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Installing Extism

The extism CLI is used to manage Extism installations. In order to run Extism, your system must be able to locate the libextism.so (on Linux) or libextism.dylib (on macos). Windows support is coming soon.

Note: If you are using the Rust Host SDK, this is not the case, and can use Extism as a crate dependency in your Cargo.toml.

The following instructions will walk you through how to install the Extism CLI, and then the installation of the shared library which a Host SDK will look for automatically.

Install the Extism CLI​

macos​

Using pip: (recommended)

pip3 install poetry
pip3 install git+https://github.com/extism/cli

Using curl:

sh <(curl https://raw.githubusercontent.com/extism/cli/main/install.sh) /usr/local/bin

# To use advanced features of the CLI, install the Extism Python SDK:
# pip3 install extism

Linux​

Using pip:

pip3 install poetry
pip3 install git+https://github.com/extism/cli

Using curl:

curl https://raw.githubusercontent.com/extism/cli/main/install.sh | sh

# To use advanced features of the CLI, install the Extism Python SDK:
# pip3 install extism

Using the Extism CLI​

The most common use-case is to to install Extism from Github releases, and then install the library and header file into the installation prefix of your choice.

macos​

extism install latest

Linux​

extism install latest

Build from source​

In order to build from source, you must have a recent version of the Rust toolchain installed.

extism install git # installs to /usr/local/lib and /usr/local/include by default

Overriding install location​

Pass the --prefix argument a path on disk where extism CLI will install the system files:

extism --prefix ~/.local install latest

Other CLI Features​

usage: extism [-h] [--quiet] [--prefix PREFIX] [--github-token GITHUB_TOKEN] [--sudo] {build,version,install,fetch,uninstall,link,info,call} ...

options:
  -h, --help            show this help message and exit
  --quiet               Limit output to errors
  --prefix PREFIX       Installation prefix
  --github-token GITHUB_TOKEN
                        Github token
  --sudo                Use sudo to install files

command:
  {build,version,install,fetch,uninstall,link,info,call}

Call plug-in functions​

You can use the extism CLI as a test runner to check your plug-ins outside of any Host program:

extism call --input "this is a test" test/code.wasm count_vowels
{"count": 4}

Note: if you encounter the error Could not find extism on this machine, please install the Extism Python SDK by running: pip3 install extism

Get installation info​

It's helpful to know where the CLI is locating the Extism shared library, and which version of the runtime it's using.

extism info
Prefix  /usr/local
Version v0.2.0

Get runtime version​

Use the version command to print the version of the Extism runtime installed on your machine:

extism version
v0.2.0