# ModRetro Agent Commerce API (UCP over MCP)

**Canonical:** https://apis.io/apis/modretro/modretro-agent-commerce-api-ucp-over-mcp/  
**Provider:** ModRetro — https://apis.io/providers/modretro/  
**Base URL:** https://modretro.com/api/ucp/mcp  
**Documentation:** https://modretro.com/agents.md

ModRetro Agent Commerce API (UCP over MCP) is published by [ModRetro](https://apis.io/providers/modretro/) on the [APIs.io](https://apis.io/) network. Tagged areas include Agentic Commerce, MCP, Universal Commerce Protocol, E-Commerce, and Catalog. The published artifact set on APIs.io includes API documentation, authentication docs, and rate-limit docs.

ModRetro's agent-facing commerce API. A remote Model Context Protocol server implementing the Universal Commerce Protocol shopping service (versions 2026-04-08 and 2026-01-23), exposing 13 tools across catalog search and lookup, cart, checkout and order. initialize and tools/list answer anonymously; every tools/call requires a fetchable UCP agent-profile URI, and the order and checkout tools additionally require a Shopify agent JWT. complete_checkout requires an idempotency key and, per ModRetro's own robots.txt and /agents.md, explicit contemporaneous human approval of payment.

## Machine-readable artifacts (8)

- **MCPServer** — https://raw.githubusercontent.com/api-evangelist/modretro/refs/heads/main/mcp/modretro-mcp.yml
- **Documentation** — https://modretro.com/agents.md
- **Authentication** — https://raw.githubusercontent.com/api-evangelist/modretro/refs/heads/main/authentication/modretro-authentication.yml
- **OAuthScopes** — https://raw.githubusercontent.com/api-evangelist/modretro/refs/heads/main/scopes/modretro-scopes.yml
- **RateLimits** — https://raw.githubusercontent.com/api-evangelist/modretro/refs/heads/main/rate-limits/modretro-rate-limits.yml
- **ErrorCatalog** — https://raw.githubusercontent.com/api-evangelist/modretro/refs/heads/main/errors/modretro-problem-types.yml
- **DataModel** — https://raw.githubusercontent.com/api-evangelist/modretro/refs/heads/main/data-model/modretro-data-model.yml
- **APIsJSON** — https://raw.githubusercontent.com/api-evangelist/modretro/refs/heads/main/apis.yml

## Tags

Agentic Commerce, MCP, Universal Commerce Protocol, E-Commerce, Catalog, Checkout

---

Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/modretro/modretro-agent-commerce-api-ucp-over-mcp/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/modretro/.