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": "example-name",
  "default_subscription": "opt_in",
  "description": "example-description",
  "visibility": "private"
}'

# POST /topics (Resend API)
Base URL: https://api.resend.com
Auth: Authorization: Bearer <RESEND_API_KEY>
Last verified: 2026-10-20

> Create a new topic

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

## 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":"example-name","default_subscription":"opt_in"}'

## 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... |
| 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... |

## Response (200 OK)
{"id":"78261eea-8f8b-4381-83c6-79fa7120f1cf","object":"topic"}

---
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POST

POST /topics — Resend API

Resend API

Create a new topic

Base URL: https://api.resend.com
Auth: Authorization: Bearer <RESEND_API_KEY>
Last verified: 2026-10-20 · upstream hash matched

Actions Try in browser→

Agents: curl -H "Accept: text/markdown" this URL
→ 228 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.

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": "example-name",  "default_subscription": "opt_in",  "description": "example-description",  "visibility": "private"}'

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"
}

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