# Choreographer Slice Map

## Purpose
The Choreographer is the server-side composition layer that turns agent intent-verbs (`give_me_work`, `i_will_work_on`, `i_am_done`, `delegate`, `submit_up`, `submit_root`, `complete`, …) into ordered sequences of atomic TaskService / GitService actions. It owns the precondition gates the lifecycle spec does not model (concurrency invariants, tracing/progress gates, free-text soup, conventions, behind-base, unchanged-PR loop-stoppers) and wraps every composed mutation in a SAVEPOINT via `VerbRunner`. Every verb returns a standardized `Envelope` (`ok` / `error` + `next` + `remediate` + `context_briefing`).

## Files

| Path | Role |
|------|------|
| `roboco/services/gateway/choreographer/_impl.py` | The `_LegacyChoreographer` / `Choreographer` class — all verb bodies + guard helpers (~6.9k lines). |
| `roboco/services/gateway/choreographer/_protocol.py` | `ChoreographerHelpers` — TYPE_CHECKING-only stub of helpers role mixins call on `self`, so mypy sees typed signatures (runtime `object`). |
| `roboco/services/gateway/choreographer/_verb_runner.py` | `VerbRunner` — composed-actions runner; wraps `composes` in `session.begin_nested()` SAVEPOINT, runs `pre_side_effects` / `side_effects` outside. |

## Key Symbols (landmarks only)

| Name | Kind | File:Line | Responsibility |
|------|------|-----------|----------------|
| `Choreographer` | class | `_impl.py:339` | Composed entry point; deps-injected; exposes verbs + helpers. |
| `ChoreographerDeps` | dataclass | `_impl.py:207` | Dependency injection container (task, work_session, git, a2a, journal, audit, evidence_repo, messaging, product, orchestrator, stream_bus). |
| `_COORDINATOR_ROLES` | ClassVar | `_impl.py:914` | `{main_pm, cell_pm}` — exempt from `already_active`/`paused` claim guards + advisory lock. |
| `give_me_work` | async verb | `_impl.py:766` | Picks next task for agent + builds briefing (institutional memory injected here). |
| `_briefing_for` | async helper | `_impl.py:820` | Builds `context_briefing`. Claim-scoped: `full=True` (context-acquisition verbs only — give_me_work/claims/plan/resume/triage) carries the heavy sections via `_heavy_briefing_sections` (company_goals, recent_team_activity, blockers, task_handoff, institutional_memory); every other verb gets slim signals-only (unread a2a/mentions/notifications + metadata gaps). AC coverage stays independent of `full`. |
| `_run_claim_guards` | async helper | `_impl.py:916` | already_active / paused / unmet_dependency (with re-check race narrowing) + `_lane_claim_guard`; `skip_dev_guards=False` param skips dev-only guards for pr_reviewer gate claims (claim_gate_review). |
| `_lane_claim_guard` | async helper | `_impl.py:977` | Out-of-order-start barrier: refuse code leaf behind an earlier open same-assignee sibling. Fail-closed on lookup error. |
| `_claim_plan_start_gate` | async helper | `_impl.py:1179` | spec gate → advisory claim lock (non-PM) → behavioral guards. |
| `_claim_plan_start_run` | async helper | `_impl.py:1251` | `runner.run_intent(verb)` + ensure_work_session + `_touch`. |
| `i_will_work_on` | async verb | `_impl.py:1326` | Dev claim+plan+start path; routes re-entry vs fresh claim. |
| `open_pr` | async verb | `_impl.py:1571` | Pre-flight + `run_intent("open_pr")` (push_branch + create_pr side effects). |
| `i_am_done` | async verb | `_impl.py:1771` | Dev pre-submit; runs `_i_am_done_gate` then `run_intent("i_am_done")`. |
| `_i_am_done_gate` | async helper | `_impl.py:1885` | Ordered gate chain: tracing → submit_qa fields → push → behind_base → quality → toolchain → conventions; then write AC status. |
| `_behind_base_gate` | async helper | `_impl.py:2154` | Refuse submit when branch behind its base (sibling PR merged); fail-open on git error. |
| `_toolchain_broken_guard` | async helper | `_impl.py:1939` | Block delivery gate when agent workspace can't run suite; `reviewer=True` for `pr_pass`. |
| `_conventions_guard` | async helper | `_impl.py:2043` | Run architectural-conventions validator; `block` finding refuses gate. |
| `_pm_task_type_error` | static method | `_impl.py:4752` | Reject a code/non-planning task_type delegated to a PM (cell or main); extracted from `_validate_assignee_task_type` to keep that dispatcher under complexity budget. |
| `i_am_blocked` | async verb | `_impl.py:3086` | Rate-limit parking vs generic block; `run_intent("i_am_blocked")`. |
| `_handle_rate_limited_parking` | async helper | `_impl.py:2983` | Park provider on 429/overload/session-limit. |
| `unclaim` | async verb | `_impl.py:3184` | Release claimed task → pending (optional reassign). |
| `reassign` | async verb | `_impl.py:3343` | Reassign task with `_validate_reassign`. |
| `resume` | async verb | `_impl.py:3422` | Resume paused/blocked task. |
| `sync_branch` | async verb | `_impl.py:3528` | Gate-level rebase verb (new since baseline). |
| `i_am_idle` | async verb | `_impl.py:3678` | Idle signal; auto-pause in_progress tasks; pending-assignment / PM review / auditor guards. |
| `i_will_plan` | async verb | `_impl.py:4071` | PM plan verb; `_pm_sub_tasks_gate` enforces substantive approach/sub_tasks. |
| `delegate` | async verb | `_impl.py:4173` | PM creates subtask; sizing, sibling-dedup, spine-cap, lifecycle guards; `_create_subtask_from_inputs`. |
| `submit_up` | async verb | `_impl.py:5348` | Cell PM opens cell→root PR + enters `awaiting_pr_review`; unchanged-PR guard. |
| `submit_root` | async verb | `_impl.py:6260` | Main PM opens root→master PR + enters gate; umbrella hard-reject + unchanged-PR guard. |
| `_submit_root_unchanged_pr_guard` | async helper | `_impl.py:6149` | Loop-stopper: refuse re-submit when PR head SHA == last `pr_fail` SHA. Fail-open on ambiguity. |
| `_current_pr_head_sha` | async helper | `_impl.py:6196` | Best-effort current PR head SHA via `_project_slug_for` + `git.get_pr_head_sha`. |
| `complete` | async verb | `_impl.py:6599` | Role-dispatch to `cell_pm_complete` / `main_pm_complete`; umbrella-in-progress bypasses spec gate. |
| `main_pm_complete` | async verb | `_impl.py:6496` | Main PM merge + escalate to CEO (never merges master itself). |
| `escalate_to_ceo` | async verb | `_impl.py:6844` | Escalate to `awaiting_ceo_approval`. |
| `VerbRunner.run_intent` | async method | `_verb_runner.py:37` | pre_side_effects → SAVEPOINT(composes) → side_effects; intermediate-None raises INVALID_STATE. |
| `VerbRunner._do_pr_merge` | async handler | `_verb_runner.py:257` | `pr_merge` with `project_id` scoping (cross-repo collision fix) + `resolve_parent_branch`. |
| `ChoreographerHelpers` | stub class | `_protocol.py:31` | TYPE_CHECKING-only typed view of `self` helpers for role mixins. |

## Data Flow
An MCP `flow/*` call hits the orchestrator → the role-specific gateway verb → `Choreographer.<verb>(agent_id, task_id, ...)`. The verb fetches the task (`self.task.get`), builds a briefing (`_briefing_for`), runs the spec gate (`spec.can_invoke_intent(role, verb, t, ctx)`) and any verb-specific preflight guards (free-text soup, claim guards, conventions, behind-base, unchanged-PR). On rejection it emits via `_emit_rejection` with `next`/`remediate`. On allow it calls `VerbRunner.run_intent(verb, t, agent, ctx)`: `pre_side_effects` (e.g. `create_root_pr` for `submit_root`) run OUTSIDE the SAVEPOINT; then `session.begin_nested()` wraps the composed atomic actions (`claim`/`set_plan`/`start`/`submit_qa`/…) re-fetching the task after each; then `side_effects` (push_branch / create_pr / pr_merge) run after the savepoint commits. An intermediate `None` from a composed action raises `INVALID_STATE` (concurrent transition); a trailing `None` flows out as the verb result. The verb wraps the final task in `Envelope.ok(status, next_hint, briefing)` with `.with_introspection(task, role)`.

## Mermaid
```mermaid
sequenceDiagram
    participant Agent
    participant Gateway as MCP flow verb
    participant Ch as Choreographer
    participant Spec as lifecycle spec
    participant VR as VerbRunner
    participant TS as TaskService
    participant Git as GitService
    Agent->>Gateway: verb(agent_id, task_id, notes)
    Gateway->>Ch: verb(agent_id, task_id, notes)
    Ch->>TS: task.get(task_id)
    Ch->>Ch: _briefing_for(...)
    Ch->>Spec: can_invoke_intent(role, verb, t, ctx)
    alt not allowed
        Ch-->>Agent: Envelope error (from_decision) + remediate
    else allowed
        Ch->>Ch: preflight guards (soup / claim / conventions / behind_base / unchanged_pr)
        alt guard rejects
            Ch-->>Agent: Envelope invalid_state + remediate
        else pass
            Ch->>VR: run_intent(verb, t, agent, ctx)
            VR->>Git: pre_side_effects (create_root_pr)
            VR->>TS: session.begin_nested() (SAVEPOINT)
            loop composes
                VR->>TS: atomic action (claim / set_plan / start / submit_qa / ...)
                TS-->>VR: updated task (None on concurrent source-state mismatch)
                alt intermediate None
                    VR-->>Ch: raise INVALID_STATE
                end
            end
            VR->>TS: commit savepoint
            VR->>Git: side_effects (push_branch / create_pr / pr_merge)
            VR-->>Ch: final task
            Ch->>TS: ensure_work_session / _touch
            Ch-->>Agent: Envelope ok(status, next, briefing)
        end
    end
```

## Logical Tree
```
Choreographer (composed class, _impl.py)
├── Deps: task / work_session / git / a2a / journal / audit / evidence_repo / messaging / product / orchestrator / stream_bus
├── Verb bodies
│   ├── Dev: give_me_work, i_will_work_on, open_pr, i_am_done, i_am_blocked, unclaim, resume, sync_branch, i_am_idle
│   ├── PM:  i_will_plan, delegate, submit_up, submit_root, complete→{cell_pm_complete, main_pm_complete}, escalate_up, triage, triage_all, unblock, reassign, pm_give_me_work
│   └── Board/CEO: escalate_to_ceo
├── Guard helpers
│   ├── _run_claim_guards → already_active / paused / unmet_dependency / _lane_claim_guard
│   ├── _i_am_done_gate chain → tracing / submit_qa_fields / push / behind_base / quality / toolchain / conventions
│   ├── _submit_up_guard / _submit_up_unchanged_pr_guard / _submit_root_unchanged_pr_guard
│   ├── _guard_free_text / _free_text_soup / _soup_or_decision_env
│   └── _conventions_guard / _toolchain_broken_guard
└── VerbRunner (_verb_runner.py)
    ├── pre_side_effects → {create_root_pr}
    ├── composes (SAVEPOINT) → {claim, set_plan, start, submit_qa, qa_pass, qa_fail, docs_complete, complete, submit_pm_review, submit_for_review, pr_pass, pr_fail, escalate_to_ceo, block, unblock, resume, pr_review_done}
    └── side_effects → {push_branch, create_pr, create_root_pr, pr_merge}
```

## Dependencies
- **Internal services**: `TaskService`, `WorkSessionService`, `GitService`, `EvidenceRepo`/`evidence_builder`, `MessagingService`/a2a, `JournalService`, `AuditService`, `ProjectService`/product, orchestrator handle, `StreamEventBus`.
- **Policy (pure)**: `roboco.foundation.policy.lifecycle` (`can_invoke_intent`, `Context`, `Role`, `_INTENT_VERBS`), `foundation.policy.batch` (`is_batch_umbrella`), `foundation.policy.content` markers + `reject_trivial`.
- **Gateway helpers**: `claim_guards` (`already_active_guard`, `paused_tasks_guard`, `unmet_dependency_guard`), `merge_chain.resolve_parent_branch`, `envelope.Envelope`, `remediation` hints.
- **External**: `structlog`, `asyncpg` (via task_service session / SAVEPOINT), `redis` (rate-limit parking), `git`/`gh` CLI (via git_service).

## Entry Points
- MCP `roboco-flow` server → per-role verb methods (manifest-driven allowlist from `role_config.py`).
- Orchestrator `/api/v1/flow/*` REST endpoints → same `Choreographer` methods.
- Internal cross-verb calls (e.g. `complete` → `cell_pm_complete` / `main_pm_complete`; `_claim_plan_start_run` shared by `i_will_work_on` + `i_will_plan`).

## Config Flags
- `ROBOCO_TOOLCHAIN_MATCH_ENABLED` — gates `_toolchain_broken_guard` (default-off).
- `ROBOCO_CONVENTIONS_ENABLED` — gates `_conventions_guard` (default-off).
- `ROBOCO_OVERLOAD_BREAK_ENABLED` — rate-limit/overload parking path (default-on).
- `ROBOCO_ORG_MEMORY_ENABLED` — institutional-memory injection in `_briefing_for` (default-off).
- `ROBOCO_GATEWAY_HEALTH_ENABLED` — reaper gateway-health probe (default-on; not directly in choreographer but feeds the parking path).

## Gotchas
- The SAVEPOINT wraps only DB atomic actions; `pre_side_effects` (e.g. `create_root_pr`) run BEFORE the savepoint and are NOT rolled back if a later composed action raises — they are idempotent by contract.
- `side_effects` (push/create_pr/pr_merge) run AFTER savepoint commit and are idempotent + retryable; a crash between commit and side-effect leaves the PR uncreated (recovered by re-issue / `open_pr` parity).
- `VerbRunner` only raises on an INTERMEDIATE `None` composed action; a trailing `None` is the verb's own "no transition" result and each verb body must handle it (submit_root_finalize, _claim_plan_start_run do; a verb that forgets will None-deref).
- `_lane_claim_guard` fail-closed on lookup error — a DB hiccup rejects the claim (calls `release_dependency_blocked_claim`); acceptable but can briefly bounce a dev.
- `_submit_*_unchanged_pr_guard` FAILS OPEN on every ambiguous case (no recorded sha, no project slug, git error, closed PR) — only exact-unchanged is hard-blocked; a regression in `_current_pr_head_sha` resolver silently re-opens the loop.
- `complete` bypasses the spec gate for an in-progress batch umbrella (`_is_umbrella_in_progress`) and relies on `main_pm_complete`'s own guards — a mis-classified umbrella could skip the AWAITING_PM_REVIEW status constraint.

## Drift from CLAUDE.md
- CLAUDE.md verb table lists `submit_root` for `main_pm` and `submit_up` for `cell_pm` — matches code (`_impl.py:5348`, `6260`). No drift.
- CLAUDE.md: "PM coordinator concurrency … claim-time concurrency guards skipped for `_COORDINATOR_ROLES`" — matches (`_impl.py:939`, `1234`). No drift.
- CLAUDE.md verb surface omits `sync_branch` from the developer list — code has `sync_branch` at `_impl.py:3528` (added since baseline; memory note `project_sync_branch_tracing_gap.md` flags it). Minor doc drift.
- CLAUDE.md: "PR is created BEFORE QA review" — `i_am_done` gate chain pushes + creates PR context but the actual `create_pr` side-effect runs in `open_pr`/`submit_up`/`submit_root`, not `i_am_done`; consistent with the described flow. No drift.
- CLAUDE.md: "only the CEO merges master; Main PM ready root PR → awaiting_ceo_approval (does NOT merge)" — `main_pm_complete` escalates; `VerbRunner._do_pr_merge` exists for cell-level merges and `create_root_pr` opens but the root merge is CEO-gated. Consistent. No drift.

## Changes Since Baseline
`git log --oneline fd10cc862c2020b3f639cdb686d427b0198a2441..HEAD -- roboco/services/gateway/choreographer/` → 2 commits touching these files (+814/−89):

1. `15effce0` — 141 Gaps fill-in (#283): added out-of-order-start guards (`_lane_claim_guard`, `_behind_base_gate`, `sync_branch`), unchanged-PR loop-stoppers (`_submit_root_unchanged_pr_guard`, `_submit_up_unchanged_pr_guard`, `_current_pr_head_sha`), `project_id` scoping on `pr_merge` (cross-repo collision fix), umbrella-in-progress bypass in `complete`, `_submit_root_finalize` None-guard, reviewer flag on `_toolchain_broken_guard`.
2. `3aff6e04` — Close gaps (#285): follow-on touch-ups in the same areas (per-cell project map root-subtask support umbrella handling).

> Post-snapshot updates (since 2026-06-29):
> - `536bbb64` — logical-gaps sweep: `_run_claim_guards` gains `skip_dev_guards: bool = False` param (pr_reviewer `claim_gate_review` calls skip dev-only already_active/paused/lane guards; dependency guard still runs). `_pm_task_type_error` extracted as new `@staticmethod` on `Choreographer` (`_impl.py:4752`) from `_validate_assignee_task_type` — fixes Main PM omission from the PM-cannot-own-code delegate gate. `_submit_*_unchanged_pr_guard` now logs a `warning` on head_sha resolver failure so fail-open behavior is observable. Matching `skip_dev_guards` stub added to `_protocol.py`. `_impl.py` +78/−0 lines; `_protocol.py` +1 line.
> - `0e7674af` — verb_runner trailing-None side-effect guard + actor_agent_id threading: `run_intent` now skips the `side_effects` loop when the trailing composed action returns `None` (prevents `_do_push_branch(None)` / `_do_pr_merge(None)` AttributeError crash, converting it to a clean caller-handled `None`). `_do_push_branch`, `_do_create_pr`, `_do_create_root_pr`, and `_do_escalate_to_ceo` all forward `actor_agent_id=agent.id` into `git_service` / `task_service`. `main_pm_complete` escalate path in `_impl.py` also forwards `actor_agent_id`. `_verb_runner.py` +52/−8 lines; `_impl.py` +8/−2 lines.

## Regression Risks

| Title | File:Line | Claim | Severity |
|-------|-----------|-------|----------|
| Intermediate-None contract depends on every verb body handling trailing None | `_verb_runner.py:89` + `_impl.py:1277,6358` | A verb that forgets the trailing-None guard None-derefs `t.status`; submit_root + claim_plan_start handle it, but any NEW verb using `run_intent` with a possibly-None last action inherits the trap. **Side-effect crash path closed (0e7674af)**: `run_intent` now skips the `side_effects` loop on a trailing `None`, so `_do_push_branch(None)` no longer crashes. Verb bodies still need to handle `None` return for their own error messaging but will not AttributeError. Risk reduced: runner-level crash path fixed; verb-body None-deref in messaging remains a code-discipline risk. | High → Medium |
| `pr_merge` project_id scoping assumes `task.project_id` is non-None | `_verb_runner.py:263` | `project_id=task.project_id` — if a coordination/umbrella task ever reaches `pr_merge` with `project_id=None`, the cross-repo collision guard silently matches nothing or None-keys the scoping; could merge the wrong PR or no-op. | High |
| `_submit_*_unchanged_pr_guard` fails open on resolver regressions | `_impl.py:6175,6240` | Any future break in `_current_pr_head_sha` / `_project_slug_for` / `git.get_pr_head_sha` makes the loop-stopper a no-op, re-opening the 2026-06-27 pr_fail re-submit loop. **Partially mitigated (536bbb64)**: `_current_pr_head_sha` now emits a `structlog.warning` on resolver failure so the fail-open path is observable in logs; the underlying fail-open behavior is intentional and unchanged. | High |
| `_lane_claim_guard` calls `release_dependency_blocked_claim` on lookup error | `_impl.py:988,996` | Fail-closed path releases the claim before returning the error envelope; if the lookup error is transient the dev is bounced + work-session abandoned even though the lane was actually free. | Medium |
| `complete` umbrella-in-progress bypass skips the spec AWAITING_PM_REVIEW status check | `_impl.py:6657` | `_is_umbrella_in_progress` mis-classification (e.g. a non-batch branchless task with matching predicates) lets a non-awaiting_pm_review task reach `main_pm_complete`/`cell_pm_complete`. | Medium |
| `_run_claim_guards` dependency re-check narrows but does not close the race | `_impl.py:965-967` | The re-check returns None (skip release) when fresh read sees deps met, but the window between re-check and the caller's claim is still unlocked; a concurrent terminal transition there is benign (monotonic), but a non-monotonic future status could re-open. | Low |
| `submit_root` runs `create_root_pr` as a pre_side_effect OUTSIDE the savepoint | `_verb_runner.py:67` + `_impl.py:6339` | If a later composed `submit_for_review` raises, the root→master PR is already opened and NOT rolled back; re-issue is idempotent-by-contract but a non-idempotent future pre_side_effect would leak. | Medium |
| `_i_am_done_gate` writes AC criteria status AFTER all gates pass but BEFORE `run_intent` | `_impl.py:1910` | `_write_criteria_status` runs in the gate phase; if `run_intent("i_am_done")` then raises, the AC status rows persist for a task that did not transition — a stale write the next attempt must overwrite. | Low |

## Health
The slice is structurally sound: the SAVEPOINT boundary, intermediate-None INVALID_STATE guard, and role-exempt coordinator concurrency model are coherent and well-documented. The highest-temperature areas are the new (since baseline) fail-open loop-stoppers and fail-closed lane guard — both correct by design but tightly coupled to resolvers (`_current_pr_head_sha`, `has_earlier_incomplete_code_sibling`) whose regressions silently revert the protection. The 814-line delta is concentrated in guard additions rather than control-flow rewrites, so baseline behavior is largely preserved; the main residual risk is verb-body discipline around the trailing-None contract for any future verb.