ThinkRail

ThinkRail is an open-source agentic IDE from a JetBrains incubator project (InnovationHub), built around the open-source pi coding agent. Its tagline: "the agentic IDE that gets better every time you use it."

It is open source under Apache-2.0 (GitHub JetBrains/thinkrail, TypeScript). The repo was created in July 2026 and introduced on the official blog on August 19. It now has about 1,200 stars and 88 forks, the latest build is v0.3.0-nightly.6 (October 25, 2026), and it newly appeared on GitHub's daily trending list in this scan.

Its philosophy is "automated agent orchestration backed by strict human gatekeeping" rather than fully autonomous software engineering.

Key features

• Isolated workspaces: each workspace is a real git worktree with its own branch, directory, terminals and chats, so several agents can work in parallel; merge the good branch and delete the rest
• A real IDE around the agent: splittable Monaco editor tabs, a file tree with live git change marks, terminals and diffs; leave anchored review comments on files and diffs and send them to a chat as structured context
• Streaming chats: several concurrent pi sessions per workspace, each with its own model and live token/cost readout; steer a running turn, queue follow-ups, delegate to subagents and co-edit a shared plan
• Specs as ground truth: a connected graph of SPEC.md files lives beside the code, and the agent reads, searches and maintains it with dedicated spec_* tools so intent survives the session
• Skills and workflows: reads the Agent Skills you already keep for other coding agents; bundled workflows for project setup, design brainstorming and shipping a PR
• MCP servers: asks in the chat before calls that are not marked read-only; OAuth sign-in from Settings
• GitHub integration: branch and PR status, CI checks and review decision, one-click push, open PR or merge
• Your own credentials: sign in with JetBrains AI or connect any provider through pi's own auth; ThinkRail has no accounts of its own

Architecture

A thin host around a real engine: the pi agent runs in-process and owns models, skills, compaction and cost; ThinkRail owns the workspace, the editor and the wire, and never assembles prompts behind your back.

Install and get started

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

• Desktop builds for macOS (Apple Silicon), Windows x64 and Linux (x64 / ARM64) are on thinkrail.ai
• Open a Git repository as a project, cut isolated worktree workspaces and start agent sessions
• Update with thinkrail update, remove with thinkrail uninstall; choose --channel stable|nightly

Who it's for

• Developers already using the pi coding agent who want a visual interface
• Teams running several AI coding tasks at once who still want every step reviewable and reversible

Website: thinkrail.ai · Blog: thinkrail.ai/blog