# Introduction

Chaser gives you on-demand cloud machines and browsers through a single API. Every session is a real Linux microVM with full isolation -- not a container, not a shared runtime. Machines boot in seconds, run anything you need, and clean up when you are done.

## Two session types

**Browser sessions** spin up a real Chromium instance inside its own VM. You get a standard Chrome DevTools Protocol (CDP) endpoint that works with Playwright, Puppeteer, or any CDP client. The browser behaves like a real desktop Chrome installation because it is one.

**Sandbox sessions** spin up a general-purpose Linux environment. You get a PTY shell, HTTP command execution, file transfer, port forwarding, and persistent workspace storage. Use it for development, CI, agent runtimes, or anything that needs a real machine.

## How it works

Every session runs inside a dedicated microVM with its own kernel. Sessions are identified by a UUID and expose control endpoints for programmatic access. Optionally, you can attach sessions to **workspaces** for persistent filesystem storage that survives across session restarts.

```
You (API / CLI / SDK / MCP)
    |
    v
POST /v1/sessions { session_type: "sandbox", workspace: "my-project" }
    |
    v
Chaser boots a microVM, attaches your workspace disk, returns endpoints
    |
    v
You connect: shell into it, run commands over HTTP, automate via CDP, or use MCP tools
```

## Ways to interact

| Surface | Best for |
|---------|----------|
| **REST API** | Full programmatic control over sessions, workspaces, execution, files, and billing |
| **CLI** | Interactive shell access, file transfer, local port forwarding |
| **TypeScript SDK** | Type-safe session and workspace automation in Node.js |
| **Python SDK** | Session and workspace automation in Python |
| **MCP** | Agent-friendly tool interface -- `terminal` for sandboxes, `browser` for automation |
| **SSH** | Direct shell access to sandbox workspaces over standard SSH |
| **Web Dashboard** | Visual session management and browser session viewing |

## Key capabilities

- **Ephemeral or persistent** -- create throwaway sessions for CI, or attach workspaces for durable state
- **Browser automation** -- CDP-compatible Chromium with residential proxy support
- **Command execution** -- interactive PTY, HTTP exec, background commands with streaming output
- **File operations** -- upload, download, and structured filesystem editing via MCP
- **Port forwarding** -- expose guest services through direct URLs or local reverse proxy
- **Workspaces** -- named persistent disks with snapshots, templates, cloning, and GitHub import
- **Teams** -- organization accounts with role-based membership, service accounts, and scoped API keys
- **Jobs** -- queued execution with scheduling, pipelines, and built-in worker kinds
- **Webhooks** -- lifecycle event notifications for session and workspace changes
- **Audit** -- account-scoped event log for governance and observability
- **MCP** -- JSON-RPC tool surface for AI agent integration with auto-provisioning

## CHASM

CHASM is Chaser's assistant runtime layer. It lets you create managed AI assistants that use the same `terminal` and `browser` tools through Chaser's MCP surface, with Chaser handling authentication on behalf of signed-in users. Assistants can bind to external channels (Telegram, Discord), store credentials securely, and maintain persistent runtime state.

## Next steps

- [Quickstart](/docs/overview/quickstart) -- create your first session in under a minute
- [Core Concepts](/docs/overview/core-concepts) -- understand sessions, workspaces, and accounts
- [REST API Reference](/api-reference/overview/rest-api-overview) -- full endpoint documentation