generated: '2026-08-27'
method: searched
source: https://lwc.dev/guide/ (LWC open-source developer guide) + https://github.com/salesforce/lwc
provider: Lightning Web Components
providerId: lightning-web-components
description: >-
  Standards conformance for Lightning Web Components. LWC is a UI component framework, not an HTTP
  API, so the cross-cutting API standards this pipeline normally checks (OAuth 2.0, OIDC, RFC 9457,
  pagination, idempotency) do not apply. The standards that DO apply are the W3C/WHATWG web-component
  family — and LWC's own documentation declares conformance to them explicitly, which is the
  domain-standard signature for this market.
domain_standard:
  market: client-side UI component frameworks
  standard: W3C / WHATWG Web Components (Custom Elements, Shadow DOM, HTML templates) + ECMAScript modules
  declared: true
  grade: verified
  evidence:
    - claim: >-
        "Lightning Web Components uses standard HTML, modern JavaScript (ES6+), and the best of
        native Web Components."
      location: https://lwc.dev/ (Standards-Based section)
    - claim: >-
        The component lifecycle guide binds constructor() behaviour directly to the spec:
        "These requirements from the HTML: Custom elements spec apply to the constructor()." —
        super() first, no return statement, no document.write()/document.open(), no attribute or
        child inspection before upgrade.
      location: https://lwc.dev/guide/lifecycle
    - claim: >-
        "All JavaScript files in Lightning web components are ES modules." The default export must
        be a class extending LightningElement, "a custom wrapper of the standard HTML element."
      location: https://lwc.dev/guide/es_modules
    - claim: >-
        Interop with third-party web components is a first-class, documented path (lwc:external),
        and the docs state custom elements "must define a component class that extends HTMLElement"
        and "register the custom element within the CustomElementRegistry using
        customElements.define(name, constructor)".
      location: https://lwc.dev/guide/third_party_web_components
    - claim: >-
        @lwc/synthetic-shadow ships a Shadow DOM polyfill and @lwc/aria-reflection ships an ARIA
        element reflection polyfill — implementations of the standards themselves, published to npm.
      location: https://www.npmjs.com/package/@lwc/synthetic-shadow
  note: >-
    Reward-only signal. A buyer who already writes standards-based web components can consume LWC
    output as native custom elements without a bespoke adapter; the docs describe exactly that path.
standards:
  - id: w3c-custom-elements
    name: HTML Custom Elements (WHATWG HTML Living Standard)
    conforms: true
    evidence: >-
      https://lwc.dev/guide/lifecycle cites the "HTML: Custom elements spec" as the normative source
      for constructor() constraints; https://lwc.dev/guide/third_party_web_components documents
      HTMLElement + CustomElementRegistry.define() interop.
  - id: w3c-shadow-dom
    name: Shadow DOM (DOM Living Standard)
    conforms: true
    evidence: >-
      Native shadow DOM is the default encapsulation model; @lwc/synthetic-shadow is published as a
      polyfill for engines without it, and https://lwc.dev/guide/light_dom documents the opt-out.
  - id: ecmascript-modules
    name: ECMAScript Modules (ES2015+)
    conforms: true
    evidence: 'https://lwc.dev/guide/es_modules — "All JavaScript files in Lightning web components are ES modules."'
  - id: wai-aria
    name: WAI-ARIA / ARIA element reflection
    conforms: true
    evidence: >-
      https://lwc.dev/guide/accessibility documents focus management, tabindex semantics (0 and -1
      only) and screen-reader attribute usage; @lwc/aria-reflection ships the ARIA reflection
      polyfill.
  - id: semver
    name: Semantic Versioning 2.0.0
    conforms: true
    evidence: >-
      https://lwc.dev/guide/versioning — "It adheres to semantic versioning (semver)
      characteristics." Documented deviation: the minor number is also incremented when compiler
      output changes.
  - id: slds
    name: Salesforce Lightning Design System (SLDS / SLDS 2)
    conforms: true
    evidence: >-
      The LWC MCP toolset ships orchestrate_lwc_slds2_uplift, explore_slds_blueprints,
      guide_slds_blueprints, explore_slds_styling and guide_slds_styling — SLDS blueprint and
      styling-hook conformance tooling documented at
      https://developer.salesforce.com/docs/platform/lwc/guide/mcp-lwc.html
  - id: mcp
    name: Model Context Protocol
    conforms: true
    evidence: >-
      Salesforce publishes @salesforce/mcp with LWC-specific toolsets, documented in the LWC
      Developer Guide at https://developer.salesforce.com/docs/platform/lwc/guide/mcp-intro.html
  - id: oauth2
    name: OAuth 2.0
    conforms: false
    evidence: >-
      Not applicable at the framework level. LWC exposes no HTTP surface of its own. The DX MCP
      server reaches a Salesforce org through the Salesforce CLI's stored OAuth connection, but that
      is the platform's authorization, not the framework's.
  - id: rfc9457
    name: RFC 9457 Problem Details for HTTP APIs
    conforms: false
    evidence: >-
      Not applicable. LWC's error surface is compile-time and run-time diagnostics in the
      LWC<NNNN> code format (see errors/lightning-web-components-error-codes.yml), not HTTP responses.
  - id: pagination
    name: HTTP pagination conventions
    conforms: false
    evidence: Not applicable — no HTTP collection endpoints.
  - id: idempotency
    name: HTTP idempotency keys
    conforms: false
    evidence: Not applicable — no HTTP write surface.
compliance_certifications:
  scope: parent-brand
  note: >-
    LWC OSS itself carries no certification program. Salesforce, LWC's parent, publishes its
    compliance and certification inventory at the URLs below; components built with LWC and running
    on the Salesforce Platform inherit that platform's certifications. Recorded with the parent-brand
    scope stated rather than claimed as an LWC certification.
  sources:
    - url: https://compliance.salesforce.com/
      status: 200
    - url: https://trust.salesforce.com/en/compliance/
      status: 200
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com