# wasmi-labs/wasmi

Efficient and versatile WebAssembly interpreter for embedded systems.

Repository: https://github.com/wasmi-labs/wasmi
Canonical: https://ross.abutalabs.com/products/wasmi
Homepage: https://wasmi-labs.github.io/wasmi/
Language: Rust
License: Apache-2.0
License Family: permissive
Topics: wasm, rust, interpreter, webassembly, runtime, embedded, lightweight, portable, sandbox, secure, wasi, virtual-machine, standalone
Last push: 2026-08-11T21:23:31+00:00

## Health v2 (maintenance only)
Score: 94/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 97, release rhythm 88, longevity 100
- inputs: {"age_days": 3145, "days_push": 22, "days_rel": 82, "gap_med": 2, "n_releases_24m": 48}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 2173, forks 360 (observed 2026-08-28T04:06:21.993495+00:00)

## What it is
Wasmi is an efficient, lightweight WebAssembly interpreter written in Rust, focused on constrained and embedded (no_std) environments. It offers 100% Wasm spec testsuite compliance, fuel metering, sandboxed deterministic execution, and an API loosely mirroring Wasmtime for drop-in replacement.

## Use cases
- run webassembly modules on embedded systems
- sandbox untrusted wasm code safely
- embed a wasm interpreter in a rust application
- replace wasmtime with a lighter interpreter
- execute wasm with fuel metering for metered execution
- run webassembly in no_std environments

## When to choose
- you need a lightweight, audited wasm interpreter for embedded or constrained targets
- you want deterministic, sandboxed wasm execution with fuel metering
- you need a Wasmtime-like API without a JIT compiler

## When to avoid
- you need maximum wasm execution throughput, where a JIT compiler like Wasmtime is faster
- you need a full wasm runtime with extensive host tooling beyond interpretation

## Facets
- artifact type: library
- maturity: active
- function: interpreter, wasm, security, embedded
- domain: web-development, embedded-systems, developer-tools, security
- platform: rust, embedded, cross-platform, wasm
- tags: wasm-runtime, virtual-machine, fuel-metering, no-std, wasi, drop-in-wasmtime-replacement, sandbox, no_std

## Member repositories
- wasmi-labs/wasmi (main) score 94

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:06:21.993495+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T02:49:03.294473+00:00, confidence not recorded.
  - readme: https://github.com/wasmi-labs/wasmi (fetched 2026-08-28T04:06:21.993495+00:00, sha 65da1098fc94)
  - homepage: https://wasmi-labs.github.io/wasmi/ (fetched 2026-08-29T10:29:13.688056+00:00, sha 44136fa355b3)
  - registry_crates: https://crates.io/api/v1/crates/wasmi (fetched 2026-08-29T10:29:13.690617+00:00, sha 0905570e169e)
- Data as of 2026-08-30T08:39:29.467469+00:00.