bun run CLI Usage

bun run <file or script>

General Execution Options

--silentboolean

Don't print the script command

--if-presentboolean

Exit without an error if the entrypoint does not exist

--evalstring

Evaluate argument as a script. Alias: -e

--printstring

Evaluate argument as a script and print the result. Alias: -p

--helpboolean

Display this menu and exit. Alias: -h

Workspace Management

--elide-linesnumber default: 10

Number of lines of script output shown when using --filter (default: 10). Set to 0 to show all lines

--filterstring

Run a script in all workspace packages matching the pattern. Alias: -F

--workspacesboolean

Run a script in all workspace packages (from the workspaces field in package.json)

Runtime & Process Control

--bunboolean

Force a script or package to use Bun's runtime instead of Node.js (via symlinking node). Alias: -b

--shellstring

Control the shell used for package.json scripts. Supports either bun or system

--smolboolean

Use less memory, but run garbage collection more often

--expose-gcboolean

Expose gc() on the global object. Has no effect on Bun.gc()

--no-deprecationboolean

Suppress all reporting of the custom deprecation

--throw-deprecationboolean

Determine whether or not deprecation warnings result in errors

--titlestring

Set the process title

--zero-fill-buffersboolean

Boolean to force Buffer.allocUnsafe(size) to be zero-filled

--no-addonsboolean

Throw an error if process.dlopen is called, and disable export condition node-addons

--unhandled-rejectionsstring

One of strict, throw, warn, none, or{" "} warn-with-error-code

--console-depthnumber default: 2

Set the default depth for console.log object inspection (default: 2)

Development Workflow

--watchboolean

Automatically restart the process on file change

--hotboolean

Enable auto reload in the Bun runtime, test runner, or bundler

--no-clear-screenboolean

Disable clearing the terminal screen on reload when --hot or --watch is enabled

Debugging

--inspectstring

Activate Bun's debugger

--inspect-waitstring

Activate Bun's debugger, wait for a connection before executing

--inspect-brkstring

Activate Bun's debugger, set breakpoint on first line of code and wait

Dependency & Module Resolution

--preloadstring

Import a module before other modules are loaded. Alias: -r

--requirestring

Alias of --preload, for Node.js compatibility

--importstring

Alias of --preload, for Node.js compatibility

--no-installboolean

Disable auto install in the Bun runtime

--installstring default: auto

Configure auto-install behavior. One of auto (default, auto-installs when no node_modules),{" "} fallback (missing packages only), force (always)

-iboolean

Auto-install dependencies during execution. Equivalent to --install=fallback

--prefer-offlineboolean

Skip staleness checks for packages in the Bun runtime and resolve from disk

--prefer-latestboolean

Use the latest matching versions of packages in the Bun runtime, always checking npm

--conditionsstring

Pass custom conditions to resolve

--main-fieldsstring

Main fields to lookup in package.json. Defaults to --target dependent

--preserve-symlinksboolean

Preserve symlinks when resolving files

--preserve-symlinks-mainboolean

Preserve symlinks when resolving the main entry point

--extension-orderstring default: .tsx,.ts,.jsx,.js,.json

Defaults to: .tsx,.ts,.jsx,.js,.json

Transpilation & Language Features

--tsconfig-overridestring

Specify custom tsconfig.json. Default $cwd/tsconfig.json

--definestring

Substitute K:V while parsing, e.g. --define process.env.NODE_ENV:"development". Values are parsed as JSON. Alias: -d

--dropstring

Remove function calls, e.g. --drop=console removes all console.* calls

--loaderstring

Parse files with .ext:loader, e.g. --loader .js:jsx. Valid loaders: js,{" "} jsx, ts, tsx, json, toml, text,{" "} file, wasm, napi. Alias: -l

--no-macrosboolean

Disable macros from being executed in the bundler, transpiler and runtime

--jsx-factorystring

Changes the function called when compiling JSX elements using the classic JSX runtime

--jsx-fragmentstring

Changes the function called when compiling JSX fragments

--jsx-import-sourcestring default: react

Declares the module specifier to be used for importing the jsx and jsxs factory functions. Default: react

--jsx-runtimestring default: automatic

automatic (default) or classic

--jsx-side-effectsboolean

Treat JSX elements as having side effects (disable pure annotations)

--ignore-dce-annotationsboolean

Ignore tree-shaking annotations such as @__PURE__

Networking & Security

--portnumber

Set the default port for Bun.serve

--fetch-preconnectstring

Preconnect to a URL while code is loading

--max-http-header-sizenumber default: 16384

Set the maximum size of HTTP headers in bytes. Default is 16KiB

--dns-result-orderstring default: verbatim

Set the default order of DNS lookup results. Valid orders: verbatim (default), ipv4first,{" "} ipv6first

--use-system-caboolean

Use the system's trusted certificate authorities

--use-openssl-caboolean

Use OpenSSL's default CA store

--use-bundled-caboolean

Use bundled CA store

--redis-preconnectboolean

Preconnect to $REDIS_URL at startup

--sql-preconnectboolean

Preconnect to PostgreSQL at startup

--user-agentstring

Set the default User-Agent header for HTTP requests

Global Configuration & Context

--env-filestring

Load environment variables from the specified file(s)

--cwdstring

Absolute path to resolve files & entry points from. This just changes the process' cwd

--configstring

Specify path to Bun config file. Default $cwd/bunfig.toml. Alias: -c

Examples

Run a JavaScript or TypeScript file:

bun run ./index.js
bun run ./index.tsx

Run a package.json script:

bun run dev
bun run lint