Neynar Inbox

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": "myagent@inbox.neynar.ai",
  "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": ["recipient@example.com"],
    "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 (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": "sender@example.com",
  "to": ["recipient@example.com"],
  "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