bun¶

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

Pass custom conditions to resolve.

Specify path to Bun config file.

Set the default depth for console.log object inspection. Defaults to 2.

Start CPU profiler and write profile to disk on exit.

Specify the directory where the CPU profile will be saved.

Specify the sampling interval in microseconds for CPU profiling. Defaults to 1000.

Output CPU profile in markdown format (grep-friendly, designed for LLM analysis).

Specify the name of the CPU profile file.

Cron period for cron execution mode.

Title for cron execution mode.

Absolute path to resolve files & entry points from.

Set the default order of DNS lookup results.

Number of lines of script output shown when using --filter . Defaults to 10.

Load environment variables from the specified file(s).

Evaluate argument as a script.

Offer h2 in fetch() TLS ALPN.

Honor Alt-Svc: h3 in fetch() and upgrade to HTTP/3.

Expose gc() on the global object.

Preconnect to a URL while code is loading.

Run a script in all workspace packages matching the pattern.

Generate V8 heap snapshot on exit (.heapsnapshot).

Specify the directory where the heap profile will be saved.

Generate markdown heap profile on exit (for CLI analysis).

Specify the name of the heap profile file.

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

Auto-install dependencies during execution.

Exit without an error if the entrypoint does not exist.

Alias of --preload, for Node.js compatibility.

Activate Bun's debugger.

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

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

Configure auto-install behavior.

Set the maximum size of HTTP headers in bytes.

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

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

Suppress all reporting of the custom deprecation.

Disable automatic loading of .env files.

Continue running other scripts when one fails (with --parallel/--sequential).

Disable auto install in the Bun runtime.

Exit when the parent process dies, and on exit SIGKILL every descendant.

Run multiple scripts concurrently with Foreman-style output.

Set the default port for Bun.serve.

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

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

Import a module before other modules are loaded.

Evaluate argument as a script and print the result.

Preconnect to $REDIS_URL at startup.

Alias of --preload, for Node.js compatibility.

Print version with revision and exit.

Run multiple scripts sequentially with Foreman-style output.

Control the shell used for package.json scripts.

Don't print the script command.

Use less memory, but run garbage collection more often.

Preconnect to PostgreSQL at startup.

Determine whether or not deprecation warnings result in errors.

Set the process title.

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

Use bundled CA store.

Use OpenSSL's default CA store.

Use the system's trusted certificate authorities.

Set the default User-Agent header for HTTP requests.

Automatically restart the process on file change.

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

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

Recursively analyze & install dependencies of files passed as arguments (using Bun's bundler).

Platform-specific optimizations for installing dependencies.

Provide a Certificate Authority signing certificate.

Store & load cached data from a specific directory path.

The same as --ca, but is a file path to the certificate.

Maximum number of concurrent jobs for lifecycle scripts. Defaults to 2x CPU cores.

Specify path to config file (bunfig.toml).

Override CPU architecture for optional dependencies (e.g., x64, arm64, * for all).

Set a specific cwd.

Add dependency to "devDependencies".

Perform a dry run without making changes.

Add the exact version instead of the ^range.

Always request the latest versions from the registry & reinstall all dependencies.

Disallow changes to lockfile.

Install globally.

Skip lifecycle scripts in the project's package.json (dependency scripts are never run).

Linker strategy (one of "isolated" or "hoisted").

Generate a lockfile without installing dependencies.

Only install packages published at least N seconds ago (security feature).

Maximum number of concurrent network requests. Defaults to 48.

Ignore manifest cache entirely.

Disable the progress bar.

Don't print a summary.

Skip verifying integrity of newly downloaded packages.

Exclude 'dev', 'optional', or 'peer' dependencies from install.

Only add dependencies to package.json if they are not already present.

Add dependency to "optionalDependencies".

Override operating system for optional dependencies (e.g., linux, darwin, * for all).

Add dependency to "peerDependencies".

Don't install devDependencies.

Only show tarball name when packing.

Use a specific registry by default, overriding .npmrc, bunfig.toml and environment variables.

Save to package.json (true by default). save=off emits --no-save.

Save a text-based lockfile.

Don't log anything.

Add to trustedDependencies in the project's package.json and install the package(s).

Excessively verbose logging.

Write a yarn.lock file (yarn v1).

Allow unresolved dynamic import()/require() specifiers matching these glob patterns.

(EXPERIMENTAL) Build a web app for production using Bun Bake.

Customize asset filenames.

Add a banner to the bundled output such as "use client"; for a bundle being used with RSCs.

Use a bytecode cache.

Customize chunk filenames.

Generate a standalone Bun executable containing your bundled code.

Enable autoloading of bunfig.toml in standalone executable. Defaults on — compile_autoload_bunfig=off emits --no-compile-autoload-bunfig.

Enable autoloading of .env files in standalone executable. Defaults on — compile_autoload_dotenv=off emits --no-compile-autoload-dotenv.

Enable autoloading of package.json at runtime in standalone executable. compile_autoload_package_json=off emits --no-compile-autoload-package-json.

Enable autoloading of tsconfig.json at runtime in standalone executable. compile_autoload_tsconfig=off emits --no-compile-autoload-tsconfig.

Prepend arguments to the standalone executable's execArgv.

Path to a Bun executable to use for cross-compilation instead of downloading.

Pass custom conditions to resolve.

Chunk CSS files together to reduce duplicated CSS loaded in a browser.

Re-emit DCE annotations in bundles.

Customize entry point filenames.

Inline environment variables into the bundle as process.env.${name}.

Exclude module from transpilation (can use * wildcards).

Add a footer to the bundled output such as // built with bun!.

Specifies the module format to build to.

Preserve original function and class names when minifying.

Write a JSON file with metadata about the build.

Write a markdown file with a visualization of the module graph (LLM-friendly).

Enable all minification flags.

Minify identifiers.

Minify syntax and inline data.

Minify whitespace.

Transpile file only, do not bundle.

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

Default to "dist" if multiple files.

Write to a file.

Add dependencies to bundle or keep them external.

Set NODE_ENV=production and enable minification.

A prefix to be appended to any import paths in bundled code.

Enable React Fast Refresh transform (does not emit hot-module code, use this for testing).

Fail the build on any dynamic import()/require() specifier that cannot be resolved at build time.

Root directory used for multiple entry points.

(EXPERIMENTAL) Enable server components.

Build with sourcemaps - 'linked', 'inline', 'external', or 'none'.

Enable code splitting.

The intended execution environment for the bundle.

Automatically restart the process on file change.

When using --compile targeting Windows, set the executable copyright.

When using --compile targeting Windows, set the executable description.

When using --compile targeting Windows, prevent a Command prompt from opening alongside the executable.

When using --compile targeting Windows, assign an executable icon.

When using --compile targeting Windows, set the executable company name.

When using --compile targeting Windows, set the executable product name.

When using --compile targeting Windows, set the executable version (e.g.

Analyze & install all dependencies of files passed as arguments recursively (using Bun's bundler).

Platform-specific optimizations for installing dependencies.

Provide a Certificate Authority signing certificate.

Store & load cached data from a specific directory path.

The same as --ca, but is a file path to the certificate.

Maximum number of concurrent jobs for lifecycle scripts. Defaults to 2x CPU cores.

Specify path to config file (bunfig.toml).

Override CPU architecture for optional dependencies (e.g., x64, arm64, * for all).

Set a specific cwd.

Add dependency to "devDependencies".

Perform a dry run without making changes.

Add the exact version instead of the ^range.

Install packages for the matching workspaces.

Always request the latest versions from the registry & reinstall all dependencies.

Disallow changes to lockfile.

Install globally.

Skip lifecycle scripts in the project's package.json (dependency scripts are never run).

Linker strategy (one of "isolated" or "hoisted").

Generate a lockfile without installing dependencies.

Only install packages published at least N seconds ago (security feature).

Maximum number of concurrent network requests. Defaults to 48.

Ignore manifest cache entirely.

Disable the progress bar.

Don't print a summary.

Skip verifying integrity of newly downloaded packages.

Exclude 'dev', 'optional', or 'peer' dependencies from install.

Only add dependencies to package.json if they are not already present.

Add dependency to "optionalDependencies".

Override operating system for optional dependencies (e.g., linux, darwin, * for all).

Add dependency to "peerDependencies".

Don't install devDependencies.

Only show tarball name when packing.

Use a specific registry by default, overriding .npmrc, bunfig.toml and environment variables.

Save to package.json (true by default). save=off emits --no-save.

Save a text-based lockfile.

Don't log anything.

Add to trustedDependencies in the project's package.json and install the package(s).

Excessively verbose logging.

Write a yarn.lock file (yarn v1).

Platform-specific optimizations for installing dependencies.

Provide a Certificate Authority signing certificate.

Store & load cached data from a specific directory path.

The same as --ca, but is a file path to the certificate.

Maximum number of concurrent jobs for lifecycle scripts. Defaults to 2x CPU cores.

Specify path to config file (bunfig.toml).

Override CPU architecture for optional dependencies (e.g., x64, arm64, * for all).

Set a specific cwd.

Perform a dry run without making changes.

Always request the latest versions from the registry & reinstall all dependencies.

Disallow changes to lockfile.

Install globally.

Skip lifecycle scripts in the project's package.json (dependency scripts are never run).

Linker strategy (one of "isolated" or "hoisted").

Generate a lockfile without installing dependencies.

Only install packages published at least N seconds ago (security feature).

Maximum number of concurrent network requests. Defaults to 48.

Ignore manifest cache entirely.

Disable the progress bar.

Don't print a summary.

Skip verifying integrity of newly downloaded packages.

Exclude 'dev', 'optional', or 'peer' dependencies from install.

Override operating system for optional dependencies (e.g., linux, darwin, * for all).

Don't install devDependencies.

Only show tarball name when packing.

Use a specific registry by default, overriding .npmrc, bunfig.toml and environment variables.

Save to package.json (true by default). save=off emits --no-save.

Save a text-based lockfile.

Don't log anything.

Add to trustedDependencies in the project's package.json and install the package(s).

Excessively verbose logging.

Write a yarn.lock file (yarn v1).

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

Pass custom conditions to resolve.

Specify path to Bun config file.

Set the default depth for console.log object inspection. Defaults to 2.

Start CPU profiler and write profile to disk on exit.

Specify the directory where the CPU profile will be saved.

Specify the sampling interval in microseconds for CPU profiling. Defaults to 1000.

Output CPU profile in markdown format (grep-friendly, designed for LLM analysis).

Specify the name of the CPU profile file.

Cron period for cron execution mode.

Title for cron execution mode.

Absolute path to resolve files & entry points from.

Substitute K:V while parsing, e.g. --define process.env.NODE_ENV:"development".

Set the default order of DNS lookup results.

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

Number of lines of script output shown when using --filter . Defaults to 10.

Load environment variables from the specified file(s).

Evaluate argument as a script.

Offer h2 in fetch() TLS ALPN.

Honor Alt-Svc: h3 in fetch() and upgrade to HTTP/3.

Expose gc() on the global object.

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

Enable a feature flag for dead-code elimination, e.g. --feature=SUPER_SECRET.

Preconnect to a URL while code is loading.

Run a script in all workspace packages matching the pattern.

Generate V8 heap snapshot on exit (.heapsnapshot).

Specify the directory where the heap profile will be saved.

Generate markdown heap profile on exit (for CLI analysis).

Specify the name of the heap profile file.

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

Auto-install dependencies during execution.

Exit without an error if the entrypoint does not exist.

Ignore tree-shaking annotations such as @PURE.

Alias of --preload, for Node.js compatibility.

Activate Bun's debugger.

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

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

Configure auto-install behavior.

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

Changes the function called when compiling JSX fragments.

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

"automatic" (default) or "classic".

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

Parse files with .ext:loader, e.g. --loader .js:jsx.

Main fields to lookup in package.json.

Set the maximum size of HTTP headers in bytes.

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

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

Suppress all reporting of the custom deprecation.

Disable automatic loading of .env files.

Continue running other scripts when one fails (with --parallel/--sequential).

Disable auto install in the Bun runtime.

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

Exit when the parent process dies, and on exit SIGKILL every descendant.

Run multiple scripts concurrently with Foreman-style output.

Set the default port for Bun.serve.

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

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

Import a module before other modules are loaded.

Preserve symlinks when resolving files.

Preserve symlinks when resolving the main entry point.

Evaluate argument as a script and print the result.

Preconnect to $REDIS_URL at startup.

Alias of --preload, for Node.js compatibility.

Run multiple scripts sequentially with Foreman-style output.

Control the shell used for package.json scripts.

Don't print the script command.

Use less memory, but run garbage collection more often.

Preconnect to PostgreSQL at startup.

Determine whether or not deprecation warnings result in errors.

Set the process title.

Specify custom tsconfig.json.

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

Use bundled CA store.

Use OpenSSL's default CA store.

Use the system's trusted certificate authorities.

Set the default User-Agent header for HTTP requests.

Automatically restart the process on file change.

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

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

Exit the test suite after failures.

Only run test files affected by changed files according to git.

Treat all tests as test.concurrent() tests.

Generate a coverage profile.

Directory for coverage files.

Report coverage in 'text' and/or 'lcov'.

Enable dots reporter.

Run each test file in a fresh global object.

Maximum number of concurrent tests to execute at once.

Exit when the parent process dies, and on exit SIGKILL every descendant.

Run only tests that are marked with "test.only()" or "describe.only()".

Only display test failures, hiding passing tests.

Run test files in parallel using N worker processes.

Milliseconds the first --parallel worker must be busy before spawning the rest.

Exit with code 0 when no tests are found.

Glob patterns for test file paths to ignore.

Run tests in random order.

Test output reporter format.

Output file path for the reporter format (required with --reporter).

Re-run each test file times, helps catch certain bugs.

Default retry count for all tests, overridden by per-test { retry: N }.

Set the random seed for test randomization.

Run a subset of test files, e.g. '--shard=⅓' runs the first of three shards.

Run only tests with a name that matches the given regex.

(internal) Run as a --parallel worker, receiving files over IPC.

Set the per-test timeout in milliseconds, default is 5000.

Include tests that are marked with "test.todo()".

Update snapshot files.

Force the command to run with Bun instead of Node.js.

Skip installation if package is not already installed.

Specify package to install when binary name differs from package name.

Suppress output during installation.

Enable verbose output during installation.