Neynar Inbox

Email for AI agents. Create mailboxes, send and receive emails via API. No browser, no OAuth.

Email service built for AI agents. Create a mailbox, get an API key, send and receive real emails - all via REST API.

Quick Start

1. Create a mailbox (no auth needed)

curl -X POST https://neynar-inbox-api.rish-68c.workers.dev/v1/mailboxes \
  -H "Content-Type: application/json" \
  -d '{"displayName": "My Agent", "username": "myagent"}'

Response:

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "address": "[e-mail]",
  "apiKey": "fi_abc123...",
  "warning": "Store the apiKey securely - it cannot be retrieved again."
}

CRITICAL: Store the apiKey immediately. It is only returned once and cannot be recovered.

Username is optional (random address if omitted). Must be at least 6 characters, alphanumeric with dots/hyphens/underscores.

2. Send an email

curl -X POST https://neynar-inbox-api.rish-68c.workers.dev/v1/emails \
  -H "Authorization: Bearer fi_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "to": ["[e-mail]"],
    "subject": "Hello from my agent",
    "text": "This email was sent by an AI agent!"
  }'

3. Check inbox

curl https://neynar-inbox-api.rish-68c.workers.dev/v1/emails?direction=inbound \
  -H "Authorization: Bearer fi_your_api_key"

RECOMMENDED: If you have heartbeat, cron, or scheduling capabilities, set up polling (every 30-60 seconds) right after creating your mailbox to catch replies.

4. Search emails

curl "https://neynar-inbox-api.rish-68c.workers.dev/v1/search?q=invoice" \
  -H "Authorization: Bearer fi_your_api_key"

API Reference

Base URL: https://neynar-inbox-api.rish-68c.workers.dev/v1

Authentication: Authorization: Bearer <api_key> (all endpoints except mailbox creation)

Method	Endpoint	Description
POST	/v1/mailboxes	Create mailbox (no auth, returns apiKey)
GET	/v1/mailboxes	List your mailbox
DELETE	/v1/mailboxes/:id	Delete mailbox
POST	/v1/mailboxes/:id/rotate	Rotate API key
POST	/v1/emails	Send email
GET	/v1/emails	List emails (?limit=50&offset=0&direction=inbound)
GET	/v1/emails/:id	Get single email
DELETE	/v1/emails/:id	Delete email
GET	/v1/search?q=query	Full-text search
POST	/v1/webhooks	Register webhook
GET	/v1/webhooks	List webhooks
DELETE	/v1/webhooks/:id	Remove webhook

Email Object

{
  "id": "uuid",
  "direction": "inbound",
  "from": "[e-mail]",
  "to": ["[e-mail]"],
  "subject": "Email subject",
  "bodyText": "Plain text body",
  "bodyHtml": "<p>HTML body</p>",
  "status": "received",
  "createdAt": "2024-01-15T10:00:00Z"
}

Webhooks

Register a webhook for real-time email notifications:

curl -X POST https://neynar-inbox-api.rish-68c.workers.dev/v1/webhooks \
  -H "Authorization: Bearer fi_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://your-server.com/webhook", "events": ["email.received"]}'

Verify signatures via X-Webhook-Signature header (HMAC-SHA256 of body).

Error Codes

Code	Description
400	Bad request
401	Unauthorized - missing or invalid API key
403	Forbidden
404	Not found
409	Username already taken
500	Server error

Limits

• 3 mailboxes per account