California Tax Appeals MCP server

@pipeworx/california-tax-appeals

California Office of Tax Appeals (OTA) opinions — search by statute citation or topic across 4,254 issued opinions (precedential and nonprecedential, 2018–2026), or retrieve one specific opinion's full text and cited provisions by its OTA citation.

Part of Pipeworx — an MCP gateway connecting AI agents to 1743+ live data sources. This is an independent, unofficial integration — not affiliated with, endorsed by, or published by the upstream provider.

Tools

opinions by topic keyword (e.g. "residency", "innocent spouse") or statute citation (e.g. "17014"). Returns citation, title, date, tax category (Franchise/Income Tax vs Business Tax), precedential status, and OTA's own one-line "Issues" tag, most recent first. Searches listing metadata only (title + Issues tag) — OTA publishes no full-text search.

• caotasearch(query, category?, precedential_only?, limit?) — find

"2020-OTA-263P"), live. Returns the full opinion text, exact date issued, OTA's internal case number, tax category, precedential status, and statute citations found in the text (best-effort R&TC/Cal. Code Regs./IRC).

• caotaopinion_lookup(cite) — fetch one opinion by its OTA citation (e.g.

Auth

Keyless. No signup — this is a read of OTA's own published, public opinions.

Data sources

(scripts/bake-index.mjs) scrapes to discover every per-year and all-precedential opinion listing page.

• — the landing page this pack's bake script

and — every opinion issued that year/category, precedential and nonprecedential alike.

• Per-year listing pages, e.g.

— fetched too, to cover any year a per-year page might omit.

• All-years precedential pages, e.g.

https://ota.ca.gov/wp-content/uploads/sites/54/2021/06/19064883MazerOpinionRevised090420P.pdf) — fetched live per caotaopinionlookup call, text extracted with shared/src/pdf-text.ts.

• Individual opinion PDFs (e.g.

Shape and known limits

ota.ca.gov (WordPress/WP Engine, TablePress tables) has no JSON search backend — every opinion-listing page renders its whole table as static HTML; the DataTables plugin paginates it client-side only (confirmed live: every DataTable('#tablepress-NNN', {...}) init call on these pages carries no ajax/serverSide option). So this pack bakes a citation-indexed table from OTA's own listing pages rather than proxying a search endpoint — see scripts/bake-index.mjs's own header for exactly which pages it fetches and how it discovers new years without a code change.

Per root CLAUDE.md's standing rule on baked data (fleet #2754), the index (4,254 rows, ~1.6MB) lives in KV, never gateway module scope — uploaded by scripts/sync-gateway-static-json.mjs and injected as args._bakedIndex (registered in workers/gateway/src/pack-baked-indexes.json).

caotasearch searches listing metadata only — the opinion title and OTA's own one-line "Issues" tag (e.g. "Residency (R&TC 17014; Reg. 17014)"). A statute cited only in an opinion's full body text, and not in its Issues tag, will not be found by search; use caotaopinion_lookup on a specific citation to read that opinion's full text.

Shortened. The full README is on GitHub.