y

https://github.com/user-attachments/assets/24f10277-bb0e-4c3f-8a05-6833363d07a2

y is a malleable desktop coding-agent app.

It is built around a simple idea: software should become malleable while you use it. The main interface is a chat, but the app can reshape its own UI through a protected Modify surface. You can ask y to change how y itself works, keep the change if it renders safely, or roll it back if it does not.

y is not a new agent model. It is a local, chat-first workspace for the coding agents you already use: Claude Code, OpenAI Codex, and other CLI-native agents over time.

Things to try

• Run Claude Code and Codex side by side from one desktop app.
• Start separate chats in isolated workspaces so agents can work in parallel without touching the same checkout.
• Ask Modify to change y's interface live, then review the generated diff before keeping it.
• Add or adjust app UI controls, layout, copy, and local workflow affordances through Modify.
• Open the file tree, terminal, and diff views while an agent is working.
• Revert a Modify change if the new UI is not what you wanted.

What Modify is

Modify is the part of y that edits y itself. It is a separate chat focused on changing the app interface, not your project code. The change still goes through code and diff review: Modify edits the local Userland UI, y renders it, and you choose whether to keep or revert it.

Modify is not meant to control the protected app core. It should not get access to auth/session internals, analytics controls, privileged host APIs, or the Modify system itself. Those boundaries live in the protected Kernel.

Why y exists

Most coding-agent apps are fixed products. You can use them, configure them, maybe install plugins, but the product itself still belongs to someone else.

y is different. It treats the app as malleable software:

• Chat first. The default surface is a focused conversation, not an editor clone.
• Self-modifying. The Modify rail can edit the live Userland UI while the protected Kernel stays locked.
• Local agents. Claude Code and Codex run as official local CLIs with the user's own login.
• Parallel work. Chats can use isolated workspaces so agents can work in parallel without stepping on the same files.
• Diff-gated changes. UI changes compile, render, show a diff, and can be kept or discarded.
• Rollback built in. The app keeps known-good snapshots so broken UI changes can recover.

How it works

y is split into two parts:

This split lets y feel self-modifying without giving the modification agent control over the protected core. The app can change its own interface, but the Kernel still owns the trust boundaries.

Claude Code and Codex

y runs coding agents locally instead of proxying them through a hosted account.

• Claude Code uses the official Claude Code CLI.
• Codex uses the official Codex CLI.
• Model and effort settings stay visible in the composer.
• Multiple chats can run against different engines.
• Isolated workspaces let parallel agents work without interfering with each other.

The user's local CLI auth remains the source of truth. y orchestrates the experience; it does not replace the agent providers.

Download

The latest macOS build is published on GitHub Releases:

Current release target: macOS Apple Silicon.

Development

cd app
pnpm install
pnpm dev

Useful checks:

pnpm typecheck
pnpm test:ui

Build a local macOS bundle:

pnpm build:mac

The generated app artifacts are written to app/dist/ and are intentionally not committed.

Privacy and analytics

y keeps the coding workflow local. Project files, terminal commands, and agent prompts are not sent to y's product analytics.

Product analytics are for app usage health: sign-in state, feature usage, feedback, and missing-brick requests. Missing-brick reports are structured and should describe the missing capability, not the user's private prompt or source code.

Status

y is under active development. The current focus is launch-readiness for macOS: packaging, auth, analytics, local app-state durability, and the self-modifying Modify workflow.

License

MIT. See LICENSE.