1# CLI Options for `wasmtime` 2 3The `wasmtime` CLI is organized into a few subcommands. If no subcommand is 4provided it'll assume `run`, which is to execute a wasm file. The subcommands 5supported by `wasmtime` are: 6 7## `help` 8 9This is a general subcommand used to print help information to the terminal. You 10can execute any number of the following: 11 12```sh 13$ wasmtime help 14$ wasmtime --help 15$ wasmtime -h 16$ wasmtime help run 17$ wasmtime run -h 18``` 19 20When in doubt, try running the `help` command to learn more about functionality! 21 22## `run` 23 24This is the `wasmtime` CLI's main subcommand, and it's also the default if no 25other subcommand is provided. The `run` command will execute a WebAssembly 26module. This means that the module will be compiled to native code, 27instantiated, and then optionally have an export executed. 28 29The `wasmtime` CLI will automatically hook up any WASI-related imported 30functionality, but at this time if your module imports anything else it will 31fail instantiation. 32 33The `run` command takes one positional argument which is the name of the module 34to run: 35 36```sh 37$ wasmtime run foo.wasm 38$ wasmtime foo.wasm 39``` 40 41Note that the `wasmtime` CLI can take both a binary WebAssembly file (`*.wasm`) 42as well as the text format for WebAssembly (`*.wat`): 43 44```sh 45$ wasmtime foo.wat 46``` 47 48## `wast` 49 50The `wast` command executes a `*.wast` file which is the test format for the 51official WebAssembly spec test suite. This subcommand will execute the script 52file which has a number of directives supported to instantiate modules, link 53tests, etc. 54 55Executing this looks like: 56 57```sh 58$ wasmtime wast foo.wast 59``` 60 61## `config` 62 63This subcommand is used to control and edit local Wasmtime configuration 64settings. The primary purpose of this currently is to configure [how Wasmtime's 65code caching works](./cli-cache.md). You can create a new configuration file for 66you to edit with: 67 68```sh 69$ wasmtime config new 70``` 71 72And that'll print out the path to the file you can edit. 73 74## `compile` 75 76This subcommand is used to Ahead-Of-Time (AOT) compile a WebAssembly module to produce 77a "compiled wasm" (.cwasm) file. 78 79The `wasmtime run` subcommand can then be used to run a AOT-compiled WebAssembly module: 80 81```sh 82$ wasmtime compile foo.wasm 83$ wasmtime foo.cwasm 84``` 85 86AOT-compiled modules can be run from hosts that are compatible with the target 87environment of the AOT-completed module. 88 89## `settings` 90 91This subcommand is used to print the available Cranelift settings for a given target. 92 93When run without options, it will print the settings for the host target and also 94display what Cranelift settings are inferred for the host: 95 96```sh 97$ wasmtime settings 98``` 99