> For the complete documentation index, see [llms.txt](/llms.txt). # Snaps configuration options This reference describes the syntax of the Snaps command line interface (CLI) configuration options. You can specify these options in the [configuration file](/snaps/learn/about-snaps/files/#configuration-file). ### `customizeWebpackConfig`[​](#customizewebpackconfig "Direct link to customizewebpackconfig") - Syntax - Example ``` customizeWebpackConfig: , ``` ``` customizeWebpackConfig: (config) => merge(config, { plugins: [ // Add a plugin. ], module: { rules: [ // Add a loader. ], }, }), ``` A function that customizes the Webpack configuration. For example, you can use this option to add a Webpack plugin, provide a polyfill, or add a loader. The function should receive the Webpack configuration object and return the modified configuration object. For convenience, the Snaps CLI exports a `merge` function that you can use to merge the configuration object with the [default Webpack configuration](https://github.com/MetaMask/snaps/blob/main/packages/snaps-cli/src/webpack/config.ts). ### `environment`[​](#environment "Direct link to environment") - Syntax - Example ``` environment: , ``` ``` environment: { SNAP_ENV: process.env.SNAP_ENV, PUBLIC_KEY: process.env.PUBLIC_KEY, }, ``` The environment configuration. You can use this to [set environment variables for the Snap](/snaps/how-to/use-environment-variables/), which can be accessed using `process.env`. ### `evaluate`[​](#evaluate "Direct link to evaluate") - Syntax - Example ``` evaluate: , ``` ``` evaluate: true, ``` Enables or disables evaluating the bundle. When set to `true`, the bundle is checked for compatibility issues with the Snaps runtime. If there are any issues, the CLI exits with an error. ### `experimental`[​](#experimental "Direct link to experimental") Experimental features. caution These features are not stable, and might change in the future. #### `experimental.wasm`[​](#experimentalwasm "Direct link to experimentalwasm") - Syntax - Example ``` experimental: { wasm: , }, ``` ``` experimental: { wasm: true, }, ``` Enables or disables WebAssembly support. When set to `true`, WebAssembly files can be imported in the Snap. For example: ``` import program from './program.wasm' // Program is initialized synchronously. // ... ``` ### `features`[​](#features "Direct link to features") #### `features.images`[​](#featuresimages "Direct link to featuresimages") - Syntax - Example ``` features: { images: , }, ``` ``` features: { images: false, }, ``` Enables or disables [image support](/snaps/features/custom-ui/#image). The default is `true`. ### `input`[​](#input "Direct link to input") - Syntax - Example ``` input: , ``` ``` input: "src/index.js", ``` The entry point of the Snap. This is the file that will be bundled. The default is `"src/index.js"`. ### `manifest`[​](#manifest "Direct link to manifest") The Snap [manifest file](/snaps/learn/about-snaps/files/#manifest-file) configuration. #### `manifest.path`[​](#manifestpath "Direct link to manifestpath") - Syntax - Example ``` manifest: { path: , }, ``` ``` manifest: { path: "snap.manifest.json", }, ``` Path to the Snap manifest file. The default is `"snap.manifest.json"`. #### `manifest.update`[​](#manifestupdate "Direct link to manifestupdate") - Syntax - Example ``` manifest: { update: , }, ``` ``` manifest: { update: false, }, ``` Enables or disables updating the manifest file with the bundle shasum, and making any other possible updates. If set to `false`, the manifest is not updated, and an error is thrown if the manifest is not up-to-date. The default is `true`. ### `output`[​](#output "Direct link to output") The output configuration. #### `output.clean`[​](#outputclean "Direct link to outputclean") - Syntax - Example ``` output: { clean: , }, ``` ``` output: { clean: true, }, ``` Enables or disables cleaning the output directory before building. The default is `false`. #### `output.filename`[​](#outputfilename "Direct link to outputfilename") - Syntax - Example ``` output: { filename: , }, ``` ``` output: { filename: "bundle.js", }, ``` The output filename. The default is `"bundle.js"`. #### `output.minimize`[​](#outputminimize "Direct link to outputminimize") - Syntax - Example ``` output: { minimize: , }, ``` ``` output: { minimize: false, }, ``` Enables or disables minimizing the bundle. Minimizing the bundle removes comments and whitespace, mangles variable names, and performs other optimizations. The default is `true`. #### `output.path`[​](#outputpath "Direct link to outputpath") - Syntax - Example ``` output: { path: , }, ``` ``` output: { path: "dist", }, ``` Path to the output directory. The default is `"dist"`. ### `polyfills`[​](#polyfills "Direct link to polyfills") - Syntax - Example ``` polyfills: ``` ``` polyfills: { buffer: true, crypto: true, path: true, } ``` Enables or disables providing polyfills for Node.js built-in modules. If set to `true`, all available polyfills are provided. The default is `false`. You can also set this option to an object with specific polyfills set to `true`. See [the list of available polyfills](https://github.com/MetaMask/snaps/blob/51a1d04ea50c5c286262df1959ef0b1ced84b6e2/packages/snaps-cli/src/config.ts#L383-L416). ### `server`[​](#server "Direct link to server") The development server configuration. The development server is used to test the Snap during development, using the [watch](/snaps/reference/cli/#w-watch) and [serve](/snaps/reference/cli/#s-serve) subcommands. #### `server.enabled`[​](#serverenabled "Direct link to serverenabled") - Syntax - Example ``` server: { enabled: , }, ``` ``` server: { enabled: false, }, ``` Enables or disables the development server. #### `server.port`[​](#serverport "Direct link to serverport") - Syntax - Example ``` server: { port: , }, ``` ``` server: { port: 9000, }, ``` The port to run the development server on. If set to `0`, a random port is used. The default is `8081`. #### `server.root`[​](#serverroot "Direct link to serverroot") - Syntax - Example ``` server: { root: , }, ``` ``` server: { root: "snap", }, ``` The root directory of the development server. This is the directory that is served by the development server. The default is the current working directory. ### `sourceMap`[​](#sourcemap "Direct link to sourcemap") - Syntax - Example ``` sourceMap: , ``` ``` sourceMap: "inline", ``` Enables or disables generating a source map. If set to `"inline"`, the source map is inlined in the bundle. If set to `true` or not specified, it is written to a separate file. The default is `true`. ### `stats`[​](#stats "Direct link to stats") The stats configuration, which controls the log output of the CLI. #### `stats.buffer`[​](#statsbuffer "Direct link to statsbuffer") - Syntax - Example ``` stats: { buffer: , }, ``` ``` stats: { buffer: false, }, ``` Enables or disables showing a warning if the `Buffer` global is used but not provided. The `Buffer` global is not available in the Snaps runtime by default. To use `Buffer`, set [polyfills](#polyfills) to `true`. The default is `true`. #### `stats.builtIns`[​](#statsbuiltins "Direct link to statsbuiltins") - Syntax - Example ``` stats: { builtIns: , }, ``` ``` stats: { builtIns: { ignore: [ // Built-in modules to ignore. ], }, }, ``` Enables or disables checking for missing built-in modules. Not specifying this option, or specifying an ignore list, enables checking for missing built-in modules. When enabled, the CLI shows a warning if a built-in is used but not provided. The Snaps CLI does not support Node.js built-ins out of the box. To use built-ins, set [polyfills](#polyfills) to `true`. You can specify a list of built-ins to ignore when checking for missing built-ins. This is useful if the built-in is not actually used in the Snap, but is added by a dependency. The default is an empty ignore list. #### `stats.verbose`[​](#statsverbose "Direct link to statsverbose") - Syntax - Example ``` stats: { verbose: , }, ``` ``` stats: { verbose: true, }, ``` Enables or disables verbose logging. If set to `true`, the CLI logs more information. The default is `false`.