Resend

Resend API integration with managed authentication. Send transactional emails, manage domains, contacts, templates, and broadcasts. Use this skill when users...

Access the Resend API with managed authentication. Send transactional emails, manage domains, contacts, templates, broadcasts, and webhooks.

Quick Start

# List sent emails
python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/resend/emails')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Base URL

https://api.maton.ai/resend/{endpoint}

Maton proxies requests to api.resend.com and automatically injects your API key.

Authentication

All requests require the Maton API key in the Authorization header:

Authorization: Bearer $MATON_API_KEY

Environment Variable: Set your API key as MATON_API_KEY:

export MATON_API_KEY="YOUR_API_KEY"

Getting Your API Key

1. Sign in or create an account at maton.ai
2. Go to maton.ai/settings
3. Copy your API key

Connection Management

Manage your Resend connections at https://api.maton.ai.

List Connections

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/connections?app=resend&status=ACTIVE')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Create Connection

python <<'EOF'
import urllib.request, os, json
data = json.dumps({'app': 'resend'}).encode()
req = urllib.request.Request('https://api.maton.ai/connections', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Get Connection

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/connections/{connection_id}')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Response:

{
  "connection": {
    "connection_id": "{connection_id}",
    "status": "ACTIVE",
    "creation_time": "2026-03-13T00:19:36.809599Z",
    "last_updated_time": "2026-03-13T09:59:08.443568Z",
    "url": "https://connect.maton.ai/?session_token=...",
    "app": "resend",
    "metadata": {},
    "method": "API_KEY"
  }
}

Delete Connection

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/connections/{connection_id}', method='DELETE')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Specifying Connection

If you have multiple Resend connections, specify which one to use with the Maton-Connection header:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/resend/emails')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Maton-Connection', '{connection_id}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

If you have multiple connections, always include this header to ensure requests go to the intended account.

Security & Permissions

• Access is scoped to emails, domains, API keys, and audiences within the connected Resend account.
• All write operations require explicit user approval. Before executing any create, update, or delete call, confirm the target resource and intended effect with the user.

API Reference

Emails

Send and manage transactional emails.

Send Email

POST /resend/emails

Example:

python <<'EOF'
import urllib.request, os, json
data = json.dumps({
    'from': '[e-mail]',
    'to': ['[e-mail]'],
    'subject': 'Hello from Resend',
    'html': '<p>Welcome to our service!</p>'
}).encode()
req = urllib.request.Request('https://api.maton.ai/resend/emails', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Request Body:

Field	Type	Required	Description
from	string	Yes	Sender email (must be from verified domain)
to	string[]	Yes	Recipient email addresses
subject	string	Yes	Email subject
html	string	No	HTML content
text	string	No	Plain text content
cc	string[]	No	CC recipients
bcc	string[]	No	BCC recipients
reply_to	string[]	No	Reply-to addresses
attachments	object[]	No	File attachments
tags	object[]	No	Email tags for tracking
scheduled_at	string	No	ISO 8601 datetime for scheduled send

Response:

{
  "id": "a52ac168-338f-4fbc-9354-e6049b193d99"
}

Send Batch Emails

POST /resend/emails/batch

Example:

python <<'EOF'
import urllib.request, os, json
data = json.dumps([
    {'from': '[e-mail]', 'to': ['[e-mail]'], 'subject': 'Email 1', 'text': 'Content 1'},
    {'from': '[e-mail]', 'to': ['[e-mail]'], 'subject': 'Email 2', 'text': 'Content 2'}
]).encode()
req = urllib.request.Request('https://api.maton.ai/resend/emails/batch', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

List Emails

GET /resend/emails

Example:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/resend/emails')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Response:

{
  "data": [
    {
      "id": "a52ac168-338f-4fbc-9354-e6049b193d99",
      "from": "[e-mail]",
      "to": ["[e-mail]"],
      "subject": "Hello from Resend",
      "created_at": "2026-03-13T10:00:00.000Z"
    }
  ]
}

Get Email

GET /resend/emails/{email_id}

Example:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/resend/emails/{email_id}')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Update Email

PATCH /resend/emails/{email_id}

Cancel Scheduled Email

DELETE /resend/emails/{email_id}

Domains

Manage sending domains.

List Domains

GET /resend/domains

Example:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/resend/domains')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Response:

{
  "data": [
    {
      "id": "5eb93a2e-e849-40a1-81b7-ed0fb574ddd8",
      "name": "yourdomain.com",
      "status": "verified",
      "created_at": "2026-03-13T10:00:00.000Z"
    }
  ]
}

Create Domain

POST /resend/domains

Example:

python <<'EOF'
import urllib.request, os, json
data = json.dumps({'name': 'yourdomain.com'}).encode()
req = urllib.request.Request('https://api.maton.ai/resend/domains', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Response:

{
  "id": "5eb93a2e-e849-40a1-81b7-ed0fb574ddd8",
  "name": "yourdomain.com",
  "status": "pending",
  "records": [
    {"type": "MX", "name": "...", "value": "..."},
    {"type": "TXT", "name": "...", "value": "..."}
  ]
}

Get Domain

GET /resend/domains/{domain_id}

Update Domain

PATCH /resend/domains/{domain_id}

Delete Domain

DELETE /resend/domains/{domain_id}

Verify Domain

POST /resend/domains/{domain_id}/verify

Contacts

Manage contact lists.

List Contacts

GET /resend/contacts

Example:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/resend/contacts')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Create Contact

POST /resend/contacts

Example:

python <<'EOF'
import urllib.request, os, json
data = json.dumps({
    'email': '[e-mail]',
    'first_name': 'John',
    'last_name': 'Doe'
}).encode()
req = urllib.request.Request('https://api.maton.ai/resend/contacts', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Response:

{
  "id": "3cdc4bbb-0c79-46e5-be2a-48a89c29203d"
}

Get Contact

GET /resend/contacts/{contact_id}

Update Contact

PATCH /resend/contacts/{contact_id}

Delete Contact

DELETE /resend/contacts/{contact_id}

Templates

Manage email templates.

List Templates

GET /resend/templates

Example:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/resend/templates')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Create Template

POST /resend/templates

Example:

python <<'EOF'
import urllib.request, os, json
data = json.dumps({
    'name': 'Welcome Email',
    'subject': 'Welcome to our service!',
    'html': '<h1>Welcome!</h1><p>Thanks for signing up.</p>'
}).encode()
req = urllib.request.Request('https://api.maton.ai/resend/templates', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Response:

{
  "id": "9b84737c-8a80-448a-aca1-c6e1fddd0f23"
}

Get Template

GET /resend/templates/{template_id}

Update Template

PATCH /resend/templates/{template_id}

Delete Template

DELETE /resend/templates/{template_id}

Publish Template

POST /resend/templates/{template_id}/publish

Duplicate Template

POST /resend/templates/{template_id}/duplicate

Segments

Create audience segments for targeting.

List Segments

GET /resend/segments

Example:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/resend/segments')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Create Segment

POST /resend/segments

Example:

python <<'EOF'
import urllib.request, os, json
data = json.dumps({
    'name': 'Active Users',
    'filter': {
        'and': [
            {'field': 'email', 'operator': 'contains', 'value': '@'}
        ]
    }
}).encode()
req = urllib.request.Request('https://api.maton.ai/resend/segments', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Get Segment

GET /resend/segments/{segment_id}

Delete Segment

DELETE /resend/segments/{segment_id}

Broadcasts

Send emails to segments.

List Broadcasts

GET /resend/broadcasts

Example:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/resend/broadcasts')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Create Broadcast

POST /resend/broadcasts

Example:

python <<'EOF'
import urllib.request, os, json
data = json.dumps({
    'name': 'Weekly Newsletter',
    'from': '[e-mail]',
    'subject': 'This Week\'s Update',
    'html': '<h1>Weekly Update</h1><p>Here\'s what happened...</p>',
    'segment_id': 'segment-uuid'
}).encode()
req = urllib.request.Request('https://api.maton.ai/resend/broadcasts', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Get Broadcast

GET /resend/broadcasts/{broadcast_id}

Update Broadcast

PATCH /resend/broadcasts/{broadcast_id}

Delete Broadcast

DELETE /resend/broadcasts/{broadcast_id}

Send Broadcast

POST /resend/broadcasts/{broadcast_id}/send

Webhooks

Configure event notifications.

List Webhooks

GET /resend/webhooks

Example:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/resend/webhooks')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Create Webhook

POST /resend/webhooks

Example:

python <<'EOF'
import urllib.request, os, json
data = json.dumps({
    'endpoint': 'https://yoursite.com/webhook',
    'events': ['email.delivered', 'email.bounced', 'email.opened']
}).encode()
req = urllib.request.Request('https://api.maton.ai/resend/webhooks', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Webhook Events:

• email.sent - Email was sent
• email.delivered - Email was delivered
• email.opened - Email was opened
• email.clicked - Link in email was clicked
• email.bounced - Email bounced
• email.complained - Recipient marked as spam

Get Webhook

GET /resend/webhooks/{webhook_id}

Update Webhook

PATCH /resend/webhooks/{webhook_id}

Delete Webhook

DELETE /resend/webhooks/{webhook_id}

API Keys

Manage API keys.

List API Keys

GET /resend/api-keys

Example:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/resend/api-keys')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Create API Key

POST /resend/api-keys

Example:

python <<'EOF'
import urllib.request, os, json
data = json.dumps({'name': 'Production Key'}).encode()
req = urllib.request.Request('https://api.maton.ai/resend/api-keys', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Note: The actual API key value is only returned once on creation.

Delete API Key

DELETE /resend/api-keys/{api_key_id}

Topics

Manage subscription topics.

List Topics

GET /resend/topics

Create Topic

POST /resend/topics

Example:

python <<'EOF'
import urllib.request, os, json
data = json.dumps({
    'name': 'Newsletter',
    'default_subscription': 'subscribed'
}).encode()
req = urllib.request.Request('https://api.maton.ai/resend/topics', data=data, method='POST')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
req.add_header('Content-Type', 'application/json')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Note: default_subscription is required. Values: subscribed or unsubscribed.

Get Topic

GET /resend/topics/{topic_id}

Update Topic

PATCH /resend/topics/{topic_id}

Delete Topic

DELETE /resend/topics/{topic_id}

Contact Properties

Manage custom contact properties.

List Contact Properties

GET /resend/contact-properties

Create Contact Property

POST /resend/contact-properties

Get Contact Property

GET /resend/contact-properties/{property_id}

Update Contact Property

PATCH /resend/contact-properties/{property_id}

Delete Contact Property

DELETE /resend/contact-properties/{property_id}

Code Examples

JavaScript

// Send an email
const response = await fetch('https://api.maton.ai/resend/emails', {
  method: 'POST',
  headers: {
    'Authorization': `Bearer ${process.env.MATON_API_KEY}`,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    from: '[e-mail]',
    to: ['[e-mail]'],
    subject: 'Hello!',
    html: '<p>Welcome!</p>'
  })
});
const data = await response.json();
console.log(data.id);

Python

import os
import requests

response = requests.post(
    'https://api.maton.ai/resend/emails',
    headers={
        'Authorization': f'Bearer {os.environ["MATON_API_KEY"]}',
        'Content-Type': 'application/json'
    },
    json={
        'from': '[e-mail]',
        'to': ['[e-mail]'],
        'subject': 'Hello!',
        'html': '<p>Welcome!</p>'
    }
)
email = response.json()
print(f"Email sent: {email['id']}")

Notes

• Sending emails requires a verified domain
• Rate limit: 2 requests per second
• Batch emails accept up to 100 emails per request
• Scheduled emails can be set up to 7 days in advance
• Attachments support base64 encoded content or URLs
• The from address must use a verified domain
• IMPORTANT: When piping curl output to jq or other commands, environment variables like $MATON_API_KEY may not expand correctly in some shell environments

Error Handling

Status	Meaning
400	Bad request or missing Resend connection
401	Invalid or missing Maton API key
403	Domain not verified or permission denied
404	Resource not found
422	Validation error (missing required fields)
429	Rate limited (2 req/sec)
4xx/5xx	Passthrough error from Resend API

Troubleshooting: API Key Issues

1. Check that the MATON_API_KEY environment variable is set:

echo $MATON_API_KEY

2. Verify the API key is valid by listing connections:

python <<'EOF'
import urllib.request, os, json
req = urllib.request.Request('https://api.maton.ai/connections')
req.add_header('Authorization', f'Bearer {os.environ["MATON_API_KEY"]}')
print(json.dumps(json.load(urllib.request.urlopen(req)), indent=2))
EOF

Troubleshooting: Domain Not Verified

To send emails, you must first add and verify a domain:

1. Create a domain: POST /resend/domains
2. Add the DNS records provided in the response
3. Verify the domain: POST /resend/domains/{id}/verify

Resources

• Resend API Documentation
• Resend Dashboard
• Maton Community
• Maton Support