feat(acp): follow every nested subsession and its asks between prompts - #58

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• Review profile: CHILL
• Plan: Advanced
• Run ID: a40e8df9-354d-4691-aef4-6943850ad75d

📥 Commits

Reviewing files that changed from the base of the PR and between 9aa59d0 and de9da81.

📒 Files selected for processing: 3

• packages/cli/src/acp/translate.ts
• packages/cli/src/acp/turn.ts
• packages/cli/test/acp/translate.test.ts

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ACP follows attached sessions and descendants between prompts. It delivers pending permission requests and forms, including after session load or resume. Tool-call references are included only when the client has received the tool call.

Changes: ACP session-tree request following

Layer / File(s)	Summary
Ask payloads and session-tree translation packages/cli/src/acp/permission.ts, packages/cli/src/acp/elicitation.ts, packages/cli/src/acp/translate.ts, packages/cli/test/acp/translate.test.ts	Permission and form asks use request records. Translation tracks asks, suppresses duplicates, and identifies events from the root session and adopted descendants. Tests cover pending asks and descendant routing.
Session following and pending-ask delivery packages/cli/src/acp/turn.ts, packages/cli/src/acp/sessions.ts, packages/cli/src/acp/replay.ts, packages/cli/src/acp/service.ts, packages/cli/test/acp/wire-fixture.ts, packages/cli/test/acp/turn.test.ts, services/www/src/docs/content/cli/acp.mdx	Turns adopt descendants, list pending asks, and follow session-tree events between prompts and after attachment. Load and resume start following. Tests and fixtures cover pending asks, descendants, retry behavior, and tool-call references. Documentation describes these flows.

Priority: ⬆️ High

Estimated code review effort: 4 (Complex) | ~45 minutes

Change: Feature

Sequence Diagram(s)

sequenceDiagram
  participant ACPService
  participant ACPTurn
  participant OpenCodeAPI
  participant ACPClient
  ACPService->>ACPTurn: follow attached session
  ACPTurn->>OpenCodeAPI: list pending permissions and forms
  OpenCodeAPI-->>ACPTurn: pending requests and forms
  ACPTurn->>ACPClient: deliver pending asks
  OpenCodeAPI-->>ACPTurn: session-tree events
  ACPTurn->>ACPClient: deliver in-tree asks
  ACPClient->>ACPTurn: reply to permission request

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Suggested reviewers: nexxeln

No actionable merge-blocking issue remains after normal checks.

Request delivery remains active for longer and includes previously undiscovered descendants. The reviewed paths retain session-tree checks, explicit approval and cancellation safeguards. Remaining uncertainty concerns request identity and lifecycle edge cases rather than a demonstrated authorization bypass.

Retained concerns
No architecture-level concerns identified.

Security review details

Security Blast Radius

• observed — The delivery scope expands temporally and includes validated descendants from earlier prompts. Approval consequences can exceed the individual child: existing always-allow behavior saves rules at project scope and reevaluates matching pending requests. This PR exposes additional asks to that existing approval mechanism rather than introducing new grant semantics.

Trust Boundaries and Controls

• observed — Permission replies carry the original request session, and the server verifies that the request belongs to that session. Settlement events are produced from stored request ownership. Generated ask IDs include random bytes, and duplicate active permission IDs are rejected.

Resilience and Maintainability Implications

• observed — Follower interruption leaves the server ask pending instead of submitting a fallback decision, allowing the next prompt to replay it. Explicit prompt cancellation instead races through reject/cancel outcomes. Outbound ACP requests receive cancellation signals.

Hardening Proposals

• proposed — Apply session-tree membership checks consistently before recording settlements, and document or enforce ask-ID nonreuse for the subscription lifetime. This would reduce dependence on stream-wide identity assumptions; the reviewed evidence does not establish an authorization bypass.

Pre-merge checks: 4 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 22.22% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 27 functions across 10 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

Passed checks: 4 passed

Check name	Status	Explanation
Title check		The title clearly and concisely describes the primary change: following nested subsessions and their asks between prompts.
Description check		The description includes the required sections, explains the problem and implementation, documents verification results, and completes the checklist. The absence of an issue number is explicitly expla…
Linked Issues check		Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check		Check skipped because no linked issues were found for this pull request.

Full details: Description check

Explanation

The description includes the required sections, explains the problem and implementation, documents verification results, and completes the checklist. The absence of an issue number is explicitly explained.

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