--- name: webspec-index description: Use webspec-index to query WHATWG, W3C, IETF and TC39 web specifications from the command line --- # webspec-index Query WHATWG, W3C, IETF and TC39 web specifications from the command line. Use `webspec-index` whenever you need to understand what a web spec says — algorithm steps, section content, cross-references, or whether a spec anchor exists. Specs are fetched and cached locally on first use. ## Available specs Assume that all specs from WHATWG, W3C, IETF and TC39 are indexed. If in doubt, run `webspec-index specs` to list all spec names and their base URLs. ## Installation If `webspec-index` is not already available in your environment, you can install it via cargo: ```bash cargo binstall webspec-index # or cargo install webspec-index ``` ## Commands Always put the section identifier in quotes to avoid shell interpretation of `#`. See `webspec-index --help` for full command list and options. ### Look up a spec section ```bash webspec-index query 'HTML#navigate' webspec-index query 'DOM#concept-tree' webspec-index query 'CSS-GRID#grid-container' webspec-index query 'https://html.spec.whatwg.org/#navigate' webspec-index query 'DOM#concept-tree' webspec-index query "RFC9000#section-22" webspec-index query "draft-ietf-tsvwg-sctp-dtls-chunk#name-security-considerations" webspec-index query 'https://w3c.github.io/webappsec-permissions-policy/#permissions-policy-header' ``` Returns the section's title, type (heading/algorithm/definition), full content as markdown, navigation tree (parent/prev/next/children), and cross-references. This is the primary command — use it to read what a spec section says. Use `--format markdown` for human-readable output, or default `--format json` for structured data. For non-hardcoded specs, URL queries are accepted for allowlisted domains (`*.spec.whatwg.org`, `drafts.csswg.org`, `w3c.github.io`, `wicg.github.io`, `webaudio.github.io`, `tc39.es`, `w3.org/TR/*`, and `webassembly.github.io`). ### Search across specs ```bash webspec-index search "tree order" webspec-index search "navigate" --spec HTML --limit 5 ``` Full-text search with snippets. Use `--spec` to narrow to one spec. ### Check if a section exists ```bash webspec-index exists 'HTML#navigate' ``` Exit code 0 = found, 1 = not found. Use this to validate anchor names before referencing them. ### Find anchors by pattern ```bash webspec-index anchors "*-tree" --spec DOM webspec-index anchors "concept-*" --spec HTML webspec-index anchors "dom-*assign*" ``` Glob matching (`*` wildcard). Useful when you know part of an anchor name but not the exact id. ### List all sections in a spec ```bash webspec-index list DOM ``` Returns all heading-level sections with their anchors, titles, types, and depths. ### Cross-references ```bash webspec-index refs 'HTML#navigate' --direction incoming webspec-index refs 'HTML#navigate' --direction outgoing webspec-index refs 'HTML#navigate' webspec-index refs 'Window.navigation' --limit 5 ``` Shows which sections reference this one (incoming), which sections this one references (outgoing), or both (default). Target can be exact (`SPEC#anchor` or full URL) or shorthand (`Interface.member`) resolved heuristically against currently indexed sections. Use `--limit` to cap results when using shorthand queries. ### WHATWG PR previews ```bash webspec-index query 'HTML#navigate' --pr 12345 webspec-index query 'HTML#navigate' --pr 12345 --diff --format markdown webspec-index query 'HTML#navigate' --pr 12345 --force-update webspec-index exists 'HTML#navigate' --pr 12345 webspec-index list HTML --pr 12345 webspec-index refs 'HTML#navigate' --pr 12345 webspec-index search 'OpaqueRange' --spec HTML --pr 12345 webspec-index anchors '*opaquerange*' --spec HTML --pr 12345 ``` Query spec sections as modified by an open WHATWG PR. Previews are lazily fetched from whatpr.org on first use and cached for 24h. - `--pr N`: query the spec as it would look after PR N is merged. Sections not modified by the PR fall back to the merge base. - `--diff`: show a section-level diff between the PR and its merge base. Lists added/modified sections with unified diffs. - `--force-update`: re-fetch the PR preview even if recently cached (use after the PR is updated). Manage cached PR data with `clear-pr`: ```bash webspec-index clear-pr # list cached PRs webspec-index clear-pr --spec HTML --pr 12345 # remove one PR webspec-index clear-pr --all # remove all ``` ### Update specs ```bash webspec-index update webspec-index update --spec HTML webspec-index update --force ``` Fetches latest spec versions. Uses 24h cache unless `--force` is given. Specs are auto-fetched on first query, so you rarely need this. Specs are checked on a 24h cadence; re-indexing happens only when fetched HTML content changed. ### Graph traversal ```bash webspec-index graph 'HTML#navigate' --direction outgoing --max-depth 2 webspec-index graph 'HTML#navigate' --graph-format mermaid webspec-index graph 'HTML#navigate' --graph-format dot webspec-index graph 'HTML#navigate' --same-spec-only webspec-index graph 'HTML#navigate' --include '*concept-*' --exclude 're:^URL#' ``` Builds a cross-reference graph rooted at a section. Supports JSON (default), Markdown, Mermaid, and Graphviz DOT output. Use `--include` and `--exclude` to filter node ids (`SPEC#anchor`) by wildcard patterns (`*`, `?`) or regex (`re:`). ### Query dedicated WebIDL definitions ```bash webspec-index idl 'HTML#dom-window-navigation' webspec-index idl 'Window.navigation' webspec-index idl 'Window.open()' webspec-index idl 'navigation' --spec HTML --limit 5 ``` Queries structured WebIDL definitions directly. Supports exact anchors (`SPEC#anchor` or URL) and canonical names (`Interface.member`, `Interface.method()`). Use this first when the task is about API shape or IDL ownership, then use `refs` to see algorithm usage. ## Usage patterns for Gecko development ### Understanding what you're implementing When working on a bug that references a spec algorithm: ```bash # Read the algorithm you need to implement webspec-index query 'HTML#navigate' --format markdown # Check what concepts it references webspec-index refs 'HTML#navigate' --direction outgoing # Look up a referenced concept you don't understand webspec-index query 'INFRA#ordered-set' ``` ### Finding the right spec section When you see a spec URL in code comments (e.g., `https://html.spec.whatwg.org/#navigate`), or a step comment like `// Step 3.2`, query the section to understand the algorithm: ```bash webspec-index query 'https://html.spec.whatwg.org/#navigate' ``` When you know a concept but not its exact anchor: ```bash # Search by text webspec-index search "tree order" --spec DOM # Or find by anchor pattern webspec-index anchors "*tree*order*" --spec DOM ``` ### Verifying spec anchors Before adding a spec URL to a code comment, verify the anchor exists: ```bash webspec-index exists 'HTML#navigate' && echo "valid" ``` ### Understanding cross-spec dependencies To see what other specs depend on a concept you're changing: ```bash webspec-index refs 'DOM#concept-tree' --direction incoming ``` ### Tracing IDL API usage in algorithms When implementing or reviewing a DOM API in Gecko: ```bash # Find canonical IDL definition + owning interface webspec-index idl 'Window.navigation' --format markdown # Find where the property is used in indexed specs webspec-index refs 'Window.navigation' --direction incoming ``` ### Finding where Gecko implements a spec section When the user asks where a spec algorithm is implemented in Gecko or SpiderMonkey, query the spec section first, then pass the `url` field from the response to `searchfox-cli`: ```bash # Step 1 — read the spec section (response includes a "url" field) webspec-index query 'HTML#navigate' --format json # Step 2 — find Gecko source files that reference that URL searchfox-cli --spec-refs 'https://html.spec.whatwg.org/#navigate' ``` Always do this when the user asks questions like "where is X implemented", "which file handles Y", or "show me the Gecko code for Z". The `url` field in the `query` response is the value to pass to `--spec-refs` — no manual URL construction needed. ### Implementing a feature from a spec PR When the bug references a spec PR that hasn't landed yet: ```bash # See what the PR changes at a section level webspec-index query 'HTML#navigate' --pr 12345 --diff --format markdown # Read the algorithm as modified by the PR webspec-index query 'HTML#navigate' --pr 12345 --format markdown # Check what new cross-references the PR introduces webspec-index refs 'HTML#navigate' --pr 12345 --direction outgoing ```