bb

bb is an agentic IDE that can control itself. You can seamlessly orchestrate all of your favorite coding agents together and have them programmatically use bb too.

Every surface — the web app, CLI, and HTTP API — is a first-class way to drive bb. Work runs in threads you can follow live, steer at any point, or hand off to another agent.

Note

bb is in active development. Core architecture is stable, but workflows and surfaces are still evolving.

Use bb

npx bb-app@latest

Then open http://localhost:38886.

bb uses the provider CLI you already have authenticated.

For install requirements, provider setup, configuration, and package-focused docs, start with packages/bb-app.

Repository Overview

This monorepo contains the packaged app plus the runtime services it bundles:

Package or app	Role
packages/bb-app	Published npm package and npx bb-app@latest launcher.
apps/app	Web UI for inspecting projects, threads, environments, and running work.
apps/server	HTTP API, WebSocket notifications, state management, and server-owned product policy.
apps/host-daemon	Host-local runtime that provisions workspaces and runs provider processes.
apps/cli	Scriptable bb CLI for users and agents.
packages/server-contract	HTTP and WebSocket contract between clients and the server.
packages/host-daemon-contract	Command/event contract between the server and host daemons.

Development

Use the development loop when working on bb itself:

pnpm dev

That starts the Vite app and proxies API and WebSocket traffic to a separate dev server. The launcher prints the actual ports at startup. Each checkout gets a data directory under ~/.bb-dev/<checkout-instance>/ and deterministic high ports derived from the checkout path. The checkout instance id is the sanitized path to the checkout, relative to your home directory, plus a short hash suffix. Separate worktrees can run alongside each other and the packaged npx bb-app@latest instance.

Development behavior is intentionally split:

• the app hot reloads itself
• the server does not hot reload
• the host daemon does not hot reload

When you want the server and host daemon to pick up the latest build output, use:

pnpm dev:restart
pnpm dev:restart-server
pnpm dev:restart-host-daemon

These rebuild first, then restart only the targeted stateful services.

To test the release-style package launcher from a source checkout:

pnpm start

That builds the local bb-app package artifacts and runs packages/bb-app/dist/bb-app.js, matching the published npx bb-app@latest path without downloading from npm.

To test an additional host against that dev server, use:

BB_HOST_DAEMON_PORT=39999 pnpm dev:host-daemon -- --auto-join

That runs a second host daemon against the dev server and stores its state under the current checkout's dev data directory. The extra daemon requires an explicit unused BB_HOST_DAEMON_PORT so it does not collide with the primary dev daemon. On first run, it requests local enrollment from the dev server; after enrollment, the daemon persists its auth state locally.

pnpm bb --help            # built CLI, targets the default/prod instance
pnpm reset                # clear production state

pnpm bb:dev --help        # source CLI, targets this checkout's dev instance
pnpm reset:dev            # clear this checkout's dev state

pnpm reset:all            # clear both production and dev states

These reset commands prompt for confirmation before deleting anything.

System Overview

The runtime pieces

Component	Role
Server	Central hub. Stores all state in a SQLite database, exposes an HTTP API, and pushes change notifications over WebSocket. Stateless itself — the DB is the source of truth. Routes work to hosts by queuing commands.
Host daemon	Runs on each host (your laptop or a remote server). Connects to the server, picks up commands, provisions workspaces, runs agent provider processes, and streams events back. Exposes a local HTTP API for the app and CLI to do machine-local things (open editor, pick folders, check daemon status).
App	Web UI for inspecting projects and threads, following progress, and steering work.
CLI (bb)	First-class interface for both users and agents. Same capabilities as the app, scriptable.

Data model

The core entities and how they relate:

Project — the top-level container, usually mapped to a repository. A project has one or more sources that say where its code lives: local paths on specific hosts.

Thread — the unit of work. Each thread tracks a conversation with an agent provider, has lifecycle state, and produces an append-only stream of events (messages, tool calls, file changes, etc.). Threads can be standard (does work directly) or manager (coordinates other threads). Threads can own child threads for delegation.

Environment — the execution context for a thread. It binds a workspace (a directory on disk) to a host. An environment can be unmanaged (point at an existing directory), or managed. Environments managed by bb will be cleaned up when there are no longer any unarchived threads using it. Multiple threads can share an environment.

Host — a long-lived machine that runs a daemon, such as your laptop or a remote server.

Commands and events — the server talks to daemons by queuing commands (provision an environment, start a thread, stop a thread). Daemons report back by posting events. This is an asynchronous command/event protocol — the server queues work, the daemon picks it up, results flow back as events.

Contracts and boundaries

Two contract packages define the boundaries between components:

@bb/server-contract — the HTTP + WebSocket API between clients (app, CLI) and the server. Route schemas, request/response types, WebSocket notification types.

@bb/host-daemon-contract — the protocol between the server and host daemons. Command types, event types, session lifecycle, the local API for app/CLI.

Implementation packages never import across these boundaries. The server doesn't know how workspaces are provisioned. The daemon doesn't know about threads or projects beyond what commands tell it.

Further Reading

• Vision
• Platform support
• Configuration
• Using bb on multiple devices
• Adding another host
• Worktrees and setup scripts

Contributing

The most useful contributions are feature requests and bug reports. If you run into something broken, confusing, or missing, open an issue with the workflow you were trying to accomplish and what happened instead.