# API errors

Sender uses conventional HTTP response codes to indicate the success or failure of an API request. In general: codes in the 2xx range indicate success. Codes in the 4xx range indicate an error that failed given the information provided (e.g., a required parameter was omitted, can not send campaign, etc.). Codes in the 5xx range indicate an error with Sender servers.

# 2xx - OK Response

It may be 200 or 201 response. Everything worked as intended.

# 4xx - Bad Request

# 400 - Bad request

It means that you sent a bad request. More information will be shown in the error message.


    "success": false,
    "message": "You must activate workflow first"

# 401 - Unauthorized

Means that we could not authenticate you. Check your API key.

# 404 - Not found

Means that we did not find the requested resource.

# 422 - Bad request parameters

Means that some parameters passed are not valid. More information will be shown in the response.

    "message": "The given data was invalid.",
    "errors": {
        "email": [
            "Required value, email"

# 429 - Too many requests

You are sending us too many requests.

Header Meaning
X-RateLimit-Limit The maximum number of API requests that the user can make per minute.
X-RateLimit-Remaining The remaining number of API requests that the user can make per minute.
X-RateLimit-Reset A date and time value indicating when the remaining limit resets.
Retry-After Indicates the seconds remaining before you can make a new request.

# 5xx - Server error

Any response starting with a 5. Problem is on our end, we will fix it shortly.

Last updated:   2024-01-09