API Reference
The SendiMessage public API — every operation below is defined by the Postman collection (rev 2026-08-21) and verified against the live backend. Base URL:
https://api.sendimessage.com/v1Authenticate every request with both headers — see the Authentication guide:
X-API-Key: key_...X-API-Secret: secret_...
Do not call the SendiMessage API directly from browser code because your API secret would be exposed. Keep credentials server-side.
Account
| GET | Who Am I | /me |
Messages
| POST | Send Message | /send-message |
| POST | Upload Media | /media |
| GET | Message Status | /status |
| GET | List Messages | /v2/messages |
| GET | Show Message | /v2/messages/{message_handle} |
Lookups
| GET | Lookup Number | /lookup |
Contacts
| GET | List Contacts | /contacts |
| POST | Create Contact | /contacts |
| GET | Get Contact | /contacts/{number_or_contact_handle} |
| PUT | Update Contact | /contacts/{number_or_contact_handle} |
| POST | Opt Out / Opt Back In | /contacts/opt-out |
| POST | Re-check Service | /contacts/{number_or_contact_handle}/lookup |
| DELETE | Delete Contact | /contacts/{number_or_contact_handle} |
Lines
| GET | List Lines | /lines |
| PUT | Update Line | /lines/{line_handle} |
| GET | Get Call Forwarding | /lines/{line_handle}/call-forwarding |
| PUT | Request Call-Forwarding Change | /lines/{line_handle}/call-forwarding |
Conversations
| GET | List Conversations | /conversations |
| GET | Conversation Messages | /conversations/{conversation_handle}/messages |
| POST | Mark Conversation Read | /conversations/{conversation_handle}/read |
Webhooks
| GET | List Webhooks | /account/webhooks |
| POST | Add Webhook | /account/webhooks |
| PUT | Replace All Webhooks | /account/webhooks |
| DELETE | Delete Webhook | /account/webhooks |
Webhook Events
Delivered to your registered webhooks (see Webhooks guide). Event names are exact contract values:
| Event | Fires when |
|---|---|
receive | An inbound message arrived on one of your lines. |
outbound | An outbound message reached a final state. |
line_blocked | A line was blocked and can no longer send. |
line_unblocked | A previously blocked line was unblocked. |