Documentation

Quick Start

From signup to your first 201 Created with zero DNS setup. Your first send works immediately for an account created with a real email address; emailing other people adds one domain step.

1. Create an account at aisend.app/signup to start your 3-day free trial (no card). AI agents: POST /api/v1/auth/agent-signup returns a key, but an agent account's address cannot receive mail, so skip the test send in step 3 and go to step 4 — an agent must verify a domain before any send
2. Click the link in the verification email — sending is blocked until you do
3. Copy your API key (format re_*) and send your first email now — from onboarding@aisend.app to your own account email. It works with no DNS setup. Sends to anyone else from that address are refused
4. To reach your users, add and verify your sending domain (one DNS step; 1 included in the trial), then send from you@yourdomain.com to anyone

# Resend
- https://api.resend.com/emails
# AISend (same body, same Bearer auth)
+ https://api.aisend.app/emails

Installation

npm install aisend-email

pnpm add aisend-email

yarn add aisend-email

Send Your First Email

import { AISend } from 'aisend-email';

const aisend = new AISend('re_your_api_key');

// Works on your first call — no domain setup. Sends to your own inbox.
const { id } = await aisend.emails.send({
  from: 'onboarding@aisend.app',
  to: 'you@youraccount.com',  // your account email on the shared address
  subject: 'Hello from AISend',
  html: '<p>Your first email!</p>',
});

console.log('Queued:', id);

// To email your users, verify your domain (1 included in the trial) and send from it:
//   from: 'you@yourdomain.com', to: anyone

# Works on your first call — no domain setup. Sends to your own inbox.
curl -X POST https://api.aisend.app/api/v1/emails \
  -H "Authorization: Bearer re_your_api_key" \
  -H "Content-Type: application/json" \
  -d '{
    "from": "onboarding@aisend.app",
    "to": "you@youraccount.com",
    "subject": "Hello from AISend",
    "html": "<p>Your first email!</p>"
  }'

import requests

# Works on your first call — no domain setup. Sends to your own inbox.
response = requests.post(
    "https://api.aisend.app/api/v1/emails",
    headers={
        "Authorization": "Bearer re_your_api_key",
        "Content-Type": "application/json",
    },
    json={
        "from": "onboarding@aisend.app",
        "to": "you@youraccount.com",
        "subject": "Hello from AISend",
        "html": "<p>Your first email!</p>",
    },
)

print(response.json())

REST API Reference

Base URL: https://api.aisend.app (use /emails or /api/v1/emails)

Authorization: Bearer re_your_api_key

{
  "from": "hello@yourdomain.com",     // Required. An address on a domain you verified
  "to": "user@example.com",         // Required. String or array of strings
  "subject": "Email subject",       // Required
  "html": "<p>HTML body</p>",       // html or text required
  "text": "Plain text body"         // html or text required
}

{
  "id": "5212c581-d1ac-433f-a8f4-7d710240ec9c"
}

Idempotency-Key: unique-request-id-123

Custom Domains

To send from your own domain, add it in the dashboard and configure DNS records. AISend automatically generates SPF and DKIM records. Verification runs when you press Verify (or call the verify endpoint) and succeeds once the records are visible in public DNS; how long that takes depends on your DNS host. A newly verified domain has a low daily sending cap that rises over its first week.

Webhooks

Receive real-time delivery events via HTTP webhooks. Configure endpoints in the dashboard.

{
  "type": "email.delivered",
  "data": {
    "email_id": "5212c581-d1ac-433f-a8f4-7d710240ec9c",
    "to": "user@example.com",
    "timestamp": "2026-03-21T00:00:00.000Z"
  }
}

Email Validation

Validate email addresses before sending to reduce bounces.

// Request
{ "email": "user@example.com" }

// Response
{
  "email": "user@example.com",
  "valid": true,
  "checks": {
    "format": true,
    "mx": true,
    "disposable": false,
    "role": false
  },
  "risk": "low"
}

AI Agent Signup

AI agents can create an account and get an API key with a single request — no browser or email verification needed. The agent's @agent.aisend.app address cannot receive mail, so it must add and verify a domain it controls (POST /api/v1/domains, then POST /api/v1/domains/:id/verify) before its first send.

// Request
{ "name": "My AI Agent" }

// Response
{
  "token": "eyJhbG...",
  "apiKey": "re_abc123...",
  "userId": "550e8400-...",
  "email": "my-ai-agent-a1b2c3@agent.aisend.app",
  "expiresAt": "2027-03-21T00:00:00.000Z"
}

Use the returned apiKey as a Bearer token. Agent accounts start on the 3-day free trial (500 emails, no credit card); after that, sending requires a paid plan.

MCP Server (Claude Integration)

Give Claude Desktop, Claude Code, or any MCP-compatible AI assistant the ability to send emails, check delivery status, validate addresses, and manage API keys — all through natural language. Works with Claude Code, Cursor, Claude Desktop, and other MCP clients that run local (stdio) servers.

claude mcp add aisend -e AISEND_API_KEY=re_your_api_key -- npx -y aisend-mcp

{
  "mcpServers": {
    "aisend": {
      "command": "npx",
      "args": ["-y", "aisend-mcp"],
      "env": { "AISEND_API_KEY": "re_your_api_key" }
    }
  }
}

{
  "mcpServers": {
    "aisend": {
      "command": "npx",
      "args": ["-y", "aisend-mcp"],
      "env": { "AISEND_API_KEY": "re_your_api_key" }
    }
  }
}

Error Handling

AISend uses standard HTTP status codes. Error responses include a JSON body with an error field.