Resend - Courier

Setup

You will need both a Courier and a Resend account.

Create a Resend API Key

In Resend, navigate to API Keys. Create an API key with appropriate permissions and copy it.

Configure in Courier

In Courier, navigate to the Resend Integration page. Paste your API key into the “API Key” field.

Set From Address

Add a verified email address to the “From Address” field (e.g., noreply@yourdomain.com). Click “Add Integration” then “Save.”

Profile Requirements

To deliver a message to a recipient over Resend, Courier must be provided the recipient’s email address. This value should be included in the recipient profile as email.

{
  "message": {
    "to": {
      "email": "alice@acme.com"
    }
    // ... rest of message definition
  }
}

Overrides

You can use a provider override to customize what Courier sends to Resend’s /emails endpoint. Overrides are useful when a field is not yet supported by Courier or you want to replace a value that Courier generates. For example, you can use Resend’s tagging feature:

{
  "message": {
    "template": "NOTIFICATION_TEMPLATE_ID",
    "to": {
      "email": "alice@acme.com"
    },
    "providers": {
      "resend": {
        "override": {
          "body": {
            "tags": [{ "name": "environment", "value": "development" }]
          }
        }
      }
    }
  }
}

Everything inside message.providers.resend.override.body is merged with Courier’s generated request body. You can also override config values:

{
  "message": {
    "providers": {
      "resend": {
        "override": {
          "config": {
            "apiKey": "<your override API key>",
            "fromAddress": "alternate-sender@yourdomain.com"
          }
        }
      }
    }
  }
}

Attachments

To include an attachment, add an attachments array in the override. File content must be base64-encoded.

{
  "message": {
    "template": "NOTIFICATION_TEMPLATE_ID",
    "to": {
      "email": "alice@acme.com"
    },
    "providers": {
      "resend": {
        "override": {
          "attachments": [
            {
              "filename": "billing.pdf",
              "contentType": "application/pdf",
              "data": "Q29uZ3JhdHVsYXRpb25zLCB5b3UgY2FuIGJhc2U2NCBkZWNvZGUh"
            }
          ]
        }
      }
    }
  }
}

​Setup

​Profile Requirements

​Overrides

​Attachments

Setup

Profile Requirements

Overrides

Attachments