curl -X POST 'https://api.resend.com/contacts/imports' \
  -H "Authorization: Bearer $RESEND_API_KEY" \
  -H 'User-Agent: my-app/1.0' \
  -F 'file=@sample.bin' \
  -F 'column_map={"email":"Email","first_name":"First Name","last_name":"Last Name","unsubscribed":"Unsubscribed","properties":{"plan":{"column":"Plan","type":"string"}}}' \
  -F 'on_conflict=skip' \
  -F 'segments=[{"id":"78261eea-8f8b-4381-83c6-79fa7120f1cf"}]' \
  -F 'topics=[{"id":"b6d24b8e-af0b-4c3c-be0c-359bbd97381e","subscription":"opt_in"}]'

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

> Create a contact import

## 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/contacts/imports' \
  -H "Authorization: Bearer $RESEND_API_KEY" \
  -H 'User-Agent: my-app/1.0' \
  -F 'file=@sample.bin'

## Parameters
| Name | In | Type | Required | Description |
| :--- | :--- | :--- | :--- | :--- |
| file | body | string | Yes | CSV file to import. Maximum size is 5... |
| column_map | body | string | No | JSON-encoded object mapping contact f... |
| on_conflict | body | string | No | Strategy to use when an imported cont... |

## Response (200 OK)
{"object":"contact_import","id":"479e3145-dd38-476b-932c-529ceb705947"}

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

POST

/contacts/imports

Resend API

Create a contact import

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
→ 211 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/contacts/imports' \  -H "Authorization: Bearer $RESEND_API_KEY" \  -H 'User-Agent: my-app/1.0' \  -F 'file=@sample.bin' \  -F 'column_map={"email":"Email","first_name":"First Name","last_name":"Last Name","unsubscribed":"Unsubscribed","properties":{"plan":{"column":"Plan","type":"string"}}}' \  -F 'on_conflict=skip' \  -F 'segments=[{"id":"78261eea-8f8b-4381-83c6-79fa7120f1cf"}]' \  -F 'topics=[{"id":"b6d24b8e-af0b-4c3c-be0c-359bbd97381e","subscription":"opt_in"}]'

Get a free Resend API key → sponsored

Parameters

Name	In	Type	Required	Description
file	body	string	Yes	CSV file to import. Maximum size is 50MB.
column_map	body	string	No	JSON-encoded object mapping contact fields and custom property keys to CSV column names. Supports `email`, `first_name`, `last_name`, `unsubscribed`, and `properties`. Custom property mappings can include `type` as `string`, `number`, or `boolean`; defaults to `string`.
on_conflict	body	string	No	Strategy to use when an imported contact already exists.
segments	body	string	No	JSON-encoded array of segments to add imported contacts to.
topics	body	string	No	JSON-encoded array of topic subscriptions to apply to imported contacts. Each `subscription` must be `opt_in` or `opt_out`.

Response 200 OK

{
  "object": "contact_import",
  "id": "479e3145-dd38-476b-932c-529ceb705947"
}