.textContent).toBe('1 turns · 1 steps|Cache hit 90%|Input 100 tok · Output 5 tok')
     const empty = makeSource()
-    const emptyView = render(<StatsLine {...props(empty.source)} />)
+    const emptyView = render(<StatsLine {...props(empty.source, {
+      tokenUsage: { uncachedInputTokens: 0, outputTokens: 0, cacheReadTokens: 0, cacheWriteTokens: 0 },
+      contextPressure: {},
+    })} />)
     expect(emptyView.container.textContent).toBe('')
   })
 
+  it('keeps durable token and context groups after the visible step window is empty', () => {
+    const { source } = makeSource()
+    const view = render(<StatsLine {...props(source, {
+      tokenUsage: USAGE,
+      contextPressure: { pressureTokens: 32_000, contextWindow: 128_000 },
+    })} />)
+    expect(view.container.textContent)
+      .toBe('Context 25% of 128K|Cache hit 90%|Input 100 tok · Output 5 tok')
+  })
+
+  it('renders context occupancy only when the projection knows a capacity', () => {
+    const { source } = makeSource({ nodes: [assistant(1, 1)] })
+    const withCapacity = render(<StatsLine {...props(source, {
+      tokenUsage: USAGE,
+      contextPressure: { pressureTokens: 32_000, contextWindow: 128_000 },
+    })} />)
+    expect(withCapacity.container.textContent).toContain('Context 25% of 128K')
+    // Pressure without capacity has no denominator: the group drops out.
+    const noCapacity = render(<StatsLine {...props(source, {
+      tokenUsage: USAGE,
+      contextPressure: { pressureTokens: 32_000 },
+    })} />)
+    expect(noCapacity.container.textContent).not.toContain('Context')
+    // Capacity arrives before usage in the log; no provider sample means there
+    // is no numerator yet, rather than a synthetic 0%.
+    const noPressure = render(<StatsLine {...props(source, {
+      tokenUsage: USAGE,
+      contextPressure: { contextWindow: 128_000 },
+    })} />)
+    expect(noPressure.container.textContent).not.toContain('Context')
+  })
+
+  it('clamps occupancy at 100% when pressure exceeds the recorded capacity', () => {
+    // Capacity and pressure are independent last-wins fields, so a model switch
+    // can pair a smaller new window with the previous route's larger prompt.
+    const { source } = makeSource({ nodes: [assistant(1, 1)] })
+    const view = render(<StatsLine {...props(source, {
+      tokenUsage: USAGE,
+      contextPressure: { pressureTokens: 300_000, contextWindow: 128_000 },
+    })} />)
+    expect(view.container.textContent).toContain('Context 100% of 128K')
+  })
+
+  it('drops every token group when no projection is composed', () => {
+    const { source } = makeSource({ nodes: [assistant(1, 1)] })
+    const view = render(<StatsLine {...props(source, {})} />)
+    expect(view.container.textContent).toBe('1 turns · 1 steps')
+  })
+
+  it('omits cache hit when nothing was billed on the input side', () => {
+    const { source } = makeSource({ nodes: [assistant(1, 1)] })
+    const view = render(<StatsLine {...props(source, {
+      tokenUsage: { uncachedInputTokens: 0, outputTokens: 7, cacheReadTokens: 0, cacheWriteTokens: 0 },
+    })} />)
+    expect(view.container.textContent).toBe('1 turns · 1 steps|Input 0 tok · Output 7 tok')
+  })
+
+  it('includes cache writes in billed input and the cache-hit denominator', () => {
+    const { source } = makeSource({ nodes: [assistant(1, 1)] })
+    const view = render(<StatsLine {...props(source, {
+      tokenUsage: {
+        uncachedInputTokens: 10,
+        outputTokens: 7,
+        cacheReadTokens: 90,
+        cacheWriteTokens: 100,
+      },
+    })} />)
+    expect(view.container.textContent)
+      .toBe('1 turns · 1 steps|Cache hit 45%|Input 200 tok · Output 7 tok')
+  })
+
   it('renders ZERO times during streaming chunk frames (RFC hard acceptance)', () => {
     const { set, source } = makeSource({ nodes: [assistant(1, 1)] })
     let renders = 0

packages/client/ui-conversation/tests/gate-branch-tails.spec.tsx

@@ -43,20 +43,24 @@ describe('render branch tails', () => {
     expect(view.container.querySelector('[data-state="ok"]')).not.toBeNull()
   })
 
-  it('StatsLine skips usage-less nodes and defaults each absent counter to zero', () => {
+  it('StatsLine counts window nodes but drops every token group without a projection', () => {
+    // Node `usage` is deliberately ignored: billing rides the durable
+    // tokenUsage projection, so an absent projection leaves counts only.
     const snap = {
       nodes: [
         { kind: 'assistant', seq: 1, turn: 1, step: 1, blocks: [] },
         { kind: 'assistant', seq: 2, turn: 1, step: 2, blocks: [], usage: { inputTokens: 4, outputTokens: 6 } },
-        // outputTokens absent: the tokens sum's ?? 0 arm for output.
         { kind: 'assistant', seq: 3, turn: 2, step: 1, blocks: [], usage: { inputTokens: 5 } },
       ],
     }
     const source = { getSnapshot: () => snap, subscribe: () => () => {} }
     const view = render(
-      <StatsLine useSession={bindSnapshotSelector(source) as unknown as UseSession<ConversationSnapshot>} />,
+      <StatsLine
+        useSession={bindSnapshotSelector(source) as unknown as UseSession<ConversationSnapshot>}
+        useProjection={() => undefined}
+      />,
     )
-    expect(view.container.textContent).toBe('2 turns · 3 steps|Cache hit 0%|Input 9 tok · Output 6 tok')
+    expect(view.container.textContent).toBe('2 turns · 3 steps')
   })
 
   it('AssistantMarkdown reasoning as the streaming tail renders the running ring', () => {

packages/client/ui-conversation/tsconfig.json

@@ -26,6 +26,9 @@
     {
       "path": "../../session-projection/session-projection"
     },
+    {
+      "path": "../../llm/token-meter"
+    },
     {
       "path": "../../plan/plan-mode"
     },

packages/cordis/tool-cordis/src/api-catalog.ts

@@ -2093,7 +2093,7 @@ export const TYPE_API: readonly TypeApiEntry[] = [
   },
   {
     name: 'PreparedLlmCall',
-    declaration: 'export interface PreparedLlmCall {\n    readonly config: LlmCallConfig;\n    readonly adapterDefaults: LlmCallConfigAdapterDefaults;\n    stream(options: GenerateOptions): AsyncIterable<StreamChunk>;\n}',
+    declaration: 'export interface PreparedLlmCall {\n    readonly config: LlmCallConfig;\n    readonly context?: LlmModelContext;\n    readonly adapterDefaults: LlmCallConfigAdapterDefaults;\n    stream(options: GenerateOptions): AsyncIterable<StreamChunk>;\n}',
   },
   {
     name: 'PreparedReferencedMessage',
@@ -2243,6 +2243,10 @@ export const TYPE_API: readonly TypeApiEntry[] = [
     name: 'RedactedSecret',
     declaration: 'export interface RedactedSecret {\n    path: string[];\n    set: boolean;\n}',
   },
+  {
+    name: 'RequestContext',
+    declaration: 'export interface RequestContext {\n    provider: string;\n    model: string;\n    contextWindow?: number;\n}',
+  },
   {
     name: 'RequestHeaderReason',
     declaration: 'export type RequestHeaderReason = \'initial\' | \'resume\' | \'change\';',
@@ -2329,7 +2333,7 @@ export const TYPE_API: readonly TypeApiEntry[] = [
   },
   {
     name: 'Session',
-    declaration: 'export class Session {\n    get surface(): SessionSurface;\n    readonly header: SessionHeader;\n    get id(): SessionId;\n    readonly firstLiveSeq: number;\n    constructor(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader);\n    get events(): readonly SessionEvent[];\n    get seq(): number;\n    append<T extends SessionEventType>(type: T, data: SessionEventMap[T], ...opts: T extends SurfaceEventType ? [\n        opts: SurfaceIntent\n    ] : [\n    ]): SessionEvent<T>;\n    requestHeader(): EpochHeader | undefined;\n    deriveMessages(): Message[];\n    deriveEventMessage(event: SessionEvent): Message | null;\n}',
+    declaration: 'export class Session {\n    get surface(): SessionSurface;\n    readonly header: SessionHeader;\n    get id(): SessionId;\n    readonly firstLiveSeq: number;\n    constructor(id: SessionId, seed?: readonly SessionEvent[], header?: SessionHeader);\n    get events(): readonly SessionEvent[];\n    get seq(): number;\n    append<T extends SessionEventType>(type: T, data: SessionEventMap[T], ...opts: T extends SurfaceEventType ? [\n        opts: SurfaceIntent\n    ] : [\n    ]): SessionEvent<T>;\n    requestHeader(): EpochHeader | undefined;\n    requestContext(): RequestContext | undefined;\n    deriveMessages(): Message[];\n    deriveEventMessage(event: SessionEvent): Message | null;\n}',
   },
   {
     name: 'SessionAvailability',
@@ -2341,7 +2345,7 @@ export const TYPE_API: readonly TypeApiEntry[] = [
   },
   {
     name: 'SessionEventMap',
-    declaration: 'export interface SessionEventMap {\n    \'turn/start\': {\n        turn: number;\n        trigger: TurnTrigger;\n    };\n    \'turn/end\': {\n        turn: number;\n        reason: TurnEndReason;\n    };\n    \'step/start\': {\n        turn: number;\n        step: number;\n    };\n    \'step/end\': {\n        turn: number;\n        step: number;\n    };\n    \'user/message\': UserMessage;\n    \'assistant/chunk\': {\n        turn: number;\n        step: number;\n        chunk: StreamChunk;\n    };\n    \'assistant/message\': {\n        turn: number;\n        step: number;\n        message: AssistantMessage;\n        usage?: TokenUsage;\n    };\n    \'tool/call\': {\n        turn: number;\n        step: number;\n        callId: CallId;\n        name: string;\n        arguments: string;\n    };\n    \'tool/result\': {\n        turn: number;\n        step: number;\n        message: ToolResultMessage;\n        error?: {\n            name: string;\n            code: string;\n        };\n        meta?: JsonValue;\n    };\n    \'steering/message\': {\n        turn: number;\n        message: UserMessage;\n    };\n    \'todo/write\': {\n        todos: TodoItem[];\n    };\n    \'request/header\': {\n        header: EpochHeader;\n        reason: RequestHeaderReason;\n    };\n    \'session/end-seed\': Record<string, never>;\n}',
+    declaration: 'export interface SessionEventMap {\n    \'turn/start\': {\n        turn: number;\n        trigger: TurnTrigger;\n    };\n    \'turn/end\': {\n        turn: number;\n        reason: TurnEndReason;\n    };\n    \'step/start\': {\n        turn: number;\n        step: number;\n    };\n    \'step/end\': {\n        turn: number;\n        step: number;\n    };\n    \'user/message\': UserMessage;\n    \'assistant/chunk\': {\n        turn: number;\n        step: number;\n        chunk: StreamChunk;\n    };\n    \'assistant/message\': {\n        turn: number;\n        step: number;\n        message: AssistantMessage;\n        usage?: TokenUsage;\n    };\n    \'tool/call\': {\n        turn: number;\n        step: number;\n        callId: CallId;\n        name: string;\n        arguments: string;\n    };\n    \'tool/result\': {\n        turn: number;\n        step: number;\n        message: ToolResultMessage;\n        error?: {\n            name: string;\n            code: string;\n        };\n        meta?: JsonValue;\n    };\n    \'steering/message\': {\n        turn: number;\n        message: UserMessage;\n    };\n    \'todo/write\': {\n        todos: TodoItem[];\n    };\n    \'request/header\': {\n        header: EpochHeader;\n        reason: RequestHeaderReason;\n    };\n    \'request/context\': RequestContext;\n    \'session/end-seed\': Record<string, never>;\n}',
   },
   {
     name: 'SessionEventMetadataFilter',

packages/core/agent-loop/src/agent.ts

@@ -45,7 +45,7 @@ import {
 } from '@deepseek-ai/dsh-llm'
 import type { GenerateOptions, LlmCallConfig, LlmFailure, Message, PreparedLlmCall, ResolvedRetryPolicy } from '@deepseek-ai/dsh-llm'
 import { canonicalHeader, headerEquals } from '@deepseek-ai/dsh-session'
-import type { AssistantMessage, EpochHeader, Session, SessionId, TurnEndReason, TurnTrigger, UserMessage } from '@deepseek-ai/dsh-session'
+import type { AssistantMessage, EpochHeader, RequestContext, Session, SessionId, TurnEndReason, TurnTrigger, UserMessage } from '@deepseek-ai/dsh-session'
 import { renderContextSnapshot, renderPrompt } from '@deepseek-ai/dsh-system-prompt'
 import type {} from '@deepseek-ai/dsh-tools'
 import { executeToolCalls } from './tool-calls.ts'
@@ -725,6 +725,24 @@ export class ReactLoopAgent implements Agent {
       session.append('request/header', { header, reason: 'change' })
     }
 
+    // TODO: This looks like code smell.
+    // Context metadata for the route this request resolved to, recorded from the same
+    // registration-bound lookup that prepared the call (no second resolve).
+    // A route with unknown capacity is still recorded so it clears any older
+    // denominator; an unchanged route logs nothing.
+    const contextWindow = preparedCall?.context?.contextWindow
+    const requestContext: RequestContext = {
+      provider: config.provider,
+      model: config.model,
+      ...contextWindow === undefined ? {} : { contextWindow },
+    }
+    const previous = session.requestContext()
+    if (previous?.provider !== requestContext.provider
+      || previous.model !== requestContext.model
+      || previous.contextWindow !== requestContext.contextWindow) {
+      session.append('request/context', requestContext)
+    }
+
     const request = markAgentLoopRequest(deepFreeze({
       ...header.config,
       messages: boundaryMessages,

packages/core/agent-loop/tests/request-reconstruction.spec.ts

@@ -8,7 +8,7 @@
 import { describe, expect, it } from 'vitest'
 import { Context } from 'cordis'
 import LlmService, { createUserMessage, LlmError, ReasoningEffortId  } from '@deepseek-ai/dsh-llm'
-import type { GenerateOptions, LlmModelReasoningInfo, LlmResolvedModelInfo } from '@deepseek-ai/dsh-llm'
+import type { GenerateOptions, LlmModelReasoningInfo, LlmResolvedModelInfo, StreamChunk } from '@deepseek-ai/dsh-llm'
 import SessionStore, { Session, SessionId, foldRequestHeader } from '@deepseek-ai/dsh-session'
 import SystemPrompt from '@deepseek-ai/dsh-system-prompt'
 import ToolRegistry, { defineContentToolFixture } from '@deepseek-ai/dsh-tools'
@@ -614,3 +614,95 @@ describe('request stability across the loop', () => {
     })
   })
 })
+
+describe('request/context capacity records', () => {
+  /** Adapter advertising a per-model capacity, keyed by model id. */
+  function capacityAdapter(windows: Record<string, number>, script: StreamChunk[][]): MockAdapter {
+    return new class extends MockAdapter {
+      override resolveModel(provider: string, model: string): Promise<LlmResolvedModelInfo> {
+        const contextWindow = windows[model]
+        return Promise.resolve({
+          provider,
+          id: model,
+          name: model,
+          ...contextWindow === undefined ? {} : { context: { contextWindow } },
+        })
+      }
+    }(script)
+  }
+
+  it('records capacity once and skips it while the route is unchanged', async () => {
+    const adapter = capacityAdapter({ mock: 128_000 }, [textResponse('a'), textResponse('b')])
+    const ctx = await harness(adapter)
+    const agent = ctx.agentLoop.create(SessionId('capacity-dedup'), { provider: 'mock', model: 'mock' })
+
+    send(agent, 'first')
+    await waitForIdle(ctx, agent)
+    send(agent, 'second')
+    await waitForIdle(ctx, agent)
+
+    const records = agent.session.events.filter(event => event.type === 'request/context')
+    expect(records).toHaveLength(1)
+    expect(records[0]?.data).toEqual({ provider: 'mock', model: 'mock', contextWindow: 128_000 })
+    // Log-only: not a SurfaceEventType, so it can never reach a model request
+    // (the type system rejects a surfaceOp here; the session invariant also
+    // requires the record to sit inside its open turn).
+    expect(agent.session.surface.nodes).not.toContain(records[0]?.seq)
+  })
+
+  it('records a second capacity when the route changes mid-session', async () => {
+    const adapter = capacityAdapter(
+      { small: 64_000, large: 256_000 },
+      [textResponse('a'), textResponse('b')],
+    )
+    const ctx = await harness(adapter)
+    const agent = ctx.agentLoop.create(SessionId('capacity-switch'), { provider: 'mock', model: 'small' })
+
+    send(agent, 'first')
+    await waitForIdle(ctx, agent)
+    ctx.on('agent/request', (subject, _turn, _step, _signal, next) => subject === agent
+      ? Promise.resolve({ provider: 'mock', model: 'large' })
+      : next())
+    send(agent, 'second')
+    await waitForIdle(ctx, agent)
+
+    expect(agent.session.events
+      .filter(event => event.type === 'request/context')
+      .map(event => event.data.contextWindow)).toEqual([64_000, 256_000])
+  })
+
+  it('records and deduplicates a route whose adapter advertises no capacity', async () => {
+    const ctx = await harness(new MockAdapter([textResponse('a'), textResponse('b')]))
+    const agent = ctx.agentLoop.create(SessionId('capacity-absent'), { provider: 'mock', model: 'mock' })
+    send(agent, 'first')
+    await waitForIdle(ctx, agent)
+    send(agent, 'second')
+    await waitForIdle(ctx, agent)
+    expect(agent.session.events
+      .filter(event => event.type === 'request/context')
+      .map(event => event.data)).toEqual([{ provider: 'mock', model: 'mock' }])
+  })
+
+  it('clears a previous capacity when the next route advertises none', async () => {
+    const adapter = capacityAdapter({ known: 64_000 }, [textResponse('a'), textResponse('b')])
+    const ctx = await harness(adapter)
+    const agent = ctx.agentLoop.create(SessionId('capacity-clear'), { provider: 'mock', model: 'known' })
+    let model = 'known'
+    ctx.on('agent/request', (subject, _turn, _step, _signal, next) => subject === agent
+      ? Promise.resolve({ provider: 'mock', model })
+      : next())
+
+    send(agent, 'first')
+    await waitForIdle(ctx, agent)
+    model = 'unknown'
+    send(agent, 'second')
+    await waitForIdle(ctx, agent)
+
+    expect(agent.session.events
+      .filter(event => event.type === 'request/context')
+      .map(event => event.data)).toEqual([
+      { provider: 'mock', model: 'known', contextWindow: 64_000 },
+      { provider: 'mock', model: 'unknown' },
+    ])
+  })
+})

packages/core/session/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/core/session/README.md
-README.md: 132e627387aff54381d10e87a52dc1440d0a5b56
-README.zh.md: edf94f765b81a81dfe39662e967cd6dfdca140fa
+README.md: 9c7d41901e6fb0133fff0e210260e5310a025f75
+README.zh.md: ca1292289901a09b83f9b0a794fa4edc9754b1da

packages/core/session/README.md

@@ -66,6 +66,8 @@ Providers stream token-sized deltas, so a raw log stores hundreds of `assistant/
 
 `request/header` records a full canonical snapshot of the non-history request envelope with reason `initial`, `resume`, or `change`. Its optional `adapterDefaults` map marks effective `reasoningEffort` or `maxTokens` values materialized by exact-model resolution, allowing the next request proposal to distinguish them from explicit conversation settings. `foldRequestHeader()` selects the latest snapshot; legacy delta events and the removed `fallback` reason are rejected. See the [reconstructable-requests Agent Note](../../../.agents/notes/implemented/architecture/2026-07-05-reconstructable-requests.md).
 
+`request/context` records registration-bound metadata for the route a request resolved to, appended inside its step beside `request/header` and only when the provider, model, or capacity differs from the previous record. `session.requestContext()` folds the latest one incrementally, mirroring `requestHeader()`. Capacity stays OUT of `EpochHeader` on purpose: it is adapter metadata describing a route, not an input the request was built from, so it must not enter request reconstruction or header equality — a capacity change is not a header `change`. A route whose adapter advertises no capacity is still recorded with `contextWindow` absent, clearing any older known capacity.
+
 A `user/message` stores the complete `UserMessage` directly, including the identity created before routing or prompt admission. It renders its `content` verbatim whether it is a direct human prompt, a synthetic injection, or an admitted goal round; its typed `source` is the only channel that tells them apart and carries any domain-specific durable facts. `assistant/message`, `tool/result`, and `steering/message` likewise store complete message values. Turn execution remains enclosed by `turn/start` and `turn/end`, while an idle injection may append and flush a `user/message` between turns without running the model.
 
 `tool/result` persists one identified user-role tool-result message, optional internal failure identity, and optional presentation metadata. A tool's successful canonical `value` and human-readable canonical failure message remain execution-local; rendered error content is the replay-authoritative message.

packages/core/session/README.zh.md

@@ -66,6 +66,8 @@
 
 `request/header` 记录非历史请求封装的完整规范快照，其原因为 `initial`、`resume` 或 `change`。其可选 `adapterDefaults` 映射会标记由精确模型解析填入的生效 `reasoningEffort` 或 `maxTokens` 值，使下一次请求提议能够将它们与显式对话设置区分开。`foldRequestHeader()` 选择最新快照；旧版增量事件和已移除的 `fallback` 原因会被拒绝。详见[可重建请求 Agent Note](../../../.agents/notes/implemented/architecture/2026-07-05-reconstructable-requests.md)。
 
+`request/context` 记录请求所解析到的路由的、绑定注册项的元数据，在其所属步骤内紧随 `request/header` 追加，且仅在提供方、模型或容量与上一条记录不同时追加。`session.requestContext()` 以增量方式归并最新一条，与 `requestHeader()` 保持一致。容量刻意不进入 `EpochHeader`：它是描述路由的适配器元数据，不是构建该请求所依据的输入，因此绝不可进入请求重建或请求头相等性判断：容量变化不构成请求头 `change`。适配器不公布容量的路由仍会被记录，但 `contextWindow` 字段缺失，从而清除较早的已知容量。
+
 `user/message` 会直接存储完整的 `UserMessage`，其中包括路由或提示词准入前创建的标识。无论它是直接人类提示词、合成注入，还是已准入的 Goal Round，都会原样呈现其 `content`；带类型的 `source` 是区分三者的唯一通道，并携带各领域专有的持久事实。`assistant/message`、`tool/result` 和 steering（中途引导）对应的 `steering/message` 也会存储完整的消息值。轮次执行仍由 `turn/start` 与 `turn/end` 包围，而空闲注入可以在轮次之间追加并刷新一条 `user/message`，无需运行模型。
 
 `tool/result` 持久保存一条带标识、user-role 的工具结果消息，以及可选内部失败标识和可选呈现元数据。工具成功时的规范 `value` 和便于人类阅读的规范失败消息只存在于执行本地；渲染后的错误内容是回放权威消息。

packages/core/session/src/index.ts

@@ -13,7 +13,7 @@ import { scopeOf, scopeTarget } from '@deepseek-ai/dsh-scope'
 import type { Scoped } from '@deepseek-ai/dsh-scope'
 import type { Message } from '@deepseek-ai/dsh-llm'
 import { SESSION_FORMAT_VERSION, SessionId } from './types.ts'
-import type { CreateSessionOptions, EpochHeader, SessionEvent, SessionEventMap, SessionEventType, SessionHeader, SurfaceIntent, SurfaceEventType } from './types.ts'
+import type { CreateSessionOptions, EpochHeader, RequestContext, SessionEvent, SessionEventMap, SessionEventType, SessionHeader, SurfaceIntent, SurfaceEventType } from './types.ts'
 import { snapshotJsonValue } from './json.ts'
 import { SurfaceManager } from './surface.ts'
 import type { SessionSurface } from './surface.ts'
@@ -606,6 +606,30 @@ export class Session {
     return this.headerFold
   }
 
+  /** Cached fold of the request-context events — see {@link requestContext}. */
+  private contextFold: RequestContext | undefined
+  /** Log position (events consumed) the context fold has reached. */
+  private contextFoldSeq = 0
+
+  /**
+   * The route metadata in force after the log's last `request/context` event —
+   * what the NEXT request deduplicates against — or undefined before any such
+   * record. Maintained incrementally like {@link requestHeader}, so a per-step
+   * read costs O(new events).
+   * @returns the folded context record, or undefined when none exists yet.
+   */
+  requestContext(): RequestContext | undefined {
+    if (this.contextFoldSeq < this.log.length) {
+      for (const event of this.log.slice(this.contextFoldSeq)) {
+        // Frozen for the same reason as the header fold: it is session state
+        // exposed by reference and every later dedup compares against it.
+        if (event.type === 'request/context') this.contextFold = deepFreeze({ ...event.data })
+      }
+      this.contextFoldSeq = this.log.length
+    }
+    return this.contextFold
+  }
+
   /** The derived-message cache: frozen projections, extended per unseen node. */
   private derived: Message[] = []
   /** Surface position (nodes projected) the cache has reached. */

packages/core/session/src/invariant.ts

@@ -149,6 +149,7 @@ function validateEvent(
       break
     case 'steering/message':
     case 'todo/write':
+    case 'request/context':
     case 'request/header': {
       if (trace.openTurn === null) {
         fail(`${event.type} appended outside any open turn (core execution events must be turn-enclosed)`)

packages/core/session/src/types.ts

@@ -172,6 +172,20 @@ export interface EpochHeader {
   tools?: ToolSchema[]
 }
 
+/**
+ * Registration-bound context metadata of one resolved model route. Adapter
+ * metadata about a route rather than a request input, which is why it lives
+ * outside {@link EpochHeader}.
+ */
+export interface RequestContext {
+  /** Registered provider route the metadata was resolved through. */
+  provider: string
+  /** Provider-owned model id the metadata belongs to. */
+  model: string
+  /** Maximum combined request and response context in tokens; absent when the adapter advertises none. */
+  contextWindow?: number
+}
+
 /**
  * Why a `request/header` snapshot was appended: `'initial'` — the log's first
  * header (a new conversation); `'resume'` — a loop instance's first request
@@ -253,6 +267,16 @@ export interface SessionEventMap {
    * It is log-only; the latest snapshot reconstructs the request header.
    */
   'request/header': { header: EpochHeader; reason: RequestHeaderReason }
+  /**
+   * Registration-bound context metadata for the route a request resolved to,
+   * appended inside its step beside `request/header` and only when the route
+   * or capacity differs from the last record. It is log-only and deliberately
+   * NOT part of {@link EpochHeader}: capacity is adapter metadata about a
+   * route, not an input the request was built from, so it must not participate
+   * in request reconstruction or header equality. `contextWindow` is absent
+   * when the route's adapter advertises no capacity.
+   */
+  'request/context': RequestContext
   /**
    * Marks the end of a constructor seed. Events before it have smaller seq
    * values and came from the seed (resume, fork, or replay); this lifecycle

packages/core/session/tests/invariant.spec.ts

@@ -144,6 +144,12 @@ describe('session-log invariants', () => {
         source: { kind: 'user' },
       }),
     }, { surfaceOp: 'append' })).toThrow(/outside any open turn/)
+    // Route capacity is core execution state like the header beside it.
+    expect(() => outside.append('request/context', {
+      provider: 'mock',
+      model: 'm',
+      contextWindow: 128_000,
+    })).toThrow(/outside any open turn/)
     // The owning plugin decides whether a merge-extensible event is log-only.
     const appendUnknown = outside.append.bind(outside) as (type: string, data: unknown) => unknown
     expect(() => { appendUnknown('plugin/marker', {}) }).not.toThrow()

packages/core/session/tests/request-header.spec.ts

@@ -114,3 +114,60 @@ describe('legacy request-header format', () => {
     expect(session.events).toHaveLength(0)
   })
 })
+
+describe('Session.requestContext', () => {
+  const CAPACITY = { provider: 'mock', model: 'm', contextWindow: 128_000 }
+
+  /** A turn-enclosed capacity record; the invariant rejects one outside a turn. */
+  function seedWith(...records: { provider: string; model: string; contextWindow?: number }[]): SessionEvent[] {
+    const events: SessionEvent[] = [{
+      type: 'turn/start', seq: 0, time: 1, data: { turn: 1, trigger: { kind: 'message', source: { kind: 'user' } } },
+    }]
+    for (const data of records) {
+      events.push({ type: 'request/context', seq: events.length, time: 1, data })
+    }
+    return events
+  }
+
+  it('reads undefined before any record exists', () => {
+    expect(new Session(SessionId('no-capacity')).requestContext()).toBeUndefined()
+  })
+
+  it('folds a seeded log on first read, taking the last record', () => {
+    // The fold watermark starts at 0 with the seed already in the log, so the
+    // first read must consume the whole seed rather than skip it.
+    const session = new Session(SessionId('seeded-capacity'), seedWith(
+      CAPACITY,
+      { ...CAPACITY, model: 'later', contextWindow: 256_000 },
+    ))
+    expect(session.requestContext()).toEqual({ provider: 'mock', model: 'later', contextWindow: 256_000 })
+  })
+
+  it('advances incrementally across appends and skips unrelated events', () => {
+    const session = new Session(SessionId('incremental-capacity'), seedWith(CAPACITY))
+    expect(session.requestContext()).toEqual(CAPACITY)
+    session.append('todo/write', { todos: [] })
+    expect(session.requestContext()).toEqual(CAPACITY)
+    session.append('request/context', { ...CAPACITY, model: 'next', contextWindow: 64_000 })
+    expect(session.requestContext()).toEqual({ provider: 'mock', model: 'next', contextWindow: 64_000 })
+    session.append('request/context', { provider: 'mock', model: 'unknown' })
+    expect(session.requestContext()).toEqual({ provider: 'mock', model: 'unknown' })
+  })
+
+  it('folds a batch appended between two reads', () => {
+    const session = new Session(SessionId('batched-capacity'), seedWith(CAPACITY))
+    expect(session.requestContext()).toEqual(CAPACITY)
+    session.append('request/context', { ...CAPACITY, contextWindow: 200_000 })
+    session.append('todo/write', { todos: [] })
+    session.append('request/context', { ...CAPACITY, contextWindow: 300_000 })
+    expect(session.requestContext()?.contextWindow).toBe(300_000)
+  })
+
+  it('exposes a frozen record so a reader cannot desync later comparisons', () => {
+    const session = new Session(SessionId('frozen-capacity'), seedWith(CAPACITY))
+    const held = session.requestContext()
+    if (held === undefined) throw new Error('expected a folded capacity record')
+    expect(Object.isFrozen(held)).toBe(true)
+    expect(() => { (held as { contextWindow?: number }).contextWindow = 1 }).toThrow()
+  })
+})

packages/llm/llm/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/llm/llm/README.md
-README.md: f4be9b298c730b7ec0a0faa4470890fe5e3f5af8
-README.zh.md: 9aa22ba861ee368523b03a5472ea783bbcbbd765
+README.md: 21f428fb22c9a59a67d86f446ea866c1629b964a
+README.zh.md: f6421f0625de7e63432a4863db6fb2d96ecd1b3f

packages/llm/llm/README.md

@@ -18,7 +18,7 @@ An adapter registry plus a single streaming call surface, interceptable via a wa
 - `ctx.llm.listModels(provider: string): Promise<LlmModelInfo[]>` Discover the models one registered provider currently advertises.
 - `ctx.llm.resolveModelInfo(provider: string, model: string, signal?: AbortSignal): Promise<LlmResolvedModelInfo>` Resolve validated exact-model identity plus available context, output-default, and reasoning metadata from the owning adapter, with optional cancellation for asynchronous adapters.
 - `ctx.llm.resolveCallConfig(config: LlmCallConfig, signal?: AbortSignal): Promise<LlmCallConfig>` Validate an explicit effort and materialize adapter-configured call defaults without clamping.
-- `ctx.llm.prepareCall(config: LlmCallConfig, signal?: AbortSignal): Promise<PreparedLlmCall>` Resolve a config and capture its current adapter registration as one cancellable, one-shot call.
+- `ctx.llm.prepareCall(config: LlmCallConfig, signal?: AbortSignal): Promise<PreparedLlmCall>` Resolve a config plus detached context metadata and adapter-default provenance in one exact-model lookup, then capture its current adapter registration as one cancellable, one-shot call.
 - `ctx.llm.stream(options: GenerateOptions): AsyncIterable<StreamChunk>` Stream one model call as raw chunks (token-level deltas). Consumers assemble the chunks into blocks/messages with `BlockAssembler`.
 
 `LlmService` preserves errors from final adapter selection, synchronous dispatch, iterator construction, and iteration, and binds their provenance to the exact stream handle returned for that model call. `isLlmAdapterFailure(stream, value)` reports only errors from that call's final adapter boundary; `llmFailureOf(stream, value)` returns the adjacent immutable `LlmFailure`; `llmRetryPolicyOf(stream)` returns the immutable policy of the exact registration selected at that boundary, even if the route is later disposed or replaced. A call that never reaches a final adapter has no serving policy. Nested model calls, `llm/stream` middleware, and downstream consumer failures remain unclassified for the outer call. Classification never replaces or mutates the adapter's original coded `Error`.
@@ -29,7 +29,7 @@ Every topology commit point — adapter routes registering or disposing, directo
 
 Exact-model metadata is a separate correctness query, not a catalog decoration or global LLM setting. `resolveModelInfo()` asks the adapter that owns the exact provider/model route once; an adapter can describe an unlisted dynamic model, and absent `context`, `defaultMaxTokens`, or `reasoning` fields preserve unknown capacity, provider-owned output defaults, or unavailable reasoning capability. Invalid identity, context, output default, or reasoning metadata fails with `INVALID_MODEL_INFO`, `INVALID_MODEL_CONTEXT`, `INVALID_MODEL_MAX_TOKENS`, or `INVALID_MODEL_REASONING`.
 
-`defaultMaxTokens` is an adapter-configured per-request output cap, not a model hard limit. `resolveCallConfig()` materializes it only when the request omits `maxTokens`; an explicit cap wins. Reasoning identifiers are opaque adapter-owned strings rather than a core enum: the same resolution accepts only an exact advertised identifier, materializes `defaultEffort` when present, and otherwise preserves the provider default. Asynchronous model resolvers receive the caller's signal and must settle promptly after cancellation. `prepareCall()` additionally reports which `maxTokens` and `reasoningEffort` fields it materialized in `adapterDefaults` and retains the exact adapter registration through header logging and terminal dispatch, so HMR cannot combine one adapter's capability result with another adapter's request; reusing its one-shot handle or changing its call-config fields fails with `INVALID_PREPARED_CALL`. An unsupported explicit or configured effort fails with `UNSUPPORTED_REASONING_EFFORT` before provider I/O.
+`defaultMaxTokens` is an adapter-configured per-request output cap, not a model hard limit. `resolveCallConfig()` materializes it only when the request omits `maxTokens`; an explicit cap wins. Reasoning identifiers are opaque adapter-owned strings rather than a core enum: the same resolution accepts only an exact advertised identifier, materializes `defaultEffort` when present, and otherwise preserves the provider default. Asynchronous model resolvers receive the caller's signal and must settle promptly after cancellation. `prepareCall()` additionally exposes detached context metadata from the same lookup, reports which `maxTokens` and `reasoningEffort` fields it materialized in `adapterDefaults`, and retains the exact adapter registration through header logging and terminal dispatch, so HMR cannot combine one adapter's capability result with another adapter's request; reusing its one-shot handle or changing its call-config fields fails with `INVALID_PREPARED_CALL`. An unsupported explicit or configured effort fails with `UNSUPPORTED_REASONING_EFFORT` before provider I/O.
 
 ### Events
 

packages/llm/llm/README.zh.md

@@ -18,7 +18,7 @@
 - `ctx.llm.listModels(provider: string): Promise<LlmModelInfo[]>` 发现某个已注册提供方当前公布的模型。
 - `ctx.llm.resolveModelInfo(provider: string, model: string, signal?: AbortSignal): Promise<LlmResolvedModelInfo>` 从拥有精确路由的适配器解析经校验的确切模型身份，以及可用上下文、输出默认值和推理（reasoning）元数据；异步适配器可选地支持取消。
 - `ctx.llm.resolveCallConfig(config: LlmCallConfig, signal?: AbortSignal): Promise<LlmCallConfig>` 校验显式推理强度，并填入适配器配置的调用默认值，但不自动调整。
-- `ctx.llm.prepareCall(config: LlmCallConfig, signal?: AbortSignal): Promise<PreparedLlmCall>` 解析配置并将其当前适配器注册捕获为一次可取消、一次性调用。
+- `ctx.llm.prepareCall(config: LlmCallConfig, signal?: AbortSignal): Promise<PreparedLlmCall>` 在一次精确模型查询中解析配置、脱耦的上下文元数据与适配器默认值溯源，再将其当前适配器注册捕获为一次可取消、一次性调用。
 - `ctx.llm.stream(options: GenerateOptions): AsyncIterable<StreamChunk>` 将一次模型调用流式输出为原始分片（token 级增量）。消费方使用 `BlockAssembler` 将分片组装为块／消息。
 
 `LlmService` 保留来自最终适配器选择、同步 dispatch、iterator 构造与迭代的错误，并将其溯源绑定到该次模型调用返回的精确流句柄。`isLlmAdapterFailure(stream, value)` 只报告该调用最终适配器边界的错误；`llmFailureOf(stream, value)` 返回关联的不可变 `LlmFailure`；`llmRetryPolicyOf(stream)` 返回在该边界选中的确切注册所对应的不可变策略，即使之后释放或替换路由也不变。未到达最终适配器的调用没有服务策略。嵌套模型调用、`llm/stream` middleware 和下游消费方失败对外层调用仍未分类。分类绝不替换或更改适配器原有的带代码 `Error`。
@@ -29,7 +29,7 @@
 
 确切模型元数据是独立的正确性查询，不是 catalog 装饰或全局 LLM 设置。`resolveModelInfo()` 会向拥有精确提供方／模型路由的适配器查询一次；适配器可以描述未列出的动态模型，缺少 `context`、`defaultMaxTokens` 或 `reasoning` 字段会分别保留未知容量、提供方持有的输出默认值或不可用的推理能力。无效的身份、上下文、输出默认值或推理元数据会以 `INVALID_MODEL_INFO`、`INVALID_MODEL_CONTEXT`、`INVALID_MODEL_MAX_TOKENS` 或 `INVALID_MODEL_REASONING` 失败。
 
-`defaultMaxTokens` 是适配器配置的单次请求输出上限，不是模型硬上限。仅当请求省略 `maxTokens` 时，`resolveCallConfig()` 才会填入该值；显式上限优先。推理标识符是由适配器持有的不透明字符串，而非核心枚举：同一次解析只接受与已公布标识符完全一致的值，在存在 `defaultEffort` 时填入它，否则保留提供方默认值。异步模型解析器会接收调用方的 signal，并且必须在取消后迅速结束。`prepareCall()` 还会通过 `adapterDefaults` 报告它填入了哪些 `maxTokens` 和 `reasoningEffort` 字段，并让精确适配器注册跨越请求头记录和最终分派，因此 HMR（热模块替换）不会将一个适配器的能力结果与另一个适配器的请求混用；复用其一次性句柄或更改调用配置字段会以 `INVALID_PREPARED_CALL` 失败。不支持的显式或配置推理强度会在提供方 I/O 前以 `UNSUPPORTED_REASONING_EFFORT` 失败。
+`defaultMaxTokens` 是适配器配置的单次请求输出上限，不是模型硬上限。仅当请求省略 `maxTokens` 时，`resolveCallConfig()` 才会填入该值；显式上限优先。推理标识符是由适配器持有的不透明字符串，而非核心枚举：同一次解析只接受与已公布标识符完全一致的值，在存在 `defaultEffort` 时填入它，否则保留提供方默认值。异步模型解析器会接收调用方的 signal，并且必须在取消后迅速结束。`prepareCall()` 还会公开同一次查询得到的脱耦上下文元数据，通过 `adapterDefaults` 报告它填入了哪些 `maxTokens` 和 `reasoningEffort` 字段，并让精确适配器注册跨越请求头记录和最终分派，因此 HMR（热模块替换）不会将一个适配器的能力结果与另一个适配器的请求混用；复用其一次性句柄或更改调用配置字段会以 `INVALID_PREPARED_CALL` 失败。不支持的显式或配置推理强度会在提供方 I/O 前以 `UNSUPPORTED_REASONING_EFFORT` 失败。
 
 ### 事件
 

packages/llm/llm/src/index.ts

@@ -11,6 +11,7 @@ import type {
   GenerateOptions,
   LlmConfigurableProvider,
   LlmFailure,
+  LlmModelContext,
   LlmModelInfo,
   LlmResolvedModelInfo,
   LlmProviderInfo,
@@ -125,6 +126,8 @@ export class LlmError extends HarnessError {
 export interface PreparedLlmCall {
   /** Detached, deep-frozen config with any adapter-owned default materialized. */
   readonly config: LlmCallConfig
+  /** Detached context metadata resolved with the registration-bound call. */
+  readonly context?: LlmModelContext
   /** Config fields materialized by the captured adapter rather than proposed by the caller. */
   readonly adapterDefaults: LlmCallConfigAdapterDefaults
   /**
@@ -564,20 +567,21 @@ export class LlmService extends Service {
    * @returns a detached config only when a default must be materialized.
    */
   async resolveCallConfig(config: LlmCallConfig, signal?: AbortSignal): Promise<LlmCallConfig> {
-    return this.resolveCallConfigFor(this.registration(config.provider), config, signal)
+    return (await this.resolveCallFor(this.registration(config.provider), config, signal)).config
   }
 
-  private async resolveCallConfigFor(
+  private async resolveCallFor(
     registration: AdapterRegistration,
     config: LlmCallConfig,
     signal?: AbortSignal,
-  ): Promise<LlmCallConfig> {
+  ): Promise<{ config: LlmCallConfig; context?: LlmModelContext }> {
     const info = await this.resolveModelInfoFor(registration, config.model, signal)
     const defaulted = config.maxTokens === undefined && info.defaultMaxTokens !== undefined
       ? { ...config, maxTokens: info.defaultMaxTokens }
       : config
     const reasoning = info.reasoning
     const requested = defaulted.reasoningEffort
+    let resolvedConfig = defaulted
     if (reasoning === undefined) {
       if (requested !== undefined) {
         throw new LlmError(
@@ -585,17 +589,22 @@ export class LlmService extends Service {
           'UNSUPPORTED_REASONING_EFFORT',
         )
       }
-      return defaulted
+    } else {
+      const effective = requested ?? reasoning.defaultEffort
+      if (effective !== undefined) {
+        if (!reasoning.efforts.some(effort => effort.id === effective)) {
+          throw new LlmError(
+            `provider "${config.provider}" model "${config.model}" does not support reasoning effort "${effective}"`,
+            'UNSUPPORTED_REASONING_EFFORT',
+          )
+        }
+        if (requested !== effective) resolvedConfig = { ...defaulted, reasoningEffort: effective }
+      }
     }
-    const effective = requested ?? reasoning.defaultEffort
-    if (effective === undefined) return defaulted
-    if (!reasoning.efforts.some(effort => effort.id === effective)) {
-      throw new LlmError(
-        `provider "${config.provider}" model "${config.model}" does not support reasoning effort "${effective}"`,
-        'UNSUPPORTED_REASONING_EFFORT',
-      )
+    return {
+      config: resolvedConfig,
+      ...info.context === undefined ? {} : { context: info.context },
     }
-    return requested === effective ? defaulted : { ...defaulted, reasoningEffort: effective }
   }
 
   /**
@@ -608,13 +617,16 @@ export class LlmService extends Service {
    */
   async prepareCall(config: LlmCallConfig, signal?: AbortSignal): Promise<PreparedLlmCall> {
     const registration = this.registration(config.provider)
-    const resolved = await this.resolveCallConfigFor(registration, config, signal)
-    const resolvedConfig = deepFreeze(structuredClone(resolved))
+    const resolved = await this.resolveCallFor(registration, config, signal)
+    const resolvedConfig = deepFreeze(structuredClone(resolved.config))
+    const context = resolved.context === undefined
+      ? undefined
+      : deepFreeze(structuredClone(resolved.context))
     const adapterDefaults = deepFreeze<LlmCallConfigAdapterDefaults>({
-      ...config.reasoningEffort === undefined && resolved.reasoningEffort !== undefined
+      ...config.reasoningEffort === undefined && resolvedConfig.reasoningEffort !== undefined
         ? { reasoningEffort: true }
         : {},
-      ...config.maxTokens === undefined && resolved.maxTokens !== undefined
+      ...config.maxTokens === undefined && resolvedConfig.maxTokens !== undefined
         ? { maxTokens: true }
         : {},
     })
@@ -622,6 +634,7 @@ export class LlmService extends Service {
     return Object.freeze({
       config: resolvedConfig,
       adapterDefaults,
+      ...context === undefined ? {} : { context },
       stream: (options: GenerateOptions): AsyncIterable<StreamChunk> => {
         if (dispatched) {
           throw new LlmError('a prepared LLM call can only be dispatched once', 'INVALID_PREPARED_CALL')
@@ -672,7 +685,7 @@ export class LlmService extends Service {
       const registration = prepared?.registration ?? this.registration(options.provider)
       failures.retryPolicy = registration.retryPolicy
       const resolvedConfig = prepared === undefined
-        ? await this.resolveCallConfigFor(registration, options, options.signal)
+        ? (await this.resolveCallFor(registration, options, options.signal)).config
         : prepared.config
       if (prepared !== undefined && !callConfigEquals(options, resolvedConfig)) {
         throw new LlmError(
@@ -680,7 +693,7 @@ export class LlmService extends Service {
           'INVALID_PREPARED_CALL',
         )
       }
-      const resolvedOptions = prepared !== undefined || callConfigEquals(options, resolvedConfig)
+      const resolvedOptions = callConfigEquals(options, resolvedConfig)
         ? options
         : Object.isFrozen(options)
           ? deepFreeze({ ...options, ...resolvedConfig })

packages/llm/llm/tests/service.spec.ts

@@ -1134,6 +1134,48 @@ describe('LlmService', () => {
     })).toThrow(expect.objectContaining({ code: 'INVALID_PREPARED_CALL' }))
   })
 
+  it('reuses one exact-model lookup for prepared config and context metadata', async () => {
+    const ctx = new Context()
+    await ctx.plugin(LlmService)
+    let resolutions = 0
+    const source = { contextWindow: 128_000 }
+    const adapter = new class extends ScriptedAdapter {
+      override resolveModel(provider: string, model: string): Promise<LlmResolvedModelInfo> {
+        resolutions += 1
+        return Promise.resolve({
+          provider,
+          id: model,
+          name: model,
+          description: 'Resolved model',
+          context: source,
+          reasoning: model === 'no-default'
+            ? { efforts: [{ id: ReasoningEffortId('high'), name: 'High' }] }
+            : {
+              efforts: [{ id: ReasoningEffortId('high'), name: 'High' }],
+              defaultEffort: ReasoningEffortId('high'),
+            },
+        })
+      }
+    }(SCRIPT)
+    ctx.llm.registerAdapter(['route'], adapter)
+
+    const prepared = await ctx.llm.prepareCall({ provider: 'route', model: 'model' })
+    source.contextWindow = 64_000
+    expect(prepared.config.reasoningEffort).toBe(ReasoningEffortId('high'))
+    expect(prepared.context).toEqual({ contextWindow: 128_000 })
+    expect(Object.isFrozen(prepared.context)).toBe(true)
+    for await (const _chunk of prepared.stream({
+      ...prepared.config,
+      messages: [],
+    })) { /* drain */ }
+    expect(resolutions).toBe(1)
+
+    const noDefault = await ctx.llm.prepareCall({ provider: 'route', model: 'no-default' })
+    expect(noDefault.config).toEqual({ provider: 'route', model: 'no-default' })
+    expect(noDefault.context).toEqual({ contextWindow: 64_000 })
+    expect(resolutions).toBe(2)
+  })
+
   it('passes cancellation through exact-model resolution', async () => {
     const ctx = new Context()
     await ctx.plugin(LlmService)

packages/llm/token-meter/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/llm/token-meter/README.md
-README.md: 578728ded9cf51a12abcd70d541404e995028f26
-README.zh.md: 9d54ddb4792e6c897af7d57a6f8ae98204caa11d
+README.md: 701893b342f9a93a75bec175634b1054f3d17151
+README.zh.md: a5844e8788422bba669632ed587fb87e1e2a1e58

packages/llm/token-meter/README.md

@@ -21,6 +21,24 @@ The fold tracks full request-header snapshots, step boundaries, surface appends
 
 Usage accounting sums disjoint input, cache-read, cache-write, and output buckets; reasoning is not added again. Every successful call records an assistant anchor, including content-less calls. An explicit empty provenance list means a known empty provider stream, while absent legacy provenance conservatively treats the durable assistant output as provider output.
 
+## Session projections
+
+When the composition provides `ctx.sessionProjections`, token-meter registers two units through an optional child fiber.
+
+`tokenUsage` carries the complete durable log's `uncachedInputTokens`, `outputTokens`, `cacheReadTokens`, and `cacheWriteTokens`. Usage chunks are counted even when a request later fails; a final assistant-message usage for the same `(turn, step)` replaces that sample instead of double-counting it. Reasoning remains an output subdivision. The single last-sample slot relies on a session-log ordering property: once a later step reports usage, a legal log never reports usage for an earlier step again.
+
+`contextPressure` carries optional `pressureTokens` — the newest provider-reported prompt size, summing uncached input plus cache reads and writes — and optional `contextWindow` from the newest `request/context` record. Pressure stays absent until a provider reports usage; capacity stays absent for a route whose adapter advertises none. Output is excluded, so the numerator holds still while a turn streams and steps forward when the next request reports its usage.
+
+Both units use the standard projection baseline, live frame, higher-seq-wins store, and JSON checkpoint paths. Unloading token-meter removes both keys. A headless or TUI composition without the projection seam keeps the measurement service's existing behavior.
+
+### Context occupancy is an approximation, by design
+
+`pressureTokens` and `contextWindow` are independent last-wins fields and are **not** one atomic observation of a single request. Switching models pairs the fresh capacity with the previous route's pressure until the next request reports usage, and `pressureTokens` describes the last request rather than the surface as it stands right now.
+
+This is deliberate. An occupancy percentage is a user-facing reference figure, not a billing record or a gating input — nothing in the harness makes decisions from it, and compaction reads `measure()` instead. The TUI status line has always computed occupancy the same way, dividing a `measure()` total by a separately-resolved capacity for the selected model.
+
+Making the pair atomic was tried and rejected: it required a transient non-replayable wire frame, which needed lifecycle fencing against cross-stream reordering and left occupancy blank after every reconnect. The [Agent Note](../../../.agents/notes/implemented/architecture/2026-07-29-projected-token-usage-and-request-context.md) records that comparison. Consumers that need an exact same-boundary figure should call `measure()` at their own request boundary rather than read this projection.
+
 ## Composition
 
 ```yaml
@@ -44,3 +62,4 @@ No direct invalidation; the named consumer owns any request-prefix changes.
 - **Every measurement clones the current surface** — coherent immutable snapshots make reads O(surface), including below-threshold pressure checks.
 - **Provider usage is only reusable for an identical canonical envelope** — prompt, prefix, tools, provider, model, or call-config changes deliberately fall back to full heuristic estimation.
 - **Legacy provenance is conservative** — assistant messages without `sourceEventSeqs` cannot distinguish provider output from listener rewrites, so the fold avoids claiming a known empty or exact chunk stream.
+- **The TUI and browser fixture retain parallel folds** — `tokenUsage` owns durable session-projection semantics; the TUI keeps its live per-step map because its composition does not mount the generic projection seam, while the browser fixture mirrors the unit for standalone demo data.

packages/llm/token-meter/README.zh.md

@@ -21,6 +21,24 @@ fold 跟踪完整请求标头快照、步骤边界、表层追加与替换、成
 
 用量计量会求和不重叠的输入、cache-read、cache-write 与输出 bucket；不会再次添加推理（reasoning）。每次成功调用都会记录一个 assistant 锚点，包括无内容调用。显式空溯源列表表示已知空提供方流，而遗留溯源缺失时，fold 会保守地将持久 assistant 输出视为提供方输出。
 
+## 会话投影
+
+当组合提供 `ctx.sessionProjections` 时，token-meter 会通过一个可选子 fiber 注册两个单元。
+
+`tokenUsage` 携带完整持久日志中的 `uncachedInputTokens`、`outputTokens`、`cacheReadTokens` 和 `cacheWriteTokens`。即使请求随后失败，用量分片仍会计入；同一 `(turn, step)` 的最终 assistant 消息用量会替换该样本，而不是重复计数。推理仍是输出的一个细分项。只保留单个最新样本，依赖的是会话日志的一条顺序性质：一旦某个更晚的步骤报告了用量，合法日志就绝不会再为更早的步骤报告用量。
+
+`contextPressure` 携带可选的 `pressureTokens`（提供方报告的最新提示词规模，为未缓存输入加缓存读取与写入之和），以及来自最新一条 `request/context` 记录的可选 `contextWindow`。提供方报告用量前压力保持缺失；路由适配器未公布容量时容量也保持缺失。输出不计入其中，因此轮次流式输出期间分子保持不动，等到下一个请求报告用量时才前进。
+
+两个单元都使用标准的投影基线、实时帧、seq 高者胜值仓和 JSON 检查点路径。卸载 token-meter 会移除这两个键。不带投影 seam 的 headless 或 TUI 组合会保留测量服务的既有行为。
+
+### 上下文占用率是刻意为之的近似值
+
+`pressureTokens` 与 `contextWindow` 是两个各自后者胜的独立字段，**不是**对单个请求的一次原子观测。切换模型时，新容量会与上一路由的压力配对，直到下一个请求报告用量为止；而 `pressureTokens` 描述的是最后一个请求，不是此刻的表层。
+
+这是刻意的选择。占用率百分比是面向用户的参考数字，既不是计费记录，也不是门控输入：harness 中没有任何环节依据它做决策，压缩改为直接读取 `measure()`。TUI 状态行一直以同样的方式计算占用率，即用 `measure()` 总量除以为所选模型单独解析出的容量。
+
+让这对值保持原子已经尝试过并被否决：它需要一个临时且不可回放的协议帧，进而需要针对跨流重排序的生命周期栅栏，还会让占用率在每次重连后变为空白。[Agent Note（agent 决策记录）](../../../.agents/notes/implemented/architecture/2026-07-29-projected-token-usage-and-request-context.md)记录了这项对比。需要同一边界精确数字的消费方应在自己的请求边界调用 `measure()`，而不是读取该投影。
+
 ## 组合
 
 ```yaml
@@ -44,3 +62,4 @@ fold 跟踪完整请求标头快照、步骤边界、表层追加与替换、成
 - **每次测量都会克隆当前表层**：一致且不可变的快照使读取成为 O(surface)，包括低于阈值的压力检查。
 - **提供方用量只能为完全相同的规范 envelope 复用**：提示词、前缀、工具、提供方、模型或调用配置变更都会有意回退到完整启发式估算。
 - **遗留溯源采取保守策略**：没有 `sourceEventSeqs` 的 assistant 消息无法区分提供方输出与 listener 改写，因此 fold 不会声称已知空流或精确分片流。
+- **TUI 与浏览器 fixture 仍保留并行 fold**：`tokenUsage` 拥有持久会话投影语义；TUI 的组合未挂载通用投影 seam，因此继续维护实时的逐步骤 map，而浏览器 fixture 会为独立 demo 数据镜像该单元。

packages/llm/token-meter/package.json

@@ -15,12 +15,17 @@
       "types": "./lib/types/invariant.d.ts",
       "default": "./lib/invariant.js"
     },
+    "./client": {
+      "types": "./lib/types/client.d.ts",
+      "default": "./lib/types/client.js"
+    },
     "./src/*": "./src/*",
     "./package.json": "./package.json"
   },
   "files": [
     "lib/index.js",
     "lib/invariant.js",
+    "lib/types/**/*.js",
     "lib/types/**/*.d.ts",
     "lib/types/**/*.d.ts.map",
     "src"
@@ -30,15 +35,18 @@
     "@deepseek-ai/dsh-invariants": "^0.0.1",
     "@deepseek-ai/dsh-llm": "^0.0.1",
     "@deepseek-ai/dsh-session": "^0.0.1",
+    "@deepseek-ai/dsh-session-projection": "^0.0.1",
     "cordis": "^4.0.0-rc.7"
   },
   "dependencies": {
-    "schemastery": "^3.18.0"
+    "schemastery": "^3.18.0",
+    "zod": "^4.4.3"
   },
   "devDependencies": {
     "@deepseek-ai/dsh-invariants": "workspace:^",
     "@deepseek-ai/dsh-llm": "workspace:^",
     "@deepseek-ai/dsh-session": "workspace:^",
+    "@deepseek-ai/dsh-session-projection": "workspace:^",
     "cordis": "^4.0.0-rc.7"
   }
 }

packages/llm/token-meter/src/client.ts

@@ -0,0 +1,7 @@
+/**
+ * Client-namespace projection of token-meter's browser-safe types.
+ *
+ * @module @deepseek-ai/dsh-token-meter/client
+ */
+
+export type * from './projection.ts'

packages/llm/token-meter/src/index.ts

@@ -10,12 +10,15 @@ import { BlockAssembler, deepFreeze } from '@deepseek-ai/dsh-llm'
 import type { ContentBlock, Message, TokenUsage } from '@deepseek-ai/dsh-llm'
 import type { EpochHeader, Session, SessionEvent, SurfaceEvent } from '@deepseek-ai/dsh-session'
 import { canonicalHeader, headerEquals, isSurfaceEvent } from '@deepseek-ai/dsh-session'
+// Type-only: resolves the optional projection registry Context seam.
+import type {} from '@deepseek-ai/dsh-session-projection'
 import type {
   TokenMeasurement,
   TokenMeasurementBaseline,
   TokenMeterConfig,
   TokenSurfaceNode,
 } from './types.ts'
+import { contextPressureProjectionDefinition, tokenUsageProjectionDefinition } from './usage-projection.ts'
 
 export type * from './types.ts'
 
@@ -90,6 +93,13 @@ export class TokenMeterService extends Service {
     super(ctx, 'tokenMeter')
     validateConfigKeys(config)
 
+    // Projection registration is an optional child: headless and TUI
+    // compositions without the generic registry keep the meter's old shape.
+    ctx.inject(['sessionProjections'], (projectionCtx) => {
+      projectionCtx.sessionProjections.register(tokenUsageProjectionDefinition)
+      projectionCtx.sessionProjections.register(contextPressureProjectionDefinition)
+    })
+
     // Readers catch up independently, while eager observation bounds ordinary
     // read latency without creating state for sessions no consumer has read.
     ctx.on('session/event', (session) => {

packages/llm/token-meter/src/invariant.ts

@@ -15,8 +15,11 @@ export const name = 'token-meter-invariant'
 export const inject = ['invariants']
 
 /**
- * No runtime invariant: token estimates are per-call outputs and the private session cache is
- * invalidated at its event mutation boundary; neither exposes an independent observation stream.
+ * No runtime invariant: token estimates are per-call outputs and the private
+ * session cache is invalidated at its event mutation boundary. The package's
+ * projection does expose an observation stream, but its schema fixes the JSON
+ * payload and its pure fold replaces same-step samples; totals need not be
+ * monotone when a final usage sample corrects an earlier chunk.
  */
 const install: InvariantInstaller = () => {}
 

packages/llm/token-meter/src/projection.ts

@@ -0,0 +1,50 @@
+/**
+ * Pure client-safe token-projection vocabulary.
+ *
+ * @module @deepseek-ai/dsh-token-meter/projection
+ */
+
+/**
+ * Durable cumulative provider usage for a complete session log.
+ *
+ * The four buckets are disjoint. In particular, reasoning tokens are already
+ * included in `outputTokens` and are not accumulated again.
+ */
+export interface TokenUsageProjection {
+  uncachedInputTokens: number
+  outputTokens: number
+  cacheReadTokens: number
+  cacheWriteTokens: number
+}
+
+/**
+ * Approximate context occupancy for a status display.
+ *
+ * The two fields, when present, are deliberately NOT one atomic request
+ * observation: `pressureTokens` is the newest provider-reported prompt size,
+ * `contextWindow` the newest recorded route capacity. Switching models can
+ * therefore pair a fresh capacity with the previous route's pressure until the
+ * next request reports usage. This is an intentional trade — the value is a
+ * user-facing reference, not a billing or gating input — and it matches how
+ * the TUI status line has always computed occupancy. See the token-meter
+ * README for the full rationale.
+ */
+export interface ContextPressureProjection {
+  /**
+   * Provider-reported prompt size of the most recent request: uncached input
+   * plus cache reads and writes. Response output is excluded, so this does not
+   * grow as the current turn streams. Absent until a provider reports usage.
+   */
+  pressureTokens?: number
+  /** Newest recorded route capacity; absent when no adapter advertised one. */
+  contextWindow?: number
+}
+
+declare module '@deepseek-ai/dsh-session-projection/types' {
+  interface SessionProjectionMap {
+    /** Provider-reported usage accumulated across the complete durable log. */
+    tokenUsage: TokenUsageProjection
+    /** Newest request pressure paired with the newest known route capacity. */
+    contextPressure: ContextPressureProjection
+  }
+}

packages/llm/token-meter/src/types.ts

@@ -6,6 +6,8 @@
 
 import type { TokenUsage } from '@deepseek-ai/dsh-llm'
 
+export type { ContextPressureProjection, TokenUsageProjection } from './projection.ts'
+
 /** Token-meter plugin configuration; the fixed estimator has no settings. */
 export type TokenMeterConfig = Record<string, never>
 

packages/llm/token-meter/src/usage-projection.ts

@@ -0,0 +1,153 @@
+/**
+ * Pure folds for durable provider-reported token usage and context occupancy.
+ */
+
+import { z } from 'zod'
+import type { TokenUsage } from '@deepseek-ai/dsh-llm'
+import type { ProjectionDefinition } from '@deepseek-ai/dsh-session-projection'
+import type { ContextPressureProjection, TokenUsageProjection } from './projection.ts'
+
+interface UsageSample {
+  turn: number
+  step: number
+  buckets: TokenUsageProjection
+}
+
+interface TokenUsageState {
+  totals: TokenUsageProjection
+  last: UsageSample | null
+}
+
+const zeroBuckets = (): TokenUsageProjection => ({
+  uncachedInputTokens: 0,
+  outputTokens: 0,
+  cacheReadTokens: 0,
+  cacheWriteTokens: 0,
+})
+
+const bucketsFrom = (usage: TokenUsage): TokenUsageProjection => ({
+  uncachedInputTokens: usage.inputTokens,
+  outputTokens: usage.outputTokens,
+  cacheReadTokens: usage.cacheReadTokens ?? 0,
+  cacheWriteTokens: usage.cacheWriteTokens ?? 0,
+})
+
+const bucketsEqual = (left: TokenUsageProjection, right: TokenUsageProjection): boolean =>
+  left.uncachedInputTokens === right.uncachedInputTokens
+  && left.outputTokens === right.outputTokens
+  && left.cacheReadTokens === right.cacheReadTokens
+  && left.cacheWriteTokens === right.cacheWriteTokens
+
+const addReplacing = (
+  totals: TokenUsageProjection,
+  previous: TokenUsageProjection | undefined,
+  next: TokenUsageProjection,
+): TokenUsageProjection => ({
+  uncachedInputTokens: totals.uncachedInputTokens - (previous?.uncachedInputTokens ?? 0) + next.uncachedInputTokens,
+  outputTokens: totals.outputTokens - (previous?.outputTokens ?? 0) + next.outputTokens,
+  cacheReadTokens: totals.cacheReadTokens - (previous?.cacheReadTokens ?? 0) + next.cacheReadTokens,
+  cacheWriteTokens: totals.cacheWriteTokens - (previous?.cacheWriteTokens ?? 0) + next.cacheWriteTokens,
+})
+
+const projectionSchema = z.object({
+  uncachedInputTokens: z.number().int().nonnegative(),
+  outputTokens: z.number().int().nonnegative(),
+  cacheReadTokens: z.number().int().nonnegative(),
+  cacheWriteTokens: z.number().int().nonnegative(),
+}).strict()
+
+// Cast for the optional values: under exactOptionalPropertyTypes zod infers
+// `number | undefined` where the interface declares absent-or-number fields.
+const pressureSchema = z.object({
+  pressureTokens: z.number().int().nonnegative().optional(),
+  contextWindow: z.number().int().positive().optional(),
+}).strict() as unknown as z.ZodType<ContextPressureProjection>
+
+/** Prompt-side pressure of one request: input plus cache traffic, no output. */
+const pressureFrom = (usage: TokenUsage): number =>
+  usage.inputTokens + (usage.cacheReadTokens ?? 0) + (usage.cacheWriteTokens ?? 0)
+
+/**
+ * Token-meter's session projection unit.
+ *
+ * Usage chunks provide an early sample that survives a later request failure;
+ * an assistant message provides the final sample for the same turn/step. A
+ * repeated sample replaces that step's earlier value instead of double
+ * counting it. The single `last` slot relies on the session-log invariant
+ * that usage reports for one turn/step are adjacent: once a later step begins,
+ * a legal log never reports usage for an earlier step again.
+ */
+export const tokenUsageProjectionDefinition:
+ProjectionDefinition<'tokenUsage', TokenUsageState> = {
+  key: 'tokenUsage',
+  schema: projectionSchema,
+  init: () => ({ totals: zeroBuckets(), last: null }),
+  apply: (state, event) => {
+    let turn: number
+    let step: number
+    let usage: TokenUsage
+    if (event.type === 'assistant/chunk' && event.data.chunk.type === 'usage') {
+      ;({ turn, step } = event.data)
+      usage = event.data.chunk.usage
+    } else if (event.type === 'assistant/message' && event.data.usage !== undefined) {
+      ;({ turn, step, usage } = event.data)
+    } else {
+      return state
+    }
+
+    const buckets = bucketsFrom(usage)
+    const previous = state.last !== null
+      && state.last.turn === turn
+      && state.last.step === step
+      ? state.last.buckets
+      : undefined
+    if (previous !== undefined && bucketsEqual(previous, buckets)) return state
+
+    return {
+      totals: addReplacing(state.totals, previous, buckets),
+      last: { turn, step, buckets },
+    }
+  },
+  view: state => state.totals,
+  stateVersion: 1,
+}
+
+/**
+ * Token-meter's context-occupancy projection unit.
+ *
+ * Two independent last-wins slots: the newest usage sample supplies the
+ * numerator, the newest `request/context` record the denominator. Both are
+ * whole values, so replay order alone decides the result and no cross-field
+ * consistency is claimed — the pair is explicitly not one atomic request
+ * observation (see {@link ContextPressureProjection}).
+ *
+ * The numerator is prompt-side only, so it holds still while a turn streams
+ * and steps forward once the next request reports its usage.
+ */
+export const contextPressureProjectionDefinition:
+ProjectionDefinition<'contextPressure', ContextPressureProjection> = {
+  key: 'contextPressure',
+  schema: pressureSchema,
+  init: () => ({}),
+  apply: (state, event) => {
+    if (event.type === 'request/context') {
+      const contextWindow = event.data.contextWindow
+      if (contextWindow === state.contextWindow) return state
+      if (contextWindow !== undefined) return { ...state, contextWindow }
+      const { contextWindow: _removed, ...withoutContextWindow } = state
+      return withoutContextWindow
+    }
+    const usage = event.type === 'assistant/chunk' && event.data.chunk.type === 'usage'
+      ? event.data.chunk.usage
+      : event.type === 'assistant/message'
+        ? event.data.usage
+        : undefined
+    if (usage === undefined) return state
+    const pressureTokens = pressureFrom(usage)
+    return pressureTokens === state.pressureTokens
+      ? state
+      : { ...state, pressureTokens }
+  },
+  view: state => state,
+  stateVersion: 2,
+}

packages/llm/token-meter/tests/token-usage-projection.spec.ts

@@ -0,0 +1,333 @@
+import { describe, expect, it } from 'vitest'
+import { Context } from 'cordis'
+import { createMessage, createUserMessage } from '@deepseek-ai/dsh-llm'
+import type { TokenUsage } from '@deepseek-ai/dsh-llm'
+import SessionStore from '@deepseek-ai/dsh-session'
+import type { Session } from '@deepseek-ai/dsh-session'
+import SessionProjectionRegistry from '@deepseek-ai/dsh-session-projection'
+import TokenMeterService from '@deepseek-ai/dsh-token-meter'
+import type { ContextPressureProjection, TokenUsageProjection } from '@deepseek-ai/dsh-token-meter/client'
+
+const ZERO: TokenUsageProjection = {
+  uncachedInputTokens: 0,
+  outputTokens: 0,
+  cacheReadTokens: 0,
+  cacheWriteTokens: 0,
+}
+
+async function harness(): Promise<{
+  ctx: Context
+  session: Session
+  meterFiber: Awaited<ReturnType<Context['plugin']>>
+}> {
+  const ctx = new Context()
+  await ctx.plugin(SessionStore)
+  await ctx.plugin(SessionProjectionRegistry)
+  const meterFiber = await ctx.plugin(TokenMeterService)
+  return { ctx, session: ctx.sessions.create(), meterFiber }
+}
+
+function startStep(session: Session, turn: number, step: number): void {
+  session.append('step/start', { turn, step })
+}
+
+function usageChunk(
+  session: Session,
+  usage: TokenUsage,
+  turn: number,
+  step: number,
+): number {
+  return session.append('assistant/chunk', {
+    turn,
+    step,
+    chunk: { type: 'usage', usage },
+  }).seq
+}
+
+function finalUsage(
+  session: Session,
+  usage: TokenUsage,
+  turn: number,
+  step: number,
+  sourceSeqs: number[],
+): void {
+  session.append('assistant/message', {
+    turn,
+    step,
+    message: createMessage({
+      role: 'assistant',
+      content: [],
+      source: { kind: 'model', provider: 'mock', model: 'mock' },
+    }),
+    usage,
+  }, { surfaceOp: 'append', sourceEventSeqs: sourceSeqs })
+  session.append('step/end', { turn, step })
+}
+
+const projected = (ctx: Context, session: Session): TokenUsageProjection => {
+  const value = ctx.sessionProjections.snapshot(session).values.tokenUsage
+  if (value === undefined) throw new Error('tokenUsage projection is not registered')
+  return value
+}
+
+describe('tokenUsage session projection', () => {
+  it('serves zero buckets for an empty log', async () => {
+    const { ctx, session } = await harness()
+    expect(projected(ctx, session)).toEqual(ZERO)
+  })
+
+  it('does not count a usage chunk and identical final usage twice', async () => {
+    const { ctx, session } = await harness()
+    const changes: unknown[] = []
+    ctx.sessionProjections.onChanged((_session, key, value) => {
+      if (key === 'tokenUsage') changes.push(value)
+    })
+    const usage = {
+      inputTokens: 10,
+      outputTokens: 4,
+      cacheReadTokens: 7,
+      cacheWriteTokens: 2,
+      reasoningTokens: 3,
+    }
+    startStep(session, 1, 1)
+    const source = usageChunk(session, usage, 1, 1)
+    finalUsage(session, usage, 1, 1, [source])
+
+    expect(projected(ctx, session)).toEqual({
+      uncachedInputTokens: 10,
+      outputTokens: 4,
+      cacheReadTokens: 7,
+      cacheWriteTokens: 2,
+    })
+    expect(changes).toHaveLength(1)
+  })
+
+  it('replaces an earlier same-step chunk sample with the final usage', async () => {
+    const { ctx, session } = await harness()
+    startStep(session, 1, 1)
+    const source = usageChunk(session, {
+      inputTokens: 10,
+      outputTokens: 2,
+      cacheReadTokens: 3,
+    }, 1, 1)
+    finalUsage(session, {
+      inputTokens: 14,
+      outputTokens: 5,
+      cacheReadTokens: 8,
+      cacheWriteTokens: 1,
+    }, 1, 1, [source])
+
+    expect(projected(ctx, session)).toEqual({
+      uncachedInputTokens: 14,
+      outputTokens: 5,
+      cacheReadTokens: 8,
+      cacheWriteTokens: 1,
+    })
+  })
+
+  it('accumulates disjoint buckets across steps without adding reasoning twice', async () => {
+    const { ctx, session } = await harness()
+    startStep(session, 1, 1)
+    const first = usageChunk(session, {
+      inputTokens: 10,
+      outputTokens: 6,
+      reasoningTokens: 5,
+      cacheReadTokens: 2,
+    }, 1, 1)
+    finalUsage(session, {
+      inputTokens: 10,
+      outputTokens: 6,
+      reasoningTokens: 5,
+      cacheReadTokens: 2,
+    }, 1, 1, [first])
+    startStep(session, 1, 2)
+    const second = usageChunk(session, {
+      inputTokens: 20,
+      outputTokens: 9,
+      reasoningTokens: 7,
+      cacheWriteTokens: 4,
+    }, 1, 2)
+    finalUsage(session, {
+      inputTokens: 20,
+      outputTokens: 9,
+      reasoningTokens: 7,
+      cacheWriteTokens: 4,
+    }, 1, 2, [second])
+
+    expect(projected(ctx, session)).toEqual({
+      uncachedInputTokens: 30,
+      outputTokens: 15,
+      cacheReadTokens: 2,
+      cacheWriteTokens: 4,
+    })
+  })
+
+  it('retains a usage chunk when the request produces no final assistant message', async () => {
+    const { ctx, session } = await harness()
+    startStep(session, 1, 1)
+    usageChunk(session, { inputTokens: 9, outputTokens: 1 }, 1, 1)
+    session.append('step/end', { turn: 1, step: 1 })
+    expect(projected(ctx, session)).toEqual({
+      uncachedInputTokens: 9,
+      outputTokens: 1,
+      cacheReadTokens: 0,
+      cacheWriteTokens: 0,
+    })
+  })
+
+  it('does not erase historical billing when the visible surface is replaced', async () => {
+    const { ctx, session } = await harness()
+    startStep(session, 1, 1)
+    const source = usageChunk(session, { inputTokens: 12, outputTokens: 3 }, 1, 1)
+    finalUsage(session, { inputTokens: 12, outputTokens: 3 }, 1, 1, [source])
+    const before = session.append('user/message', createUserMessage({
+      content: [{ type: 'text', text: 'before compaction' }],
+      source: { kind: 'user' },
+    }), { surfaceOp: 'append' })
+    session.append('user/message', createUserMessage({
+      content: [{ type: 'text', text: 'compacted' }],
+      source: { kind: 'plugin', plugin: 'test' },
+    }), {
+      surfaceOp: { op: 'replace', start: before.seq, end: before.seq },
+      sourceEventSeqs: [before.seq],
+    })
+
+    expect(projected(ctx, session)).toEqual({
+      uncachedInputTokens: 12,
+      outputTokens: 3,
+      cacheReadTokens: 0,
+      cacheWriteTokens: 0,
+    })
+  })
+
+  it('unregisters with the token-meter fiber and restores from a JSON checkpoint', async () => {
+    const { ctx, session, meterFiber } = await harness()
+    startStep(session, 1, 1)
+    usageChunk(session, { inputTokens: 8, outputTokens: 2, cacheReadTokens: 5 }, 1, 1)
+    const checkpoint = JSON.parse(JSON.stringify(
+      ctx.sessionProjections.checkpoint(session),
+    )) as ReturnType<typeof ctx.sessionProjections.checkpoint>
+
+    await meterFiber.dispose()
+    expect(ctx.sessionProjections.snapshot(session).values).not.toHaveProperty('tokenUsage')
+
+    await ctx.plugin(TokenMeterService)
+    expect(ctx.sessionProjections.viewCheckpoint(checkpoint).tokenUsage).toEqual({
+      uncachedInputTokens: 8,
+      outputTokens: 2,
+      cacheReadTokens: 5,
+      cacheWriteTokens: 0,
+    })
+  })
+})
+
+const pressure = (ctx: Context, session: Session): ContextPressureProjection => {
+  const value = ctx.sessionProjections.snapshot(session).values.contextPressure
+  if (value === undefined) throw new Error('contextPressure projection is not registered')
+  return value
+}
+
+function recordContext(session: Session, model: string, contextWindow?: number): void {
+  session.append('request/context', {
+    provider: 'mock',
+    model,
+    ...contextWindow === undefined ? {} : { contextWindow },
+  })
+}
+
+describe('contextPressure session projection', () => {
+  it('serves no pressure or capacity for an empty log', async () => {
+    const { ctx, session } = await harness()
+    expect(pressure(ctx, session)).toEqual({})
+  })
+
+  it('does not synthesize zero pressure before a provider usage sample', async () => {
+    const { ctx, session } = await harness()
+    startStep(session, 1, 1)
+    recordContext(session, 'small', 64_000)
+    expect(pressure(ctx, session)).toEqual({ contextWindow: 64_000 })
+  })
+
+  it('sums prompt-side buckets and excludes response output', async () => {
+    const { ctx, session } = await harness()
+    startStep(session, 1, 1)
+    usageChunk(session, {
+      inputTokens: 100,
+      outputTokens: 4_000,
+      cacheReadTokens: 20,
+      cacheWriteTokens: 5,
+    }, 1, 1)
+    // Output is deliberately absent: occupancy describes the prompt that was
+    // sent, so it holds still while the response streams.
+    expect(pressure(ctx, session).pressureTokens).toBe(125)
+  })
+
+  it('replaces pressure with the newest request rather than accumulating', async () => {
+    const { ctx, session } = await harness()
+    startStep(session, 1, 1)
+    const first = usageChunk(session, { inputTokens: 100, outputTokens: 10 }, 1, 1)
+    finalUsage(session, { inputTokens: 100, outputTokens: 10 }, 1, 1, [first])
+    startStep(session, 2, 1)
+    usageChunk(session, { inputTokens: 250, outputTokens: 10 }, 2, 1)
+    expect(pressure(ctx, session).pressureTokens).toBe(250)
+  })
+
+  it('carries the newest recorded capacity and replaces it on a model switch', async () => {
+    const { ctx, session } = await harness()
+    startStep(session, 1, 1)
+    recordContext(session, 'small', 64_000)
+    usageChunk(session, { inputTokens: 100, outputTokens: 10 }, 1, 1)
+    expect(pressure(ctx, session)).toEqual({ pressureTokens: 100, contextWindow: 64_000 })
+    recordContext(session, 'large', 256_000)
+    expect(pressure(ctx, session)).toEqual({ pressureTokens: 100, contextWindow: 256_000 })
+  })
+
+  it('removes an older capacity when the newest route advertises none', async () => {
+    const { ctx, session } = await harness()
+    startStep(session, 1, 1)
+    recordContext(session, 'small', 64_000)
+    usageChunk(session, { inputTokens: 100, outputTokens: 10 }, 1, 1)
+    recordContext(session, 'unknown')
+    expect(pressure(ctx, session)).toEqual({ pressureTokens: 100 })
+  })
+
+  it('pushes no change for unrelated events or a restated capacity', async () => {
+    // The registry gates its change feed on Object.is, so a unit that rebuilt
+    // state for an event it does not care about would push phantom updates.
+    const { ctx, session } = await harness()
+    startStep(session, 1, 1)
+    recordContext(session, 'small', 64_000)
+    usageChunk(session, { inputTokens: 100, outputTokens: 10 }, 1, 1)
+    const changed: string[] = []
+    ctx.sessionProjections.onChanged((_session, key) => { changed.push(key) })
+
+    session.append('todo/write', { todos: [] })
+    expect(changed).not.toContain('contextPressure')
+    // A repeated capacity record for the same window is also a no-op.
+    recordContext(session, 'small', 64_000)
+    expect(changed).not.toContain('contextPressure')
+    // A real capacity change still reports.
+    recordContext(session, 'large', 256_000)
+    expect(changed).toContain('contextPressure')
+  })
+
+  it('restores from a JSON checkpoint and unregisters with the token-meter fiber', async () => {
+    const { ctx, session, meterFiber } = await harness()
+    startStep(session, 1, 1)
+    recordContext(session, 'small', 64_000)
+    usageChunk(session, { inputTokens: 42, outputTokens: 2 }, 1, 1)
+    const checkpoint = JSON.parse(JSON.stringify(
+      ctx.sessionProjections.checkpoint(session),
+    )) as ReturnType<typeof ctx.sessionProjections.checkpoint>
+    expect(checkpoint.contextPressure?.ver).toBe(2)
+
+    await meterFiber.dispose()
+    expect(ctx.sessionProjections.snapshot(session).values).not.toHaveProperty('contextPressure')
+
+    await ctx.plugin(TokenMeterService)
+    expect(ctx.sessionProjections.viewCheckpoint(checkpoint).contextPressure).toEqual({
+      pressureTokens: 42,
+      contextWindow: 64_000,
+    })
+  })
+})

packages/llm/token-meter/tsconfig.json

@@ -23,6 +23,9 @@
     {
       "path": "../../core/session"
     },
+    {
+      "path": "../../session-projection/session-projection"
+    },
     {
       "path": "../../support/invariants"
     }

packages/session-persistence/session-checkpoint-policy/tests/crash-recovery.e2e.ts

@@ -85,7 +85,7 @@ describe.skipIf(process.platform === 'win32')('semantic checkpoint hard-crash re
     expect(crashed.markerText).toBe('request-dispatched')
     const events = await load(crashed.root)
     expect(events.map(event => event.type)).toEqual([
-      'turn/start', 'user/message', 'step/start', 'request/header', 'step/end', 'turn/end',
+      'turn/start', 'user/message', 'step/start', 'request/header', 'request/context', 'step/end', 'turn/end',
     ])
     expect(events.at(-1)).toMatchObject({
       type: 'turn/end', data: { reason: { kind: 'interrupted' } },

packages/support/acp-snapshot/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/support/acp-snapshot/README.md
-README.md: 948c33a91977f078d16842c285011bf8f83623bd
-README.zh.md: fb86bd4e236be1c79f66dc46fbaac4d7dfbf9977
+README.md: e7988733827ef1d4de67d6d49764a4836e33d17c
+README.zh.md: e2466feb5e2025cb99f252b4206bfacb711bccda

packages/support/acp-snapshot/README.md

@@ -8,8 +8,8 @@ Four layers, importable separately:
 
 - **`launchAcpTestAgent` (launcher)** — boots a source agent under tsx or a built `lib` agent under plain Node from a supplied cwd, connects the SDK client over a raw-byte stdout tee, collects session updates and stderr, surfaces asynchronous spawn failures through startup, fails closed on unhandled permission requests, and owns graceful or signalled shutdown. Shutdown waits for process exit, inherited stdio closure, and ACP parser exhaustion before resolving or propagating a child error, so captures are complete and callers can remove owned paths after either outcome. When Windows accepts forced termination but publishes its exit marker asynchronously, shutdown gives that marker a bounded grace before treating fallback refusal as a second failure. Snapshot and ordinary e2e suites share this process boundary; a test supplies only agent paths, cwd, environment overrides, and any permission policy.
 - **`runScenario` (harness)** — drives ACP JSON-RPC stdio from a deterministic `input.json` script through the launcher, tees raw stdout for the expected-output and purity checks, and harvests every persisted raw JSONL session log (parent and subagent children, primary-first) after graceful stdin EOF. `AgentUnderTest` supplies absolute `binScript`, optional `libBinScript`, `configPath`, and `tsconfigPath` paths because the subprocess cwd is outside the repo; `workspaceParent` may move the generated child cwd from the platform temp directory when that grant is itself under test. Startup failures preserve captured agent stderr in the rejected diagnostic.
-- **Normalizers** — pure functions turning captured surfaces into stable text or portable fixtures: `normalizeStdout` (JSON-RPC ids → first-seen sequence; UUIDs and every native/JavaScript filesystem spelling of the generated cwd → tokens, longest-first; cwd-rooted separators selected as canonical `/` or host-native; doubles as the stdout-purity check), `normalizeSessionLog` (times zeroed, `seq` kept, the same cwd-path policy), `tokenizeSessionFixtureCwd` (the generated workspace and its filesystem aliases → `{{cwd}}`, authored temp paths unchanged), `scrubSystemPrompts` (prompt text → `{{system}}`), `scrubToolSchemas` (schema bulk → `{{tools}}`), and `scrubRequestHeaders` (all header bulk → `{{system}}`/`{{tools}}`/`{{messagePrefix}}` outside each pin, structure kept — [pinned-header Agent Note](../../../.agents/notes/archived/testing/2026-07-06-pin-request-header-content-in-one-scenario.md)).
-- **`defineAcpSnapshotSuite` (factory)** — registers the whole describe/it tree for a scenario table: per-scenario expected-output and re-persisted-log comparisons, record/refresh fixture write-back, rejection of structured `UNKNOWN_TOOL` results, a tokenized pin per header class composed with independently shared `system-prompt.expected.md` and `tool-schemas.expected.json` sidecars, and a live uniformity guard. Its fixture guards reject orphan scenario dirs, missing files, multiple pins for one class, duplicate sidecar content, unscrubbed JSONL headers, and malformed pinning headers. Refresh evaluates fresh leaves with the harvested run's ids, cwd, and every cwd alias, then reuses normalized-equivalent leaves only when the complete logical-record layout aligns and volatile string replacements form a bijection; ambiguous logs keep fresh strings, and fresh semantic values remain authoritative. It also expands packed timing envelopes before aligning event times, so switching between packed and unpacked layouts cannot shift later records. A newly inserted `session/title` receives its preceding event's time so feature-driven insertions do not churn the remainder of a fixture. Each scenario directory's `session.jsonl` plus contiguous `session.<n>.jsonl` siblings are the ordered primary/child inventory; the scenario table does not duplicate their count. Must be called at vitest collection time.
+- **Normalizers** — pure functions turning captured surfaces into stable text or portable fixtures: `normalizeStdout` (JSON-RPC ids → first-seen sequence; UUIDs and every native/JavaScript filesystem spelling of the generated cwd → tokens, longest-first; cwd-rooted separators selected as canonical `/` or host-native; doubles as the stdout-purity check), `normalizeSessionLog` (times zeroed, `seq` kept, the same cwd-path policy), `tokenizeSessionFixtureCwd` (the generated workspace and its filesystem aliases → one canonical `{{cwd}}`, including an already-tokenized macOS `/private` alias; authored temp paths unchanged), `scrubSystemPrompts` (prompt text → `{{system}}`), `scrubToolSchemas` (schema bulk → `{{tools}}`), and `scrubRequestHeaders` (all header bulk → `{{system}}`/`{{tools}}`/`{{messagePrefix}}` outside each pin, structure kept — [pinned-header Agent Note](../../../.agents/notes/archived/testing/2026-07-06-pin-request-header-content-in-one-scenario.md)).
+- **`defineAcpSnapshotSuite` (factory)** — registers the whole describe/it tree for a scenario table: per-scenario expected-output and re-persisted-log comparisons, record/refresh fixture write-back, rejection of structured `UNKNOWN_TOOL` results, a tokenized pin per header class composed with independently shared `system-prompt.expected.md` and `tool-schemas.expected.json` sidecars, and a live uniformity guard. Its fixture guards reject orphan scenario dirs, missing files, multiple pins for one class, duplicate sidecar content, noncanonical macOS-prefixed cwd tokens, unscrubbed JSONL headers, and malformed pinning headers. Refresh evaluates fresh leaves with the harvested run's ids, cwd, and every cwd alias, then reuses normalized-equivalent leaves only when the complete logical-record layout aligns and volatile string replacements form a bijection; ambiguous logs keep fresh strings, and fresh semantic values remain authoritative. It also expands packed timing envelopes before aligning event times, so switching between packed and unpacked layouts cannot shift later records. A newly inserted `session/title` receives its preceding event's time so feature-driven insertions do not churn the remainder of a fixture. Each scenario directory's `session.jsonl` plus contiguous `session.<n>.jsonl` siblings are the ordered primary/child inventory; the scenario table does not duplicate their count. Must be called at vitest collection time.
 
 Committed session fixtures use canonical packed rows. An in-flight branch that merges this contract runs the [temporary repository migrator](../../../scripts/migrate-packed-session-fixtures.ts) with `pnpm run migrate:packed-session-fixtures`; its [removal proposal](../../../.agents/notes/proposed/process/2026-07-26-remove-packed-session-fixture-migrator.md) owns deletion after affected branches converge.
 

packages/support/acp-snapshot/README.zh.md

@@ -8,8 +8,8 @@ ACP 快照套件工具包：无密钥快照层（`pnpm run test:snapshot`，见[
 
 - **`launchAcpTestAgent`（启动器）**：从指定 cwd 在 tsx 下启动源 agent，或在普通 Node 下启动已构建 `lib` agent；通过原始字节 stdout tee 连接 SDK 客户端，收集会话更新和 stderr，在启动过程中公开异步 spawn 失败，对未处理权限请求快速失败，并负责优雅或带信号关闭。关闭会等待进程退出、继承 stdio 关闭和 ACP parser 耗尽，然后才解析或传播子级错误，使捕获内容完整，且调用方可在任一结果后移除自有路径。当 Windows 接受强制终止但异步发布退出标记时，关闭会给该标记有界宽限，然后才将回退拒绝视为第二次失败。快照和普通 e2e 套件共享该进程边界；测试只需提供 agent 路径、cwd、环境覆盖和任何权限策略。
 - **`runScenario`（harness）**：通过启动器从确定性 `input.json` 脚本驱动 ACP JSON-RPC stdio，将原始 stdout tee 给预期输出和纯度检查，并在优雅 stdin EOF 后收集每个持久化原始 JSONL 会话日志（父级和 subagent 子级，主级优先）。`AgentUnderTest` 提供绝对 `binScript`、可选 `libBinScript`、`configPath` 和 `tsconfigPath` 路径，因为子进程 cwd 位于仓库外。当生成子级 cwd 自身位于待测授权中时，`workspaceParent` 可以将它从平台临时目录移出。启动失败会在拒绝诊断中保留已捕获 agent stderr。
-- **规范化器**：将已捕获接口转换为稳定文本或可移植 fixture 的纯函数：`normalizeStdout`（JSON-RPC id → 首次出现序列；UUID 以及生成 cwd 的每个原生/JavaScript 文件系统写法 → token，按最长优先；根据 cwd 的分隔符选择规范 `/` 或宿主原生形式；同时作为 stdout 纯度检查）、`normalizeSessionLog`（时间归零、保留 `seq`、使用同一 cwd 路径策略）、`tokenizeSessionFixtureCwd`（生成的 workspace 及其文件系统别名 → `{{cwd}}`，手工编写的临时路径保持不变）、`scrubSystemPrompts`（提示词文本 → `{{system}}`）、`scrubToolSchemas`（schema bulk → `{{tools}}`）和 `scrubRequestHeaders`（每个 pin 之外的所有 header bulk → `{{system}}`/`{{tools}}`/`{{messagePrefix}}`，保留结构；见[header 固定 Agent Note](../../../.agents/notes/archived/testing/2026-07-06-pin-request-header-content-in-one-scenario.md)）。
-- **`defineAcpSnapshotSuite`（工厂）**：为场景表注册完整 describe/it 树：每场景预期输出与重新持久化日志比较、录制/刷新 fixture 回写、拒绝结构化 `UNKNOWN_TOOL` 结果、每个 header 类别一个 token 化 pin（由可独立共享的 `system-prompt.expected.md` 和 `tool-schemas.expected.json` sidecar 组合而成），以及实时一致性保护。其 fixture 保护会拒绝遗留场景目录、缺失文件、一个类别包含多个 pin、重复的 sidecar 内容、未擦除的 JSONL header，以及格式错误的 pin header。刷新会使用收集所得本次运行的 id、cwd 及全部 cwd 别名评估本次生成的叶值；只有完整逻辑记录布局对齐且易变字符串替换形成双射时，才会复用规范化后等价的叶值；有歧义的日志保留本次生成的字符串，而本次生成的语义值仍为权威数据。它还会在对齐事件时间前展开打包时序 envelope，因此切换打包/非打包布局无法移动后续记录。新插入的 `session/title` 使用前一个事件的时间，因此功能驱动的插入不会扰动 fixture 余下部分。每个场景目录的 `session.jsonl` 和连续 `session.<n>.jsonl` 同级文件是有序主级/子级清单；场景表不重复其数量。必须在 vitest 收集时调用。
+- **规范化器**：将已捕获接口转换为稳定文本或可移植 fixture 的纯函数：`normalizeStdout`（JSON-RPC id → 首次出现序列；UUID 以及生成 cwd 的每个原生/JavaScript 文件系统写法 → token，按最长优先；根据 cwd 的分隔符选择规范 `/` 或宿主原生形式；同时作为 stdout 纯度检查）、`normalizeSessionLog`（时间归零、保留 `seq`、使用同一 cwd 路径策略）、`tokenizeSessionFixtureCwd`（生成的 workspace 及其文件系统别名，包括已 token 化的 macOS `/private` 别名 → 单一规范 `{{cwd}}`；手工编写的临时路径保持不变）、`scrubSystemPrompts`（提示词文本 → `{{system}}`）、`scrubToolSchemas`（schema bulk → `{{tools}}`）和 `scrubRequestHeaders`（每个 pin 之外的所有 header bulk → `{{system}}`/`{{tools}}`/`{{messagePrefix}}`，保留结构；见[header 固定 Agent Note](../../../.agents/notes/archived/testing/2026-07-06-pin-request-header-content-in-one-scenario.md)）。
+- **`defineAcpSnapshotSuite`（工厂）**：为场景表注册完整 describe/it 树：每场景预期输出与重新持久化日志比较、录制/刷新 fixture 回写、拒绝结构化 `UNKNOWN_TOOL` 结果、每个 header 类别一个 token 化 pin（由可独立共享的 `system-prompt.expected.md` 和 `tool-schemas.expected.json` sidecar 组合而成），以及实时一致性保护。其 fixture 保护会拒绝遗留场景目录、缺失文件、一个类别包含多个 pin、重复的 sidecar 内容、带非规范 macOS 前缀的 cwd token、未擦除的 JSONL header，以及格式错误的 pin header。刷新会使用收集所得本次运行的 id、cwd 及全部 cwd 别名评估本次生成的叶值；只有完整逻辑记录布局对齐且易变字符串替换形成双射时，才会复用规范化后等价的叶值；有歧义的日志保留本次生成的字符串，而本次生成的语义值仍为权威数据。它还会在对齐事件时间前展开打包时序 envelope，因此切换打包/非打包布局无法移动后续记录。新插入的 `session/title` 使用前一个事件的时间，因此功能驱动的插入不会扰动 fixture 余下部分。每个场景目录的 `session.jsonl` 和连续 `session.<n>.jsonl` 同级文件是有序主级/子级清单；场景表不重复其数量。必须在 vitest 收集时调用。
 
 签入仓库的会话 fixture 使用规范打包行。合并此契约的在途分支通过 `pnpm run migrate:packed-session-fixtures` 运行[临时仓库迁移器](../../../scripts/migrate-packed-session-fixtures.ts)；待受影响分支收敛后，由其[移除提案](../../../.agents/notes/proposed/process/2026-07-26-remove-packed-session-fixture-migrator.md)负责删除该迁移器。
 

packages/support/acp-snapshot/src/normalize.ts

@@ -197,7 +197,7 @@ function tokenizeFixtureString(value: string, ctx: NormalizeContext, basename: s
     + String.raw`(?=$|[\\/\s<>'"()\[\]{},;:!?=])`,
     'g',
   )
-  return exact.replace(absoluteCwd, CWD)
+  return exact.replace(absoluteCwd, CWD).split(`/private${CWD}`).join(CWD)
 }
 
 /** Recursively replace generated-cwd spellings while preserving every other JSON value. */

packages/support/acp-snapshot/src/suite.ts

@@ -1269,9 +1269,10 @@ export function defineAcpSnapshotSuite(options: SnapshotSuiteOptions): void {
       assertUniqueSnapshotContents('tool-schema', schemas)
     })
 
-    it('every committed JSONL has valid tool results and canonical header storage', async () => {
+    it('every committed JSONL has valid tool results and canonical fixture storage', async () => {
       // Prompts and schemas always leave JSONL. Header pins retain prefixes;
-      // every other fixture tokenizes those too. Fixed-point checks make both
+      // every other fixture tokenizes those too. Portable cwd tokens never
+      // retain a platform realpath prefix. Fixed-point checks make these
       // storage rules fail loud.
       for (const scenario of scenarios) {
         const dir = join(snapshotsDir, scenario.name)
@@ -1280,6 +1281,8 @@ export function defineAcpSnapshotSuite(options: SnapshotSuiteOptions): void {
           const fixture = await readFile(join(dir, file), 'utf8')
           expect(unknownToolCallIds(fixture), `${scenario.name}/${file} contains UNKNOWN_TOOL`)
             .toEqual([])
+          expect(fixture, `${scenario.name}/${file} carries a non-canonical macOS cwd token`)
+            .not.toContain('/private{{cwd}}')
           expect(scrubSystemPrompts(fixture), `${scenario.name}/${file} carries an unscrubbed system prompt`)
             .toEqual(fixture)
           expect(scrubToolSchemas(fixture), `${scenario.name}/${file} carries unscrubbed tool schemas`)

packages/support/acp-snapshot/tests/normalize.spec.ts

@@ -470,6 +470,24 @@ describe('tokenizeSessionFixtureCwd', () => {
     expect(tokenizeSessionFixtureCwd(out)).toBe(out)
   })
 
+  it('collapses a residual macOS realpath prefix around an existing cwd token', () => {
+    const raw = [
+      JSON.stringify({ type: 'session', id: 's', createdAt: 1, cwd: '{{cwd}}' }),
+      JSON.stringify({
+        type: 'tool/result',
+        seq: 1,
+        time: 2,
+        data: { content: [{ type: 'text', text: 'wrote /private{{cwd}}/proof.txt' }] },
+      }),
+      '',
+    ].join('\n')
+
+    const out = tokenizeSessionFixtureCwd(raw)
+    expect(out).toContain('wrote {{cwd}}/proof.txt')
+    expect(out).not.toContain('/private{{cwd}}')
+    expect(tokenizeSessionFixtureCwd(out)).toBe(out)
+  })
+
   it('rejects a log without a session cwd', () => {
     expect(() => tokenizeSessionFixtureCwd('')).toThrow(
       'acp-snapshot: cannot tokenize a cwd without a basename',

packages/ui/app-boot/README.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write packages/ui/app-boot/README.md
-README.md: 54f754842d9a6673ed6791b94656139f0f1be6a3
-README.zh.md: dd56084812e8241f0db24601ce2baeba51252d42
+README.md: 51bc5082512632dd493956b96c605aff47dc872e
+README.zh.md: 644d3a3613a9516cb02881fac8ba7531bffa81eb

packages/ui/app-boot/README.md

@@ -14,6 +14,7 @@ Shared boot glue for the app bins ([`dsh`](../../../apps/cli/README.md), [`dsh-c
 | `loadPersonalPatches(binName, dir?)` | Parse the optional `config.yaml` in the Harness home (default [`resolveDshHome()`](../../util/paths/README.md): `$DSH_HOME`, else `~/.dsh`) — a top-level YAML array of include `PatchOptions` (id-targeted config overrides, `insert` lists, `!!js` allowed); absent file → `undefined`, an unreadable/unparsable/non-array file throws |
 | `loadOverlayPatches(binName, file)` | Parse a required patch-list file with the same shape as personal config; read or parse failures throw a labelled error |
 | `boot(binName, absoluteConfigPath, patches?, prepare?)` | Create the root context, install Loader, run optional host preparation before config-tree entries mount (`prepare` may use Loader and provide launcher-owned context slots such as [`MAIN_SESSION_ID_KEY`](../tui/README.md)), then mount and await the include tree, assert entries loaded and activated, and return the root context |
+| `renderConfigDump(binName, absoluteConfigPath, layers, warn?)` | Compose the base config and labeled overlay layers offline — the include's own parser and patch algorithm (`entryListSchema`/`applyEntryPatches`), so the result equals what `boot()` mounts — and render YAML with `!!js` expressions verbatim; each run of same-provenance rows is preceded by a `# ==` comment naming the contributing file and the layers that patched it, keeping the output one loadable document; a patch matching no row goes to `warn` with its layer label (default: one stderr line), read/parse/shape failures throw |
 | `addHarnessSourceSection(ctx, sourceRoot)` | Add a global `harness:source` prompt section (ordered just after the harness identity, before the persona) telling the agent the on-disk path to its own source checkout; a no-op returning `undefined` when the booted tree has no `systemPrompt` service. The section is registered against that service's fiber, so a dev HMR reload of the system prompt drops it until the next boot |
 | `HARNESS_SOURCE_SECTION` | The `'harness:source'` section name `addHarnessSourceSection` registers under |
 

packages/ui/app-boot/README.zh.md

@@ -14,6 +14,7 @@
 | `loadPersonalPatches(binName, dir?)` | 解析 Harness home 中可选的 `config.yaml`（默认使用 [`resolveDshHome()`](../../util/paths/README.md)：先取 `$DSH_HOME`，否则取 `~/.dsh`）：其顶层是一个 YAML 数组，内容为 include 的 `PatchOptions`（按 id 定位的配置覆盖、`insert` 列表，允许 `!!js`）；文件不存在时返回 `undefined`，文件不可读、不可解析或内容不是数组时抛出异常 |
 | `loadOverlayPatches(binName, file)` | 解析一份必需的 patch 列表文件，其形状与个人配置相同；读取或解析失败时抛出带标签的错误 |
 | `boot(binName, absoluteConfigPath, patches?, prepare?)` | 创建根上下文并安装 Loader，在配置树条目挂载前执行可选的宿主准备操作（`prepare` 可以使用 Loader，也可以提供由启动器拥有的上下文插槽，例如 [`MAIN_SESSION_ID_KEY`](../tui/README.md)），再挂载并等待 include 树结算，断言所有条目均已加载并激活，最后返回根上下文 |
+| `renderConfigDump(binName, absoluteConfigPath, layers, warn?)` | 离线合成基础配置与带标签的覆盖层——使用 include 自己的解析器和补丁算法（`entryListSchema`/`applyEntryPatches`），因此结果与 `boot()` 挂载的内容一致——并渲染为 YAML，`!!js` 表达式原样保留；每段来源相同的连续行之前都有一条 `# ==` 注释，标明贡献该段的文件以及修补过它的层，输出仍是一份可加载的文档；未匹配到行的补丁连同其层标签交给 `warn`（默认：一行 stderr），读取／解析／形状失败则抛出 |
 | `addHarnessSourceSection(ctx, sourceRoot)` | 添加全局 `harness:source` 提示词段落（顺序紧随 harness 身份、位于 persona 之前），告知 agent（智能体）自身源代码 checkout 的磁盘路径；如果已启动树没有此项服务，则不执行操作并返回 `undefined`。这里的服务是 `systemPrompt`；该段落注册到它的 fiber，因此开发环境 HMR（热模块替换）重新加载系统提示词后，它会消失直至下次启动 |
 | `HARNESS_SOURCE_SECTION` | `'harness:source'` 段落名称，供 `addHarnessSourceSection` 注册使用 |
 

packages/ui/app-boot/src/index.ts

@@ -12,7 +12,7 @@ import { basename, dirname, join, resolve } from 'node:path'
 import * as yaml from 'js-yaml'
 import { Context, type FiberState } from 'cordis'
 import Loader from '@cordisjs/plugin-loader'
-import Include, { type PatchOptions } from '@cordisjs/plugin-include'
+import Include, { applyEntryPatches, entryListSchema, type PatchOptions } from '@cordisjs/plugin-include'
 import { resolveDshHome } from '@deepseek-ai/dsh-paths'
 // Side-effect type import: resolves `ctx.get('systemPrompt')` to the service.
 import type {} from '@deepseek-ai/dsh-system-prompt'
@@ -60,16 +60,12 @@ export function loadEnv(
 /** File inside the Harness home holding the personal loader overlay patches. */
 export const PERSONAL_CONFIG_FILENAME = 'config.yaml'
 
-// The include's YAML dialect: `!!js` scalars become expression nodes the
-// Loader interpolates against each entry's context at mount time. Personal
-// patches are parsed with the same schema so they may reference `process.env`.
-// Load-only: this schema never dumps, so no `predicate`/`represent`.
-const jsExprType = new yaml.Type('tag:yaml.org,2002:js', {
-  kind: 'scalar',
-  resolve: data => typeof data === 'string',
-  construct: data => ({ __jsExpr: String(data) }),
-})
-const personalPatchesSchema = yaml.JSON_SCHEMA.extend(jsExprType)
+// The include's YAML dialect (`!!js` scalars become expression nodes the
+// Loader interpolates against each entry's context at mount time), imported
+// from the include itself so patch parsing and config dumping can never drift
+// from what the include mounts. Personal patches share it so they may
+// reference `process.env`.
+const personalPatchesSchema = entryListSchema
 
 /**
  * Load the optional personal overlay patches (`config.yaml` under the Harness
@@ -149,6 +145,141 @@ function parsePatchList(
   return parsed as PatchOptions[]
 }
 
+/** One overlay patch list with the label provenance comments print for it. */
+export interface ConfigDumpLayer {
+  /** Source name shown in provenance comments (a file basename or path). */
+  label: string
+  /** The layer's patches, from {@link loadOverlayPatches} / {@link loadPersonalPatches}. */
+  patches: PatchOptions[]
+}
+
+/**
+ * Compose the effective entry list exactly as `boot()` would mount it: parse
+ * the base config file with the include's entry-list dialect, apply every
+ * layer's patches as ONE flattened list through the include's own patch
+ * algorithm (`applyEntryPatches`) — the same single call `boot()` makes, so
+ * even patch-visibility corner cases (a later layer targeting a group child a
+ * plain config replacement introduced, which the single-pass id index never
+ * sees) compose identically — then render the result as YAML in the same
+ * dialect (`!!js` expressions print verbatim, unevaluated).
+ *
+ * Every run of rows with the same provenance is preceded by a `# ==` comment
+ * naming the file that contributed the rows and any layers that patched them,
+ * so the output stays a loadable YAML document while showing which section
+ * comes from which file. Provenance is derived from single-call prefix
+ * snapshots (base + layers 1..k), diffed positionally: the patch algorithm
+ * only rewrites rows in place or appends, so a top-level index identifies one
+ * row across snapshots, and a layer whose addition changes the row (config
+ * replacement, disable, group insert) is listed as having patched it.
+ *
+ * A patch that matches no row is reported through `warn` with its layer
+ * label, mirroring the Loader's boot-time warning. Earlier layers' patches
+ * see an identical preceding state in every snapshot that includes them, so
+ * each snapshot's warning list extends the previous one and the new tail
+ * belongs to the added layer.
+ * @param binName - the diagnostic prefix on read/parse errors.
+ * @param absoluteConfigPath - the base config file `boot()` would include.
+ * @param layers - overlay layers in application order (later wins).
+ * @param warn - sink for skipped-patch diagnostics; defaults to stderr.
+ * @returns the composed entry list rendered as a YAML document with
+ * provenance comment separators.
+ */
+export function renderConfigDump(
+  binName: string,
+  absoluteConfigPath: string,
+  layers: ConfigDumpLayer[],
+  warn: (line: string) => void = line => void process.stderr.write(`${line}\n`),
+): string {
+  let content: string
+  try {
+    content = readFileSync(absoluteConfigPath, 'utf8')
+  } catch (error) {
+    throw new Error(`${binName}: failed to read config ${absoluteConfigPath}: ${String(error)}`)
+  }
+  let parsed: unknown
+  try {
+    parsed = yaml.load(content, { schema: entryListSchema })
+  } catch (error) {
+    throw new Error(`${binName}: failed to parse config ${absoluteConfigPath}: ${String(error)}`)
+  }
+  if (!Array.isArray(parsed)) {
+    throw new Error(`${binName}: config ${absoluteConfigPath} must be a top-level YAML array of entries`)
+  }
+  const baseLabel = basename(absoluteConfigPath)
+  // The YAML boundary yields untyped rows; the include validates entry shape
+  // at mount, and the dump prints whatever the file holds, so `EntryOptions`
+  // here is structural trust in the same file `boot()` would include.
+  const base = parsed as Parameters<typeof applyEntryPatches>[0]
+  // snapshot_k = ONE application of layers 1..k flattened — boot's exact call
+  // shape for that prefix. snapshot_N is therefore the mounted composition.
+  // The patches are cloned per call: applyEntryPatches detaches the entry
+  // list but pushes `insert` rows by reference from the patch list, so
+  // sharing patch objects across snapshot calls would leak a later
+  // snapshot's mutations into an earlier one's result.
+  const snapshot = (count: number, warnings: string[]): ReturnType<typeof applyEntryPatches> => {
+    const flattened = structuredClone(layers.slice(0, count).flatMap(layer => layer.patches))
+    return applyEntryPatches(base, flattened, (message: string, ...args: unknown[]) => {
+      // The include logs through cordis's printf-style logger (`%C` = code); a
+      // dump has no logger, so substitute inline for a plain line.
+      let index = 0
+      warnings.push(message.replace(/%C/g, () => JSON.stringify(args[index++])))
+    })
+  }
+  let previous = base
+  let previousWarnings: string[] = []
+  const provenance: { origin: string; patchedBy: string[] }[] = base.map(() => ({ origin: baseLabel, patchedBy: [] }))
+  let composed = base
+  for (let count = 1; count <= layers.length; count += 1) {
+    const layer = layers[count - 1]
+    /* v8 ignore next -- count iterates 1..length, so the slot exists */
+    if (layer === undefined) continue
+    const warnings: string[] = []
+    composed = snapshot(count, warnings)
+    for (const line of warnings.slice(previousWarnings.length)) {
+      warn(`${binName}: [${layer.label}] ${line}`)
+    }
+    const before = previous.map(entry => JSON.stringify(entry))
+    for (let index = 0; index < composed.length; index += 1) {
+      if (index >= before.length) provenance.push({ origin: layer.label, patchedBy: [] })
+      else if (JSON.stringify(composed[index]) !== before[index]) provenance[index]?.patchedBy.push(layer.label)
+    }
+    previous = composed
+    previousWarnings = warnings
+  }
+  return groupedDump(composed, provenance)
+}
+
+/** Render the composed rows grouped under one provenance comment per contiguous run. */
+function groupedDump(
+  composed: readonly unknown[],
+  provenance: readonly { origin: string; patchedBy: string[] }[],
+): string {
+  const lines: string[] = []
+  let currentLabel: string | undefined
+  let group: unknown[] = []
+  const flush = (): void => {
+    if (currentLabel === undefined || group.length === 0) return
+    lines.push(`# == ${currentLabel}`)
+    lines.push(yaml.dump(group, { schema: entryListSchema, noRefs: true }).trimEnd())
+    group = []
+  }
+  for (let index = 0; index < composed.length; index += 1) {
+    const record = provenance[index]
+    /* v8 ignore next -- provenance is index-aligned with composed by construction */
+    if (record === undefined) continue
+    const label = record.patchedBy.length === 0
+      ? record.origin
+      : `${record.origin}, patched by ${record.patchedBy.join(', ')}`
+    if (label !== currentLabel) {
+      flush()
+      currentLabel = label
+    }
+    group.push(composed[index])
+  }
+  flush()
+  return lines.join('\n') + '\n'
+}
+
 /**
  * The slice of `process` {@link installFailLoud} needs — injectable so tests
  * exercise the handler without registering on (or exiting) the real process.

packages/ui/app-boot/tests/config-dump.spec.ts

@@ -0,0 +1,187 @@
+/**
+ * `renderConfigDump` behavior: the offline composition must equal what
+ * `boot()` mounts (same parser, same patch algorithm), print `!!js`
+ * expressions verbatim, separate provenance runs with comment lines while
+ * staying one loadable YAML document, and report skipped patches through
+ * `warn` instead of failing — mirroring the Loader's boot-time warning for a
+ * shared overlay whose row exists only on another surface.
+ */
+
+import { mkdtempSync, writeFileSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { join } from 'node:path'
+import { describe, expect, it, vi } from 'vitest'
+import * as yaml from 'js-yaml'
+import { entryListSchema } from '@cordisjs/plugin-include'
+import { loadOverlayPatches, renderConfigDump } from '../src/index.ts'
+
+const NAME = 'dsh-test-bin'
+
+const tmp = (): string => mkdtempSync(join(tmpdir(), 'dsh-config-dump-'))
+
+function writeBase(dir: string): string {
+  const base = join(dir, 'base.yml')
+  writeFileSync(base, [
+    '- id: shared',
+    '  name: ./noop.mjs',
+    '  config:',
+    '    value: base',
+    '    key: !!js process.env.DSH_DUMP_SPEC',
+    '- id: untouched',
+    '  name: ./noop.mjs',
+    '',
+  ].join('\n'))
+  return base
+}
+
+describe('renderConfigDump', () => {
+  it('composes overlay layers in order, prints !!js verbatim, and labels each section with its provenance', () => {
+    const dir = tmp()
+    const base = writeBase(dir)
+    const surface = join(dir, 'surface.yml')
+    writeFileSync(surface, [
+      '- id: shared',
+      '  config:',
+      '    value: surface',
+      '    key: !!js process.env.DSH_DUMP_SPEC',
+      '- insert:',
+      '    - id: surface-extra',
+      '      name: ./noop.mjs',
+      '',
+    ].join('\n'))
+    const personal = join(dir, 'personal.yml')
+    writeFileSync(personal, [
+      '- id: surface-extra',
+      '  config:',
+      '    value: personal',
+      '',
+    ].join('\n'))
+
+    const dump = renderConfigDump(NAME, base, [
+      { label: 'surface.yml', patches: loadOverlayPatches(NAME, surface) },
+      { label: 'personal.yml', patches: loadOverlayPatches(NAME, personal) },
+    ], () => {})
+    // Comments do not break loadability: the dump parses as one document
+    // equal to what boot() would mount.
+    const parsed = yaml.load(dump, { schema: entryListSchema }) as {
+      id: string
+      config?: Record<string, unknown>
+    }[]
+    expect(parsed).toEqual([
+      {
+        id: 'shared',
+        name: './noop.mjs',
+        config: { value: 'surface', key: { __jsExpr: 'process.env.DSH_DUMP_SPEC' } },
+      },
+      { id: 'untouched', name: './noop.mjs' },
+      { id: 'surface-extra', name: './noop.mjs', config: { value: 'personal' } },
+    ])
+    // Unevaluated: the expression text round-trips as a !!js scalar.
+    expect(dump).toContain('!!js process.env.DSH_DUMP_SPEC')
+    // Provenance separators: origin file, plus every layer that changed the
+    // row; an inserted row carries the inserting layer as its origin.
+    expect(dump).toContain('# == base.yml, patched by surface.yml')
+    expect(dump).toContain('# == base.yml\n- id: untouched')
+    expect(dump).toContain('# == surface.yml, patched by personal.yml\n- id: surface-extra')
+    expect(dump.indexOf('# == base.yml, patched by surface.yml')).toBeLessThan(dump.indexOf('# == base.yml\n- id: untouched'))
+  })
+
+  it('groups contiguous same-provenance rows under one separator', () => {
+    const dir = tmp()
+    const base = join(dir, 'base.yml')
+    writeFileSync(base, [
+      '- id: a',
+      '  name: ./noop.mjs',
+      '- id: b',
+      '  name: ./noop.mjs',
+      '',
+    ].join('\n'))
+    const dump = renderConfigDump(NAME, base, [], () => {})
+    expect(dump.match(/# == base\.yml/g)).toHaveLength(1)
+    expect(dump).toContain('# == base.yml\n- id: a')
+  })
+
+  it('composes all layers as one flattened patch list, exactly like boot()', () => {
+    // boot() flattens every layer into ONE applyEntryPatches call, whose id
+    // index sees inserted rows but NOT children introduced by a plain group
+    // `config` replacement. A per-layer composition would rebuild the index
+    // between layers and let the second layer patch that child — a tree the
+    // real boot never mounts. Pin the single-call semantics: the child patch
+    // is skipped (with the layer-labeled warning), matching boot.
+    const dir = tmp()
+    const base = join(dir, 'base.yml')
+    writeFileSync(base, [
+      '- id: g',
+      '  name: ./group.mjs',
+      '  group: true',
+      '  config: []',
+      '',
+    ].join('\n'))
+    const warnings: string[] = []
+    const dump = renderConfigDump(NAME, base, [
+      {
+        label: 'a.yml',
+        patches: [{ id: 'g', config: [{ id: 'child', name: './noop.mjs', config: { v: 1 } }] }],
+      },
+      { label: 'b.yml', patches: [{ id: 'child', config: { v: 2 } }] },
+    ], line => void warnings.push(line))
+    expect(warnings).toEqual([`${NAME}: [b.yml] patch: entry "child" not found`])
+    const parsed = yaml.load(dump, { schema: entryListSchema }) as {
+      config?: { config?: { v?: number } }[]
+    }[]
+    expect(parsed[0]?.config?.[0]?.config?.v).toBe(1)
+    // The skipped layer did not change the row, so it is not in provenance.
+    expect(dump).toContain('# == base.yml, patched by a.yml\n- id: g')
+    expect(dump).not.toContain('b.yml\n- id: g')
+  })
+
+  it('reports a patch whose target row is absent through warn with its layer label and keeps composing', () => {
+    const dir = tmp()
+    const base = writeBase(dir)
+    const overlay = join(dir, 'overlay.yml')
+    writeFileSync(overlay, [
+      '- id: only-on-another-surface',
+      '  config:',
+      '    value: ignored',
+      '- id: shared',
+      '  config:',
+      '    value: patched',
+      '',
+    ].join('\n'))
+    const warnings: string[] = []
+    const dump = renderConfigDump(
+      NAME, base,
+      [{ label: 'overlay.yml', patches: loadOverlayPatches(NAME, overlay) }],
+      line => void warnings.push(line),
+    )
+    expect(warnings).toEqual([`${NAME}: [overlay.yml] patch: entry "only-on-another-surface" not found`])
+    const parsed = yaml.load(dump, { schema: entryListSchema }) as { config?: { value?: string } }[]
+    expect(parsed[0]?.config?.value).toBe('patched')
+  })
+
+  it('defaults its warn sink to one stderr line per skipped patch', () => {
+    const dir = tmp()
+    const base = writeBase(dir)
+    const write = vi.spyOn(process.stderr, 'write').mockReturnValue(true)
+    try {
+      renderConfigDump(NAME, base, [{ label: 'x.yml', patches: [{ id: 'absent', config: {} }] }])
+      expect(write).toHaveBeenCalledWith(`${NAME}: [x.yml] patch: entry "absent" not found\n`)
+    } finally {
+      write.mockRestore()
+    }
+  })
+
+  it('fails loud on a missing, unparsable, or non-array base config', () => {
+    const dir = tmp()
+    expect(() => renderConfigDump(NAME, join(dir, 'absent.yml'), [], () => {}))
+      .toThrow(new RegExp(`^${NAME}: failed to read config `))
+    const invalid = join(dir, 'invalid.yml')
+    writeFileSync(invalid, 'invalid: [unclosed\n')
+    expect(() => renderConfigDump(NAME, invalid, [], () => {}))
+      .toThrow(new RegExp(`^${NAME}: failed to parse config `))
+    const scalar = join(dir, 'scalar.yml')
+    writeFileSync(scalar, 'id: not-a-list\n')
+    expect(() => renderConfigDump(NAME, scalar, [], () => {}))
+      .toThrow('must be a top-level YAML array of entries')
+  })
+})