Bonsai is a toolkit for building chat apps where conversations with an AI don't have to stay a single, linear thread.
Most AI chat apps force every conversation down one straight line: you ask, it answers, you ask again, and the whole history piles up in order. If you want to explore a tangent — "what if we tried a different approach?" — you either derail the conversation or start over from scratch and lose the context you'd already built up.
Bonsai lets a conversation branch. From any point in a chat, you can branch off to explore an idea, without disturbing the original thread. If the branch turns out useful, you can merge a summary of it back into the main conversation. If it's a dead end, you just abandon it — nothing about it leaks back in. And when a conversation (or a branch) produces something worth keeping long-term, you can distill it into a wiki page that future conversations can draw on, instead of re-explaining it every time.
Crucially, Bonsai never does any of this automatically behind your back. Branching, merging, and distilling are all actions your app's user explicitly takes — and at every step, Bonsai can show you exactly what information was assembled and sent to the model for a given reply, so "why did the AI say that?" always has a concrete answer.
Bonsai is not a finished chat app you install and open in a browser — it's a library that developers embed into their own product. If you're building a chat-based app (a support tool, a research assistant, an internal copilot) and want branching, mergeable context, and durable memory as building blocks, Bonsai gives you the underlying pieces — the tree/branch/merge/distill logic, plus swappable adapters for where you store data, which LLM you call, and how you search past knowledge — so you don't have to build that plumbing yourself.
Tree Model— every project starts as onemain
branch; branching off at any message creates a new branch that can be explored independently.ContextPacket— before (or instead of) sending a prompt to the model, you can inspect the exact packet of messages, merges, and wiki pages that would be included — no hidden retrieval step.Merge— land a reviewed summary of a branch back onto its parent branch, as an explicit, user-approved action.** Distill**— turn a branch or merge's transcript into a durable Markdown wiki page that later conversations can retrieve.** Wiki**— the durable, human-readable knowledge base distill writes into: plain Markdown files with frontmatter, easy to read, grep, or back up outside of Bonsai entirely.Retrieval— a pluggable interface for searching that wiki (full-text search out of the box; embeddings-based search can be swapped in later).
Read the Concepts pages or the docs site for the full explanation of each, or the Quickstart for a working example.
A Bonsai project, built on @bonsai/core
: the branch graph on the right shows main
with three branches (i-like-dogs
, i-like-hotdogs
, i-loke-motorb...
) explored independently, two of them already merged back with a reviewed summary and a one-click "Distill to Wiki" action, while the chat on the left only ever sees main
's own history plus what was explicitly merged into it:
Phase 1 scaffold. No package is published yet.
packages/
core/ # @bonsai/core — framework-agnostic domain (Storage/LLMProvider/WikiStore/Retriever interfaces)
storage-postgres/ # @bonsai/storage-postgres — Postgres migrations + repositories + FTS retriever
provider-openai/ # @bonsai/provider-openai — OpenAI-compatible chat/streaming provider
wiki-fs/ # @bonsai/wiki-fs — Markdown-on-disk WikiStore
server/ # @bonsai/server — thin optional HTTP layer
examples/ # example embedders (added in later phases)
-
Node
>=20.11.0 -
pnpm
9.15.4
(pinned viapackageManager
)
pnpm install # install workspace dependencies
pnpm typecheck # tsc -b across all packages via project references
pnpm build # build all packages that define a build script
pnpm test # run tests across the workspace
pnpm lint # ESLint (incl. `no-restricted-imports` boundary rules on packages/core)
pnpm depcruise # dependency-cruiser — forbid core -> adapter imports
pnpm boundary:verify # positive test: fixture must be rejected by lint + depcruise
pnpm publint # publint --strict per package (release gate)
pnpm attw # arethetypeswrong per package (release gate, ESM-only profile)
pnpm release:gate # build + publint + attw (run before publishing)
pnpm changeset # add a changeset entry for a release
pnpm changeset:status # show pending changesets
pnpm docs:dev # run the docs site locally (Astro Starlight)
pnpm docs:build # build the static docs site under docs/dist
pnpm docs:preview # preview a built docs site
Public documentation lives under docs/ as its own pnpm workspace package (
@bonsai/docs
, private), built with Astro Starlight. The API Reference is auto-generated from each package's src/index.ts
via TypeDoc + starlight-typedoc
. Landing page, quickstart, concept pages, and recipes are verified against the current @bonsai/*
API surface.@bonsai/core
is framework- and adapter-agnostic by contract. Two layers defend that boundary:
ESLint(scoped tono-restricted-imports
packages/core/**
) bansreact
,react-dom
,next/*
,tailwindcss
,pg
/postgres
/sqlite*
,fs
/node:fs
,net
, node http clients, and provider SDKs.dependency-cruiser forbidspackages/core → packages/{storage-*, provider-*, wiki-fs, server}
(both by resolved path and by@bonsai/*
module name).
pnpm boundary:verify
runs both tools against intentional violation fixtures under packages/core/src/__fixtures__/
and fails if either tool accepts them. CI runs it on every push/PR.