BailingHub MCP Server

Use MCP hosts to submit and inspect governed business-system actions through a self-hosted BailingHub control plane.

This package is a thin integration adapter. It does not embed BailingHub, grant business permissions, authenticate an end user, or replace the downstream business system's final authorization.

What It Exposes

The route, BailingHub URL, and Client Token are process configuration. They are never MCP tool arguments and therefore cannot be selected or replaced by model output.

Security Model

MCP host / model
    |
    | request_id + untrusted input
    v
BailingHub MCP Server
    |
    | fixed route + route-scoped Client Token
    v
BailingHub
    |
    | governed dispatch
    v
Business system
    |
    +-- resolves trusted subject and performs final authorization

The adapter intentionally does not accept:

• an acting subject or identity claim;
• a Client Token, administrator token, or business-system credential as tool input;
• an approval decision or approval evidence;
• an executor identity;
• arbitrary metadata or callback URLs;
• an arbitrary route.

Use a dedicated BailingHub Client Token restricted to the one route configured for this server process. Run separate server instances when different MCP clients need different route boundaries.

Install

Prerequisites:

• Node.js 20.15 or newer;
• a reachable BailingHub deployment;
• one BailingHub Client Token restricted to the required route.

Configure an MCP host to spawn:

{
  "mcpServers": {
    "bailinghub": {
      "command": "npx",
      "args": ["-y", "bailinghub-mcp-server"],
      "env": {
        "BAILINGHUB_BASE_URL": "https://hub.example.com",
        "BAILINGHUB_CLIENT_TOKEN": "replace-with-a-route-scoped-client-token",
        "BAILINGHUB_ROUTE": "order_assistant"
      }
    }
  }
}

For a local BailingHub process, loopback HTTP is accepted:

BAILINGHUB_BASE_URL=http://127.0.0.1:3000

Non-loopback HTTP is rejected by default. BAILINGHUB_ALLOW_INSECURE_HTTP=true exists only for an operator-controlled private network where TLS terminates elsewhere. Do not use it across an untrusted network.

Correct Job Flow

1. Create a stable request_id for one business request.
2. Call submit_governed_job with that ID and the task text.
3. Preserve the returned job_id.
4. Call wait_for_governed_job for a short bounded wait, or call get_governed_job later.
5. If submission must be retried, reuse the exact same request_id and task meaning.

queued, running, and dispatched are non-terminal. done, error, and rejected are terminal. A wait timeout is not a failed task and must not cause a replacement submission.

First Success and Feedback

Use the MCP integration path as the canonical start page. The first integration is successful when an MCP host submits through the operator-fixed route, the same job_id reaches a terminal state, BailingHub retains its approval and audit state, and the MCP host never receives administrator or business-system credentials.

Report a PASS, partial result, or failure through the BailingHub independent validation form and select the MCP track. Never include tokens, model keys, personal information, or production business data.

Project Boundaries

The dependency direction is one-way:

bailinghub-mcp-server -> BailingHub public Client API
BailingHub may consume ACC declarations
ACC has no dependency on either implementation

See:

• Project boundaries
• Threat model
• Compatibility contract
• Privacy
• Security policy

Development

npm install
npm run verify
npm pack --dry-run

The integration uses the stable bailing.client-api.v1 surface only:

• POST /run
• GET /jobs/{job_id}

No administrator, executor, approval-decision, tool-proxy, configuration, or direct business API is called.