bb plugin atlas

This site explains how bb plugins work and documents every surface a plugin can occupy. bb (getbb.app) is an open “agentic IDE that builds itself”. It runs as a Node server with SQLite as the source of truth, a host daemon on every executor machine, a client application (web, Electron, mobile) and the bb CLI. Almost everything visible in its interface and almost everything its agent does is a plugin on one public SDK, and that SDK is the subject of this site.

Reading path

Read the first four pages in order. Each one builds on the previous one, from bb as a whole down to the code of one plugin.

1. How bb works: the three processes and the objects bb manages in them.
2. How a plugin works: the three entries, how they talk, where state lives, and what a reload does.
3. Your first plugin: scaffold a plugin, install it, use it from three places, change it.
4. Choosing a surface: from an idea to the surface that fits and a first-party plugin to read.

Then keep the reference open while you build. It is generated from a pinned release of bb, so a page either matches shipped code or fails the build:

• Surfaces: every place a plugin can appear or act.
• Frontend slots: the registration points an app entry reaches surfaces through.
• Backend namespaces: the members of the plugin API a server entry is handed.
• UI zone map: the same surfaces, numbered in place on the real window.

The pinned release

Version	@get-bb/plugin-sdk 0.4.104, application 0.43.3
Release	the shipped tag desktop-v0.43.3; every generated link on this site resolves against that commit
Contracts	packages/plugin-sdk/src/backend-contract.ts · app-contract.ts · host-contract.ts
Count	23 BbPluginApi members · 22 app.slots.* methods · 46 surfaces in 7 groups · 36 first-party plugins + 9 examples

Agents can read the whole site as text: /llms.txt, /llms-full.txt, any page at /<path>.md, and the brief corpus at /briefs.json.

How to read this

Every symbol on this site carries one of two status chips, and only these two carry a colored dot:

• stable, emerald: the name carries no prefix, and a breaking change would require a major version.
• experimental_, cobalt: the prefix is part of the name itself, and docs/api_to_audit.md lists what must be audited before it is dropped.

A card whose members are partly stable and partly prefixed carries both chips. A plain tag without a dot is a label, such as a member name, a slot kind or a surface role, and says nothing about stability.

Every name, path and number links to GitHub at the pinned commit, with the exact line where one is known. The links are generated from data/symbols.json, never typed by hand. Identifiers, paths, commands and bb’s own UI strings appear exactly as the repository writes them. Where the research could not confirm a fact, the text says not verified instead of guessing.

Agent brief buttons: what lands on the clipboard

Every surface, slot, namespace and advanced-point card carries three actions. Each one copies ready context for the agent that will write the plugin.

Button	What it puts on the clipboard	Where to paste it
Brief for agent	A Markdown brief: what the capability is, which entry it lives in, the exact registration call, the props type, the slot kind, stability, SDK symbols with paths and lines, which first-party plugin to read, the rules authors trip over, and acceptance criteria	any terminal agent (Claude Code, Codex, Cursor): paste it as the first message of the task
as a bb mention	Exactly the format the built-in Plugin Guide produces: text/plain with Build a plugin that uses @<Title>, plus text/html carrying data-prompt-mention. In the bb composer this becomes a real mention of the surface	the bb composer, as long as the plugin-api-docs plugin is enabled; otherwise plain text is pasted
add to set	Collects surfaces into a set; the panel in the bottom right copies one brief for several capabilities: shared scaffold, architecture, a block per capability, merged rules and a checklist	a plugin that does several things at once: one request instead of three

The set survives navigation and a page reload (localStorage). The “open in bb” links, including the one to the built-in Plugin Guide, point at a bb running on this machine (http://localhost:38886).