Base URL
A 30-second tour
Quickstart
Make your first request and build a list from a live prospect search in about five minutes.
Authentication
Create an API key and learn both accepted forms of the Authorization header.
Guides
Task-oriented walkthroughs: search, lists, custom columns, exports, and campaigns.
API Reference
Every endpoint with schemas, examples, and an interactive playground.
What you can build
Conventions used throughout
- IDs are opaque strings (
"68a1f20b9c41d20014b3e901"). Never parse or construct them. - Timestamps are ISO 8601 in UTC (
"2026-07-27T10:00:00.000Z"). - Success responses are keyed by the entity they carry —
{ "list": ... },{ "campaign": ... },{ "user": ... }. Paginated collections use{ "data": [...], "pagination": ... }(pagination). - Errors always use one envelope with a stable machine-readable
code(errors). - Asynchronous work (exports, saving search results, campaign initialization) returns
202 Acceptedwith an id you poll. Nothing long-running blocks a request.
Need help?
Write to support@fuseai.com and include therequest_id from any error response — it lets us trace the exact request in our logs.