apicheats.dev resend/llms.txt Raw .md
POST

/topics

Resend API

Create a new topic

Base URL
https://api.resend.com
Auth
Authorization: Bearer <RESEND_API_KEY>
Last verified
2026-09-03 · upstream hash matched
Actions
Agents: curl -H "Accept: text/markdown" this URL
→ 219 tokens · Vary: Accept

Critical gotchas

All requests must include a User-Agent header (e.g. User-Agent: my-app/1.0) or the API returns HTTP 403.

The to field is an array of strings, even when sending to a single recipient.

cURL

curl -X POST 'https://api.resend.com/topics' \  -H "Authorization: Bearer $RESEND_API_KEY" \  -H 'User-Agent: my-app/1.0' \  -H 'Content-Type: application/json' \  -d '{  "name": "string",  "default_subscription": "opt_in",  "description": "string",  "visibility": "private"}'
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Parameters

Name In Type Required Description
name body string Yes The name of the topic. Max 50 characters.
default_subscription body string Yes The default subscription status for the topic. Cannot be changed after creation.
description body string No A description of the topic. Max 200 characters.
visibility body string No The visibility of the topic. Public topics are visible to all contacts on the unsubscribe page. Private topics are only visible to opted-in contacts.

Response 200 OK

{
  "id": "78261eea-8f8b-4381-83c6-79fa7120f1cf",
  "object": "topic"
}