roboco/docs/map/worksession-git.md

RoboCo Slice Map — worksession-git

Scope key: worksession-git Repo root: /Users/renzof/Documents/GitHub/ZZZ/roboco-master/roboco Files in scope:

• roboco/services/work_session.py
• roboco/services/git.py
• roboco/templates/git/ (__init__.py, branch.py, commit.py, constants.py, pr_internal.py, pr_root.py)
• roboco/services/forge/ (__init__.py, base.py, github.py, gitea.py, gitlab.py, registry.py, router.py, shaping.py)
• roboco/foundation/policy/forge.py
• roboco/foundation/policy/pr_labels.py

Purpose

This slice is the git substrate every delivery agent works on. GitService runs all git subprocesses (status/commit/branch/push/rebase), mints branches + commit messages + PR bodies from templates, and drives the REST API for PR create/merge/close — now routed through a multi-forge layer (roboco/services/forge/) instead of talking to GitHub directly. WorkSessionService persists the per-claim row that links an agent to a task's branch/commits/PR and enforces the single-active-per-task invariant. The roboco/templates/git/ package is the pure rendering layer for branch names, commit messages, and internal/root PR bodies. roboco/foundation/policy/pr_labels.py derives the org-structure label vocabulary (to master/to slave, root, MegaTask, layer labels) applied at PR-open. Together they are the boundary between the task lifecycle and the actual git history on disk + the configured forge (GitHub, Gitea, or GitLab).

Files

Path	Role	approx LOC
roboco/services/work_session.py	WorkSession CRUD, commit/file tracking, PR-lifecycle record, single-active invariant	685
roboco/services/git.py	Git subprocess execution, branch/commit/PR/rebase/merge/sync, GitHub REST API, conventions validator runner	4596
roboco/templates/git/__init__.py	Package re-exports for branch/commit/PR templates	48
roboco/templates/git/branch.py	Hierarchical branch name builder + root-task resolver	131
roboco/templates/git/constants.py	BRANCH_TYPES, COMMIT_TYPES, MAX_TASK_DEPTH, length constants	52
roboco/templates/git/commit.py	CommitContext + build_commit_message (traceability links)	114
roboco/templates/git/pr_internal.py	Internal (subtask→parent) PR title/body builder	140
roboco/templates/git/pr_root.py	Root (→master, CEO-level) PR title/body builder with task tree	245
roboco/services/forge/__init__.py	Package re-exports (ForgeRouter, GitProvider, GitHubProvider, GiteaProvider, GitLabProvider, RepoRef, provider_for, register_project_forge)	32
roboco/services/forge/base.py	Pure contract: RepoRef dataclass + the GitProvider ABC (~20 abstract methods every forge implements)	208
roboco/services/forge/github.py	GitHub.com/GHE REST transport — the pre-existing inline httpx logic pulled out unchanged; owns the sole retry policy in the package (list_ci_runs)	432
roboco/services/forge/gitea.py	Self-hosted Gitea REST transport, adapting the wire contract back into GitHub shapes	471
roboco/services/forge/gitlab.py	GitLab REST v4 transport — heaviest adaptation (MR iid, diff reassembly, pipelines)	679
roboco/services/forge/registry.py	Host↔provider(+scheme) map + provider_for(project) resolution, self-healing per-process	104
roboco/services/forge/router.py	ForgeRouter — implements GitProvider by picking a transport per call from RepoRef.host	195
roboco/services/forge/shaping.py	ShapedResponse — an httpx.Response-compatible stand-in a non-GitHub provider returns when it must synthesize a status the wire call didn't produce (e.g. a shaped 501 for merge_branch)	51
roboco/foundation/policy/forge.py	Pure host/provider detection (extract_host, detect_provider) + registration-time validation (validate_project_forge)	99
roboco/foundation/policy/pr_labels.py	derive_pr_labels — the org-structure label vocabulary (to <base_branch>, root, MegaTask, layer labels) applied at every PR-open site	~90

Key Symbols

Name	Kind	File:Line	Responsibility
WorkSessionService	class	work_session.py:29	Session lifecycle + single-active invariant
WorkSessionService.create	method	work_session.py:50	Validate project/task, refuse duplicate, supersede stale ACTIVE, insert row
WorkSessionService.get_active_for_task	method	work_session.py:184	Most-recent ACTIVE row (resilient to dup-rows defect)
WorkSessionService.supersede_active_sessions_for_task	method	work_session.py:247	ABANDON every other ACTIVE session for a task (single-active)
WorkSessionService.add_commit	method	work_session.py:363	Append dedup'd commit SHA to session.commits
WorkSessionService.create_pr	method	work_session.py:427	Record pr_number/pr_url/pr_created_at
WorkSessionService.merge_pr	method	work_session.py:488	Record merge + COMPLETED; idempotent active-guard (F062)
WorkSessionService.close	method	work_session.py:618	Idempotent COMPLETED on task completion
WorkSessionService.abandon	method	work_session.py:577	ABANDONED + ended_at (non-active → warning + None)
WorkSessionService.has_unpushed_commits	method	work_session.py:662	PR-existence proxy for unpushed commit detection
WorkSessionService.task_team_for_session	method	work_session.py:147	Return the task's team (cell) for a given session; used by route layer's PM cell-ownership check on merge_pr
get_work_session_service	factory	work_session.py:682	Construct service from AsyncSession
GitService	class	git.py:234	All git operations + GitHub API
_GIT_EXECUTOR	module const	git.py:116	Dedicated ThreadPoolExecutor for git subprocesses (16 workers)
resolve_git_dir	func	git.py:129	Resolve .git dir for clone OR linked worktree
_remove_stale_git_locks	func	git.py:156	Best-effort clear orphaned .git/**/*.lock after timeout SIGKILL
_select_ci_head_run	func	git.py:220	Pick CI run matching current HEAD (anti-stale-green)
GitService._run_git	method	git.py:247	Run git subprocess in dedicated pool, token header, chown-back, lock cleanup
GitService._token_for_project	method	git.py:344	Decrypted project PAT (logs loudly on key-rotation failure)
GitService.get_workspace	method	git.py:387	Resolve/clone agent workspace (auto_clone aware)
GitService.get_status	method	git.py:499	Porcelain status + ahead/behind
GitService._classify_porcelain	static	git.py:439	Split porcelain into staged/unstaged/untracked (column-safe)
GitService._parse_git_url	static	git.py:557	Extract (owner,repo) from tokened/https/ssh GitHub URL
GitService.create_commit	method	git.py:640	Stage + commit with template message + worktree ensure
GitService._worktree_for_task	static	git.py:747	Per-task worktree path {clone_root}/.worktrees/{task_id[:8]} (F123)
GitService._ensure_worktree_for_commit	method	git.py:756	Re-attach a pruned worktree before cwd-dependent op
GitService._assert_on_task_branch	method	git.py:771	Recover drifted clone onto task branch (never discards work)
GitService.commit_for_task	method	git.py:875	Agent-facing commit verb backing the commit content tool
GitService.create_branch	method	git.py:989	Build branch name, fetch base, worktree add (F123), push -u
GitService.create_branch_for_task	method	git.py:1188	Resolve workspace/team, create branch, commit DB
GitService.checkout_branch_for_agent	method	git.py:1276	Allowlist-bounded checkout for agent verb
GitService.push_for_task	method	git.py:1428	Push the task's recorded branch by name (clone-checkout-independent); runs _run_codegen_and_commit first so any codegen drift lands in the SAME push
GitService._codegen_command_for	staticmethod	git.py:4397	The project's codegen_command (nullable string column, migration 078), or None — a bare MagicMock test double auto-vivifies attributes, so the isinstance check also keeps unrelated tests inert
GitService._run_codegen_and_commit	method	git.py:4474	Runs the project's codegen_command in the task's worktree right before push (hooked at both push_for_task/push_branch at git.py:1886 and push_task_branch at git.py:4689); fail-open (a broken/timeout command logs a warning and lets the push proceed — CI's own drift gate is the safety net) and a no-op for the common case of no declared command; a clean run with actual drift stages + commits it under the task's normal commit format before the push carries it
GitService.push_task_branch	method	git.py:1467	Gateway branch-keyed push
GitService.create_pull_request	method	git.py:2132	Open PR via GitHub API (legacy project-scoped)
GitService.create_pr_for_task	method	git.py:2639	Agent-facing open_pr verb
GitService.update_pr_for_task	method	git.py:2506	Patch PR title/body; 404→typed GitError
GitService.get_pr_head_sha	method	git.py:2451	PR head SHA for pr_fail re-submit loop guard (fail-open)
GitService.get_latest_ci_conclusion	method	git.py:1929	Per-project CI signal (unknown never false-green)
GitService.get_pr_ci_status	method	git.py:2662	CI status of a PR's current head commit for the in-path pr_pass gate; returns {state, failing_checks?, head_sha} or None on config gaps (fail-open)
GitService._ci_status_prereqs	method	git.py:2698	Resolve (owner, repo, auth headers, head_sha) for CI-status lookup or None on any gap
GitService._fetch_check_runs	method	git.py:2730	GET check-runs for head_sha; None on any API failure
GitService._classify_check_runs	method	git.py:2770	State classification: success/failure/pending from check-run conclusions list
GitService._classify_zero_check_runs	method	git.py:2790	State classification when zero check-runs exist: pending_not_scheduled or no_ci_configured (depends on workflow count)
GitService.list_open_prs	method	git.py:1844	Normalized open-PR list
GitService.post_pr_review	method	git.py:2329	Post reviewer comments via GitHub API
GitService.merge_pull_request	method	git.py:2914	GitHub merge API + method fallback + already-merged disambiguation
GitService.merge_pr_for_task	method	git.py:3046	Role-gated merge + recorded-PR verification + auto-complete
GitService._assert_merge_role	method	git.py:2989	PM/CEO approval-chain role gate
GitService.pr_merge	method	git.py:3616	Gateway merge: project_id-scoped, parent row lock, 409 retry, CEO-only default guard
GitService._merge_with_retry	method	git.py:3555	Single 409 retry + already-merged disambiguation → MergeConflictError
GitService._lock_parent_task_for_merge	method	git.py:3503	SELECT FOR UPDATE on parent task (sibling merge serialization)
GitService._resolve_merger_id	static	git.py:3530	merged_by attribution: actor→assigned→created→UUID(0)
GitService.rebase_onto_base	method	git.py:3733	Rebase primitive: rebased/superseded/conflicts classification
GitService.rebase_pr_for_task	method	git.py:3792	PR-keyed rebase via PR refs (project_id scoped)
GitService.sync_task_branch	method	git.py:3847	Task-keyed rebase through dev sync_branch verb (pre-PR)
GitService.is_behind_base	method	git.py:3889	(behind, ahead) counts for i_am_done submit gate
GitService.close_pull_request	method	git.py:3940	Close superseded PR + optional comment + branch cleanup (idempotent)
GitService._delete_remote_branch_best_effort	method	git.py:3608	Best-effort remote delete; skips main/master/develop + open-dependent-PR branches, UNIONED with _protected_branches_for_deletion(project_slug) — the shared chokepoint every remote-delete path (task cleanup, PR-merge/close cleanup, the stale-branch sweep) routes through; returns bool (issued vs skipped/failed)
GitService._protected_branches_for	method	git.py:1183	The project's own declared protected_branches, normalized (stripped, deduped into a frozenset) and unioned into the hardcoded {master, main} floor for rebase refusal (rebase_onto_base) and sync_task_branch's force-push refusal; fails OPEN (empty set, logs a warning) on a project-lookup error — a wrongly-blocked rebase over a transient DB blip is the worse tradeoff
GitService._protected_branches_for_deletion	method	git.py:1219	Deletion-only superset of _protected_branches_for: the declared field UNIONED with the project's env-ladder rung branches (effective_environments — a null ladder's synthesized single rung off default_branch is protected too, so a renamed trunk like trunk is covered even with no declared list); fails CLOSED (returns the hardcoded floor only, on a lookup error) since a skipped delete is free (next sweep retries) but silently deleting a real declared rung on an unresolvable project is not
GitService.delete_task_branch	method	git.py:3671	Cancel-path remote branch delete; chokepoint for the environment-ladder skip (effective_environments) so a task's branch_name can never collide-delete a ladder rung; returns bool
GitService.close_task_pr_best_effort	method	git.py:3655	No-clone-needed cancel-path cleanup: resolves the project token + git_url→RepoRef, fetches the PR via self._forge.get_pr, no-ops unless state=="open", else update_pr(payload={"state":"closed"}); every failure path (missing token/project, unparseable URL, httpx.HTTPError) returns False rather than raising
GitService.cleanup_stale_branches	method	git.py:3697	POST /git/branches/cleanup backing sweep: terminal (completed/cancelled) tasks' branches, remote (delete_task_branch) + local force-delete in the assignee's clone; capped 200/call, cursor-resumable
GitService._stale_branch_window	method	git.py:3767	One deterministic ORDER BY id window of sweep candidates; ladder rungs excluded from results but still advance the cursor
GitService._live_task_dependents	method	git.py:3810	Companion sweep guard: excludes a terminal candidate's branch when a non-terminal task still records that exact branch_name, or when a non-terminal task is a direct child of the candidate (the child's future PR base would resolve to the parent's branch via resolve_parent_branch even before it has opened a PR — catches what the OPEN-PR-only _branch_has_open_dependents can't see)
GitService._cleanup_one_stale_branch	method	git.py:3841	Per-branch remote+local delete for one sweep candidate; raises on unexpected failure so the caller's try/except counts it as an error
GitService.pr_target	method	git.py:4021	Return PR base branch (project_id scoped)
GitService.create_pr	method	git.py:3418	Branch-keyed open PR (gateway path; ensures base on remote)
GitService._record_pr_atomically	method	git.py:2601	Atomic pr_number/url write to task
GitService.run_pre_submit_quality_gate	method	git.py:3208	make quality gate before submit
GitService.conventions_check_for_task	method	git.py:4368	Run conventions validator on changed files (fail-closed)
GitService._run_conventions_validator	method	git.py:4408	Subprocess python -m roboco.conventions with 120s cap
GitService.open_conventions_pr	method	git.py:4456	Scaffold .roboco/conventions.yml on a branch + open PR
GitService.diff / list_changed_files / read_file_at_branch	methods	git.py:4192/4225/4259	Read-only git queries (gateway + routes)
GitService.commit	method	git.py:4286	Gateway content-verb commit (branch-keyed)
get_git_service	factory	git.py:4594	Construct GitService from AsyncSession
build_branch_name	func	templates/git/branch.py:37	{type}/{team}/{root}--{sub}--... up to MAX_TASK_DEPTH
get_root_task_id	func	templates/git/branch.py:97	Walk parent chain to root
BranchNameError	exc	templates/git/branch.py:33	Bad type / missing task / over-depth
build_commit_message	func	templates/git/commit.py:63	Rich commit msg with task/root/agent/session links
CommitContext	dataclass	templates/git/commit.py:34	Validated commit-message input
build_pr_body_internal / build_pr_title_internal	funcs	templates/git/pr_internal.py:75/130	Subtask→parent PR rendering
build_pr_body_root / build_pr_title_root	funcs	templates/git/pr_root.py:167/235	Root PR rendering with task tree + AC checklist
MAX_TASK_DEPTH	const	templates/git/constants.py:45	4 (umbrella→root→cell→dev)
BRANCH_TYPES / COMMIT_TYPES	consts	templates/git/constants.py:10/21	Allowed prefixes
RepoRef	dataclass	forge/base.py:26	Provider-opaque repo identity (owner, repo, host); GitLab packs the full URL-encoded namespace path into owner, leaving repo empty
GitProvider	ABC	forge/base.py:49	The ~20-method transport contract every forge implements (PR CRUD, review flow, merge_branch, CI signal surface, repo/label/branch/release/provisioning)
GitService._forge	property	git.py:399	A fresh ForgeRouter() per access (cheap, no I/O — built this way, not __init__-cached, so tests can GitService.__new__ bypass the constructor)
ForgeRouter	class	forge/router.py:37	Implements GitProvider by picking a transport per call from RepoRef.host
ForgeRouter._provider_for_ref	staticmethod	forge/router.py:40	None host → GitHubProvider(); a registered "gitea"/"gitlab" host → that provider constructed with its remembered scheme; unregistered → GitError naming the fix
register_project_forge	func	forge/registry.py:50	Records a project's host→provider(+scheme) mapping; called from ProjectService.create/update/get/get_by_slug — in-memory, per-process, self-healing (a restart forgets it; the next project read re-registers)
provider_for	func	forge/registry.py:77	Resolve a GitProvider for a project (duck-typed on .git_provider/.git_url)
GitHubProvider	class	forge/github.py:71	GitHub.com/GHE REST transport — the pre-existing inline httpx logic, byte-for-byte; owns the sole retry policy in the package (list_ci_runs, 3 attempts/0.5s backoff, retryable on 429+5xx)
GiteaProvider	class	forge/gitea.py:55	Self-hosted Gitea transport: token-scheme auth (Bearer is rejected by classic PATs); duplicate-PR 409→422 reshape on create_pr; merge_pr POSTs (not PUTs) with the method under a "Do" key; commit-status → synthetic check_runs/workflow_runs; branch names with slashes URL-quote()-encoded before hitting Gitea's router (caught live by the e2e suite)
GitLabProvider	class	forge/gitlab.py:85	GitLab REST v4 transport — the most semantically divergent: MR iid→number, source_branch/target_branch→head.ref/base.ref; get_pr_diff reassembles a unified-diff string from up to 3 pages of per-file JSON diffs (no raw-diff media type); post_review routes APPROVE to /approve and everything else to a plain note (no request-changes verb exists); request_reviewers synthetic-skips (needs numeric user ids RoboCo doesn't store); create_org_repo resolves a group path to a numeric namespace id, falling back to the token's personal namespace on 404
ShapedResponse	class	forge/shaping.py:17	httpx.Response-compatible stand-in a non-GitHub provider returns to synthesize a status the wire call didn't produce (e.g. merge_branch's shaped 501)
extract_host / detect_provider / validate_project_forge	funcs	foundation/policy/forge.py:27/45/62	Pure host extraction (https/ssh/scp-like URLs), github.com/gitlab.com auto-detection, and registration-time validation (a self-hosted host with no explicit git_provider is a registration-time rejection — the GHE/self-hosted escape hatch requires the operator to set the column)
derive_pr_labels	func	foundation/policy/pr_labels.py	Org-structure label vocabulary: base_branch (required kwarg, the PR's real resolved target — never assumed from is_root_pr) → f"to {base_branch}", plus root/MegaTask/layer labels (main-pm, cell/{team}, subtask/{team})

Neither Gitea nor GitLab has GitHub's server-side merges API for the env-sync cascade: both return a shaped 501 from merge_branch, landing GitService.sync_env_branch on the local-git fallback (_local_merge_branch: throwaway clone → merge → push; a conflict aborts leaving the remote untouched, same status vocabulary as the GitHub server-side path) — this fallback lives entirely in GitService, not the forge package. Plain git (clone/fetch/push) needed zero forge-specific work: all three forges accept a PAT as the Basic-auth password with username ignored, so the existing x-access-token:<token> extraheader works unchanged (verified live against a dockerized Gitea).

Data Flow

A developer claims a task → the orchestrator/choreographer calls create_branch_for_task → build_branch_name walks the task parent chain (TaskService.get) up to MAX_TASK_DEPTH=4, joins ---separated 8-char UUID prefixes, and yields {type}/{team}/{root}--{sub}--.... create_branch fetches only the needed refs from origin, runs git worktree add under {clone_root}/.worktrees/{task_id[:8]} (F123 per-task isolation), force-pushes the branch with -u, and stores branch_name on the task. A WorkSession row is created (WorkSessionService.create), first superseding any other agent's stale ACTIVE session on that task.

The agent commits via the commit content verb → GitService.commit (or commit_for_task route), which ensures the worktree is attached, asserts the workspace is on the task branch (recovering a drifted clone), stages, runs build_commit_message (CommitContext → header + metadata + links), commits, then best-effort links the SHA to the task + work session (_link_commit_to_task). Every _run_git call re-chowns the tree to the agent uid and clears orphaned lock files on timeout.

open_pr → create_pr resolves the task by branch name, ensures the parent branch exists on origin, POSTs the PR via GitHub REST, and atomically records pr_number/pr_url on the task (_record_pr_atomically) and work session (create_pr). PR title/body come from task.title/task.description for gateway PRs; the rich build_pr_body_root/_internal templates are used by the older create_pull_request path.

Merge: a cell PM complete/submit_up → pr_merge (gateway) scopes the task lookup by project_id (cross-repo PR-number collision guard), takes a SELECT FOR UPDATE lock on the parent task, calls _merge_with_retry (squash; on 409 re-syncs target + retries once; on 405 disambiguates already-merged vs real conflict → MergeConflictError), deletes the PR branch, syncs the local target, and records the merge on the work session (merge_pr, idempotent). The CEO-only root→master merge goes through merge_pr_for_task (role-gated, recorded-PR verification) → merge_pull_request. The CEO-merge never targets the default branch via pr_merge (the target == default_branch guard refuses it) — default_branch here is _project_default_branch, which now resolves via roboco.models.env_branches.head_branch(project) (the env-ladder head rung) rather than reading project.default_branch directly; a project with no declared ladder resolves to the same value via the read-time shim.

Behind-base recovery: is_behind_base feeds the i_am_done submit gate; on a non-zero behind, the dev calls sync_branch → sync_task_branch → rebase_onto_base (rebased/superseded/conflicts). On a merge conflict, the choreographer calls rebase_pr_for_task, then either re-merges or close_pull_requests a superseded PR. get_pr_head_sha feeds the submit_root re-submit loop guard.

Mermaid

stateDiagram-v2
    [*] --> Active: create() (supersede stale)
    Active --> Active: add_commit / add_files_modified
    Active --> Active: create_pr (pr_number set)
    Active --> Completed: merge_pr (idempotent active-guard)
    Active --> Completed: close() (task completion)
    Active --> Abandoned: abandon() / supersede_active_sessions_for_task
    Completed --> [*]: terminal
    Abandoned --> [*]: terminal
    note right of Active
      single-active per task enforced at
      create + DB partial-unique index (mig 047)
    end note

sequenceDiagram
    participant G as Choreographer/Gateway
    participant GS as GitService
    participant GH as GitHub REST API
    participant WS as WorkSessionService
    participant DB as DB (TaskTable)

    G->>GS: pr_merge(pr_number, target, project_id)
    GS->>DB: SELECT task WHERE pr_number AND project_id (scoped)
    GS->>DB: SELECT FOR UPDATE parent_task (serialize siblings)
    GS->>GH: PUT /pulls/{n}/merge (squash)
    alt 409 conflict
        GS->>GS: _sync_target_branch (re-pull)
        GS->>GH: PUT /pulls/{n}/merge (retry once)
    end
    alt non-success
        GS->>GH: GET /pulls/{n} (already-merged?)
        opt already merged
            GS-->>G: idempotent success
        end
        opt real conflict
            GS-->>G: raise MergeConflictError
        end
    end
    GS->>GH: DELETE PR branch (best-effort)
    GS->>GS: _sync_target_branch_best_effort
    GS->>WS: merge_pr(session_id, merger_id)
    WS->>WS: guard status==ACTIVE else return unchanged
    WS-->>GS: COMPLETED + merged_by
    GS-->>G: {"merge_commit_sha": ...}

Logical Tree

roboco/
├── services/
│   ├── work_session.py
│   │   └── WorkSessionService (BaseService)
│   │       ├── create / get / get_or_raise / update
│   │       ├── get_active_for_task(_and_agent)
│   │       ├── supersede_active_sessions_for_task   # single-active invariant
│   │       ├── list_by_agent / list_by_project / list_active_sessions
│   │       ├── add_commit / add_files_modified
│   │       ├── create_pr / update_pr_status / merge_pr
│   │       ├── complete / abandon / close
│   │       └── files_changed / has_unpushed_commits  # gateway backfill
│   └── git.py
│       ├── _GIT_EXECUTOR (ThreadPoolExecutor, 16)
│       ├── resolve_git_dir / _remove_stale_git_locks / _select_ci_head_run
│       └── GitService (BaseService)
│           ├── _run_git (token, timeout, chown, lock-cleanup)
│           ├── _token_for_project / _token_for_workspace / get_workspace
│           ├── status: get_status / get_current_branch / _classify_porcelain / _ahead_behind
│           ├── commit: create_commit / commit_for_task / commit (gateway) / _link_commit_to_task
│           ├── worktree (F123): _worktree_for_task / _ensure_worktree_for_commit / _assert_on_task_branch
│           ├── branch: create_branch / create_branch_for_task / create_branch_from_pr_head / checkout*
│           ├── push/pull/fetch/rebase: push_for_task / push_task_branch / pull / fetch / rebase
│           ├── PR context: _build_root_pr_context / _build_internal_pr_context / _generate_pr_title_body
│           ├── PR list/find: _find_existing_pr / list_open_prs / _fetch_open_prs / _normalize_open_pr
│           ├── PR create: create_pull_request / create_pr_for_task / create_pr (branch-keyed)
│           ├── PR update/review: update_pr_for_task / post_pr_review / _patch_pr_title_body
│           ├── PR read: get_pr_diff / get_pr_head_sha / pr_target
│           ├── CI: get_latest_ci_conclusion / _get_ci_runs_response / _fetch_latest_ci_run
│           ├── merge: merge_pull_request / merge_pr_for_task / pr_merge / _merge_with_retry
│           │            _assert_merge_role / _lock_parent_task_for_merge / _resolve_merger_id
│           │            _pr_is_merged / _auto_complete_on_merge / _first_allowed_merge_method
│           ├── branch cleanup: _delete_remote_branch_best_effort / _delete_pr_branch_best_effort
│           │            delete_task_branch / _branch_has_open_dependents
│           │            cleanup_stale_branches / _stale_branch_window / _cleanup_one_stale_branch (sweep)
│           ├── rebase/sync: rebase_onto_base / rebase_pr_for_task / sync_task_branch / is_behind_base
│           ├── close: close_pull_request
│           ├── quality: run_pre_submit_quality_gate / toolchain_status_for_task / _fast_gate_commands
│           ├── conventions: conventions_check_for_task / _run_conventions_validator / open_conventions_pr
│           ├── read-only: diff / list_changed_files / read_file_at_branch / _ref_exists / _resolve_diff_base
│           └── helpers: _task_for_branch / _project_for_task / _workspace_for_branch / _token_for_branch ...
└── templates/git/
    ├── __init__.py            # re-exports
    ├── constants.py           # BRANCH_TYPES / COMMIT_TYPES / MAX_TASK_DEPTH=4
    ├── branch.py              # build_branch_name / get_root_task_id / BranchNameError
    ├── commit.py              # CommitContext / build_commit_message / CommitMessageError
    ├── pr_internal.py         # InternalPRContext / build_pr_body_internal / build_pr_title_internal
    └── pr_root.py             # RootPRContext / SubtaskInfo / build_pr_body_root / build_pr_title_root

Dependencies

Internal:

• roboco.config.settings (timeouts, URLs, workspace root, auto_clone)
• roboco.exceptions (GitCommandError, GitError, GitTimeoutError, MergeConflictError)
• roboco.foundation.policy.lifecycle (role/intent parity)
• roboco.models.base (AgentRole, TaskStatus)
• roboco.models.work_session (WorkSessionCreate/Update/Status)
• roboco.db.tables (ProjectTable, TaskTable, WorkSessionTable)
• roboco.services.base (BaseService, NotFoundError, ConflictError, ValidationError, UnauthorizedError, ServiceError)
• roboco.services.project / roboco.services.task / roboco.services.workspace (composed for clone/workspace/branch resolution)
• roboco.services.gateway.quality_gate (GateResult, run_quality_commands)
• roboco.templates.git (all template builders)
• roboco.utils.converters.require_uuid, roboco.utils.crypto.EncryptionError
• roboco.api.schemas.git (TYPE_CHECKING only — runtime duck-typed)

External:

• sqlalchemy / sqlalchemy.ext.asyncio
• httpx (GitHub REST API)
• asyncio, subprocess, concurrent.futures.ThreadPoolExecutor
• dataclasses, pathlib, uuid, base64, re, json, time, os, sys

Entry Points

• HTTP routes (roboco/api/routes/git.py): get_status, log, diff, commit_for_task, push_for_task, create_branch_for_task, checkout_branch_for_agent, create_pr_for_task, merge_pr_for_task, pull, fetch, rebase, cleanup_stale_branches (POST /git/branches/cleanup, PM/CEO role-gated like /rebase, rate-limit 5/60) — all construct via get_git_service(db).
• HTTP routes (roboco/api/routes/tasks.py:253): get_git_service for task-scoped git.
• Gateway Choreographer (roboco/services/gateway/choreographer/):
  • _verb_runner._do_pr_merge → pr_merge
  • _impl → conventions_check_for_task (i_am_done + pr_pass gates), is_behind_base (submit gate), sync_task_branch (sync_branch verb), pr_merge / rebase_pr_for_task / close_pull_request (merge-conflict resolution), get_pr_head_sha (submit_root re-submit guard)
  • pr_gate.py → get_pr_head_sha
  • qa.py → conventions_check_for_task
• WorkspaceService calls ensure_worktree / ensure_worktree_for_resume (F123).
• Lifespan/CLI: none direct; git_service is constructed per-request via deps.py (git=GitService(db_session)).

Config Flags

Flag / setting	Source	Used for
ROBOCO_GIT_EXECUTOR_WORKERS (env, default 16)	os.environ at git.py:117	Dedicated git subprocess pool size
settings.git_command_timeout_seconds	config.py:728	Default _run_git timeout
settings.git_commit_timeout_seconds	config.py:737	Staging/commit large changeset timeout
settings.git_network_timeout_seconds	config.py:748	fetch/pull/push/ls-remote timeout
settings.workspaces_root	config.py:603	Workspace path root (token derivation)
settings.workspace_auto_clone	config.py:607	get_workspace auto-clone branch
settings.public_base_url	config.py:827	Commit/PR template link base (+ /api)
settings.internal_api_url	config.py:57	Internal PR body link base
settings.github_api_base_url	config.py:327	GitHub REST API base (PR/CI/review)
settings.release_ci_workflow	config.py:597	Named workflow file (e.g. ci.yml) used by the release CI gate in get_latest_ci_conclusion; always resolves a named workflow so the gate never degrades to the imprecise all-workflows mode

Module-level tunables (not env): _SLOW_GIT_OP_MS=5000, _CI_RUN_WINDOW=20, _CI_FETCH_ATTEMPTS=3, _CI_FETCH_BACKOFF_SECONDS=0.5, _CI_RETRYABLE_STATUS, _CONVENTIONS_VALIDATOR_TIMEOUT_SECONDS=120, _GH_UNPROCESSABLE=422, _HTTP_NOT_FOUND=404, _HTTP_CONFLICT=409.

Gotchas

• protected_branches is exact-match, case-sensitive, and additive-only: an operator-declared list (panel: chips editor in the edit-project dialog) is UNIONED into — never replaces — the hardcoded {master, main} floor. The two consuming scopes deliberately fail differently on a project-lookup error: _protected_branches_for (rebase + sync_task_branch force-push refusal) fails OPEN to the hardcoded floor (a skipped rebase gets no free retry, so refusing wrongly is worse); _protected_branches_for_deletion (the shared remote-delete chokepoint) fails CLOSED (a skipped delete just retries at the next sweep, so silently proceeding on an unresolvable project is worse). An empty protected_branches list degrades to exactly the prior hardcoded-only behavior.
• Token resolution is GitHub-App-first, PAT-fallback: ProjectService._resolve_token (roboco/services/project.py, called from GitService._token_for_project → get_decrypted_token_by_slug) mints a short-lived installation token via github_app_auth.mint_installation_token when project.github_installation_id is set AND App credentials are stored; ANY minting failure (App not configured, installation revoked, network hiccup, the JWT/HTTP/parse path all wrapped so nothing escapes uncaught) falls back to the stored PAT instead of raising — a GitHub App outage never bricks git ops for an App-bound project that also has a PAT on file. github_app_credentials.py mirrors the x_credentials/telegram_credentials singleton-Fernet-row pattern (migration 077); the PEM is validated at credential-SET time (not first-mint) and the installation-token cache clears when credentials are deleted.
• Token transport split: git-over-HTTPS uses HTTP Basic (x-access-token:...) via http.extraheader (git.py:289); the GitHub REST API uses Bearer. Swapping them causes silent credential-prompt failures.
• pr_number is NOT repo-scoped in tasks.pr_number — every gateway merge/close path (pr_merge, close_pull_request, pr_target, rebase_pr_for_task) requires project_id to scope the task lookup. The route merge_pr_for_task instead verifies data.pr_number == task.pr_number (recorded PR is source of truth).
• get_active_for_task returns the most-recent ACTIVE row, not scalar_one_or_none — the historical duplicate-ACTIVE defect would otherwise raise MultipleResultsFound. The invariant is also enforced at create and by a DB partial-unique index (migration 047).
• merge_pr idempotency guard (F062): a terminal session is returned unchanged; complete/abandon on a non-active session return None (warning). close returns the session unchanged. Behavior differs between these three on terminal state — merge_pr/close are silent, complete/abandon warn-and-None.
• F123 per-task worktrees: commit/checkout/rebase/conventions MUST run inside {clone_root}/.worktrees/{task_id[:8]}, not the clone root (which sits on the default branch). _worktree_for_task + _ensure_worktree_for_commit are the seam; forgetting them makes checkout fail with "already checked out at ''" or false-passes the conventions validator.
• create_branch runs reset --hard on a no-commit branch in the worktree (git.py:1104) — safe because unique == 0, but a branch carrying real work is left as-is. The fresh-claim path only; resume short-circuits before it.
• _run_git re-chowns the tree after every op (root → agent uid 1000); without it the agent's next commit fails with "unable to append to .git/logs/refs/...".
• Porcelain parsing uses splitlines() not strip().split("\n") — strip eats the leading space on D file and false-stages deletions.
• get_current_branch raises on detached HEAD instead of returning "" — the empty string used to leak "(HEAD detached at ...)" into checkout -b.
• MAX_TASK_DEPTH=4 (was 3) — MegaTask's umbrella→root→cell→dev needs 4; validator rejects a child whose depth would reach MAX_TASK_DEPTH, so 4 permits dev at depth 3.
• Branch name uses 8-char UUID prefix (_SHORT_ID_LEN=8), not full UUID — full UUIDs produced 140-char branch names.
• rebase_onto_base force-pushes with --force-with-lease only the head branch; never touches base. superseded (unique==0) means close-without-merge.
• is_behind_base raises on git failure; the i_am_done gate fail-opens on the raised error so a flaky fetch can't strand the task.
• Conventions validator fails closed (could_not_run=True blocks submit) on resolution error / timeout / non-zero exit; branchless + no-changed-files fail open.
• _assert_on_task_branch never discards work — it does checkout, not reset --hard, to preserve a resumed agent's unpushed commits.
• CEO-only master merge: pr_merge refuses target == default_branch for agents; only merge_pr_for_task (CEO role-gated from awaiting_ceo_approval) may merge to master. default_branch resolves through the env-ladder head rung (_project_default_branch → head_branch(project)), not the raw projects.default_branch column.
• cleanup_stale_branches cursor is required, not optional: task rows never change as a side effect of the sweep (unlike, say, a queue that drains), so a repeat call with no after_cursor re-scans the identical first 200-row window forever instead of progressing. _stale_branch_window still advances the cursor past ladder-rung rows even though they're excluded from candidates, so truncated can't false-negative when a rung lands inside the window.
• Local branch delete in the sweep is always force=True (-D) regardless of completed vs cancelled — a completed task's PR was squash-merged, so its local ref is never an ancestor of base and a "safe" -d would refuse every single candidate.

Drift from CLAUDE.md

• CLAUDE.md "WorkSessionService" table claims the service handles "Git session management, PR lifecycle" — accurate. No drift.
• CLAUDE.md says ROBOCO_WORKSPACE_CLONE_TIMEOUT=300 is a WorkspaceService config; not referenced in this slice (lives in workspace.py). No drift in scope.
• CLAUDE.md verb table lists sync_branch for developers and /rebase for PM/CEO. The code matches: sync_task_branch is the dev path, rebase_pr_for_task the PR-keyed path. No drift.
• CLAUDE.md states "A task has at most one active WorkSession ... enforced both at the service layer and by a DB partial-unique index (migration 047)." Code matches (supersede_active_sessions_for_task + get_active_for_task resilient return). No drift.
• CLAUDE.md "PR is created BEFORE QA review" — create_pr/create_pr_for_task only sets pr_number; QA pass requires it. Matches.
• Minor doc vs code: CLAUDE.md commit-format example is [{task-id[:8]}] {message} (single ID), but build_commit_message (templates/git/commit.py:80) emits [{root_short}:{task_short}] {type}({scope}): {desc} — a richer two-ID header. The doc undersells the actual format; not a bug, but the template header is not the literal [{task-id[:8]}] the doc shows.
• CLAUDE.md lists merge_pull_request-style PM merges; the agent-facing path is now pr_merge (gateway) with parent-row locking + 409 retry, which the doc does not describe. Additive (the route merge_pr_for_task still exists) — doc is incomplete rather than wrong.

Changes Since Baseline

Baseline: fd10cc862c2020b3f639cdb686d427b0198a2441 (master tip before the metrics-granularity branch). Diff stat: git.py +614/-107-ish, work_session.py +11, branch.py +9/-, constants.py +12/-. Commits touching these files: 15effce0 (#283 "141 Gaps fill-in"), 3aff6e04 (#285 "Close gaps").

Commit	IMPACT (one line)
15effce0 (141 Gaps fill-in)	Added resolve_git_dir + worktree-aware _remove_stale_git_locks; added F123 _worktree_for_task/_ensure_worktree_for_commit and routed commit/checkout/rebase/conventions into the per-task worktree; added get_pr_head_sha (pr_fail re-submit guard); added sync_task_branch + is_behind_base (dev sync_branch verb + i_am_done behind gate); added rebase_onto_base/rebase_pr_for_task (merge-conflict resolver); added close_pull_request (superseded-PR close); added pr_merge with project_id scoping + parent-row lock + 409 retry + CEO-only default-branch guard + already-merged disambiguation; added _merge_with_retry/_pr_is_merged/_resolve_merger_id/_lock_parent_task_for_merge; added conventions validator runner (conventions_check_for_task/_run_conventions_validator/open_conventions_pr); raised MAX_TASK_DEPTH 3→4 (MegaTask depth-cap fix); WorkSessionService.merge_pr idempotent active-guard (F062).
3aff6e04 (Close gaps)	Same mega-commit (the PR body is identical — #285 is the merge closure of the #283 batch); the in-scope file deltas are the same set of additions. No additional logic change to these files beyond what #283 listed.

Post-snapshot updates (since 2026-06-29): 536bbb64 (Chore/all/logical gaps sweep #286 — closed regression risks #108 and #109 in this slice: _merge_with_retry now falls back to a permitted merge method on 405 via _first_allowed_merge_method before raising MergeConflictError; close_pull_request default flipped to delete_branch=False, choreographer caller now passes delete_branch=True explicitly). 00513399 ([bug] push_branch — push_branch(branch_name) now passes branch=branch_name to self.push() so the gateway open_pr path pushes the actual named task branch rather than the clone root's current checkout; fixes the "No commits between" 422 → i_am_blocked wedge observed in the F123 per-worktree model). 2759edf7 ([B-REL] release executor — added _CiRunQuery dataclass at git.py:241 to bundle per-project CI-fetch inputs; get_latest_ci_conclusion and _fetch_latest_ci_run now accept an optional head_sha so the release CI gate polls a specific release commit's own run rather than branch-latest; settings.release_ci_workflow config flag added). 69071030 ([chore] work-session-routes — added WorkSessionService.task_team_for_session helper (route layer PM cell-ownership check for merge_pr); route layer now stamps merged_by from the authenticated caller rather than the request body — WorkSessionService.merge_pr signature is unchanged, but MergePRRequest schema dropped merged_by field).

496c24d1 (PR #548, "git hygiene", 2026-07-17) Local branch refs stop leaking alongside remote ones: delete_task_branch now also skips environment-ladder rungs (previously only the remote-delete's own main/master/develop guard existed) and returns bool; new cleanup_stale_branches + _stale_branch_window + _cleanup_one_stale_branch back a PM/CEO-only POST /git/branches/cleanup sweep of terminal tasks' remote+local branches, exposed as a confirm-dialog button on the panel Git page. See docs/map/task-service.md for the paired per-task reap at cancel/completion and docs/map/workspace.md for the new WorkspaceService.delete_local_branch primitive both routes share.

Forge providers — GitHub + Gitea + GitLab (2026-07-18/19, PRs #569/#571/#575/#579/#581). A new roboco/services/forge/ package (base.py/github.py/gitea.py/gitlab.py/registry.py/router.py/shaping.py) plus roboco/foundation/policy/forge.py route every REST call GitService makes (PRs/CI/reviews/labels/releases/provisioning) through a provider-agnostic transport. 388bab24 (Phase 0, #569): projects.git_provider column (migration 076, nullable, plain string not a pg enum — validated at the service layer, not the DB) + validate_project_forge/detect_provider (github.com auto-detects, self-hosted needs an explicit column value — the GHE/self-hosted escape hatch). 461a6e1a (Phase 1, #571): the GitProvider ABC + GitHubProvider extracted byte-for-byte from GitService's old inline httpx calls; GitService._forge (git.py:399) becomes the seam every call site routes through. 96401f4c (Phases 2/2.1/3, #575): GiteaProvider + GitLabProvider + ForgeRouter (per-call transport dispatch off RepoRef.host) + the local-git merge_branch fallback for forges with no server-side merges API. 5f32d876 (Phase 4, #581): roboco/services/github_provisioning.py becomes provider-aware (ROBOCO_PROVISIONING_PROVIDER/ROBOCO_PROVISIONING_HOST — see docs/map/product-strategy-research-pitch.md) so pitch-driven repo creation works on all three forges. d4cb5797 (#579) + the pre-existing tests/e2e_smoke/test_gitea_live.py are the live contract suites (self-seeding against a dockerized gitea/gitea / real gitlab.com, env-gated) that caught the slash-encoding and http-scheme gaps in the Gitea provider. Panel: the edit-project dialog's "Forge" <Select> (edit-project-dialog.tsx) offers Auto-detect/GitHub/Gitea/GitLab.

Protected branches + env-ladder deletion protection (#649, #651). GitService._protected_branches_for/_protected_branches_for_deletion (git.py:1183/1219) consult the new projects.protected_branches column end-to-end for the first time (the column previously existed with nothing reading it): the deletion scope additionally unions in the project's env-ladder rung branches (effective_environments), closing the gap where the post-merge PR-source cleanup and the stale-branch sweep could still delete a branch that IS a ladder rung — delete_task_branch's own local rung check is now exactly subsumed and removed. Panel: a chips editor on the edit-project dialog.

GitHub App credentials + auto-regenerated codegen drift (#621/#633/5ca8a9c4, #632). roboco/services/github_app_auth.py/github_app_credentials.py (new files) add a singleton Fernet-encrypted App id + private key (migration 077) and RS256 JWT + cached-installation-token minting; ProjectTable.github_installation_id lets a project bind to an installation (create-dialog repo picker, or an existing PAT project via the edit dialog's Unbind/re-bind section) with PAT fallback on any mint failure (see Gotchas). Independently, GitService._run_codegen_and_commit (git.py:4474, migration 078's projects.codegen_command) runs a per-project codegen command in the task's worktree right before every push and commits any resulting drift into the SAME push — RoboCo's own codegen_command='make codegen' keeps its checked-in lifecycle renders/verb tables from drifting invisibly past the agent's own gate (which omits foundation-check) until CI's separate drift gate catches it with no link back to the task.

Branch-list route fix (#610). roboco/api/routes/git.py's list_branches classified a remote-tracking ref by a literal 'remotes/' prefix that git for-each-ref --format=%(refname:short) never emits, so every origin/* ref (including the symbolic origin/HEAD) rendered as a fake LOCAL branch. Listing now reads the full %(refname) and _parse_branch_line classifies on refs/heads/ vs refs/remotes/ (dropping origin/HEAD); the route also runs a best-effort git remote prune origin before listing so a branch already deleted upstream stops persisting in the panel's Git page forever, and the manual Fetch action now fetches with --prune.

PR label base-branch agnosticism + cancel-path PR close (2026-07-18/19, "agnosticism-residue" + "cancel-pr-dependents-guard"). derive_pr_labels gained a required base_branch: str keyword-only param; the label is now f"to {base_branch}" (the PR's real resolved target) instead of "to master" if is_root_pr else "to slave" — a prerequisite for the env-branches ladder and non-GitHub forges, where "master"/"slave" aren't universal. All three GitService call sites (_labels_for_pr_request, the assembled cell→root/root→master PR opener) now thread the real resolved base branch through. Separately, GitService.close_task_pr_best_effort (git.py:3655) closes a task's forge PR on cancel — TaskService._close_task_pr_best_effort (task.py:6767) calls it once per cascaded descendant and once for the cancelled task itself, alongside the existing _delete_task_branch_best_effort — closing a gap where a cancelled task's branch was force-deleted but its open PR lingered on the forge forever. The same change adds GitService._live_task_dependents (git.py:3810) so cleanup_stale_branches never deletes a terminal task's branch while a non-terminal task still records it, or is a direct child of it (whose future PR base would resolve to that branch before it even opens a PR).

Regression Risks

Title	File:Line	Claim	Severity
merge_pr idempotent guard silently drops retried merge attribution	work_session.py:517	A retried merge after a successful-but-unconfirmed GitHub merge returns the existing COMPLETED row unchanged, so the retry's merged_by/pr_merged_at are NOT updated. Correct for audit-trail integrity, but a caller that relied on merge_pr returning a freshly-updated row (e.g. reading pr_merged_at as "now") now gets the original timestamp. Low risk but a behavior change worth a regression test.	low
pr_merge CEO-only guard refuses default-branch target	git.py:3671	If a non-root PR's target legitimately resolves to the repo default branch (e.g. a mis-configured default_branch or a single-branch repo), pr_merge now hard-fails with UnauthorizedError. Any cell that previously merged a leaf PR into master via this path (shouldn't happen per policy, but the route existed) is now blocked. Since the env-branches ladder (#534) the comparison target is the env-ladder head rung (_project_default_branch → head_branch(project)), not necessarily prod — a project that declares head != prod has this guard protect the head rung, not the CEO's actual prod branch.	medium
pr_merge parent-row SELECT FOR UPDATE can deadlock	git.py:3503/3683	Two PMs merging sibling subtasks of different parents that share an ancestor, under并发 lock ordering, could deadlock if lock acquisition order diverges. Lock is only on the immediate parent, so risk is bounded, but a deadlock surfaces as a rollback (not a clean 409 retry).	medium
create_branch reset --hard on zero-commit branch inside worktree	git.py:1104	If rev-list --count {base_ref}..{branch_name} returns 0 for a branch that actually carries work (e.g. base_ref mis-resolved to a ref that already contains the work), the worktree is hard-reset and uncommitted work in the worktree is lost. The unique==0 check is the only guard; a stale base_ref could trip it.	medium
Panel Forge-select help text is stale vs. the shipped GitLab provider	panel/src/components/projects/edit-project-dialog.tsx:315	The HelpTip copy next to the Forge <Select> still reads "...GitLab support is planned" even though gitlab is a live SelectItem one line below and the backend has full GitLab Phase 3 support (GitLabProvider, ForgeRouter) — cosmetic only, no functional gap, but confusing to an operator reading the tooltip before picking GitLab.	low
F123 worktree routing — commit/conventions/rebase run in worktree, merge sync runs in clone root	git.py:3696/3785	pr_merge calls _sync_target_branch_best_effort(workspace,...) with the clone-root workspace (from get_workspace), not the per-task worktree. If the target branch is checked out in a worktree, the sync's checkout of target in the clone root fails ("already checked out"). Best-effort swallows it, but the local target ref may stay stale for the next sibling merge.	medium
_merge_with_retry retries on 409 only; 405 falls through to already-merged check then MergeConflictError	git.py:3597	FIXED (536bbb64 #108) — _merge_with_retry now falls back to a permitted merge method (via _first_allowed_merge_method, exclude='squash') on 405 before raising MergeConflictError, mirroring the CEO merge_pull_request path. A 405 with no permitted fallback or a second 405 still falls through to disambiguation/MergeConflictError.	medium resolved
is_behind_base raises on fetch failure; gate fail-opens	git.py:3922/3938	A flaky origin fetch makes is_behind_base raise; the i_am_done gate catches it and fail-opens, letting a behind branch submit. The merge layer's own behind check is the backstop, but a genuinely-behind branch can reach QA. Documented, but a regression in the "gate is authoritative" expectation.	low
MAX_TASK_DEPTH 3→4 changes branch-name length + validation	constants.py:45 / branch.py:71	Any pre-existing task hierarchy at depth 4 that was previously rejected now builds a 4-segment branch name; tasks created under the old cap that stored a shorter branch are unaffected, but new subtasks of a previously-maxed tree now cut branches where they couldn't before — could surface latent assumptions in downstream consumers parsing branch names.	low
close_pull_request deletes branch on close by default	git.py:4005	FIXED (536bbb64 #109) — default flipped to delete_branch=False (opt-in deletion); the choreographer supersede caller now passes delete_branch=True explicitly when it wants deletion, matching the orchestrator supersede path. A superseded PR's branch is preserved by default.	medium resolved
Conventions validator fail-closed on resolution error	git.py:4392	A workspace resolution failure (missing clone, diff error) returns could_not_run=True, which the block-gate treats as a hard refuse. A transient workspace/clone issue can now block i_am_done/pr_pass where previously the gate would have passed. Intentional but a new stranding vector.	low
get_pr_head_sha fail-open returns None on any error	git.py:2496	The submit_root re-submit loop guard only hard-blocks on an exact unchanged head SHA; any GitHub error / closed PR returns None and the guard passes, so a flaky API call lets a weak coordinator re-submit the same failed PR. Documented fail-open, but a regression vs. a strict gate.	low

Health

Integrity is good and actively hardened. The slice carries the scars of multiple live meltdowns (single-active work-session defect, pr_fail re-submit loop, cell_pm merge block<->unblock, MegaTask depth cap, cross-repo PR-number collision) and each is closed with a deterministic guard plus a comment explaining the failure mode. The F123 per-task-worktree routing is consistently threaded through commit/checkout/rebase/conventions, and the merge path has layered defenses (parent-row lock, 409 retry, already-merged disambiguation, CEO-only master guard). Two formerly-medium risks in the merge path have since been closed: _merge_with_retry now has the 405 method-fallback that merge_pull_request has (536bbb64), and close_pull_request now defaults to delete_branch=False (536bbb64). The remaining residual risk is pr_merge's post-merge target sync running in the clone root (not the worktree) and best-effort-swallowing a checkout conflict — the local target ref may stay stale for the next sibling merge. Test coverage of the work-session lifecycle is solid; the newer pr_merge/sync_task_branch/rebase_onto_base/close_pull_request quartet deserves the most scrutiny on any future change. No outright bugs found; the drift vs CLAUDE.md is documentation undersell (commit header format, gateway merge-path description), not behavioral mismatch. The forge-providers rollout (GitHub/Gitea/GitLab) added real breadth without touching the merge-path defenses above — GitService's callers still reason in GitHub-shaped responses, and ForgeRouter/GiteaProvider/GitLabProvider carry the entire adaptation burden behind that seam; the live-forge e2e suites (tests/e2e_smoke/test_gitea_live.py/test_gitlab_live.py, both env-gated and self-seeding) are the only coverage that exercises a real forge over the wire rather than a mocked transport, and they already caught two real gaps (slash-encoding, http scheme) the mocked unit tests couldn't have found.