malvin

Installation

Requires Node.js ≥ 22.13 (with npm on PATH). During cargo install / cargo build, malvin's build script installs the Cursor SDK (@cursor/sdk) under ~/.malvin_home/sdk-bridges/ (skipped when the repo already has a built in-tree bridge).

cargo install malvin

Without Node/npm the Rust build fails unless you set MALVIN_SKIP_SDK_BRIDGES=1 (agent backends will not work).

Usage

malvin [OPTIONS] [REQUEST]
malvin [OPTIONS] <COMMAND>

Most of the time, just ask for what you want:

malvin "What time is it?"

By default malvin prints a full agent stream. For the final answer only:

malvin -q "Where (geographically) am I?"

By default, malvin runs an investigation. The larger or more complex the task, the more helpful this is. You can ask difficult questions or request complex changes somewhat tersely:

malvin "Speed up my_function.py by at least 3x."

and expect good results. For a simple one-shot turn:

malvin --do "Hello"

You can also pass a request file instead of a string:

malvin code_review.md

That works well in CI or cron. For no stdout at all, use -b:

malvin -b overnight_logs_alerter.md

For example, overnight_logs_alerter.md might tell malvin to scan prod logs and report oddities via Slack. Malvin always writes run logs under ~/.malvin_home/logs (useful for process improvement and as later context).

Flag reference: malvin --help. Behavioral contracts: malvin --doc and malvin <COMMAND> --doc.

Notes

malvin allows all tool calls by default.

Speed

malvin likes to run linters and unit tests. It does its best to only run what's necessary, but these tools can help speed things up:

[Python] pytest-testmon Runs only unit tests affected by code changes
[Rust] cargo-nextest Faster than cargo test
[Rust] cargo-difftests Re-runs only tests whose executed code changed (LLVM coverage indexes)
[Rust] sccache Speeds up builds by caching build artifacts

EXPERIMENTAL - USE AT YOUR OWN RISK