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v53

latestOpenAPI 3.0.1raw.githubusercontent.com2026-07-31147343479.6 KB
Send

Send a message

Sends a message to one or more recipients and returns a requestId. Courier routes it to email, SMS, push, chat, or in-app based on your rules.

post/send

Headers

Idempotency-Keystring

A unique key that makes this request idempotent. If Courier receives another request with the same Idempotency-Key, it returns the stored response from the first request without performing the operation again (including the original status code and any error). Use it to safely retry POST requests after network failures without risking duplicate sends. The key is scoped to this endpoint.

x-idempotency-expirationstring

How long the idempotency key remains valid, as a Unix epoch timestamp in seconds or an ISO 8601 date string. Only applies when Idempotency-Key is provided. If omitted, the key is retained for 25 hours; the maximum is 1 year.

Request body

Response

requestIdstring required

A successful call to POST /send returns a 202 status code along with a requestId in the response body. For single-recipient requests, the requestId is the derived message_id. For multiple recipients, Courier assigns a unique message_id to each derived message.

Example response

{
  "requestId": "1-69f561d3-7ad9d453fb6a7012efc2c5ad"
}