extism CLI

The Extism CLI can be used to generate or execute Extism plugins and manage libextism installations.

Installation

Using curl/sh:

curl https://get.extism.org/cli | sh

See the help output for more options:

curl https://get.extism.org/cli | sh -s -- -h

From source:

go install github.com/extism/cli/extism@latest

Using Nix:

nix-shell -p extism-cli

Manual

You can also download and extract the latest release from https://github.com/extism/cli/releases

Generate a Plugin

To quickly start writing an Extism plugin in any of the supported PDK languages, using extism CLI to generate minimal boilerplate may be helpful:

mkdir js-plugin && cd js-plugin
extism generate plugin 

  Select a PDK language to use for your plugin:  
                                                 
    1. Rust                                      
  > 2. JavaScript                                
    3. Go                                        
    4. Zig                                       
    5. C#                                        
    6. F#                                        
    7. C                                         
    8. Haskell                                   
    9. AssemblyScript                            
# or pass a path to the output via `-o`, see more options running `extism generate -h`

This will output a quickstart plugin project with the necessary configuration and dependencies ready. If no output directory was specified, the current directory will be used.

NOTE:: You may still need to install language tools such as compilers or other system dependencies to compile the plugin to WebAssembly.

To further improve this, we will eventually include a Dockerfile in each generated project, so a build environment can be easily created with all tools necessary. If you're interested in contributing to this effort, please join us on Discord, and check out the PDK template repository of interest, listed in pdk-templates.json

Call a plugin

The following will call the count_vowels function in the count_vowels.wasm module with the input "qwertyuiop":

PLUGIN_URL="https://github.com/extism/plugins/releases/latest/download/count_vowels.wasm"
extism call $PLUGIN_URL count_vowels --input qwertyuiop

Note: The first parameter to call can also be a path to a Wasm file on disk.

See extism call --help for a list of all the flags

Listing libextism versions

To list the available libextism versions:

extism lib versions

To list the available triples for a version:

extism lib versions v0.0.1-alpha

Install libextism

To install the latest version of libextism to /usr/local on macOS and Linux and . on Windows, this will overwrite any existing installation at the same path:

sudo PATH=$PATH env extism lib install

To install to $HOME/.local:

extism lib install --prefix ~/.local

To install the latest build from github:

sudo PATH=$PATH env extism lib install --version git

Uninstall libextism

To uninstall the shared object and header installed in /usr/local:

sudo PATH=$PATH env extism lib uninstall

Or from another prefix:

extism lib uninstall --prefix ~/.local

Check a libextism installation

The lib check command will print the version of the installed libextism library:

extism lib check