Ar

The AnchorRegistry MCP server. Resolve any AR-ID, manifest hash, or provenance tree from any MCP-compatible AI client.

License: MIT MCP Cloudflare Workers

Endpoint: https://mcp.anchorregistry.ai/mcp

Install

Claude Desktop

Settings → Integrations → Add server. URL: https://mcp.anchorregistry.ai/mcp

Claude Code

claude mcp add --transport http anchorregistry https://mcp.anchorregistry.ai/mcp

Cursor

Settings → MCP → Add new MCP server. Name: anchorregistry · Type: http · URL: https://mcp.anchorregistry.ai/mcp

Tools

ar_verify_arid

Resolves an AR-ID to its full provenance record.

"What's at AR-2026-qnPOJ1z?"

ar_verify_by_hash

Resolves an artifact by SHA-256 manifest hash.

ar_resolve_tree

Returns the full provenance tree for any AR-ID.

How it works

ar-mcp is a thin proxy. Every tool call hits api.anchorregistry.ai and returns the JSON unchanged. No data is logged, no credentials are stored, no state is held between requests.

The full surface is documented at:

• https://anchorregistry.ai/llms.txt
• https://anchorregistry.ai/agents.json
• https://api.anchorregistry.ai/openapi.json

Roadmap

v0.2 will add ar_check_balance and ar_register_artifact once the MCP credential-handling pattern stabilizes across clients. ar_seal_tree is deferred indefinitely (irreversible action; needs robust user-confirmation primitives the protocol does not yet provide). The deferred tools are fully implemented and live in src/future-tools.ts — enabling them is a one-line flip per tool.

Develop

npm install
npm test           # vitest, hits live api.anchorregistry.ai
npm run type-check
npm run dev        # wrangler dev — http://localhost:8787
npm run deploy     # wrangler deploy

Verify locally with the MCP inspector:

npx @modelcontextprotocol/inspector http://localhost:8787/mcp

License

MIT.

See also

• AnchorRegistry: https://anchorregistry.com
• Python SDK: https://pypi.org/project/anchorregistry/
• Source: https://github.com/AnchorRegistry/ar-mcp
• Spec: https://anchorregistry.ai/agents.json
• Contracts: https://github.com/AnchorRegistry/ar-contracts-v1