Contacts let you maintain an audience within Posthawk. Each contact has an email, optional name, tags (string array), and arbitrary metadata (JSON).

Key features:

• Workspace-scoped — contacts are isolated per workspace
• Tags — organize contacts into groups (e.g. "newsletter", "beta-users")
• Send by tag — use the "tag" field in POST /v1/send to send to all contacts with that tag
• Unsubscribe — contacts with unsubscribed: true are automatically excluded from tag-based sends
• Upsert — creating a contact with an existing email updates the record
• Bulk import — import up to 1000 contacts at once

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Adding Contacts from Your Own Forms

You can collect contacts (newsletter signups, contact forms, waitlists, etc.) from any frontend by calling the Posthawk API with your API key.

Step 1 — Create an API Key

Go to Settings → API Keys in the Posthawk dashboard and create a new key with the "sending" scope. Copy the key (it starts with ck_live_ or ck_test_).

Step 2 — Build Your Form (HTML)

<form id="signup-form">
  <input type="email" name="email" placeholder="you@example.com" required />
  <input type="text" name="name" placeholder="Your name" />
  <button type="submit">Subscribe</button>
</form>

<script>
document.getElementById('signup-form').addEventListener('submit', async (e) => {
  e.preventDefault();
  const form = e.target;
  const res = await fetch('https://api.posthawk.dev/v1/contacts', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Authorization': 'Bearer YOUR_API_KEY',
    },
    body: JSON.stringify({
      email: form.email.value,
      name: form.name.value,
      tags: ['newsletter'],
    }),
  });
  if (res.ok) {
    form.reset();
    alert('Subscribed!');
  }
});
</script>

Step 3 — Server-Side (Node.js / Express)

For production use, call the API from your backend to keep your API key secret:

app.post('/subscribe', async (req, res) => {
  const { email, name } = req.body;

  const response = await fetch('https://api.posthawk.dev/v1/contacts', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/json',
      'Authorization': 'Bearer ' + process.env.POSTHAWK_API_KEY,
    },
    body: JSON.stringify({
      email,
      name,
      tags: ['newsletter'],
      metadata: { source: 'website-footer' },
    }),
  });

  if (response.ok) {
    res.json({ success: true });
  } else {
    const data = await response.json();
    res.status(400).json({ error: data.message });
  }
});

Step 4 — Using the TypeScript SDK

import { Posthawk } from 'posthawk';

const posthawk = new Posthawk('ck_live_...');

// Add a contact
await posthawk.contacts.create({
  email: 'user@example.com',
  name: 'Jane Doe',
  tags: ['newsletter', 'early-access'],
  metadata: { source: 'signup-page' },
});

// List contacts filtered by tag
const { data } = await posthawk.contacts.list({ tag: 'newsletter' });

To send to everyone carrying a tag, use the singular tag selector on the REST POST /v1/send endpoint (recipients are resolved from your contacts). Note: the SDK's emails.send() takes explicit to recipients — tag-based recipient resolution is a REST-API feature.

Contact Form with Subject & Message

To build a full contact form (not just email collection), store the subject and message in metadata:

await fetch('https://api.posthawk.dev/v1/contacts', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'Authorization': 'Bearer ' + apiKey,
  },
  body: JSON.stringify({
    email: 'visitor@example.com',
    name: 'Jane',
    tags: ['contact-form'],
    metadata: {
      subject: 'Partnership inquiry',
      message: 'Hi, I would like to discuss...',
      source: 'contact-page',
    },
  }),
});

You can then view all contact form submissions in the Posthawk dashboard under Contacts, filtered by the "contact-form" tag.

Tips

• Upsert behavior: If the email already exists in your workspace, the contact is updated (tags merged, metadata overwritten). No duplicates.
• Rate limiting: The API is rate-limited per API key. For high-traffic forms, add a CAPTCHA (like Cloudflare Turnstile) on your frontend.
• Unsubscribe: Set unsubscribed: true via PATCH /v1/contacts/:id to exclude a contact from tag-based sends.
• Bulk import: Use POST /v1/contacts/import to upload up to 1000 contacts at once from a CSV or database export.