What did people actually pay for X, here, recently? ProofPrice answers that one question for AI agents: a price range (median, 10th–90th percentile), sample size, period, confidence, source and licence, built from official open data.
Live: https://proofprice.com
Ready answers for people and crawlers: https://proofprice.com/prices
MCP server (Streamable HTTP, no key, no sign-in): https://proofprice.com/api/mcp
REST API: https://proofprice.com/api/v1/<category> (openapi.json, llms.txt)
Official data only. Official open data, licensed data or partner data. Nothing scraped against a site's terms.
Aggregates only. No figure comes from fewer than 5 records and no individual's home or purchase is shown.
Licence on every answer. Each answer carries its source, attribution, licence and a price type, so asking prices, posted prices and official averages are never passed off as paid prices.
Information, not a valuation or advice.
Related MCP server: CostAPI
Tool | Answers |
| What homes actually sold for in a town or area |
| Rents tenants actually pay or have agreed |
| Current pump prices near a place |
| Household electricity and gas prices |
| Grocery and everyday prices (milk, bread, eggs, ...) |
| Farm and wholesale food prices |
| Farmland prices and rents |
| Car-related prices actually paid |
| Airfares paid |
| Mobile and broadband prices |
| Childcare fees |
| Doctor and hospital prices paid |
| Official pharmacy prices of medicines |
| What public buyers paid in government contracts |
| Check a proposed price against the recorded evidence |
| What is covered: countries, categories, sources |
A history tool appears automatically once the price library holds enough days of data. Coverage grows as sources are added; call pricepaid_coverage for the current list.
Claude (claude.ai / desktop): Customize > Connectors > Add custom connector > https://proofprice.com/api/mcp (no sign-in).
Claude Code:
claude mcp add --transport http proofprice https://proofprice.com/api/mcpCursor (.cursor/mcp.json):
{ "mcpServers": { "proofprice": { "url": "https://proofprice.com/api/mcp" } } }VS Code / GitHub Copilot (.vscode/mcp.json):
{ "servers": { "proofprice": { "type": "http", "url": "https://proofprice.com/api/mcp" } } }curl:
curl "https://proofprice.com/api/v1/home-sales?country=IE&town=Dublin&property_type=second-hand"More clients (ChatGPT, Windsurf, OpenAI and other SDKs): https://proofprice.com/connect
skills/proofprice/SKILL.md tells an agent when to call ProofPrice and how to cite the answer.
npm ci && npm test && npm run typecheck && npm run buildOne folder per data source in sources/<id>/, one folder per category in categories/<id>/; the registry builds the tools, REST routes, coverage, OpenAPI and llms.txt from them. See CLAUDE.md and sources/_template/README.md.
Ops note: GitHub's "Run failed" emails for Actions can be muted at github.com/settings/notifications (Actions section).
Code: MIT. Data: each source's own licence, stated on every answer.
Contact: hello@proofprice.com
This server cannot be deployed
Prices people actually paid, from official open data: homes, rents, fuel, energy, food, medicines.
Norwegian prices and what they consist of, from open data. Norske priser fra åpne kilder.
Macroeconomic and other official data from 170+ publishers, resolved from natural language with provenance.
Query official statistics through MCP, with periods, places and citable sources in every answer.
