OwnerSpec

OwnerSpec MCP Server

The official Model Context Protocol server for OwnerSpec.com, an independent, numbers-first reference for the equipment people own and maintain at home, in three categories: home water treatment (softeners, sediment and carbon filters, reverse osmosis, UV, iron, hardness, sulfur smell, well water testing), home plumbing (water heaters, leaks, freeze protection, toilets, faucets, sump pumps, dehumidifiers) and home air (air purifiers and CADR, humidifiers, furnace filters and MERV). Every figure on the site is cited to EPA, NSF/ANSI, WQA, DOE, AHAM, a state extension service or the manufacturer's own document, and every page carries the date its facts were verified.

Live endpoint: https://ownerspec.com/mcp

Stateless Streamable HTTP transport (JSON-RPC 2.0 over POST), no authentication, no sessions. Any MCP client can connect and start calling tools immediately.

Connect

Claude Code

claude mcp add --transport http ownerspec https://ownerspec.com/mcp

Claude.ai / Claude Desktop: Settings, Connectors, Add custom connector, https://ownerspec.com/mcp, no authentication.

ChatGPT: Settings, Connectors, Advanced, Developer mode, then add https://ownerspec.com/mcp as an MCP connector (no auth).

MCP Inspector

npx @modelcontextprotocol/inspector https://ownerspec.com/mcp

Tools

Tool	What it does
search_pages	Full-text search over every page, filterable by layer (guides, calculators, parts, reviews) and topic
get_page	Fetch one page as clean Markdown with canonical URL, dates and sources
get_quick_answer	The page's cited 134 to 167 word quick answer, its fact sheet (answer, formula or compatibility basis, inputs, assumptions, method, typed primary source), verified date, FAQ and typed source list: the passage to quote
read_water_report	Lab, test-kit or utility results in, each compared with the EPA limit on OwnerSpec's EPA table, with unit conversion and the guide to read
diagnose_water_problem	Symptom or lab result in, the matching diagnosis guides and their quick answers out
troubleshoot_home_equipment	A beeping alarm, a popping water heater, a pump that will not start: the guides that explain it
find_replacement_part	Model or part number in, the cartridges, lamps or parts that fit out, with the cross-reference page
get_product_picks	The picks from the review and parts pages that match a need, with the review page that compares them
list_calculators	Every OwnerSpec calculator with its id and input fields
run_calculator	One calculator prefilled with the user's numbers: the page's live calculator in apps, the formula in text
convert_water_hardness	gpg, mg/L, dH, fH, Clark and mmol/L, with the USGS band
size_water_softener	Grain capacity between regenerations, nearest nominal size and the salt-efficient Fleck 5600SXT row
plan_home_maintenance	A dated maintenance schedule, each interval quoted from the maker or body that prints it

All tools are read-only and annotated readOnlyHint: true, destructiveHint: false.

MCP App

In hosts that support MCP Apps (io.modelcontextprotocol/ui), eight tools render an interactive view: the live calculator with the user's numbers, a flagged water report table, a dated maintenance plan, and cards for guides, parts and picks. The view (functions/_lib/widget.js, served as ui://ownerspec/view-v1.html) is one self-contained HTML document with a hand-written postMessage bridge, no SDK and no third-party origin. Calculators run the site page's own form and script, taken from /index.json, so the in-chat answer is the page's answer.

Every answer ends with the URL to cite and the facts-verified date. The two ported calculator tools use the same constants as the calculator pages on the site, run_calculator runs the page's own code, and the site's build fails if either side drifts.

The server also exposes resources (llms.txt, llms-full.txt, the sitemap, the search index, the OpenAPI description, auth.md) and one prompt, answer_from_ownerspec.

A2A agent

functions/a2a.js is a minimal A2A agent at https://ownerspec.com/a2a: a question in a SendMessage (or message/send) call, a completed task out whose artifact holds the matching pages, quick answers and URLs to cite. Card: https://ownerspec.com/.well-known/agent-card.json.

Markdown for agents

The whole site is agent-readable, not just this server:

• Any page returns Markdown when requested with Accept: text/markdown, or at its URL plus index.md.
• Discovery files: /.well-known/mcp/server-card.json, /llms.txt, /.well-known/agent-skills/index.json, /.well-known/api-catalog, /.well-known/ard.json, /openapi.json, /auth.md.
• Human documentation: ownerspec.com/mcp-server.

Transparency

OwnerSpec is an affiliate-funded site, but this server returns no product links, no prices and no ads: picks come back with the OwnerSpec review page that compares them, and the affiliate links and their disclosure live on that page. Editorial content is free to read, with no paywall and no auth. The site makes no medical claims and neither do the tools: contaminant figures are quoted as EPA, WHO or state limits. Privacy: ownerspec.com/legal/privacy (section 2.5).

Self-hosting

This is a Cloudflare Pages Function (functions/mcp.js, functions/a2a.js, shared code in functions/_lib/). To run your own instance:

1. Deploy the functions/ directory with a Cloudflare Pages project in front of a static site.
2. The server reads its content live from the site it fronts: a build that emits /index.json (one record per page: title, url, layer, topic, dates, quick answer, FAQ, sources, picks, text) and a Markdown twin at <page>/index.md. Point the SITE constant at your deployment.
3. Replace the calculator constants in mcp.js with the ones printed on your own pages, or remove those two tools.

This repository mirrors the production functions. Keep them in sync with your own site config if you fork it.

License

MIT