ARNO MCP server

ARNO — Agent Repository Navigation & Operations

The IDE for agents

ARNO gives coding agents what an IDE gives you, served over MCP. Read by symbol, edit against a known revision, get the compiler's diagnostics back with the edit, validate with the repository's own commands, see what changed, and revert to a checkpoint — each step one tool call, none of it through the shell.

Symbol-aware reading is how ARNO finds its way around; the transaction is what it is for. Where the shell is still the better tool, use it — the question ARNO has to answer is whether an agent gets more done, at acceptable cost, with it than without (docs/benchmark.md).

Half the tokens, more issues fixed. Claude Code on 12 real closed issues from cobra (Go), ky (TypeScript), requests (Python) and ripgrep (Rust), judged by each upstream fix's own hidden tests:

Not just a shorter tool list: against a shell trimmed to Bash, Read, Edit and Write, ARNO still used 18–25% fewer tokens and fewer turns, in two separate runs. Sonnet 5, one run per task, four languages — results and caveats · how to set it up.

Status: 0.0.11 shipped as Jade; 0.0.12 is the first release called ARNO — early, usable, and looking for feedback. Testing it? Start with the tester guide.

curl -fsSL https://raw.githubusercontent.com/julianbei/arno/main/install.sh | sh

For macOS and Linux — Windows isn't supported (here's why, and where to upvote). Run it again to update. Other ways to install.

Table of contents

• Trying ARNO: a guide for testers
• Why ARNO exists
• Install
• Configure your MCP client
• Use it in a container
• The tools
• Repository commands
• Language support
• Design principles
• When the shell is still the right tool
• What ARNO does not do yet
• Stability and versioning

Trying ARNO: a guide for testers

Thanks for testing. Half an hour gets you set up; the useful part is a week or two of your normal work with it switched on, and then telling us how it went — including if you turned it off.

1. Install ARNO and your language servers

macOS and Linux:

curl -fsSL https://raw.githubusercontent.com/julianbei/arno/main/install.sh | sh

Windows isn't supported, sorry! If you'd like it to be, please 👍 issue #2 or tell us there why it matters to you. (WSL 2 runs Linux, so the Linux build may work there, but we don't test it or take bug reports for it.)

Shortened. The full README is on GitHub.