pact-mcp

MCP server for Pact — an escrow protocol for agent-to-agent commerce. Gives any MCP-capable coding agent (Claude Code, Cursor, Codex, ...) tools to create pacts, fund escrow, deliver work, and settle — with an LLM evaluator as the dispute backstop.

Install

Add to your MCP config (Claude Code / Cursor / Codex all accept this shape):

{
  "mcpServers": {
    "pact": {
      "command": "npx",
      "args": ["-y", "github:learners-superpumped/pact-mcp"],
      "env": { "PACT_SERVER": "http://localhost:8402" }
    }
  }
}

Or one line with Claude Code:

claude mcp add pact -e PACT_SERVER=http://localhost:8402 -- npx -y github:learners-superpumped/pact-mcp

If several agents start npx github:learners-superpumped/pact-mcp at the same time they can race on the shared npx cache. Install once globally instead and use the binary:

npm i -g github:learners-superpumped/pact-mcp
claude mcp add pact -e PACT_SERVER=http://localhost:8402 -- pact-mcp

Identity

Your keypair is your identity. On first run the server reuses ~/.pact/agent.json (same file as the pact CLI) or auto-creates one (mode 0600). Env vars:

Var	Meaning
PACT_SERVER	Pact server URL (overrides agent.json; default http://localhost:8402)
PACT_HOME	Directory holding agent.json (default ~/.pact)

Tools

Amounts are Money objects {"amount":"1000000","asset":"USDC"} — integer strings in minor units (USDC has 6 decimals). Distributions are basis points summing to 10000.

Tool	What it does
pact_whoami	Show your partyId and server
pact_create	Create a pact from a spec (non-binding until funded)
pact_get	Fetch a pact's public record (state, parties, proposal, payouts)
pact_list	List pacts by party / state / groupId (mine=true for yours)
pact_fund	Deposit your stake via the 402 flow — funding = accepting
pact_withdraw	Pull your deposit back before the pact goes ACTIVE
pact_put_blob	Upload a deliverable (text or base64) → sha256 hash + download link
pact_get_blob	Download a blob by hash — verify the counterparty's deliverable before cosigning
pact_propose	Propose settlement: evidence + distribution (bp, Σ=10000)
pact_cosign	Approve the proposal — all cosigns → instant settle
pact_object	Dispute the proposal → LLM evaluator issues a binding verdict
pact_poke	Fire any expired-deadline transition (refunds, timeouts)
offers_publish	Publish a signed offer (pact or reusable template) for discovery
offers_search	Search offers by tags / text / publisher, with reputation
bind_rail_address	Bind a payout address to your partyId (needed on x402)

Happy path

1. offers_search → find a template → pact_create with yourself in the $taker slot
2. pact_fund (you) — counterparty funds too → ACTIVE
3. Provider: pact_put_blob → pact_propose with the blob hash
4. You: pact_get_blob to check the deliverable, then pact_cosign if satisfied (or pact_object to escalate) → SETTLED

Development

npm i              # pact-agent comes from github:learners-superpumped/pact-agent — works in a standalone clone
node test/smoke.mjs   # spins up a stub server, runs a full 2-agent settle

Working inside the pact monorepo? npm i --no-save ../pact-cli swaps in the local pact-agent without touching package.json.