Bun

Bun is an all-in-one JavaScript and TypeScript toolchain shipped as a single bun binary. It combines runtime execution, package management, testing, bundling, and one-off package execution for local app and monorepo workflows.

• Run TypeScript or JavaScript files and package.json scripts directly, including workspace-wide script runs in monorepos.
• Install, update, audit, and inspect npm dependencies, including filtered workspace installs, dependency explanations, and registry metadata queries.
• Run tests, emit JUnit for CI, build bundles, and execute npm package binaries on demand with bunx.

• The main subcommands are clear and mostly non-interactive, so Bun fits script, CI, and local agent loops around existing JS or TS repos.
• Structured output exists where inspection matters, including bun info --json, bun audit --json, and JUnit test reports, but run/install/build output is otherwise mostly human-readable.
• Best for agents operating inside a checked-out project; bun run and package scripts execute arbitrary repo code, so side effects and project trust boundaries matter.

• bun init, bun create, and interactive dependency updates can prompt by default, so unattended setup needs the right flags or an existing project.
• Compatibility aims at Node.js projects, but behavior still depends on Bun-specific runtime support, lockfile state, and project configuration.