Adapt workspace context to session prefixes

packages/core/session/src/index.ts

@@ -11,7 +11,7 @@ import { isAbsolute } from 'node:path'
 import { deepFreeze } from '@deepseek-ai/dsh-llm'
 import type { ContentBlock, Message, MessageSource } 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 { ContextEnvelope, CreateSessionOptions, EpochHeader, SessionEvent, SessionEventMap, SessionEventType, SessionHeader, SurfaceIntent, SurfaceEventType } from './types.ts'
 import { isJsonValue } from './json.ts'
 import { SurfaceManager, isSurfaceEligibleType } from './surface.ts'
 import { foldRequestHeader } from './request-header.ts'
@@ -77,6 +77,22 @@ function renderTagged(tag: string, content: ContentBlock[], source: MessageSourc
   ]
 }
 
+/**
+ * Render one context contribution exactly as it will appear in model history.
+ * @param content - content blocks supplied by the context producer.
+ * @param source - attribution used by the canonical context envelope.
+ * @param envelope - canonical tagged framing or caller-owned raw framing.
+ * @returns a detached block list ready for the derived model transcript.
+ */
+export function renderContextContent(
+  content: ContentBlock[],
+  source: MessageSource,
+  envelope: ContextEnvelope = 'context',
+): ContentBlock[] {
+  const cloned = structuredClone(content)
+  return envelope === 'raw' ? cloned : renderTagged('context', cloned, source)
+}
+
 /**
  * An event-sourced session: an append-only log of {@link SessionEvent}s.
  *
@@ -355,8 +371,8 @@ export class Session {
         }
       }
       case 'context/message': {
-        const { content, source } = event.data
-        return { role: 'user', content: renderTagged('context', structuredClone(content), source) }
+        const { content, source, envelope } = event.data
+        return { role: 'user', content: renderContextContent(content, source, envelope) }
       }
       case 'steering/message': {
         const { content, source } = event.data

packages/core/session/src/types.ts

@@ -1,5 +1,9 @@
 import type { Branded } from '@deepseek-ai/dsh-brand'
 import type { CallId, ContentBlock, LlmCallConfig, Message, MessageSource, StreamChunk, TokenUsage, ToolSchema } from '@deepseek-ai/dsh-llm'
+import type { JsonValue } from './json.ts'
+
+/** Canonical context-tag framing, or caller-owned framing rendered verbatim. */
+export type ContextEnvelope = 'context' | 'raw'
 
 /** Identifies one session in the store (and its persistence artifacts). */
 export type SessionId = Branded<'SessionId'>
@@ -306,9 +310,16 @@ export interface SessionEventMap {
   /**
    * In-session context injection (file-change notices, subdir AGENTS.md,
    * skill content, cron notifications, …). Rendered into the derived history
-   * as tagged synthetic context — NOT a user prompt.
+   * as synthetic context — NOT a user prompt. `envelope: 'raw'` lets a caller
+   * own the complete model-facing frame; `meta` is durable JSON state omitted
+   * from the model projection.
    */
-  'context/message': { content: ContentBlock[]; source: MessageSource }
+  'context/message': {
+    content: ContentBlock[]
+    source: MessageSource
+    envelope?: ContextEnvelope
+    meta?: JsonValue
+  }
   /** Raw stream chunk — token-level replay fidelity. */
   'assistant/chunk': { turn: number; step: number; chunk: StreamChunk }
   /**