# POST /domains (Resend API)
Base URL: https://api.resend.com
Auth: Authorization: Bearer <RESEND_API_KEY>
Last verified: 2026-09-03

> Create a new domain

## 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/domains' \
  -H "Authorization: Bearer $RESEND_API_KEY" \
  -H 'User-Agent: my-app/1.0' \
  -H 'Content-Type: application/json' \
  -d '{"name":"string","region":"us-east-1"}'

## Parameters
| Name | In | Type | Required | Description |
| :--- | :--- | :--- | :--- | :--- |
| name | body | string | Yes | The name of the domain you want to cr... |
| region | body | string | No | The region where emails will be sent... |
| custom_return_path | body | string | No | For advanced use cases, choose a subd... |

## Response (200 OK)
{"id":"string","name":"string"}

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Need an API key? Get one at https://resend.com/signup