activity-posthog

name	activity-posthog
description	Configures PostHog as the event source for Autoplay by adding the browser snippet, calling posthog.identify() with product_id, and setting up the PostHog webhook destination. The PostHog session ID is the scoping key used throughout the Autoplay integration. Use when the user mentions PostHog, posthog-js, posthog.identify, product_id, or asks how to capture user events for Autoplay.
disable-model-invocation	true

Activity Source — PostHog

Read autoplay-core first. The PostHog session_id is the session_id used for all session scoping throughout your Autoplay integration.

Step 1 — Add the browser snippet

import posthog from 'posthog-js'

posthog.init('YOUR_AUTOPLAY_API_KEY', {
    api_host: 'https://us.i.posthog.com',
    person_profiles: 'identified_only',
    session_idle_timeout_seconds: 120,
    loaded: (posthog) => {
        posthog.identify(posthog.get_distinct_id(), {
            product_id: 'YOUR_PRODUCT_ID',
        });
    },
})

---

Step 2 — Identify on login (highly recommended)

Run this immediately after your login flow completes:

posthog.identify(user.id, {
    product_id: 'YOUR_AUTOPLAY_PRODUCT_ID',
    email: user.email,  // optional but enables email-based session scoping
})

Without identify, users are tracked anonymously. session_id still works for scoping; user_id and email will be None on ActionsPayload until identity is set.

---

Step 3 — Session ID in your backend

# The session_id on every ActionsPayload is the PostHog session ID
# Retrieve it in browser:
#   posthog.get_distinct_id()   — stable user/device ID
#   posthog.get_session_id()    — current session ID (resets on idle)

# Guard for None before identity linking:
async def on_actions(payload):
    if not payload.session_id:
        return   # anonymous pre-identity event — skip or queue
    await agent_writer.add(payload)

---

Step 4 — PostHog webhook destination

In PostHog, add a Webhook destination:

• Webhook URL: result.webhook_url from onboard_product
• X-PostHog-Secret header: result.webhook_secret from onboard_product

Or message #just-integrated in the Autoplay Slack for managed setup.

---

Step 5 — Verify the webhook is firing

After setting up the destination in PostHog, trigger a page event in your app and check the PostHog destination logs (PostHog → Data pipelines → your webhook destination → Logs). You should see a 200 response within a few seconds.

If you see 401:

• Check that X-PostHog-Secret is copied verbatim (exact casing) — see Common mistakes below.

If you see no delivery at all:

• Confirm the destination is enabled and the filter is not excluding your events.

---

Common mistakes

X-PostHog-Secret header lookup is case-sensitive. PostHog delivers the secret in inputs.headers["X-PostHog-Secret"] (exact casing). Reading inputs.headers["x-posthog-secret"] or any other casing returns None and your webhook handler will return 401 on every request. Always copy the key name verbatim from the onboard_product response.

---

Reference

• Quickstart: https://developers.autoplay.ai/quickstart
• PostHog identify docs: https://posthog.com/docs/product-analytics/identify