Contract (no new event types): heartbeat every N s (automatic timer), unresponsive after K x N s without an event, `started` within T s of the injection, retained per-job state, and a remote transport. - registry: heartbeat_sec / heartbeat_misses / ack_timeout_sec / transport fields; idle_timeout_sec derives K x N unless explicit (defaults 30/4/60 keep the historical 120 s idle window). - heartbeat.py + publish_event --heartbeat N: detached fixed-cadence timer publishing signed `progress` heartbeats (threaded wire publish, local record first); stopped by the terminal event via pidfile, by re-dispatch and by lifetime. Terminal events refuse --heartbeat. - publish_event: retained `<prefix>/state` (status, last_event, seq, HMAC) sent on the same connection after every event (--no-state to skip); publisher.publish_raw takes extra messages. - job_subscriber: subscribes the state topic, recovers terminal status from retained state, resets idle on any accepted message, records seq_gap and reconnected in the audit log, idle budget before the first event is T + K x N (--ack-timeout), --remote mirrors started/terminal events into the registry through the transition boundary. - lib.sh send_keys_safe: an accepted-but-unconfirmed submission is confirmed by agent_status working or the job's own `started` (_sks_job_started); pane change and busy token are no longer delivery signals. - wrapper: --heartbeat/--heartbeat-misses/--ack-timeout (MAM_* env), injected start command arms the timer, brief states the contract, _wait_started (registry / events.log / subscriber log, bounded by T and the wall clock) replaces the 10 s inject grace, R1 grace uses only the on-disk event age (herdr/pane logged once as a diagnostic), remote:<name> sessions skip preflight/idle/pane and dispatch over the broker (remote_dispatch). - remote.py (+ scripts shim): signed retained dispatch (MAM_DISPATCH_SECRET) and a runner that mirrors the job into its own registry with the orchestrator's identity, publishes started --heartbeat, runs --exec and publishes the terminal event. - loop runner: passes MAM_HEARTBEAT_SEC / MAM_HEARTBEAT_MISSES / MAM_ACK_TIMEOUT_S through; YAML rows with transport: remote delegate as remote:<name>. - docs: MESSAGING.md 2.5 contract + remote transport, delegate-job SKILL.md, registry.md, loop SKILL.md. - tests: tests/test_issue18_liveness_contract.py (16); issue 14 pane-signal tests flipped to started-based; issue 6 working-agent tests acknowledge with started; CLI snapshot/help captures refreshed. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01VCgu9Fa9iT7TbJUSzdq4Ff
herdr-agent-orchestration
An advanced, high-reliability Multi-Agent Orchestration & Messaging Backplane framework built on Herdr and MQTT. It is designed to coordinate, isolate, and audit long-running agent tasks (such as code generation, refactoring, and security reviews) across multiple LLM backend clients (claude, agy, hermes, grok, opencode, codex).
🚀 Overview
Modern agentic workflows often suffer from session timeout, lack of process isolation, terminal viewport truncation (scrollback limits), and complex concurrency issues.
herdr-agent-orchestration addresses these problems by providing:
- Herdr-based Process Isolation: Spawning LLM client sessions inside dedicated, isolated herdr environments to support persistent background runs. Background daemon servers detach into their own OS session/process group (
start_new_session=True), ensuring they survive signal broadcasts to the parent shell. - Asynchronous Event-Driven Architecture: Leveraging an MQTT broker as a message backplane to coordinate state transitions (
started,progress,completed,error) between collaborating agents. - Multi-Agent Mux (MAM): Combining local file-based locks (fcntl) and an ACID-compliant SQLite WAL database (
.mam/agent-sessions.db) to manage concurrent job claims and track running agent sessions without drift. - Automated Review & Quality Loop: Implementing parallel reviewer loops where worker agents must receive a
PASSrating from various specialized verification agents (e.g., Claude, Hermes, Grok, OpenCode, Codex) before merging code.
📦 Installation & Setup
You can bootstrap the Multi-Agent Mux (MAM) framework in any workspace directory with a single command:
curl -fsSL https://git.godopu.com/tmpl/multi-agent-mux/raw/branch/main/deploy/install.sh | bash
Alternatively, if you have already cloned the repository locally, run the installer directly:
bash deploy/install.sh
The idempotent installer automatically validates system dependencies (herdr, python3, and PyYAML), creates the python virtual environment (.venv), installs dependencies, copies .mam.env.example as .mam.env, and initializes the .agents/ scaffolding.
🛠️ Core Skills & Scaffolding
All orchestration functionalities are structured under the .agents/skills/ directory:
multi-agent-mux-create: Spawns isolated herdr sessions running specified agent CLI wrappers. It captures system processes, updates metadata registries, and enforces authentication checks.multi-agent-mux-stop: Gracefully terminates agent CLI sessions (using key macros like/exitorExit) and handles disk purge operations (removing conversation JSON files and SQLite logs for deleted workspaces).multi-agent-mux-resume: Restores stopped sessions by resolving workspace UUIDs from disk or cache, and invokes the underlying agent using session-resume parameters (e.g.,claude -r <uuid>,agy --conversation <uuid>,hermes --resume <uuid>,grok --resume <uuid>,opencode --session <uuid>, orcodex resume <uuid>).multi-agent-mux-status: Queries the running states of all active sessions, detecting PID mismatches, command signatures, and drifts between actual herdr instances and the registry database.multi-agent-mux-monitor: A long-running reconcile worker that dynamically monitors herdr sessions and synchronizes states to.mam/agent-sessions.yaml.multi-agent-mux-delegate-job: The core asynchronous task distribution module (core implementation in.agents/skills/lib_py/delegation/;scripts/*.pyserves as compatibility shims):registry.py: Atomically registers and claims jobs using file advisory locks (fcntl).job_subscriber.py: Connects to the MQTT backplane, captures live events, and appends them to audit trails.publish_event.py: Emits execution status transitions and error details from workspace scripts.mqtt_common.py: Manages connection policies, authentication, and HMAC signing.
multi-agent-mux-loop: Autonomous planning-execution-review orchestration loop across Planner, Creator, and Reviewers until unanimous consensus (driven by Python loop runtime inlib_py.loop, eager-import immutable runtime, strict verdict parser).multi-agent-mux-orc-onboard: Helper to register and isolate orchestrator session UUIDs to prevent sub-agent discovery capture.
📐 Big-Picture Architecture
The system coordinates LLM agents across multiple workspaces through two core layers:
- Layer A — Herdr Orchestration (lib.sh + status/resume/stop/create): Runs the agents (one herdr session per agent-workspace combination) and maintains an authoritative registry in
.mam/agent-sessions.yaml(+.mam/agent-sessions.db). - Layer B — Async Job Delegation (delegate-job): Dispatches a task to an agent and observes progress and completion via an event channel.
These two layers share one lock-guarded chokepoint for file I/O: lib.sh::atomic_dump_yaml. Every write is protected by an exclusive SQLite database transaction lock and schema validation.
Data Flow Overview
+-----------+ register_job +-------------------+
| delegator | ---------------> | .mam/jobs/<id>.json| <-- live record
+-----------+ +---------+---------+
|
| atomic rename + fsync
v
+-----------------+
| audit log | <-- append-only
| .mam/delegate_ | events.ndjson
| job_logs/<id>/ |
+--------+--------+
^
| (best-effort mirrors)
|
+-----------+ publish_event +-----+-----+ +---------+
| agent | ---------------> | MQTT broker | <--- | monitor |
| (claude) | +-------------+ +----+----+
+-----------+ |
^ v
| subscriber atomic_dump_yaml
| (job_subscriber.py) (.mam/agent-sessions.yaml)
| ^
+-------- delegator waits here ----------+ |
+---+---+
| reconcil|
| e.sh |
+--------+
🔒 Herdr Server Isolation
To prevent workspace herdr processes from interfering with each other or with system herdr servers, the framework enforces isolated herdr environments:
- Per-Workspace Shim:
_init_herdr_isolationand_resolve_real_herdr_pathinstantiate a per-workspace shim directory under/tmp/multi-agent-herdr-shim/<HERDR_SERVER_NAME>/herdrthat intercepts herdr commands and wraps them inherdr -L <server>. - PATH Rewriting: The
PATHenvironment variable is dynamically prepended with the shim path in all child processes. This ensures anyherdrinvocation within the agent's process tree is restricted to its isolated socket server. - Environment Restoration: If
HERDR_SERVER_NAMEis set todefault, the PATH override is removed, reverting to the default global herdr server.
🛡️ Concurrency Design & Write Serialization
The framework implements lock-guarded execution pathways to prevent race conditions during parallel agent operations:
- SQLite Database Locks (
BEGIN IMMEDIATE): Every mutation ofagent-sessions.yamland the SQLite registry runs throughatomic_dump_yamlinsidelib.sh, which serializes writes via an exclusiveBEGIN IMMEDIATEtransaction lock on the SQLite database.mam/agent-sessions.db. - Dual-Interpreter Strategy: To minimize dependency bloat and guarantee stability, the backplane splits execution environments: the virtual environment
.venvhandles MQTT communication and async jobs (requiringpaho-mqtt), while the systempython3executesatomic_dump_yaml(relying on system-widePyYAML). - NFS and Network FS Safeguards: Since file locking (
flock) and SQLite WAL behave unreliably over network protocols (NFS, CIFS, SSHFS),lib.shperforms filesystem detection. If a network mount is identified, it outputs a safety warning and SQLite automatically switches its journaling mode fromWALtoDELETE.
📐 Architecture & Coordination Loop
The interaction between roles (Project Manager, Worker, and Reviewer) is structured as a strict iterative loop:
sequenceDiagram
autonumber
actor User as User
participant PM as Project Manager
participant W as Worker
participant R as Reviewers
participant M as MQTT Backplane
User->>PM: Hand over requirements
Note over PM: Plan tasks & register jobs
PM->>M: Register Job & start Subscriber
PM->>W: Delegate task (Provide Job ID & Brief)
W->>M: Publish 'started' event
Note over W: Implement & verify code
W->>M: Publish 'completed' (or 'error')
PM->>R: Request parallel reviews (Provide Diff)
Note over R: Parallel analysis (Claude, Hermes, Grok, OpenCode, Codex)
alt Review Feedback (NOT PASS)
R->>PM: NOT PASS (Feedback with code blocks)
Note over PM: Apply fixes or re-delegate
PM->>W: Re-delegate with comments
else Verification PASS
R->>PM: PASS
end
PM->>User: Commit changes & Report completion
🔒 Security & Replay Attack Defense
To ensure communication integrity across public MQTT brokers, the backplane integrates an HMAC-SHA256 signature protocol:
- PoC Mode (Unauthenticated): Default mode where
auth_tokenisnull, skipping cryptographic validations for quick setups. - Production Mode (Authenticated): A unique cryptographic token is issued per job. Event payloads must include an
hmac_sigcomputed with the token. - Replay Attack Mitigation: Each event carries a monotonically increasing integer sequence counter (
seq). The subscriber (job_subscriber.py) drops any payload whose sequence number is not strictly greater than the highest sequence number it has already accepted for that job. Combined with the HMAC signature on the payload body, this rejects both re-injected and out-of-order packets without relying on clock synchronization. The wire-format timestamp field is advisory metadata only; the backplane does not enforce a clock-skew window.
📁 Repository Layout
.
├── .agents/
│ ├── MULTI_AGENT_RULES.md # Agent roles, snapshottings, and execution charter
│ ├── MULTI_AGENT_RULES.ko.md # Agent roles, snapshottings, and execution charter (Korean)
│ └── skills/ # Core orchestration shell wrappers & libraries
│ ├── lib.sh # Shared orchestration library
│ ├── lib_py/ # Python core orchestration engine
│ │ ├── agents/ # Multi-agent CLI lifecycle adapters
│ │ ├── delegation/ # Asynchronous delegation & CAS state engine
│ │ └── loop/ # Autonomous planning-execution-review loop runtime
│ ├── multi-agent-mux-create/
│ ├── multi-agent-mux-stop/
│ ├── multi-agent-mux-resume/
│ ├── multi-agent-mux-status/
│ ├── multi-agent-mux-monitor/
│ ├── multi-agent-mux-delegate-job/
│ │ ├── requirements.txt # Python dependency declaration
│ │ └── scripts/ # Wire-compatibility shims (Python)
│ ├── multi-agent-mux-loop/
│ └── multi-agent-mux-orc-onboard/
├── .mam/ # Multi-Agent Mux metadata (git-ignored)
│ ├── agent-sessions.db # SQLite WAL session database
│ ├── agent-sessions.yaml # Human-readable session registry
│ └── jobs/ # Asynchronous job metadata files
├── deploy/ # Distribution and installation package
│ ├── INSTALL.md # User manual for installation and quick-start
│ ├── install_mam.sh # Local/Clone installer script
│ ├── generate-env.sh # Environment bootstrap helper
│ ├── install.sh # Remote/Network installer script
│ ├── update.sh # Updater script
│ └── remove.sh # Uninstaller script
├── docs/ # Specifications, guides, and architectural contracts
│ ├── contracts/ # Issue/backplane contracts and migration roadmaps
│ ├── MAM_WEB_PTY_BRIDGE_PLAN.md # Web PTY terminal bridge design plan
│ ├── NEW_AGENT_INTEGRATION_GUIDE.md # Guide for integrating new AI coding agents
│ └── OPENCODE_OLLAMA_GUIDE.md # OpenCode interpreter + Ollama integration guide
├── nats-docker/ # Private NATS broker deployment submodule
├── tests/ # Comprehensive test suite (32 modules)
├── AGENTS.md # Behavioral guidelines and orchestrator scope guards
├── BOOTSTRAP.ko.md # Installation and verification guide (Korean)
├── BOOTSTRAP.md # Detailed installation and verification guide
├── IMPROVEMENTS.md # Backlog tracking issues and completed architectural tasks
├── MESSAGING.md # MQTT wire protocol specification and internals
├── README.ko.md # Project introduction and overview (Korean)
├── README.md # Project introduction and overview (this file)
└── VERSIONS.md # Release notes and 4-way lockstep version ledger
🚦 Quick Start
For detailed setup instructions, please consult the BOOTSTRAP.md file. Below is a quick summary:
- Initialize Environment Config:
./deploy/generate-env.sh - Create Virtual Environment and Install Dependencies:
python3 -m venv .venv source .venv/bin/activate pip install -r .agents/skills/multi-agent-mux-delegate-job/requirements.txt - Run Registry Diagnostics:
.venv/bin/python3 .agents/skills/multi-agent-mux-delegate-job/scripts/registry.py list
📝 Guidelines for Collaborating Agents
If you are an AI agent newly onboarded to this project:
- Read MULTI_AGENT_RULES.md to align on development constraints and roles (PM, Worker, Reviewer).
- Adhere to the Pane Snapshotting Rules in
MULTI_AGENT_RULES.md(Section 4) to prevent scrollback data loss during long execution steps. - Never modify core logic without submitting a diff to the reviewer sessions for evaluation.