# WebAssembly/spec

WebAssembly specification, reference interpreter, and test suite.

Repository: https://github.com/WebAssembly/spec
Canonical: https://ross.abutalabs.com/products/webassembly-spec
Homepage: https://webassembly.github.io/spec/
Language: WebAssembly
License: NOASSERTION
License Family: other
Topics: specification
Last push: 2026-08-26T22:07:09+00:00

## Health v2 (maintenance only)
Score: 77/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 35, longevity 100
- inputs: {"age_days": 4039, "days_push": 7, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 3442, forks 534 (observed 2026-08-28T04:08:05.126151+00:00)

## What it is
The official WebAssembly specification repository containing the normative spec documents, a reference interpreter (OCaml), and the official conformance test suite. It defines the core semantics, JavaScript and web embedding APIs, and metadata/legacy extensions across WebAssembly versions 1.0 through 3.0.

## Use cases
- implement a WebAssembly engine and verify conformance
- read the formal semantics of WebAssembly instructions and validation
- run the official WebAssembly test suite against my runtime
- understand the JavaScript and web embedding APIs for wasm
- cite the WebAssembly specification in academic work

## When to choose
- building or validating a WebAssembly compiler, runtime, or toolchain
- you need the authoritative, formal definition of WebAssembly semantics
- you want the canonical conformance test suite for wasm engines

## When to avoid
- you want a production WebAssembly runtime or compiler to execute code
- you need tutorials or beginner-friendly introductions to WebAssembly
- you want tooling for building or bundling wasm modules

## Facets
- artifact type: learning-resource
- maturity: active
- function: interpreter, testing, documentation, programming-language
- domain: programming-languages, compilers, web-development, developer-tools
- platform: wasm, browser, cross-platform
- tags: webassembly, specification, reference-interpreter, test-suite, standards, w3c

## Member repositories
- WebAssembly/spec (main) score 77

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:05.126151+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 2026-08-29T18:37:38.224411+00:00, confidence not recorded.
  - readme: https://github.com/WebAssembly/spec (fetched 2026-08-28T04:08:05.126151+00:00, sha 2f65f4f9f614)
  - homepage: https://webassembly.github.io/spec/ (fetched 2026-08-29T09:31:29.938969+00:00, sha ef76a5778f06)
- Data as of 2026-08-30T08:39:29.467469+00:00.