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Identify users to link their sessions and track authenticated user behavior.

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Why identify users?

  • Link sessions - Connect multiple sessions from the same user
  • Track user journey - See the complete user journey across sessions
  • Revenue attribution - Link payments to users via email
  • User analytics - See behavior by user segment

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How it works

When a user logs in, identify them with PostMetric: 
postMetric("identify", {
  userId: "user_123",
  email: "user@example.com",
  name: "John Doe",
});
This links all future sessions to this user.

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Implementation

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When user logs in

async function handleLogin(email, password) {
  const user = await login(email, password);

  // Identify user with PostMetric
  if (window.postMetric) {
    window.postMetric("identify", {
      userId: user.id,
      email: user.email,
      name: user.name,
    });
  }

  return user;
}

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React example

function LoginButton() {
  const handleLogin = async () => {
    const user = await login();

    if (typeof window !== "undefined" && window.postMetric) {
      window.postMetric("identify", {
        userId: user.id,
        email: user.email,
        name: user.name,
      });
    }
  };

  return <button onClick={handleLogin}>Login</button>;
}

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Vue example

<script>
export default {
  methods: {
    async handleLogin() {
      const user = await this.login();

      if (window.postMetric) {
        window.postMetric("identify", {
          userId: user.id,
          email: user.email,
          name: user.name,
        });
      }
    },
  },
};
</script>

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Server-side identification

You can also identify users server-side using the API: 
curl -X POST https://your-domain.com/api/identify \
  -H "Content-Type: application/json" \
  -d '{
    "site": "YOUR_TRACKING_CODE",
    "userId": "user_123",
    "email": "user@example.com",
    "name": "John Doe",
    "visitorId": "visitor_456",
    "sessionId": "session_789"
  }'

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Revenue attribution

When user identification is enabled, payments can be linked to users via email matching:
  1. User is identified with email user@example.com
  2. Payment is made with customer email user@example.com
  3. Payment is automatically linked to the user

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View user data

Once users are identified, you can:
  • See user journey across sessions
  • Track user lifetime value
  • Analyze behavior by user segment
  • Link revenue to specific users

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Privacy

User identification is optional. You can use PostMetric without identifying users. When users are identified, their data is stored securely and only accessible to you.

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Next steps

Connect payment providers

Learn how to link revenue to identified users