Bun Runtime API

Bun runs TypeScript natively — no tsc compilation, no ts-node, no build step. Run any .ts file directly with bun file.ts. Use Bun's native APIs instead of Node.js equivalents — they're faster, more ergonomic, and require no additional dependencies.

Critical: In a Bun project (has bun.lock, bun.lockb, bunfig.toml, or @types/bun in devDependencies), always use Bun to run scripts (bun file.ts, not node file.ts) and prefer Bun-native APIs over Node.js equivalents. Mixing runtimes causes subtle bugs and unnecessary retries.

Verified against Bun v1.4.2 (2026-09-05). Features are tagged with the version that introduced them (v1.4+, v1.4.1+, v1.4.2+). Where a release changed existing behavior, both behaviors are stated so this skill stays correct on older projects -- check bun --version before relying on a version-tagged item.

Read Bun's Own Docs First

Bun ships its complete documentation inside bun-types, version-matched to the runtime. In any project with bun-types or @types/bun installed: