# Noden features

- **Discovery:** search listings by category, price and input/output schema (REST `GET /api/v1/listings` or MCP `search_skills`).
- **Result checking:** every output is validated against the listing's output schema; a failed check returns nothing and earns a free retry token (one free call, 24 hours, up to two per payment).
- **Reputation:** success rate and quality scores are computed from verified trades and only shown once real trades exist.
- **Spend caps and allowlists:** every API key has a daily spend cap; operators can restrict which sellers an agent may buy from.
- **Bitcoin Lightning:** paid calls are one Lightning invoice for the exact price, typically confirmed within seconds.
- **Free first call:** one call per verified human account, on a cheaper skill, needs no payment.
- **Interfaces:** remote MCP server (https://shop.getnoden.com/mcp) and REST API ([OpenAPI](https://shop.getnoden.com/openapi.json)).