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Extism is a lightweight framework for building with WebAssembly (Wasm). Itsupports running Wasm code on servers, the edge, CLIs, IoT, browsers andeverything in between. Extism is designed to be "universal" in that it supportsa common interface, no matter where it runs.

Note: One of the primary use cases for Extism isbuilding extensiblesoftware & plugins. You want to be able to execute arbitrary, untrusted codefrom your users? Extism makes this safe and practical to do.

Additionally, Extism adds some extra utilities on top of standard Wasm runtimes.For example, we support persistent memory/module-scope variables, secure &host-controlled HTTP without WASI, runtime limiters & timers, simpler hostfunction linking, and more. Extism users build:

• plug-in systems
• FaaS platforms
• code generators
• web applications
• & much more...

We currently provide releases for the following targets:

• aarch64-apple-darwin
• aarch64-unknown-linux-gnu
• aarch64-unknown-linux-musl
• x86_64-apple-darwin
• x86_64-pc-windows-gnu
• x86_64-pc-windows-msvc
• x86_64-unknown-linux-gnu
• x86_64-unknown-linux-musl

For Android we suggest taking a look at theChicory SDK for a pure JavaExtism runtime.

Pick a SDK to import into your program, and refer to the documentation to getstarted:

Type	Language	Source Code	Package
Rust SDK		https://github.com/extism/extism/tree/main/runtime	Crates.io
JS SDK		https://github.com/extism/js-sdk (supports Web, Node, Deno & Bun!)	NPM
Elixir SDK		https://github.com/extism/elixir-sdk	Hex
Go SDK		https://github.com/extism/go-sdk	Go mod
Haskell SDK		https://github.com/extism/haskell-sdk	Hackage
Java SDK		https://github.com/extism/java-sdk	Sonatype
.NET SDK		https://github.com/extism/dotnet-sdk (supports C# & F#!)	Nuget
OCaml SDK		https://github.com/extism/ocaml-sdk	opam
Perl SDK		https://github.com/extism/perl-sdk	CPAN
PHP SDK		https://github.com/extism/php-sdk	Packagist
Python SDK		https://github.com/extism/python-sdk	PyPi
Ruby SDK		https://github.com/extism/ruby-sdk	RubyGems
Zig SDK		https://github.com/extism/zig-sdk	N/A
C SDK		https://github.com/extism/extism/tree/main/libextism	N/A
C++ SDK		https://github.com/extism/cpp-sdk	N/A

Extism Hosts (running the SDK) must execute WebAssembly code that has aPDK, or Plug-in Development Kit, librarycompiled in to the.wasm binary. PDKs make it easy for plug-in / extensioncode authors to read input from the host and return data back, read providedconfiguration, set/get variables, make outbound HTTP calls if allowed, and more.

Pick a PDK to import into your Wasm program, and refer to the documentation toget started:

Type	Language	Source Code	Package
Rust PDK		https://github.com/extism/rust-pdk	Crates.io
JS PDK		https://github.com/extism/js-pdk	N/A
Python PDK		https://github.com/extism/python-pdk	N/A
Go PDK		https://github.com/extism/go-pdk	Go mod
Haskell PDK		https://github.com/extism/haskell-pdk	Hackage
AssemblyScript PDK		https://github.com/extism/assemblyscript-pdk	NPM
.NET PDK		https://github.com/extism/dotnet-pdk (supports C# & F#!)	Nuget
C PDK		https://github.com/extism/c-pdk	N/A
C++ PDK		https://github.com/extism/cpp-pdk	N/A
Zig PDK		https://github.com/extism/zig-pdk	N/A

It's often very useful to define a schema to describe the function signaturesand types you want to use between Extism SDK and PDK languages.

XTP Bindgen is an open sourceframework to generate PDK bindings for Extism plug-ins. It's used by theXTP Platform, but can be used outside of the platformto define any Extism compatible plug-in system.

See installation instructionshere.

version:v1-draftexports:CountVowels:input:type:stringcontentType:text/plain; charset=utf-8output:$ref:"#/components/schemas/VowelReport"contentType:application/json# components.schemas defined in example-schema.yaml...

See an example inexample-schema.yaml, or a full"kitchen sink" example onthe docs page.

xtp plugin init --schema-file ./example-schema.yaml  > 1. TypeScript                          2. Go                                  3. Rust                                4. Python                              5. C#                                  6. Zig                                 7. C++                                 8. GitHub Template                     9. Local Template

This will create an entire boilerplate plugin project for you to get startedwith. Implement the empty function(s), and runxtp plugin build to compileyour plugin.

For more information about XTP Bindgen, see thedylibso/xtp-bindgen repository andthe officialXTP Schema documentation.

If you experience any problems or have any questions, please join ourDiscord and let us know. Our community is veryresponsive and happy to help get you started.

Head to theproject website for more information and docs.Also, consider reading anoverview of Extismand its goals & approach.

Thank you for considering a contribution to Extism, we are happy to help youmake a PR or find something to work on!

The easiest way to start would be to join theDiscord or open an issue on theextism/proposals issue tracker, whichcan eventually become an Extism Improvement Proposal (EIP).

For more information, please read theContributing guide.

Extism is an open-source product from the team at:

Reach out and tell us what you're building! We'd love to help:hello@dylibso.com