ucp.trychannel3.com. It speaks UCP (Universal Commerce Protocol), so shopping agents can search and look up products without learning a custom Channel3 API.
For most agents, MCP is the simpler approach. See MCP. Examples in this section show UCP CLI and curl side by side.
What you can do
| Action | Tool name |
|---|---|
| Search many stores at once | search_catalog |
| Look up by product ID or store URL | lookup_catalog, get_product |
com.trychannel3.catalog.global extension. See Extension reference.
Two URLs to know
| URL | What it does |
|---|---|
GET https://ucp.trychannel3.com/.well-known/ucp | Tells your agent what’s available (profile JSON) |
POST https://ucp.trychannel3.com/mcp | Where you call the tools |
Auth
Channel3 supports two tiers. See Authentication and Rate limits.| Tier | How | Good for |
|---|---|---|
| Anonymous | No API key | Quick tests, quickstart |
| Token | x-api-key header on each /mcp POST | Production traffic, monetized buy links |
--header "x-api-key: …" or configure profile headers.json for Token tier on ucp.trychannel3.com.
Same data as the REST API
UCP uses the same products asPOST /v1/search, POST /v1/lookup, and GET /v1/products/{ID}. Put the query in catalog; responses include products, pagination, and sometimes messages.
Where to start
Quickstart
Install the UCP CLI and run your first search. Quickstart
Add a key (step 6)
Token tier for production traffic, monetizable links, and placements.
Authentication · Rate
limits
Search and lookup
Search · Lookup · Get
product