Integrate the Gateway
Listrar Product Data Gateway answers questions about products — identity, publisher, passport data, and the evidence behind each answer — over a REST API and an MCP endpoint that share one response envelope and one error model.
No agreement, licence or affiliation with GS1 exists. Nothing on this site should be read as implying one.What is actually built today
Section titled “What is actually built today”This section exists because a documentation site is the point where an internal gap becomes something an integrator builds against. Everything below is true of the running service as of 2026-08-23.
- 13 REST routes and 6 MCP tools. The API reference is generated from the service’s own route table, and the tool list from the same catalogue the MCP endpoint returns. Neither is written by hand.
claimsandsourcesare populated byget_dpponly. Every other operation returns them as empty arrays. They are not a hint that no evidence exists — they mean that operation does not yet project it.provenance,confidence,freshnessandagent_guidanceare never emitted. Each needs a mechanism that does not exist yet — evidence aggregation, a scoring method, a freshness predicate, licence gating. They are absent from responses rather than present and empty.- There is no cache and no
ETag. Nothing in a response describes cache state. - Authentication is API keys. OAuth 2.1 is specified and not implemented; do not build against it.
- There is no public sandbox yet. Examples on this site are shown against a local instance, not a hosted playground.
Start here
Section titled “Start here”- Typed absence — why a missing product is a
200, and what that means for your retry logic. Read this first; it is the single most common integration mistake. - Claims and evidence — what the Gateway asserts, and what backs each assertion.
- Trust levels — the L0–L5 scale, and what no level means.
- Untrusted content — the shared responsibility around strings the Gateway did not author.
- Errors and Rate limits.
Machine surfaces
Section titled “Machine surfaces”The integrator here is frequently an agent, so the contract is served, not just rendered:
| Path | Serves |
|---|---|
/v1/openapi.json (on the API host) |
The OpenAPI 3.1 document, generated from the route table |
/v1/mcp |
The MCP endpoint; tools/list returns the catalogue |
The reference pages on this site are rendered from that document, but they are not the
contract — the document is. In particular, operationId values do not appear in these
pages; read them from /v1/openapi.json.