Orchestration MCP

TypeScript MCP server for launching and tracking external coding-agent runs.

The MCP surface stays stable while the internal execution backend can target:

• local codex

• local claude_code

• remote remote_a2a

This lets a top-level agent call one MCP toolset while the orchestration layer decides whether subagents are local SDK processes or remote A2A-compatible agents.

Install And Build

cd orchestration-mcp
npm install
npm run build

Run The MCP Server

cd orchestration-mcp
npm start

This starts the MCP server from dist/index.js.

Codex MCP Config Example

If you want Codex to load this MCP server, add an entry like this to ~/.codex/config.toml:

[mcp_servers.orchestration-mcp]
command = "node"
args = ["/abs/path/to/orchestration-mcp/dist/index.js"]
enabled = true

Example using this repository path:

[mcp_servers.orchestration-mcp]
command = "node"
args = ["/Users/fonsh/PycharmProjects/Treer/nanobot/orchestration-mcp/dist/index.js"]
enabled = true

After updating the config, restart Codex so it reloads MCP servers.

What The MCP Exposes

The server registers these tools:

• spawn_run

• get_run

• poll_events

• cancel_run

• continue_run

• list_runs

• get_event_artifact

Typical MCP Flow

1. Call spawn_run to create a subagent run.

2. Call poll_events until you see a terminal event or a waiting state.

3. If the run enters input_required or auth_required, call continue_run.

4. Call get_run for the latest run summary.

5. If an event contains artifact_refs, call get_event_artifact to fetch the full payload.

spawn_run notes

• backend: "codex", "claude_code", or "remote_a2a"

• role: orchestration role label such as planner, worker, or reviewer

• prompt: plain-text instruction for simple runs

• input_message: optional structured message for multipart/A2A-style inputs

• cwd: absolute working directory

• session_mode: new or resume

• session_id: required when resuming a prior session

• profile: optional path to a persona/job-description file for future profile-driven behavior

Unless you are explicitly instructed to use a profile, leave profile empty.

• output_schema: optional JSON Schema for structured final output

• metadata: optional orchestration metadata stored for correlation and auditing

• backend_config: optional backend-specific settings. For remote_a2a, set agent_url and any auth headers/tokens here.

For all backends, cwd is the orchestration-side working directory used for run/session storage.

For remote_a2a, spawn_run.cwd is also forwarded to the remote subagent and becomes that A2A task context's execution directory.

At least one of prompt or input_message is required.

Simple example:

{
  "backend": "codex",
  "role": "worker",
  "prompt": "Inspect the repository and summarize the architecture.",
  "cwd": "/abs/path/to/project",
  "session_mode": "new"
}

Remote A2A example:

{
  "backend": "remote_a2a",
  "role": "worker",
  "prompt": "Inspect the repository and summarize the architecture.",
  "cwd": "/abs/path/to/project",
  "session_mode": "new",
  "backend_config": {
    "agent_url": "http://127.0.0.1:53552"
  }
}

continue_run notes

Use continue_run when a run enters input_required or auth_required and the backend supports interactive continuation.

Inputs:

• run_id

• input_message

get_event_artifact notes

Use get_event_artifact when a sanitized event returned by poll_events contains event.data.artifact_refs and you need the full original payload.

Inputs:

• run_id

• seq

• field_path: JSON Pointer relative to event.data, for example /stdout, /raw_tool_use_result, or /input/content

• offset: optional byte offset, default 0

• limit: optional byte limit, default 65536

Typical flow:

1. Call poll_events.

2. Inspect event.data.artifact_refs on any sanitized event.

3. Call get_event_artifact with the same run_id, the event seq, and one of the exposed field_path values.

Backend defaults

• codex: uses the current @openai/codex-sdk defaults plus non-interactive execution settings already wired in the adapter

• claude_code: uses @anthropic-ai/claude-agent-sdk with permissionMode: "bypassPermissions" so the MCP call stays non-blocking, and reuses persisted backend session ids for resume

• remote_a2a: connects to a remote A2A-compatible agent using @a2a-js/sdk, streams task updates into normalized orchestration events, and supports continue_run for input_required

For claude_code, make sure the local environment already has a working Claude Code authentication setup before testing.

Test A2A agents

The repo includes helper modules for local A2A-wrapped test agents:

• dist/test-agents/codex-a2a-agent.js

• dist/test-agents/claude-a2a-agent.js

• dist/test-agents/start-a2a-agent.js

These export startup helpers that wrap the local Codex and Claude SDKs behind an A2A server so the orchestration MCP can test its internal remote_a2a backend against realistic subagents.

To start an interactive wrapper launcher:

npm run start:a2a-agent

The script will ask whether to wrap codex or claude_code.

After startup, it prints the agent_url and a ready-to-use spawn_run payload for the MCP layer. The wrapper no longer locks a working directory at startup. Each remote_a2a call uses the cwd provided to spawn_run, and the wrapper keeps that cwd fixed for the lifetime of the same A2A contextId.

Storage

Run data is stored under:

<cwd>/.nanobot-orchestrator/
  runs/
    <run_id>/
      run.json
      events.jsonl
      result.json
      artifacts/
        000008-command_finished/
          manifest.json
          stdout.0001.txt
          stdout.0002.txt
  sessions/
    <session_id>.json

Notes:

• events.jsonl stores sanitized events intended for poll_events consumption.

• Oversized raw payloads are moved into per-event artifact files and referenced from event.data.artifact_refs.

• run.json and result.json keep the current run snapshot and final result behavior.

• The storage directory name is currently .nanobot-orchestrator/ for backward compatibility with the existing implementation.