> ## Documentation Index
> Fetch the complete documentation index at: https://developers.autoplay.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Identity

> The one rule that makes live activity work for any AI agent and any activity source: the user_id the agent sends must equal the id activity was stored under.

Everything in [Live user activity](/activity/overview) hinges on one rule:

> **The `user_id` an agent sends must equal the `user_id` activity was stored under** — the stable id your **activity source** identifies the user with.

Activity is keyed by that id. If an agent asks for a different value (an email, a support agent contact id, an anonymous session id), it reads the wrong bucket — or an empty one — and the user looks inactive even though they've been clicking around.

<Note>
  **The id depends on your activity source.** Autoplay is source-agnostic — the source set grows over time:

  | Source        | The stable user id                                                    |
  | ------------- | --------------------------------------------------------------------- |
  | **PostHog**   | the id you pass to `posthog.identify(user_id, …)` (the `distinct_id`) |
  | **Amplitude** | the Amplitude `user_id` set on events                                 |
  | *others*      | whatever stable id that source stamps on events                       |

  Whichever source you use, the rule is the same: the agent must send **that** id.
</Note>

## 🧩 The three layers that must agree

```
1. your activity source identifies the user   ← PostHog identify / Amplitude user_id / …
2. the connector's activity store              ← keyed by that same id
3. the id your AI agent sends                  ← must equal layer 1
```

Layers 1 and 2 line up automatically — the connector stores activity under the stable id your source sends. The work is making **layer 3** carry that exact value.

<Warning>
  Use a **stable user id** — your internal user primary key, the same one your activity source identifies with. Do **not** key on **email**: emails change, and activity is stored under the stable id, so an email lookup reads the wrong bucket.
</Warning>

## 🤝 How each agent satisfies layer 3

Every agent has its own way of passing a trusted identity to the connector. The mechanism differs per agent; the required *value* is always the same (your activity source's stable user id).

| Agent                        | How it passes identity                                                                                                                                                                                                                                      |
| ---------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Intercom Fin**             | Messenger **JWT identity verification** — sign a JWT carrying the user id and boot the Messenger with it. See [the Intercom Fin recipe → Verify identity](/recipes/intercom-tutorial/step-1-connect-real-time-events#verify-identity-with-a-messenger-jwt). |
| *Other agents (Maven, etc.)* | Their own verified-identity mechanism — bind it to the same stable user id.                                                                                                                                                                                 |

<Note>
  For **anonymous** (not-logged-in) users there's no trusted identity to pass, so an agent can't reliably pull their activity. This surface is designed for **logged-in** users your source has identified.
</Note>

## 🛟 Debugging "no recent activity"

Almost always an identity mismatch. Confirm the **same** value appears in all three places:

1. the id your activity source identifies the user with (e.g. PostHog `identify`, Amplitude `user_id`),
2. whatever your agent uses as its verified identity (e.g. Fin's JWT `user_id` claim),
3. the `{user_id}` the agent actually sends to the endpoint / MCP tool.

For where identity is set on the source side, see your source's setup — e.g. the [Quickstart](/quickstart) covers `posthog.identify`.