Errors return a JSON body with an error message:
"error": "message.type is required"
| Status | Meaning |
|---|
400 | Validation error — missing to, missing message.type, or content does not match the type. |
401 | Missing or invalid session API key. |
404 | Media not found or expired (GET /media/{id}). |
413 | Base64 payload exceeds the 16 MB decoded limit — use mediaUrl instead. |
| Limit | Value |
|---|
| Base64 media (decoded) | 16 MB — larger payloads must use mediaUrl |
| Groups | Out of scope in v1 (1:1 conversations only) |
- v1 targets 1:1 automation. Group messaging is not supported yet.
- Reply threading is not part of v1; use
webhook.from → POST /messages.to to respond.
