seo-sitemaps (M17)

Sitemaps are the discovery contract you hand the crawler — they should list exactly the canonical, indexable URLs and nothing else. Schema rules for related markup: references/schema-tier1.md.

Inputs

Work from the PageSnapshot named in your dispatch envelope: read parsed from <run_dir>/pages/<slug>.json plus <run_dir>/site/sitemaps.json (+ site/sitemap-urls.txt), <run_dir>/site/robots.json, and <run_dir>/crawl.json for orphan reconciliation and per-URL status; Grep pages/<slug>.html for verbatim evidence. Deterministic findings already emitted by audit.mjs are listed in <run_dir>/findings.deterministic.json — do not re-emit those ids; add model-judged findings only. If invoked directly with a URL/path and no snapshot exists, first run node "${CLAUDE_PLUGIN_ROOT}/scripts/snapshot.mjs" <target> --out "${CLAUDE_PLUGIN_DATA}/runs" and use the printed snapshot path.

Audits

Working from the PageSnapshot (parsed_rendered when render.used is not none, else parsed) plus site/sitemaps.json and site/robots.json:

1. Presence & validity: locate XML sitemap(s) (/sitemap.xml, robots Sitemap: lines, sitemap index); parse as well-formed XML against the sitemaps.org schema.
2. Size limits: each sitemap <=50,000 URLs and <=50MB uncompressed; if exceeded, expect a sitemap index splitting the set.
3. Extensions: where relevant, validate image:, video:, and news: namespace entries (correct namespace declared, required child elements present).
4. lastmod accuracy: <lastmod> is valid ISO 8601 and reflects real last-modified time — not a build-time stamp on every URL (which trains crawlers to ignore it).
5. robots referencing: at least one absolute Sitemap: line in robots.txt.
6. Sitemap-to-canonical consistency: no URL in the sitemap is noindex, redirected, 4xx/5xx, or non-canonical (self-referencing canonical only). Cross-check indexability with M-indexability.
7. Orphan reconciliation: diff sitemap URLs against the internal link graph — flag indexable pages absent from the sitemap and sitemap URLs unreachable by internal links.

Fixes

• AUTO: generate or repair XML sitemap entries (correct <loc>, accurate <lastmod> from observed last-modified data, valid image:/video: extension children where media exists) and add an absolute Sitemap: line to robots.txt. These are additive/deterministic diffs for fix.
• PROPOSED: removing or splitting entries (e.g. dropping non-canonical/noindex URLs, sharding into a sitemap index) — drafted, accepted per-item.
• ADVISORY: changing site-wide lastmod strategy or canonical decisions — described, never written by the tool.
• Never fabricate lastmod times, media URLs, or canonical targets — pull from observed data, ask the user, or leave a clearly-marked TODO placeholder per the schema fixable contract.

Verification

• From the run (no network): read <run_dir>/site/sitemaps.json and <run_dir>/site/robots.json — the crawl already walked the index, followed gzipped children and recorded the per-file errors.
• Re-fetch: node "${CLAUDE_PLUGIN_ROOT}/scripts/parse-robots-sitemap.mjs" --url <final_url> [--max-sitemaps 50] [--max-urls 100000] [--no-well-known] — method xml_parse: parses robots.txt + every declared and probed sitemap, checks well-formedness, size caps, namespace/extension validity, and the canonical/noindex consistency assertion. --sitemap <sitemap url> targets one file and --file <robots.txt> [--path /x] parses an offline robots file. This script has no --snapshot mode: sitemaps are site-level artifacts, not page snapshots.
• When the required data tier (live fetch of sitemap/robots, or the resolved link graph) is unavailable, status is needs_api — never a false pass.

Findings

Emit findings per schema/finding.schema.json. Examples:

• M17.sitemap.missing — no XML sitemap found at /sitemap.xml or in robots.txt (status fail, severity 3, fixable: auto, axis search, confidence established).
• M17.robots.no_sitemap_line — sitemap exists but no Sitemap: line in robots.txt (status warn, severity 3, fixable: auto, axis search, confidence established).
• M17.sitemap.noindex_url — a <loc> in the sitemap points to a noindex/non-canonical URL (status fail, severity 3, fixable: proposed, axis search, confidence established).
• M17.sitemap.error_url — a <loc> the crawl fetched returned 4xx/5xx (status fail, severity 3, fixable: proposed, axis search, confidence established).
• M17.sitemap.redirected_url — a <loc> redirects instead of returning the final URL (status warn, severity 3, fixable: proposed, axis search, confidence established).
• M17.sitemap.missing_indexable_url — an indexable URL the crawl found is listed in no sitemap (status warn, severity 3, fixable: proposed, axis search, confidence directional — a well-linked page is discovered without a sitemap).
• M17.sitemap.lastmod_identical — every <loc> carries the same <lastmod>, so the file cannot distinguish a changed page from an unchanged one (status warn, severity 2, fixable: advisory, axis search, confidence directional). Per-URL verdicts are only emitted for <loc> entries the crawl actually fetched; a URL that was never visited is left unreported rather than guessed. M17.sitemap.missing is also emitted as needs_api when sitemap discovery never ran in the run (--artifacts none / --no-sitemaps), which is a different fact from "no sitemap exists". Platform-conditional ids. This module also emits 8 ids that fire only when profile.json names the platform (shopify, wordpress, nextjs, nuxt, astro, gatsby, hugo). They are indexed in references/routing.md § Platform-conditional finding ids and specified in references/platforms/<id>.md §10.

Each finding: evidence.observed quotes the page/sitemap verbatim; verification.reproduce is the runnable command above; expected_impact is banded + confidence-tagged (no naked %).

Honesty

• A sitemap is a discovery aid, not a ranking signal or an indexing guarantee — Google treats <lastmod>, <priority>, and <changefreq> as hints, and <priority>/<changefreq> are largely ignored, so don't promise ranking lift from tuning them (label any such tactic low-magnitude/directional).
• Submitting a sitemap won't force indexing of low-quality or non-canonical pages; orphan and canonical hygiene matters more than sitemap size.