Files
multi-agent-mux/.agents/skills/multi-agent-mux-delegate-job/SKILL.md
T
GodopuandClaude Fable 5.1 af0a2a2557 fix(issue-30): review - the stall watcher's lifetime is bounded on both sides and it re-checks its dispatch before acting
Round-1 review of PR #41 (claude N1, codex R1/R2).

N1 - the wrapper stopped its stall watcher with `kill` followed by an
unbounded `wait`. A TERM that lands in the watcher's fork-exec window is
swallowed (bash defers terminating signals in the forked child until the
exec), the watcher then installs its own handler and lives until the job
closes, and the wrapper hung until someone killed the watcher by hand
(reproduced twice in test_issue14's ack test; the wrapper trace stops at
`kill` + `wait`).
R1 - a wrapper that is itself terminated left the watcher orphaned.
R2 - a `completed` or a re-dispatch that landed during a blocking herdr
wait (up to 60 s) was still followed by the idle notice and the nudge.

- multi-agent-mux-delegate-job: `stop_stall_watch` sends TERM, polls up
  to 5 s, then KILLs and reports "ignored TERM; killed"; `start_stall_watch`
  passes `--watch-pid $$`.
- lib_py/stall_watch.py: `--watch-pid` (rc 0 once that pid is gone, checked
  between herdr calls); `_dispatch_open()` re-reads the record after every
  wait and right before the nudge - terminal status, another dispatch token
  or attempt, or a missing record ends the run without a notice; a refused
  `stalled:idle` publish withholds the nudge (`_notify` returns False).
- delegate-job SKILL.md: the watcher's lifetime contract; exit-code rows 2
  and 3 name the idle clock and the wall-clock label; "before v4.7.5" ->
  v4.8.0 (M5, NB2).
- tests/test_issue30_stall_watch.py (M8): the module-wide Linux mark is
  narrowed to S6 (/proc); r4's stub stamps time.time() so its cross-process
  comparison holds on macOS too (47 passed, 1 skipped here).
- tests/test_issue30_stall_watch_stop.py (new, macOS and Linux): the stop
  routine against a TERM-ignoring stand-in returns in 4-12 s; the wrapper
  returns (rc 3) with a TERM-ignoring watcher shim; `--watch-pid` ends the
  watcher; a TERM to the real wrapper leaves no watcher; a job completed or
  re-dispatched during the wait is not nudged; a refused notice withholds
  the nudge. Every one of them hangs or fails on the round-1 code.

Not in this commit (follow-ups): M7 test hook in product code (no adapter
is unreliable, a seam is needed), M9/B3 public-broker latency (on this host
even `started` sometimes never reaches the subscriber), the leading-zero
budget parse (NB1) and M1/M2/M4/M6 go on the #17 item 4 list.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VCgu9Fa9iT7TbJUSzdq4Ff
2026-09-26 13:17:24 +09:00

13 KiB

name, description, version, author, license, platforms, environments, metadata
name description version author license platforms environments metadata
multi-agent-mux-delegate-job Delegate a unit of work to any autonomous agent (claude-code, hermes, agy, grok-build, codex, or a human) and observe it asynchronously over an MQTT event channel. Supported roles include orchestrator, worker, and reviewer. 4.7.4 godopu MIT
linux
macos
windows
terminal
herdr
hermes
tags related_skills prereq_skills
agent
herdr
multi-agent
delegate
mqtt
async
job
multi-agent-mux-create
multi-agent-mux-resume
multi-agent-mux-loop
multi-agent-mux-create

multi-agent-mux-delegate-job — Async Job Delegation over MQTT

Delegate a unit of work to any autonomous agent, then observe it asynchronously instead of blocking. Every job gets a unique ID and a registry record. The worker agent publishes lifecycle events (started, permission_required, progress, completed, error) to a per-job MQTT topic, and the delegator/orchestrator subscribes to verify the final state.

This skill allows any agent (claude-code, hermes, agy, grok-build, etc.) to play any role: Orchestrator/Delegator, Worker/Implementer, or Reviewer.


Roles in Multi-Agent Mux

  • Orchestrator (Delegator): Initiates the job, coordinates other agents, handles loops and reviews, and commits final changes.
  • Worker (Implementer): Receives the brief file or task prompt, performs the implementation, and emits started/completed/error events.
  • Reviewer: Evaluates git diffs or artifacts produced by the worker, and responds with a completed event containing "PASS" or feedback.

Core Commands (CLI)

The multi-agent-mux-delegate-job bash wrapper handles job registration, subscriber management, agent session targeting, and validation hooks:

# 1) Submit a new job to a targeted agent session (e.g. herdr session name 'demo')
multi-agent-mux-delegate-job submit \
  --agent <claude-code|hermes-agent|agy-agent|grok-build|human> \
  --agent-session herdr:<session_name> \
  --prompt "Task description or instructions here" \
  --role <Worker|Planner|Reviewer> \
  --timeout 3600 [--heartbeat 30 --heartbeat-misses 4 --ack-timeout 180] [--idle-timeout <sec>]
  #   Liveness contract (Issue #18): the agent heartbeats every N s (automatic),
  #   the job is unresponsive after K x N s (--idle-timeout overrides), `started`
  #   must arrive within T s of the injection or the inject fails closed.
  #   --prompt-file <path> replaces --prompt for long prompts (Issue #36): one
  #   argv string is capped at 131,072 bytes on Linux. The loop always uses it.
  #   MAM_JOB_TIMEOUT_S: the budget when --timeout is not given (default 3600).
  #   MAM_STALL_IDLE_S (600) / MAM_STALL_HERDR_FAIL_S (120) / MAM_STALL_WATCH=0: the stall watcher (Issue #30).
  #   The watcher lives exactly as long as the job's wrapper: the wrapper stops it (TERM, 5 s, then KILL)
  #   when its subscriber ends, and the watcher exits on its own once the wrapper pid is gone.
  #   --parent-job <id> (Issue #34): this job is delegated from job <id>, which
  #   must exist in the registry (else exit 1). A loop waiting on <id> waits for
  #   it too and shows it to reviewers. Default: $MAM_JOB_ID (the remote runner
  #   sets it), ignored with a warning when the registry lacks that job.
  #   `registry.py list --parent <id>` lists a job's direct children.

# 1b) Same, for an agent on another host (no herdr pane, no shared disk):
#     the brief travels over the broker as a signed retained dispatch and a
#     `remote.py run --session <name>` runner on that host executes it.
multi-agent-mux-delegate-job submit --agent remote --agent-session remote:<runner_session> \
  --prompt "Task description" --role Worker      # needs MAM_DISPATCH_SECRET on both hosts

# 2) Submit a job with a feedback loop (Worker-Reviewer Loop)
multi-agent-mux-delegate-job submit \
  --agent <worker_agent> --agent-session herdr:<worker_session> \
  --type loop --reviewer <reviewer_agent> --reviewer-session herdr:<reviewer_session> \
  --prompt "Task description"

# 3) Check job status and audit logs
multi-agent-mux-delegate-job status --job <JOB_ID>
multi-agent-mux-delegate-job logs   <JOB_ID>            # Chronological log of events
multi-agent-mux-delegate-job list                       # Summary of all registered jobs

# 4) Verify job artifacts with a validation script
multi-agent-mux-delegate-job verify --job <JOB_ID> --validate ./validate.sh

Task Delegation Types

Supported job types include:

  • direct (default): Single agent execution (direct tasking).
  • loop (Worker-Reviewer Loop): Alternates worker execution and reviewer evaluation until reviewer approves (PASS) or iterations run out.
  • discuss (Research & Discussion): Collaboration between two agents to reach a consensus (e.g., agreeing on a design or plan).

For detailed state machine diagrams and configurations, see DELEGATION_TYPES.md.


Exit Codes & Failure Handling

Under fail-closed operation (MAM_DELEGATE_FAIL_CLOSED=1, default), the CLI returns deterministic exit codes:

Exit Code Meaning Final Registry Status Failure Behavior & Resilience
0 Success completed Job succeeded and completed event received or verified on disk with approval (PASS/AGREE).
1 Failure error Execution failure / delivery failure: no started within --ack-timeout T s after the injection (agent_blocked; the prompt is never re-injected), or the input never reached the pane.
2 Timeout error (deadline_timeout) Subscriber idle timeout (K x N without an event; the total budget is the wall-clock row below). R1 liveness grace (Issue #18): after the subscriber idles out the wrapper keeps re-observing the disk while the job's events.log shows an event at most K x N (--idle-timeout) old - the automatic heartbeat counts - up to the wall-clock --timeout. herdr status and the pane are logged as a diagnostic only.
2 Wall clock error (wall_clock_timeout) The budget (--timeout) ran out, events or not (Issue #33; was deadline_timeout before v4.8.0).
3 Broker Error error (wall_clock_timeout once the budget is spent, else deadline_timeout) Broker unavailable (MQTT_BROKER_UNAVAILABLE) and terminal status not found on disk during deadline.
5 Session Busy cancelled (session_busy) Precondition failed / session_busy: Preflight check (preflight_agent) or TUI idle handshake wait failed (prompt never delivered, retryable).

In all execution paths, the final line of standard output prints the persistent audit log directory path (<logs_root>/<job_id>), fulfilling the parsing contract for orchestrator runners.


Where the Implementation Lives (v4.3.0)

The implementation moved to the lib_py.delegation package in issue #5 phase 1. scripts/{mqtt_common,registry,publish_event,job_subscriber}.py remain as compatibility shims and their paths are unchanged -- every command in this document still works verbatim. Each shim binds the lib_py.delegation package to the tree next to itself, once per process, without touching sys.path, so import mqtt_common yields the same module object as lib_py.delegation.mqtt_common.

Which tree wins, by execution context:

Context Resolved by Tree that wins
Loop process and its children (frozen lib.sh sourced) the helper's explicit bootstrap from SKILL_DIR the frozen snapshot
Agent session running a frozen script path while PYTHONPATH still points live the shim, from its own location the frozen snapshot (B-13 preserved)
Live helpers (create/stop/resume/reconcile) PYTHONPATH or the shim (same tree) the live tree
Standalone, no PYTHONPATH the shim's fallback append the shim's own tree

lib.sh calls the package through _delegation_py, which inserts its own SKILL_DIR at the front of the import path. It deliberately does not use python -m: for -m the current directory precedes PYTHONPATH, so a frozen loop whose working directory happened to contain a lib_py package would have silently executed live code. The working directory is left untouched; the registry and audit-log paths resolve to MAM_JOBS_DIR / DELEGATE_JOB_LOGS_DIR when set, otherwise to $WORKSPACE_ROOT/.mam/jobs and $WORKSPACE_ROOT/.mam/delegate_job_logs (the workspace lib.sh exports), and only without either to the cwd-relative .mam/... (Issue #15 — this is what stops a caller whose cwd is not the workspace, such as the pytest suite, from registering jobs into a foreign registry).

Setting MAM_DELEGATION_PY=0 switches the shell helpers back to their preserved legacy bodies with no redeploy.

One in-process caveat: the package binds once per process and is never rebound, so do not import a frozen shim after a live lib_py.delegation is already bound inside the same interpreter. Production never does this — each delegated job is a fresh interpreter — but a test harness could.


The Event Protocol Contract

Every agent participating in the delegation contract must follow the same lifecycle publishing protocol using publish_event.py:

  1. On Start (first thing, within the ack timeout T): Publish started and arm the heartbeat timer. python3 .agents/skills/multi-agent-mux-delegate-job/scripts/publish_event.py --job "$JOB_ID" --event started --heartbeat <N> The timer publishes progress every N s until your terminal event (Issue #18); the brief and the injected instructions carry the exact command.
  2. On Tool/Permission Prompt: Publish permission_required event. python3 ... --job "$JOB_ID" --event permission_required --detail "<tool>:<reason>"
  3. On Progress Update: Publish progress at check-points (the heartbeat timer already satisfies the every-N-seconds obligation). python3 ... --job "$JOB_ID" --event progress --detail "<status_update>"
  4. On Success: Publish completed event. python3 ... --job "$JOB_ID" --event completed --detail "<summary>" (Reviewer should include "PASS" in the detail to approve).
  5. On Failure/Feedback: Publish error event. python3 ... --job "$JOB_ID" --event error --detail "<reason_or_feedback>"

Audit Logs

Job lifecycle execution events are persistently mirrored to an append-only log under .mam/delegate_job_logs/<job_id>/ (containing meta.json, events.ndjson, and status.json). Use multi-agent-mux-delegate-job logs <job_id> to view the timeline.


Best Practices and Pitfalls

  • Subscribe-Before-Publish: The subscriber must be running before the agent starts publishing. The submit command handles this automatically by launching the subscriber in the background first.
  • Sub-delegation carries --parent-job (Issue #34): an agent that hands part of its job to another agent must pass --parent-job <its own job_id> (the injected instructions and brief.md say so). Without it the loop does not wait for the sub-job; reviewers see it only as an unattributed open job. From a git worktree the worktree's copy of this wrapper runs; the pane's MAM_JOBS_DIR keeps the registry the same one. The target may live in another herdr workspace of the same server: inside a pane, the pane's own HERDR_WORKSPACE_ID (the one matching HERDR_PANE_ID) is not used as a scope for name lookups, since live agent names are unique per server; a HERDR_WORKSPACE_ID you set yourself still scopes. A target the preflight cannot see is cancelled with detail target_not_found (exit 5), not session_busy.
  • Fresh job_id Propagation: Make sure the worker agent receives the correct JOB_ID generated for the current run, rather than reusing stale IDs from previous sessions.
  • Brief delivery via file path: For long or complex prompts, write the instructions to a file (e.g. /tmp/task-brief.md) and pass a short prompt pointing to the file path to prevent terminal buffer overflows.
  • Prompts injected into a live agent session MUST be English, ASCII-only, and short — this is exactly what --prompt/the instructions string sent to run_agent() end up as. Any Korean (or other non-ASCII) content the task needs to convey must go in a markdown brief file (e.g. .mam/jobs/<id>/brief.md, written in Korean is fine) that the injected prompt merely tells the agent to read. Two independent bugs in send_keys_safe's paste-verification (in lib.sh) made this matter in practice: (a) its marker was taken with a byte-based tail -c 24, which can slice a multi-byte UTF-8 (e.g. Korean) character in half; (b) the rendered pane soft-wraps long lines at the terminal width, which can split the marker across two visual lines. Both are now fixed at the source (character-safe truncation + newline-stripped matching before comparison), but keeping injected prompts short/English/file-referencing is still the cheapest way to avoid ever exercising this edge case at all — it's also simply what submit's own default instruction template already does (see Core Commands above).
  • Batch Grouping: Group non-overlapping tasks into batches to parallelize execution across multiple agent sessions, reducing overhead.