Introduction
Understand authentication, errors and webhooks.
Base URL
The Sendo API is built on REST principles. We enforce HTTPS for every request to improve data security, initegrity and privacy. The API does not support HTTP requests.
All request should be sent to the following base URL:
Authentication
To authenticate your requests, you must add an Authorization header with the contents of the header being Bearer {token} where {token} is your API key.
You can generate an API key for your account on your dashboard.
Response codes
Sendo uses standard HTTP codes to indicate the success or failure of requests.
In general, 2XX HTTP codes mean your request was successful, 4XX codes are for user-related failures, and 5XX codes are for internal server issues.
| Status | Description |
|---|---|
200 | Successful request |
400 | Check the parameters were correct |
401 | The API key was missing |
403 | The API key was invalid |
404 | The resource was not found |
429 | The rate limit was exceeded |
5XX | Internal error, contact support |
Rate limits
The maximum number of API requests that users can send is 20 per second. The headers below will be sent with every response in accordance with the IETF standard:
| Header name | Description |
|---|---|
X-RateLimit-Limit | Maximum number of requests allowed within a window. |
X-RateLimit-Remaining | How many requests you have left within the window. |
X-RateLimit-Reset | The timestamp at which the rate limit will reset. |
When the limit is reached, you will receive a 429 HTTP error code.
To prevent this, we recommend reducing the rate at which you send requests. This can be done by introducing a queue mechanism or reducing the number of concurrent requests per second. If you have specific requirements, contact support to request a rate increase.
Compliance
Before sending any messages with Sendo, please ensure that you have read and understood our Messaging Policy and our Compliance overview. We reserve the right to suspend your account or block your messaging services if any misuse is reported.