---
title: What is a session
description: A session is one agent run bound to a cloud VM, tracked by the broker through a lifecycle from warm pool to release.
status: verified
sidebar:
  order: 1
---

A **session** is a single agent run bound to a cloud machine. When you start
one, the broker hands your chosen agent a fresh, isolated VM, connects your
integrations, and streams the work back to you — usually a Slack or Discord
thread.

## Lifecycle

The broker keeps a **warm pool** of machines so sessions start fast. Each
machine moves through a lifecycle:

```
bootstrapping → ready → claimed (active ⇄ idle) → dead
```

1. **Ready** — a provisioned VM waits in the warm pool.
2. **Claimed** — a request (from Slack, Discord, the web dashboard, or a
   [trigger](/sessions/guides/triggers/)) claims a ready VM; your org setup
   and the selected [personality](/sessions/concepts/harnesses-and-personalities/)
   are applied.
3. **Active / idle** — the agent works (`active`); between turns the claim
   sits `idle`. Idle timeouts eventually wind the session down and reclaim
   the machine.
4. **Dead** — ending a session (for example replying `!done` in the thread)
   releases the machine, and the pool is replenished.

Exact state names, the timeouts that drive them, and the resume contract are
in the [lifecycle reference](/sessions/reference/lifecycle/).

## What a session gives the agent

- An isolated cloud VM scoped to your org's [fleet](/sessions/concepts/fleets-and-providers/).
- Your selected **harness** (Claude Code, Codex, Gemini, or a custom agent)
  and model.
- Your connected [integrations](/sessions/guides/integrations/) and
  short-lived credentials.
- Durable [checkpoints](/sessions/concepts/checkpoints-and-resume/) so work
  survives the machine it ran on.

The point of a session is that none of this lives on your laptop — the agent
runs in the cloud, on your terms, and reports back.

## Next steps

- [Fleets, brokers & compute](/sessions/concepts/fleets-and-providers/) — where sessions run and who schedules them.
- [Session lifecycle reference](/sessions/reference/lifecycle/) — every state, timeout, and failure mode.
- [Quickstart](/sessions/start/quickstart/) — from signup to a working session.