API Reference

All AgentCart UCP endpoints follow the pattern:

https://app.agentcart.io/api/ucp/{slug}

Where {slug} is your store’s unique identifier, visible in the AgentCart dashboard under Settings.

Authentication

No API key required. The slug in the URL is sufficient to identify the merchant. Endpoints return 404 if the slug is invalid or UCP is not enabled for that store.

CORS

All UCP endpoints allow cross-origin requests from any origin:

Access-Control-Allow-Origin: *
Access-Control-Allow-Methods: POST, GET, PUT, OPTIONS
Access-Control-Allow-Headers: content-type, ucp-agent, request-id, idempotency-key

UCP version envelope

Every response includes a ucp envelope with the protocol version:

{
  "ucp": {
    "version": "2026-01-23",
    "capabilities": {
      "dev.ucp.shopping.checkout": { "version": "2026-01-23" },
      "dev.ucp.shopping.catalog": { "version": "2026-01-23" }
    }
  }
}

Amounts

All monetary amounts are in minor units (e.g. 4999 = $49.99). Currency is specified separately as an ISO 4217 code (e.g. "USD").

Full OpenAPI spec

Download the full spec: /openapi.yaml