Fix Code Mode workspace context propagation

packages/hooks/hooks-codex/README.md

@@ -43,7 +43,7 @@ The hooks themselves run in the agent's session workspace: for the agent-scoped
 | `SessionStart` | `agent/session-start` (emit) | a plain-stdout hook's output → additionalContext → `agent.inject()` |
 | `UserPromptSubmit` | `agent/prompt-submit` (waterfall) | `block` (exit 2) → `PromptDecision.block`; additionalContext-only → delegate via `next()` then fold context onto the downstream decision |
 | `PreToolUse` | `tools/pre-execute` (waterfall) | `block` → `PreToolDecision.deny` (no `allow`/`ask`) |
-| `PostToolUse` | `tools/post-execute` (waterfall) | `block` → `block` with feedback; additionalContext-only → delegate via `next()` then fold context onto the downstream decision (a Code Mode sub-call’s context is dropped by the run_code bridge — see [the pipeline doc](../../../docs/tool-execution-pipeline.md)) |
+| `PostToolUse` | `tools/post-execute` (waterfall) | `block` → `block` with feedback; additionalContext-only → delegate via `next()` then prepend a separately sourced context to the downstream decision; Code Mode defers sub-call contexts until the outer `run_code` result |
 | `Stop` | `agent/turn-continuation` (waterfall) | a blocking Stop hook forces `continue` with the reason as next-step steering |
 
 A tool call's payload carries the real `tool_name` (the same value the matcher tests) and Codex's `tool_input: { command }` shape (the `command` arg when present, else `''`). The matcher subject is the tool name (`PreToolUse`/`PostToolUse`) or the session source (`SessionStart`); `UserPromptSubmit`/`Stop` ignore matchers.

packages/hooks/hooks-codex/src/index.ts

@@ -177,9 +177,9 @@ export function apply(ctx: Context, config: Config): void {
   }
 
   /**
-   * Concatenate this bridge's {@link HookContext} (`ours`, always present at the
-   * call sites) with a downstream listener's optional one, so folding our
-   * additionalContext onto a delegated decision drops neither. The merged block
+   * Concatenate this bridge's prompt {@link HookContext} with a downstream
+   * prompt listener's optional one, so folding additionalContext drops neither.
+   * The merged block
    * carries a single `source` — this bridge's — because a `HookContext` holds one
    * `MessageSource` and the seam cannot represent mixed provenance; the rendered
    * `context/message` only distinguishes by `source.kind` ('plugin'), so a
@@ -190,6 +190,11 @@ export function apply(ctx: Context, config: Config): void {
     return { content: [...ours.content, ...theirs.content], source: ours.source }
   }
 
+  /** Prepend one post-tool context without flattening downstream provenance. */
+  function prependContext(ours: HookContext, theirs: HookContext[] | undefined): HookContext[] {
+    return [ours, ...theirs ?? []]
+  }
+
   // SessionStart: emit. Codex passes a plain-stdout hook's output as additionalContext.
   // TODO(session-start-gating): a synchronous emit + detached `.then`, so the
   // injected context is BEST-EFFORT — not guaranteed before the first turn reaches
@@ -235,19 +240,19 @@ export function apply(ctx: Context, config: Config): void {
     const merged = await runPoint('PostToolUse', exec.name, postToolPayload(exec, result, model), { ...exec.agent ? { agent: exec.agent } : {}, turn, ...exec.signal ? { signal: exec.signal } : {} })
     const context = contextFrom(merged)
     if (merged.decision === 'deny') {
-      return { kind: 'block', feedback: [{ type: 'text', text: merged.reason ?? 'blocked by PostToolUse hook' }], ...context ? { additionalContext: context } : {} }
+      return { kind: 'block', feedback: [{ type: 'text', text: merged.reason ?? 'blocked by PostToolUse hook' }], ...context ? { additionalContexts: [context] } : {} }
     }
     // Context alone is not a veto: DELEGATE, then fold our context onto the
     // downstream decision (a downstream block carries it too).
     const downstream = await next()
     if (!context) return downstream
     if (downstream.kind === 'block') {
-      return { ...downstream, additionalContext: concatContext(context, downstream.additionalContext) }
+      return { ...downstream, additionalContexts: prependContext(context, downstream.additionalContexts) }
     }
     return {
       kind: 'accept',
       ...downstream.content !== undefined ? { content: downstream.content } : {},
-      additionalContext: concatContext(context, downstream.additionalContext),
+      additionalContexts: prependContext(context, downstream.additionalContexts),
     }
   })
 

packages/hooks/hooks-codex/tests/coverage.spec.ts

@@ -118,6 +118,33 @@ describe('hooks-codex coverage — decision mapping paths', () => {
     expect(events(agent).some(e => e.type === 'context/message' && e.data.content.some(b => b.type === 'text' && b.text.includes('bridge-note')))).toBe(true)
   })
 
+  it('keeps bridge and downstream PostToolUse contexts as separate sourced events', async () => {
+    const d = dir()
+    hooks(d, { PostToolUse: [{ hooks: [{ type: 'command', command: sh(d, 'pc.sh', '#!/usr/bin/env bash\necho \'{"hookSpecificOutput":{"hookEventName":"PostToolUse","additionalContext":"bridge-note"}}\'\n') }] }] })
+    const adapter = new MockAdapter([toolCallResponse('c1', 'echo', {}), textResponse('done')])
+    const ctx = await harness(join(d, 'hooks.json'), adapter)
+    ctx.tools.register(defineTool({ name: 'echo', description: 'e', parameters: {}, async execute() { return [{ type: 'text', text: 'ok' }] } }))
+    ctx.on('tools/post-execute', async () => ({
+      kind: 'accept' as const,
+      additionalContexts: [{
+        content: [{ type: 'text' as const, text: 'downstream-note' }],
+        source: { kind: 'plugin' as const, plugin: 'policy' },
+        envelope: 'raw' as const,
+        meta: { owner: 'policy' },
+      }],
+    }))
+    const agent = ctx.agentLoop.create(AgentId('a1'), { model: 'mock' })
+    agent.send([{ type: 'text', text: 'go' }]); await waitForIdle(ctx, agent)
+
+    const contexts = events(agent).filter(event => event.type === 'context/message')
+    expect(contexts.map(event => event.type === 'context/message' && event.data.source)).toEqual([
+      { kind: 'plugin', plugin: 'hooks-codex' },
+      { kind: 'plugin', plugin: 'policy' },
+    ])
+    expect(contexts[1]?.type === 'context/message' && contexts[1].data.envelope).toBe('raw')
+    expect(contexts[1]?.type === 'context/message' && contexts[1].data.meta).toEqual({ owner: 'policy' })
+  })
+
   it('folds the bridge PostToolUse context onto a downstream listener BLOCK', async () => {
     const d = dir()
     hooks(d, { PostToolUse: [{ hooks: [{ type: 'command', command: sh(d, 'pc.sh', '#!/usr/bin/env bash\necho \'{"hookSpecificOutput":{"hookEventName":"PostToolUse","additionalContext":"bridge-note"}}\'\n') }] }] })
@@ -395,7 +422,7 @@ describe('hooks-codex coverage — decision mapping paths', () => {
     const { CallId } = await import('@deepseek-ai/dsh-llm')
     const result = await ctx.tools.execute({ callId: CallId('c1'), name: 'Bash', arguments: { command: 'x' } })
     expect(result.isError).toBeFalsy()
-    expect(result.additionalContext?.content.some(b => b.type === 'text' && b.text === 'x')).toBe(true)
+    expect(result.additionalContexts?.[0]?.content.some(b => b.type === 'text' && b.text === 'x')).toBe(true)
   })
 
   it('when the bash executor REJECTS, the hook/result omits exitCode (non-blocking)', async () => {