Tiny, and held there
About 3 MiB and 2 ms to start, measured on every run against a ceiling of 8 MiB and 5 ms. A build fails when either is crossed, and the argument and configuration paths never load the agent runtime.
Apache-2.0 · open source · native, no runtime
A tiny coding agent
harness in Rust.
About 3 MiB and 2 ms to start, with a build that fails if either grows. Ask where a limit came from and it names the file that set it.
$
brew install aadixc0de/tap/rune
$
git clone https://github.com/AadiXC0DE/Rune && cd Rune && cargo build --release
$
cargo install --git https://github.com/AadiXC0DE/Rune rune
rune is taken in Homebrew core by an unrelated language, so the tap is named explicitly. Then connect a provider, because a fresh install has none.
rune doctor
$ rune doctor
rune 0.1.0
ok workspace /Users/you/project
ok state root ~/.local/state/rune
ok configuration every layer parsed
? provider no provider connected
run 'rune connect' to choose one
ok sandbox seatbelt restricts every command
$ rune "why does the build fail on CI?"
- binary
- about 3 MiB
- startup
- about 2 ms
- runtime
- none, one binary
- license
- Apache-2.0
- telemetry
- none
what it does differently
Model and provider agnostic
Any OpenAI-compatible endpoint, the Responses API, Anthropic, or one you name yourself. Connect it once and it is remembered.
Every decision names its source
A limit, a permission, a setting: each one reports where it came from, so
rune permissions and rune config answer the
question rather than restating the value.
Sandboxed execution
Commands run under the platform sandbox where one exists, so an agent
cannot write outside your workspace. rune doctor reports what
your host can enforce.
Sessions you can resume
Every turn is written as it runs. Interrupt anything and pick the session back up, or copy a damaged one into a new one rather than losing it.
Local by default
Sessions, usage, and credentials stay on your machine. --offline
refuses every outbound request, and a test proves it makes none.
the surface
| Command | What it does |
|---|---|
| rune | Start an interactive session. |
| rune ask "..." | One request, prints the answer. Pipe it, script it, read it as JSON. |
| rune review | Review the pending changes in this repository. |
| rune resume last | Continue the most recent session in this workspace. |
| rune connect | Connect a provider and remember the choice. |
| rune permissions | See the rules, and why one of them decided what it did. |
| rune doctor | Check what this machine supports. |
| rune acp | Serve the Agent Client Protocol so an editor can drive a session. |
Custom slash commands live in .rune/commands/*.md in a repository,
so a team can ship a workflow alongside the code.