Technology5 min read

ThinkRail from JetBrains

By · Published by Everything Blog

In short

ThinkRail is an open-source agentic IDE that enhances development workflows by improving agent collaboration and project management. It supports multiple agents working in parallel, ensuring project integrity and project-specific tools. Available on macOS, Windows, and Linux, it can be installed via local launchers or PowerShell scripts.

Key points

  • ThinkRail enhances development workflows by improving agent collaboration and project man…: ThinkRail enhances development workflows by improving agent collaboration and project management.
  • It supports multiple agents working in parallel, ensuring project integrity and project-s…: It supports multiple agents working in parallel, ensuring project integrity and project-specific tools.
  • Available on macOS, Windows, and Linux, it can be installed via local launchers or PowerS…: Available on macOS, Windows, and Linux, it can be installed via local launchers or PowerShell scripts.

Sources checked by our analysis pipeline: 1

<!-- README.md -->

JetBrains InnovationHub Apache-2.0 open source

ThinkRail

The agentic IDE that gets better every time you use it.

Open a repo as a project. Cut isolated git-worktree workspaces. Pair with a real agent across Monaco tabs, terminals, and diffs — while your project's intent lives in a spec graph the agent actually reads.

ThinkRail runs on macOS, Windows, and Linux.

macOS

Browser UI via command line

Install the local launcher; run thinkrail

to open the browser UI.

curl -fsSL https://raw.githubusercontent.com/JetBrains/thinkrail/main/install.sh | bash

Windows

Browser UI via command line

Install the local launcher; run thinkrail

to open the browser UI.

PowerShell

irm https://raw.githubusercontent.com/JetBrains/thinkrail/main/install.ps1 | iex

Command Prompt (cmd)

powershell -c "irm https://raw.githubusercontent.com/JetBrains/thinkrail/main/install.ps1 | iex"

WSL

curl -fsSL https://raw.githubusercontent.com/JetBrains/thinkrail/main/install.sh | bash

Linux

Browser UI via command line

Install the local launcher; run thinkrail

to open the browser UI.

curl -fsSL https://raw.githubusercontent.com/JetBrains/thinkrail/main/install.sh | bash

<!-- WHY ThinkRail -->

Why ThinkRail

Agents deserve worktrees, not your working tree.

Every workspace is a real git worktree

— its own branch, its own

cwd. Run several agents in parallel; each one's mess stays on its branch, and

main

stays clean until you say otherwise.

Specs are the ground truth.

ThinkRail is built spec-first, and so are your projects: a connected graph of spec files lives beside the code, and the agent reads, searches, and maintains it with dedicated tools. Intent survives the session.

A thin host, a real engine.

The pi

coding agent

runs in-process and owns models, skills, compaction, and cost. ThinkRail owns

the workspace, the editor, and the wire — it never assembles prompts behind

your back.

<!-- FEATURES / worktrees -->

Projects → workspaces

A project is any local git repo. A workspace is a git worktree

cut from

it — created in one click, listed in the rail, disposable without ceremony.

# one repo, three parallel lines of thought

~/code/my-repo ← project

└─ ~/.thinkrail/worktrees/

├─ workspace-1 ⎇ feature/auth agent A building

├─ workspace-2 ⎇ fix/flaky-test agent B fixing

└─ workspace-3 ⎇ spike/ideas you, exploring

- Own branch + cwd per workspace — files, diffs, terminals, and chats all scope to it.

- Switch workspaces instantly; nothing reloads, nothing leaks across.

- Merge the good one, delete the rest. Your repo never noticed the chaos.

<!-- FEATURES / editor -->

A real IDE around the agent

Watch the agent work — or work beside it — without leaving the page.

Monaco editor tabs

The VS Code editor engine: syntax everywhere, rendered markdown with a source toggle, file tabs per workspace.

Files tree

The active worktree at a glance — like the rail on the right of this very page.

Changes

A live git diff of the workspace branch, so you review the agent's work as it lands.

Terminals

Real PTYs scoped to the worktree — run the tests yourself while the agent keeps typing.

<!-- FEATURES / agent-chat -->

Chats that stream like the engine thinks

This transcript is a real pi

session, captured in ThinkRail while it

worked on its own repo:

goal-and-requirements.md

· architecture.md

ThinkRail is the agentic IDE built around the pi

coding agent —

a thin host that runs pi

in-process and bridges it to a rich UI,

while pi

owns models, skills, compaction, cost, and session state.

The three rings:

- Engine host (

packages/server

) —createServer()

runs an HTTP+WS host plus anAgentSessionManager

: one in-processpi

session per tab. - The wire (

packages/contracts

) — the typed, versioned protocol between host and UI. Types only. - UI client (

apps/web

) — mobile-first React that ships independently and dials any host over the wire.

- Several sessions per workspace, streaming concurrently.

- Pick the model per session; tokens and cost tick live in the header.

- Steer a running turn or queue a follow-up — no waiting for the agent to finish.

- Interactive tools: the agent can ask structured questions back, right in the chat.

<!-- FEATURES / specs -->

Specs are first-class

Every module carries a SPEC.md

with frontmatter linking it into a graph —

goal, architecture, modules, tasks. The bundled pi-spec-graph

extension

gives the agent spec_*

tools to search, navigate, and maintain it, and

the Specs tab renders the live graph of your worktree:

---

id: module-server

type: module-design

status: active

parent: architecture

---

Plain markdown, plain frontmatter, versioned with the code — reading the specs is enough to understand an area and formulate the next task. The agent keeps them honest as it builds.

<!-- INSTALL.md -->

Install

Choose your platform and start working.

Linux: extract the archive, run ./installer

, and check the native library requirements.

Browser UI via command line

Install the local launcher, then run thinkrail

to open the browser UI.

curl -fsSL https://raw.githubusercontent.com/JetBrains/thinkrail/main/install.sh | bash

irm https://raw.githubusercontent.com/JetBrains/thinkrail/main/install.ps1 | iex

powershell -c "irm https://raw.githubusercontent.com/JetBrains/thinkrail/main/install.ps1 | iex"

Requires git

and an authenticated pi

provider. See all releases and advanced CLI options.

Original source: thinkrail.ai

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