API reference

The Clement API is REST over HTTPS, JSON in and JSON out, bearer-auth'd. Every endpoint is documented from the OpenAPI 3.1 spec served at api.clement.so/openapi.json. The spec is the source of truth — these pages are generated from it.

Conventions

  • Base URL: https://api.clement.so
  • Auth: Authorization: Bearer cl_live_… (or cl_test_… for sandbox)
  • IDs: type-prefixed ULIDs — inb_… for inboxes, cmp_… for campaigns, etc.
  • Pagination: cursor-based; limit (max 200), starting_after, ending_before.
  • Idempotency: Idempotency-Key header required on side-effect-bearing POSTs (sends, imports).
  • Errors: see Errors for the envelope and per-code list.

Resources

Meta

1 endpoint

Health and metadata.

Workspace

1 endpoint

The workspace bound to your key — plan, limits, and current-month usage. Useful for agents bootstrapping context.

API keys

4 endpoints

Workspace bearer credentials. Read, write, admin scopes.

Inboxes

7 endpoints

Connected sending accounts (Gmail, Outlook, SMTP).

Sends

4 endpoints

The send primitive — single, fan-out, scheduled, threaded.

Messages

3 endpoints

Outbound and inbound emails, full body and headers.

Threads

3 endpoints

Conversations grouping outbound + inbound messages.

Contacts

10 endpoints

People you might message. Email + arbitrary attributes.

Audiences

7 endpoints

Named collections of contacts.

Sequences

9 endpoints

Reusable multi-step email templates.

Campaigns

21 endpoints

Audience × sequence × inbox set × schedule. Lifecycle: start / pause / resume.

Suppressions

5 endpoints

Workspace-global block list of recipient addresses.

Events

2 endpoints

Immutable log of state changes — back-fill source for webhooks.

Webhooks

10 endpoints

Signed event delivery, retries, deliveries log.