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

# Sessions and capabilities

> The handshake: initialize, manifest exchange, negotiation, and session.ready.

A session is the negotiated contract binding an agent to an embodiment in a world.

```mermaid theme={null}
sequenceDiagram
    participant A as Agent
    participant W as World
    A->>W: initialize {agent manifest, versions}
    W-->>A: world manifest {embodiments, channels, actions, time models, safety}
    A->>W: session.open {embodiment, mode, subscriptions, requested grants}
    W-->>A: session.ready {granted subset, stream endpoints, frame tree, clock anchor}
```

The **world manifest** is what makes AWP worlds self-describing: a generic agent discovers at runtime what bodies exist, what it can perceive, and what it can do — the same way an MCP client discovers tools. The **agent manifest** declares supported modalities and protocol versions so the world can tailor or reject.

Negotiation always resolves to a subset: the world MAY grant fewer channels, action types, or looser rates than requested, and MUST say exactly what was granted in `session.ready`. Renegotiation mid-session uses the same messages. Normative rules: [session lifecycle](/spec/session/lifecycle) and [negotiation](/spec/session/negotiation).