shelley

Getting started

What is Shelley?

An open source coding agent that you run yourself and use from a browser tab.

.md

Shelley is a coding agent. You tell it what you want; it gets there by running shell commands, editing files, driving a browser, and showing you its work as it goes. It is one binary that serves a web UI, so the place you use it is a browser tab, on your laptop or your phone. Ask it to fix a bug, build a web site, set up and run some software (say, a Marimo notebook on port 8000), or go read something on the web, and anything in between.

It is mobile-friendly, web-based, multi-conversation, multi-modal, multi-model, and single-user. It was built for exe.dev, where it comes running on every VM, but it isn’t exclusive to it: it runs anywhere you can run a macOS or Linux binary.

The shape of it

  • One process, one user. shelley serve starts a web server and keeps everything in a SQLite database. There are no accounts and no sandbox; it runs commands as you. Read Running it safely before you expose it to anything.
  • Many conversations. Each conversation is its own agent, with its own model and working directory. Run several at once. See Conversations.
  • Tools that do things. A shell, precise file patches, a headless browser, subagents, and more. See Tools.
  • Any model you like. Anthropic, OpenAI, Gemini, Fireworks, and custom OpenAI-, Anthropic-, or Gemini-compatible endpoints. See Models and API keys.
  • Yours to bend. Guidance files (AGENTS.md), skills, MCP servers, and hooks. Or ask Shelley to change its own source; it rebases your changes onto each new release.

Getting going

  1. Install it. One binary, or Homebrew, or from source.
  2. Give it a model. An API key in the environment is enough.
  3. Run shelley serve and open the tab.

No keys, no install? Shelley is already running on every exe.dev VM, behind exe.dev’s auth, with models included. Try it.

Where it came from

Shelley grew out of Sketch, an earlier coding agent from the same people. Unsurprisingly, much of Shelley is written by Shelley, Sketch, Claude Code, and Codex. It’s Apache-2.0 licensed and on GitHub. For the name and the logo, see the FAQ.