Underdog

Underdog UCP Commerce MCP API

The Universal Commerce Protocol (UCP) shopping service Underdog serves from its own domain. A remote MCP endpoint that answers tools/list anonymously with 13 tools covering catalog search and lookup, cart create/read/update/cancel, checkout create/read/update/complete/cancel, and order lookup. complete_checkout requires an idempotency-key and buyer approval. Merchant profile and supported protocol versions are published at https://underdog.shop/.well-known/ucp.

GitHub

Documentation

📖
Documentation
https://underdog.shop/agents.md

Other Resources

🔗
MCPServer
https://raw.githubusercontent.com/api-evangelist/underdog/refs/heads/main/mcp/underdog-mcp.yml
🔗
ToolCrosswalk
https://raw.githubusercontent.com/api-evangelist/underdog/refs/heads/main/mcp/underdog-tool-crosswalk.yml
🔗
Specification
https://ucp.dev/2026-04-08/specification/overview/
🔗
APIsJSON
https://raw.githubusercontent.com/api-evangelist/underdog/refs/heads/main/apis.yml

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API entry from apis.yml

apis.yml Raw ↑ 
aid: underdog-ucp-commerce
name: Underdog UCP Commerce MCP API
description: The Universal Commerce Protocol (UCP) shopping service Underdog serves from its own domain.
  A remote MCP endpoint that answers tools/list anonymously with 13 tools covering catalog search and
  lookup, cart create/read/update/cancel, checkout create/read/update/complete/cancel, and order lookup.
  complete_checkout requires an idempotency-key and buyer approval. Merchant profile and supported protocol
  versions are published at https://underdog.shop/.well-known/ucp.
humanURL: https://underdog.shop/agents.md
baseURL: https://underdog.shop/api/ucp/mcp
tags:
- MCP
- Agentic Commerce
- Universal Commerce Protocol
- Checkout
- Catalog
properties:
- type: MCPServer
  url: mcp/underdog-mcp.yml
- type: ToolCrosswalk
  url: mcp/underdog-tool-crosswalk.yml
- type: Documentation
  url: https://underdog.shop/agents.md
- type: Specification
  url: https://ucp.dev/2026-04-08/specification/overview/