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

# Session Storage

> Store user sessions at the edge with Telnyx KV and expire them with a server-side TTL.

Store user sessions at the edge and expire them after a day. This uses the [KV binding](/docs/edge-compute/kv/quick-start#path-a-the-function-binding) (bound as `MY_KV`) with a **server-side TTL**: pass `expirationTtl` on the write and KV deletes the session automatically once it elapses. Each write renews the TTL, so an active session slides forward and an abandoned one expires. Requires `@telnyx/edge-runtime` ≥ 0.2.2.

```ts theme={null}
import { env } from "@telnyx/edge-runtime";

const SESSION_TTL = 86_400; // 24 hours

interface Session {
    created: number;
    views: number;
}

export async function handler(request: Request): Promise<Response> {
    const sessionId = request.headers.get("X-Session-ID");
    if (!sessionId) {
        return new Response("Missing X-Session-ID", { status: 400 });
    }
    const key = `session/${sessionId}`;

    // Read session (null if missing or expired)
    const existing = await env.MY_KV.get<Session>(key, { type: "json" });
    const data = existing
        ? { ...existing, views: existing.views + 1 }
        : { created: Date.now(), views: 0 };

    // Store with a 24h server-side TTL — renewed on every write
    await env.MY_KV.put(key, JSON.stringify(data), { expirationTtl: SESSION_TTL });

    return new Response(JSON.stringify(data), {
        headers: { "Content-Type": "application/json" },
    });
}
```

<Note>
  Non-TypeScript functions get the same behavior with the `ttl_secs` parameter on a [REST API write](/docs/edge-compute/kv/quick-start#path-b-the-rest-api). If you need to inspect *when* a session expires, use the application-level envelope instead — see [Key Expiration](/docs/edge-compute/kv/ttl-and-metadata).
</Note>