@writhq/mcp

Writ — KYA (Know Your Agent). A verifiable agent passport, over MCP.

An MCP server that gives an MCP-capable runtime (Claude Code, and any other MCP client) a Writ passport: it holds the agent's local keypair and exposes tools to check status and present signed X-Passport assertions for real economic actions.

npx @writhq/mcp

Tools

| Tool | What it does | |---|---| | passport_status | Show the agent's identity: registered agt_ id, configured mandate/platform, and whether the passport is reachable. Call this first. | | passport_present | Sign an assertion and present it to any platform endpoint via the X-Passport header. Amount in minor units (cents). | | passport_sign | Present signed authority to sign a document — class, counterparty, liability. Writ attests the authority; the counterparty executes the signature. | | passport_refill_demo | Refill the Northbank Sandbox brokerage with a signed assertion. Amount in dollars. Demonstrates ALLOW / per-tx DENY / period DENY / revoked DENY. |

passport_sign — signature authority

The second thing a mandate can authorize. Instead of may this agent move $500, it asks may this agent put its principal's name on this paper, at this liability:

passport_sign
  url               https://esign.example.com/envelopes/env_8821/sign
  document_class    nda            # nda | msa | sow | order_form | dpa | other
  counterparty      Northwind Logistics GmbH
  liability_minor   2500000        # $25,000 of exposure, in cents
  document_text     "MUTUAL NON-DISCLOSURE AGREEMENT\n\n…"

Pass either document_text (hashed locally with the same function the counterparty uses — nothing but the digest ever leaves the machine) or document_hash if you already computed it. Supplying both, or neither, is an error rather than a guess.

The mandate decides. Paper of a class it does not list denies document_class; a document over the per-document liability cap denies per_tx_cap; too much cumulative exposure this period denies period_cap.

Writ attests the authority — that a live, scoped mandate from a KYC'd principal covered paper of this class at this liability — and signs a record of that decision. It never produces the signature; the e-signature platform still does that. None of this is a qualified electronic signature (eIDAS/QES).

Configure it in Claude Code

Add to your MCP config (e.g. ~/.claude/mcp.json, or a project .mcp.json):

{
  "mcpServers": {
    "writ": {
      "command": "npx",
      "args": ["-y", "@writhq/mcp"],
      "env": {
        "PASSPORT_URL": "https://api.writhq.com"
      }
    }
  }
}

Generic MCP client

Any stdio MCP client can launch it:

{
  "command": "npx",
  "args": ["-y", "@writhq/mcp"],
  "env": { "PASSPORT_URL": "https://api.writhq.com" }
}

Point it at a local stack by setting PASSPORT_URL to it — e.g. http://localhost:8787 for wrangler dev. Production is the default precisely so that forgetting the variable cannot leave an agent talking to nothing.

Configuration

| Env var | Default | Purpose | |---|---|---| | PASSPORT_URL | https://api.writhq.com | Passport service base URL. Set it to point at a local stack. | | NORTHBANK_URL | http://localhost:3100 | Demo brokerage base URL (for passport_refill_demo). | | PASSPORT_AGENT_HOME | ./.passport-agent | Where the agent keypair + context are stored. |

Before it can transact

The agent needs a registered identity and a mandate first. Either:

• run @writhq/sdk / passport-agent CLI to create the keypair, have a principal register the public key, and set the mandate/platform context; or
• run the repo's npm run seed, which provisions a KYC'd principal, registers the agent, issues the Northbank mandate, and wires the context in one step.

Then passport_status will show registered: true and passport_refill_demo will run the full ALLOW/DENY flow. The keystore is shared with @writhq/sdk (same PASSPORT_AGENT_HOME), so seeding once wires both.

To see the entire flow end to end without any setup, run npx @writhq/demo against the live sandbox.

Home: https://writhq.com · Docs: https://writhq.com/docs/ · API: https://api.writhq.com

License

MIT © Tundra Industries