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.

When to Use

• Scripts for generating files, parsing data, running migrations
• File processing and transformation pipelines
• Shell scripting and automation
• Database operations with SQLite (bun:sqlite)
• Database queries via connection URL -- project has DATABASE_URL in .env or environment (PostgreSQL, MySQL, SQLite via Bun.sql())
• S3 storage operations -- project has AWS_ACCESS_KEY_ID or uses S3-compatible storage (Bun.s3)
• Redis/Valkey caching and pub/sub -- project has REDIS_URL or VALKEY_URL (Bun.redis)
• Any scripting task in a Bun project

HTTP Server (Bun.serve)