
| Continuous Integration |     Test Coverage    |  Documentation   |      Crates.io       |
|:----------------------:|:--------------------:|:----------------:|:--------------------:|
| [![ci][1]][2]          | [![codecov][3]][4]   | [![docs][5]][6] | [![crates][7]][8]  |

[1]: https://github.com/wasmi-labs/wasmi/actions/workflows/rust.yml/badge.svg
[2]: https://github.com/wasmi-labs/wasmi/actions/workflows/rust.yml
[3]: https://codecov.io/gh/wasmi-labs/wasmi/branch/main/badge.svg
[4]: https://codecov.io/gh/wasmi-labs/wasmi/branch/main
[5]: https://docs.rs/wasmi/badge.svg
[6]: https://docs.rs/wasmi
[7]: https://img.shields.io/crates/v/wasmi.svg
[8]: https://crates.io/crates/wasmi

[license-mit-badge]: https://img.shields.io/badge/license-MIT-blue.svg
[license-apache-badge]: https://img.shields.io/badge/license-APACHE-orange.svg

# 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](https://doc.rust-lang.org/stable/rustc/platform-support.html).
- Compiler/JIT bomb resisting translation.
- Loosely mirrors the [Wasmtime API](https://docs.rs/wasmtime/) to act as drop-in replacement.
- 100% WebAssembly spec testsuite compliance.
- Built-in support for fuel metering.
- Supports the official [Wasm C-API](https://github.com/WebAssembly/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](./resources/audit-2024-11-27.pdf) |
| `0.31.0` | [SRLabs] | [Parity Technologies] | [PDF](./resources/audit-2023-12-20.pdf) |

[Wasmtime]: https://github.com/bytecodealliance/wasmtime
[SRLabs]: https://www.srlabs.de/
[Runtime Verification Inc.]: https://runtimeverification.com/
[Stellar Development Foundation]: https://stellar.org/foundation
[Parity Technologies]: https://www.parity.io/

## Docs

- 📖 [Usage Guide](./docs/usage.md): learn how to use the [Wasmi API](https://crates.io/crates/wasmi) properly.
- 🛠️ [Development Guide](./docs/developement.md): learn how to develop for Wasmi.
- ✨ [Crate Features](https://docs.rs/wasmi/latest/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`][(#1197)] |
| ✅ | [`saturating-float-to-int`] | ≥ `0.14.0` | | ✅ | [`memory64`] | [≥ `0.41.0`][(#1357)] |
| ✅ | [`sign-extension`] | ≥ `0.14.0` | | ✅ | [`wide-arithmetic`] | [≥ `0.42.0`][(#1369)] |
| ✅ | [`multi-value`] | ≥ `0.14.0` | | ✅ | [`simd`] | [≥ `0.43.0`][(#1364)] |
| ✅ | [`bulk-memory`] | [≥ `0.24.0`][(#628)] | | ✅ | [`relaxed-simd`] | [≥ `0.44.0`][(#1443)] |
| ✅ | [`reference-types`] | [≥ `0.24.0`][(#635)] | | 📅 | [`function-references`] | [Tracking Issue][(#774)] |
| ✅ | [`tail-calls`] | [≥ `0.28.0`][(#683)] | | 📅 | [`gc`] | [Tracking Issue][(#775)] |
| ✅ | [`extended-const`] | [≥ `0.29.0`][(#707)] | | 📅 | [`threads`] | [Tracking Issue][(#777)] |
| ✅ | [`multi-memory`] | [≥ `0.37.0`][(#1191)] | | 📅 | [`exception-handling`] | [Tracking Issue][(#1037)] |

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

[`mutable-global`]: https://github.com/WebAssembly/mutable-global
[`saturating-float-to-int`]: https://github.com/WebAssembly/nontrapping-float-to-int-conversions
[`sign-extension`]: https://github.com/WebAssembly/sign-extension-ops
[`multi-value`]: https://github.com/WebAssembly/multi-value
[`reference-types`]: https://github.com/WebAssembly/reference-types
[`bulk-memory`]: https://github.com/WebAssembly/bulk-memory-operations
[`simd` ]: https://github.com/webassembly/simd
[`tail-calls`]: https://github.com/WebAssembly/tail-call
[`extended-const`]: https://github.com/WebAssembly/extended-const
[`function-references`]: https://github.com/WebAssembly/function-references
[`gc`]: https://github.com/WebAssembly/gc
[`multi-memory`]: https://github.com/WebAssembly/multi-memory
[`threads`]: https://github.com/WebAssembly/threads
[`relaxed-simd`]: https://github.com/WebAssembly/relaxed-simd
[`exception-handling`]: https://github.com/WebAssembly/exception-handling
[`custom-page-sizes`]: https://github.com/WebAssembly/custom-page-sizes
[`memory64`]: https://github.com/WebAssembly/memory64
[`wide-arithmetic`]: https://github.com/WebAssembly/wide-arithmetic

[WASI]: https://github.com/WebAssembly/WASI
[C-API]: https://github.com/WebAssembly/wasm-c-api
[`wasmi_wasi` crate]: ./crates/wasi
[`wasmi_c_api_impl` crate]: ./crates/c_api

[(#363)]: https://github.com/wasmi-labs/wasmi/issues/363
[(#364)]: https://github.com/wasmi-labs/wasmi/issues/364
[(#496)]: https://github.com/wasmi-labs/wasmi/issues/496
[(#628)]: https://github.com/wasmi-labs/wasmi/pull/628
[(#635)]: https://github.com/wasmi-labs/wasmi/pull/635
[(#638)]: https://github.com/wasmi-labs/wasmi/pull/638
[(#683)]: https://github.com/wasmi-labs/wasmi/pull/683
[(#707)]: https://github.com/wasmi-labs/wasmi/pull/707
[(#774)]: https://github.com/wasmi-labs/wasmi/pull/774
[(#775)]: https://github.com/wasmi-labs/wasmi/pull/775
[(#776)]: https://github.com/wasmi-labs/wasmi/pull/776
[(#777)]: https://github.com/wasmi-labs/wasmi/pull/777
[(#1037)]: https://github.com/wasmi-labs/wasmi/issues/1137
[(#1197)]: https://github.com/wasmi-labs/wasmi/issues/1197
[(#1191)]: https://github.com/wasmi-labs/wasmi/issues/1191
[(#1357)]: https://github.com/wasmi-labs/wasmi/issues/1357
[(#1364)]: https://github.com/wasmi-labs/wasmi/issues/1364
[(#1369)]: https://github.com/wasmi-labs/wasmi/issues/1369
[(#1443)]: https://github.com/wasmi-labs/wasmi/pull/1443

## Used by

If you want your project on this list [please inform me](mailto:robin.freyler@gmail.com) about you project and how Wasmi is used.

 
 
 
 
 
 
 
 
 
 

## Sponsors

Special thanks to the past and present sponsors of the Wasmi project.

Sponsoring since Oct. 2024

Sponsored until Oct. 2024

## License

Licensed under either of

  * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or <https://www.apache.org/licenses/LICENSE-2.0>)
  * MIT license ([LICENSE-MIT](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.
