Pact MCP Server

pact-mcp — MCP Servers for Pact & Chainweb

Model Context Protocol servers for Pact 5 smart-contract development on Kadena-style Chainweb networks (KDA-CE).

Give your AI agent safe, auditable access to the full Pact development loop: run REPL tests, scan modules for critical language traps, estimate gas, query and submit to Chainweb nodes, and manage local devnets — all behind a strict, tested security baseline.

Servers

Quick Start

From npm (recommended)

All servers are published to the public npm registry and run via npx — no clone or build required. Register them with your MCP client. For Claude Code:

claude mcp add pact -e PACT_COMMUNITY_WORKSPACE_ROOT=/path/to/your/project \
  -- npx -y @pact-community/mcp-pact

Or in JSON client configuration (Claude Desktop, Cursor, VS Code, …):

{
  "mcpServers": {
    "pact": {
      "command": "npx",
      "args": ["-y", "@pact-community/mcp-pact"],
      "env": {
        "PACT_COMMUNITY_WORKSPACE_ROOT": "/path/to/your/project",
        "PACT_COMMUNITY_PACT_BIN": "pact"
      }
    },
    "chainweb": {
      "command": "npx",
      "args": ["-y", "@pact-community/mcp-chainweb"],
      "env": {
        "PACT_COMMUNITY_WORKSPACE_ROOT": "/path/to/your/project",
        "PACT_COMMUNITY_CHAINWEB_MODE": "devnet",
        "PACT_COMMUNITY_CHAINWEB_PROFILE": "devnet",
        "PACT_COMMUNITY_CHAINWEB_BASE_URL": "http://localhost:8081",
        "PACT_COMMUNITY_CHAINWEB_NETWORK_ID": "development"
      }
    }
  }
}

Each package README documents its full tool list and environment variables.

From source (for contributors)

git clone https://github.com/Pact-Community-Organization/pact-mcp.git
cd pact-mcp
pnpm install
pnpm build

A ready-made project configuration pointing at the local builds ships in .mcp.json (used automatically by Claude Code when you open this repository).

Security Model

Every server implements the same tested baseline (see SECURITY.md):

• Root refusal — exits immediately when run as uid 0
• Audit logging — every tool call logged with SHA-256 input hashes (never raw inputs) to ~/.pact-community/
• Prompt-injection stripping — tool outputs are sanitized before they reach the model
• Tool schema locking — servers refuse to start if a tool schema drifts from the shipped tools.lock.json
• Network allowlists — only approved origins are reachable; public Chainweb profiles are read-only
• Filesystem boundaries — path traversal and symlink escapes are rejected
• Safe spawning — no shells, argument validation, binary allowlists

chainweb.send, chainweb.deploy_module, and chainweb.continue_pact never accept private keys: signatures must be produced externally (Ledger, @kadena/client, …) and passed in pre-signed.

Support Matrix

Network posture: mcp-chainweb defaults to the devnet profile. The opt-in testnet06 and mainnet profiles are read-only — write tools return PROFILE_WRITE_BLOCKED.

Validation Proof Levels

Run L3 only when a devnet is actually reachable:

pnpm build
PACT_COMMUNITY_ENABLE_DEVNET_E2E=true pnpm test:e2e:devnet

Development

pnpm install          # install workspace dependencies
pnpm build            # build all packages (TypeScript composite)
pnpm test             # run all test suites serially
pnpm typecheck        # tsc --noEmit across packages
pnpm audit            # dependency vulnerability audit
pnpm lock:regen       # regenerate tools.lock.json after schema changes

• Node.js >= 20.11, pnpm >= 9
• Coverage gates: 90% functions / 85% lines / 80% branches, enforced in CI
• See CONTRIBUTING.md for workflow and commit conventions

VS Code Distribution

See docs/VS-CODE-DISTRIBUTION.md for extension packaging options and a secure update strategy.

License

Apache-2.0