California Tax Appeals

io.github.pipeworx-iov0.1.0Updated Oct 9, 2026

California Office of Tax Appeals (OTA) opinions — search by statute

VerifiedStreamable HTTPWeb executableFinanceKnowledge & Memory

Overview

AI-generated overview

Lets an assistant search California Office of Tax Appeals opinions by topic or statute citation and retrieve a specific opinion's full text.

What it does
Provides two tools over a remote endpoint: ca_ota_search finds opinions by topic keyword or statute citation and returns citation, title, date, tax category, precedential status and OTA's one-line Issues tag, most recent first; ca_ota_opinion_lookup fetches one opinion by its OTA citation and returns the full text, exact issue date, internal case number, tax category, precedential status and statute citations found in the text. Search covers listing metadata only, since OTA publishes no full-text search. The endpoint also lists shared gateway meta-tools such as ask_pipeworx and discover_tools.
When to use it
Useful when researching California tax law, checking how OTA has treated a statute or topic, or pulling the text of a known opinion. Best when you already have a topic, statute number or OTA citation to work from.
Requirements
A remote MCP endpoint; no signup, API key or environment variable is declared. Network access to the gateway is required. A local stdio variant is described as an npm package run with npx, which needs Node.js.
Before you install
Read-only access to public OTA opinions; no credentials, payments or write actions are described. Search matches only titles and OTA's Issues tags, so a statute cited only in an opinion's body will not be found by search. The integration is described as independent and unofficial, not affiliated with or endorsed by the upstream provider.

Installation

In SourceWeft

  1. Open California Tax Appeals in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "california-tax-appeals": {
      "type": "http",
      "url": "https://gateway.pipeworx.io/california-tax-appeals/mcp"
    }
  }
}

README

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of Tax Appeals (OTA) opinions — search by statute citation or topic across 4,254 issued opinions (precedential and nonprecedential, 2018–2026), or retrieve one specific opinion's full text and cited provisions by its OTA citation.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

  • ca_ota_search(query, category?, precedential_only?, limit?) — find 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.
  • ca_ota_opinion_lookup(cite) — fetch one opinion by its OTA citation (e.g. "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).

Auth

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

Data sources

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).

ca_ota_search 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 ca_ota_opinion_lookup on a specific citation to read that opinion's full text.

"Case number" = OTA's own citation (e.g. "2020-OTA-263P", the trailing "P" marking Precedential status) — what OTA itself cites opinions by, not the PDF's internal 8-digit "OTA Case No." docket number (which only appears inside the PDF body and is surfaced in ca_ota_opinion_lookup's response as ota_case_no, read live, not indexed). The trailing precedential marker may be omitted when looking up a citation; ca_ota_opinion_lookup tries both forms before reporting a miss. Some opinions carry other OTA suffix letters (e.g. "...SCP" for a Summary Conclusion of Proceedings) — those must be typed exactly.

A transport failure (non-200) or a listing/PDF mismatch (a 404 for a citation the index says has a PDF) throws loudly naming the upstream status — never a silent found: false. A PDF that exists but fails to extract (rare; e.g. a scanned, non-text PDF) degrades to full_text: null with a warning rather than throwing, since the opinion's metadata (title, date, decision type, Issues tag) is still valid from the listing page.

Re-run node scripts/bake-index.mjs > src/ca-ota-index-data.ts periodically to pick up newly issued opinions — it refuses to write a suspiciously small index (fewer than 2,000 opinions or fewer than 15 listing pages fetched), so a silent partial bake from an OTA markup change is caught rather than shipped.

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

json
{  "mcpServers": {    "california-tax-appeals": {      "url": "https://gateway.pipeworx.io/california-tax-appeals/mcp"    }  }}

What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/california-tax-appeals/mcp returns the tools in the table above plus the shared Pipeworx meta-tools — ask_pipeworx, discover_tools, search_within, remember/recall and the rest of the gateway-wide set. So the tool count you see is larger than this table: a single-pack endpoint currently lists roughly 30 shared tools alongside the pack's own. The connection's initialize response states its exact scope, and is the authoritative answer for a given day.

This is deliberate, not multiplexing by accident. The meta-tools are what let a scoped connection answer a question this pack does not cover — via ask_pipeworx, which routes across the whole catalog — without you adding a second MCP server. There is currently no way to mount a pack endpoint without them; if the extra schemas cost you more context than the routing is worth, connect to the full gateway once rather than to several pack endpoints.

Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:

json
{  "mcpServers": {    "pipeworx": {      "url": "https://gateway.pipeworx.io/mcp"    }  }}

Both URLs reach the same gateway and the same 1743+ data sources. The only difference is which pack's tools are listed directly; ask_pipeworx reaches all of them from either one.

No MCP client? Call it over HTTP

bash
curl -X POST https://gateway.pipeworx.io/v1/tools/ca_ota_search \  -H 'Content-Type: application/json' \  -d '{"query":"residency"}'

No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/ca_ota_search. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.

Standalone (no gateway account)

This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:

json
{  "mcpServers": {    "california-tax-appeals": {      "command": "npx",      "args": ["-y", "@pipeworx/mcp-california-tax-appeals"]    }  }}

Or run it directly to confirm it starts:

bash
npx -y @pipeworx/mcp-california-tax-appeals

It speaks MCP over stdin/stdout and answers initialize/tools/list/tools/call for only this pack's tools — none of the shared meta-tools the gateway connection above adds. Same source, same tools, no ask_pipeworx routing.

Using with ask_pipeworx

Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:

ask_pipeworx({ question: "your question about California Tax Appeals data" })

The gateway picks the right tool and fills the arguments automatically.

More

License

MIT

Source: README.md at commit 52935a5

Tools

0
Tool metadata has not been indexed yet.

Version history

1
  1. v0.1.0LatestOct 9, 2026