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

# Overview

> Build your own support UI on top of Gleap — the Server-to-Server Conversations API

The Server-to-Server (S2S) Conversations API gives your backend headless access to Gleap conversations: create and read conversations, send messages as your end customer, drive bot workflows, upload files, and receive every change as an event — without the Gleap SDK or widget in your app.

```
Your app  →  Your backend  →  https://api.gleap.io/v3/s2s/…
```

It is an **access layer, not a separate product**: a conversation your backend opens is indistinguishable from one opened through the widget. The same inbox, the same agents, the same workflows, AI agents, routing rules and reporting apply — your support team changes nothing.

## The two planes

<CardGroup cols={2}>
  <Card title="REST" icon="server">
    Contacts, conversations, messages, workflows and uploads. Everything you write here is authored **as the end customer** — the key difference from the admin REST API, which always acts as a teammate.
  </Card>

  <Card title="Events" icon="bolt">
    A single Pusher-protocol **realtime stream** per backend instance (recommended) and/or HMAC-signed **webhooks**. Same event types, same envelope on both.
  </Card>
</CardGroup>

## Core concepts

* **Contacts are addressed by *your* user identifier** — `/v3/s2s/contacts/{userId}` — with no session handshake and no identity-verification hashing. Contacts deduplicate against SDK-created contacts on the same `userId`.
* **Conversation and message ids are opaque** (`cnv_…`, `msg_…`). Treat them as strings.
* **Event payloads are authoritative** for the conversation they carry; order and dedupe events by `(conversation id, sequence)`.
* **Recovery is per-conversation catch-up**, the same model the Gleap widget uses: re-pull a contact's conversation list and each conversation's messages (`?after=<last id you have>`) whenever your app opens the support screen or your consumer suspects a gap.

## Start here

1. [Authentication](/documentation/s2s/authentication) — create your token (2 minutes, self-serve).
2. [Quickstart](/documentation/s2s/quickstart) — the full conversation loop in six requests.
3. [Realtime stream](/documentation/s2s/stream) — the recommended event channel; [Webhooks & events](/documentation/s2s/webhooks) covers the catalog, envelope and signatures.