wasmi-labs/wasmi

Efficient and versatile WebAssembly interpreter for embedded systems.

2,296

stars

1,507

commits

Rust

primary language

Sep 1, 2026

updated

wasmi-labs.github.io/wasmi/

embedded

interpreter

lightweight

portable

runtime

rust

sandbox

secure

standalone

virtual-machine

wasi

wasm

webassembly

Browse cluster: WebAssembly Compilation & Tooling →

README

Continuous Integration	Test Coverage	Documentation	Crates.io

Wasmi - WebAssembly (Wasm) Interpreter

Wasmi is an efficient and lightweight WebAssembly interpreter with a focus on constrained and embedded systems.

Distinct Features

Simple, correct and deterministic execution of WebAssembly.
Efficient and cross-platform WebAssembly runtime for no_std embedded environments.
Compiler/JIT bomb resisting translation.
Loosely mirrors the Wasmtime API to act as drop-in replacement.
100% WebAssembly spec testsuite compliance.
Built-in support for fuel metering.
Supports the official Wasm C-API.

Security Audits

Wasmi is suitable for safety critical use cases and has been audited twice.

Wasmi Version(s)	Auditor	Contractor	Report
`0.36.0`-`0.38.0`	Runtime Verification Inc.	Stellar Development Foundation	PDF
`0.31.0`	SRLabs	Parity Technologies	PDF

Docs

📖 Usage Guide: learn how to use the Wasmi API properly.
🛠️ Development Guide: learn how to develop for Wasmi.
✨ Crate Features: learn about wasmi crate features.

WebAssembly Features

	WebAssembly Proposal			WebAssembly Proposal
✅	`mutable-global`	≥ `0.14.0`	✅	`custom-page-sizes`	≥ `0.41.0`
✅	`saturating-float-to-int`	≥ `0.14.0`	✅	`memory64`	≥ `0.41.0`
✅	`sign-extension`	≥ `0.14.0`	✅	`wide-arithmetic`	≥ `0.42.0`
✅	`multi-value`	≥ `0.14.0`	✅	`simd`	≥ `0.43.0`
✅	`bulk-memory`	≥ `0.24.0`	✅	`relaxed-simd`	≥ `0.44.0`
✅	`reference-types`	≥ `0.24.0`	📅	`function-references`	Tracking Issue
✅	`tail-calls`	≥ `0.28.0`	📅	`gc`	Tracking Issue
✅	`extended-const`	≥ `0.29.0`	📅	`threads`	Tracking Issue
✅	`multi-memory`	≥ `0.37.0`	📅	`exception-handling`	Tracking Issue

	Embeddings
✅	WASI	WASI (`wasip1`) support via the `wasmi_wasi` crate.
✅	C-API	Official Wasm C-API support via the `wasmi_c_api_impl` crate.

Used by

If you want your project on this list please inform me about you project and how Wasmi is used.

Soroban · Typst · Zellij · Josh · Ripple · Firefly Zero · icu4x · orbitinghail · smoldot · Munal OS · Ayaka · Project Oak

License

Licensed under either of

Apache License, Version 2.0, (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or https://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Contributors

(top 30 of 84)

1,166 commits

125 commits

51 commits

22 commits

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wasmi-labs/wasmi

Efficient and versatile WebAssembly interpreter for embedded systems.

2,296

stars

1,507

commits

Rust

primary language

Sep 1, 2026

updated

wasmi-labs.github.io/wasmi/

embedded

interpreter

lightweight

portable

runtime

rust

sandbox

secure

standalone

virtual-machine

wasi

wasm

webassembly

Browse cluster: WebAssembly Compilation & Tooling →

README

Continuous Integration	Test Coverage	Documentation	Crates.io

Wasmi - WebAssembly (Wasm) Interpreter

Wasmi is an efficient and lightweight WebAssembly interpreter with a focus on constrained and embedded systems.

Distinct Features

Simple, correct and deterministic execution of WebAssembly.
Efficient and cross-platform WebAssembly runtime for no_std embedded environments.
Compiler/JIT bomb resisting translation.
Loosely mirrors the Wasmtime API to act as drop-in replacement.
100% WebAssembly spec testsuite compliance.
Built-in support for fuel metering.
Supports the official Wasm C-API.

Security Audits

Wasmi is suitable for safety critical use cases and has been audited twice.

Wasmi Version(s)	Auditor	Contractor	Report
`0.36.0`-`0.38.0`	Runtime Verification Inc.	Stellar Development Foundation	PDF
`0.31.0`	SRLabs	Parity Technologies	PDF

Docs

📖 Usage Guide: learn how to use the Wasmi API properly.
🛠️ Development Guide: learn how to develop for Wasmi.
✨ Crate Features: learn about wasmi crate features.

WebAssembly Features

	WebAssembly Proposal			WebAssembly Proposal
✅	`mutable-global`	≥ `0.14.0`	✅	`custom-page-sizes`	≥ `0.41.0`
✅	`saturating-float-to-int`	≥ `0.14.0`	✅	`memory64`	≥ `0.41.0`
✅	`sign-extension`	≥ `0.14.0`	✅	`wide-arithmetic`	≥ `0.42.0`
✅	`multi-value`	≥ `0.14.0`	✅	`simd`	≥ `0.43.0`
✅	`bulk-memory`	≥ `0.24.0`	✅	`relaxed-simd`	≥ `0.44.0`
✅	`reference-types`	≥ `0.24.0`	📅	`function-references`	Tracking Issue
✅	`tail-calls`	≥ `0.28.0`	📅	`gc`	Tracking Issue
✅	`extended-const`	≥ `0.29.0`	📅	`threads`	Tracking Issue
✅	`multi-memory`	≥ `0.37.0`	📅	`exception-handling`	Tracking Issue