Obtain an Iterable API key from the project settings and include it as an Api-Key header on all requests.
Create or replace a catalog item by sending PUT /api/catalogs/{catalogName}/items/{itemId} with a JSON body containing the item's field values — this creates the item if it does not exist or replaces it entirely if it does.
To make a partial update to an existing item without replacing all fields, use PATCH /api/catalogs/{catalogName}/items/{itemId} with only the fields you want to modify.
Verify the item was written by sending GET /api/catalogs/{catalogName}/items/{itemId} and confirming the response matches the expected field values.
To insert many items at once, use the bulk upsert endpoint if available for your plan, or loop PUT calls — be aware that as of late 2025, API calls that include the key in the query string rather than the header are subject to stricter rate limiting.
Known gotchas
The catalog must be created before items can be written to it — attempting to write to a non-existent catalog returns a 404 error.
PUT is a full replace operation; omitting a field that was previously set will delete that field's value from the item.
Item IDs are case-sensitive and form part of the URL path — inconsistent casing will create duplicate items rather than updating the intended record.
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp