The Sendmux API is a read-only REST API that gives you programmatic access to your email infrastructure data. Use it to build monitoring dashboards, alerting systems, and automated reporting workflows.
Base URL
All API requests should be made to:
https://app.sendmux.ai/api/v1
Authentication
Authenticate using an API key from your Sendmux dashboard. Pass it as a Bearer token in the Authorization header.
curl https://app.sendmux.ai/api/v1/providers \
-H "Authorization: Bearer smx_root_your_key_here"
Permissions
Each endpoint requires a specific permission. Keys with wildcard permissions (e.g. provider.*) satisfy any permission in that namespace.
| Endpoint group | Required permission |
|---|
| Providers | provider.read |
| Email metrics | analytics.read |
| Email logs | logs.read |
| Billing | billing.read |
Use the root:readonly role for monitoring integrations — it covers all read permissions.
Success
{
"ok": true,
"data": { ... },
"meta": {
"request_id": "req_clxxxxxxxxxxxxxxxxxxxxxxxxx"
}
}
Paginated success
List endpoints include a pagination object alongside data.
{
"ok": true,
"data": [ ... ],
"pagination": {
"has_more": true,
"next_cursor": "dlog_xxxxxxxx"
},
"meta": {
"request_id": "req_clxxxxxxxxxxxxxxxxxxxxxxxxx"
}
}
Error
{
"ok": false,
"error": {
"code": "invalid_parameter",
"message": "The 'from_date' parameter must be a valid ISO 8601 date.",
"param": "from_date",
"doc_url": "https://docs.sendmux.ai/api-reference/errors#invalid_parameter"
},
"meta": {
"request_id": "req_clxxxxxxxxxxxxxxxxxxxxxxxxx"
}
}
Errors
| HTTP status | Error code | Description |
|---|
| 400 | invalid_parameter | Bad query parameter format |
| 400 | missing_parameter | Required parameter missing |
| 401 | authentication_required | No or invalid API key |
| 403 | insufficient_permissions | Key lacks required permission |
| 404 | not_found | Resource does not exist |
| 429 | rate_limit_exceeded | Rate limit hit |
| 500 | internal_error | Server error |
Rate limiting
Each API key is rate-limited to 600 requests per minute. Rate limit headers are included on every response:
X-RateLimit-Limit: 600
X-RateLimit-Remaining: 594
X-RateLimit-Reset: 1679313700
429 status with a Retry-After header.
Conventions
- snake_case fields in all JSON responses
- UTC ISO 8601 timestamps in RFC 3339 format:
2026-03-19T10:30:00Z
- Public IDs only — internal database IDs are never exposed
Cache-Control: no-store on all responses- JSON only —
Content-Type: application/json
OpenAPI specification
The full OpenAPI 3.1 specification is available at:
https://app.sendmux.ai/api/v1/openapi.json
