# MarketCheck Developer Portal

> MarketCheck is an automotive data platform: 40M+ active vehicle listings
> across cars, RVs, motorcycles, and heavy equipment, plus VIN decoding, price
> prediction, vehicle history, and sold-market insights. This portal
> (developers.marketcheck.com) is where developers get API keys, manage plans,
> billing and usage, and connect AI assistants over MCP. The full REST API
> documentation lives at docs.marketcheck.com.

## Build against the API (for coding assistants)
- OpenAPI 3.1 spec, every endpoint with parameters and real examples: https://developers.marketcheck.com/openapi.json
- Repo conventions file, drop into your project root: https://developers.marketcheck.com/AGENTS.md (curl -O it)
- Docs MCP server, free and keyless (semantic docs search + endpoint reference inside Claude Code, Cursor, VS Code, Windsurf): https://developers.marketcheck.com/api/docs-mcp
- Auth is always the api_key QUERY PARAMETER on every request, never a header.
- Quickstart: GET https://api.marketcheck.com/v2/search/car/active?api_key=YOUR_API_KEY&make=Toyota&zip=30301&radius=50
- Rate limits: Free 500 calls/month at 5 rps; Basic 5,000/month at 5 rps; Standard pay-as-you-go at 40 rps; Enterprise custom. On 429 honor Retry-After and distinguish RateLimit-* (per second) from Quota-* (per month) headers. Server timeout 120 s.
- Pagination: start + rows, rows max 50; paging past your plan's limit returns 422 (treat as end of results).

## Full REST documentation (canonical)
- Docs index for LLMs: https://docs.marketcheck.com/llms.txt
- Every page, fully resolved, one file: https://docs.marketcheck.com/llms-full.txt
- Any docs page URL + .md returns raw markdown, e.g. https://docs.marketcheck.com/docs/api/cars/inventory/inventory-search.md

## MCP servers
- Docs MCP (documentation, no auth): https://developers.marketcheck.com/api/docs-mcp
  Tools: search_docs, get_doc_page, list_endpoints, get_endpoint, get_plans_and_limits.
  Claude Code: claude mcp add --transport http marketcheck-docs https://developers.marketcheck.com/api/docs-mcp
- Data MCP (live vehicle data, account required): https://developers.marketcheck.com/api/mcp (Streamable HTTP, OAuth 2.1 + PKCE). Add it as a custom connector in Claude or ChatGPT; per-tool scopes are managed in the portal.
- IDE agents with an API key: npx @marketcheck/mcp-client (stdio proxy). Config snippets: https://developers.marketcheck.com/mcp

### Data MCP tools (US)
- search_active_cars: listings search across 40M+ active inventory with 100+ filters.
- search_past_90_days: recently sold or expired dealer listings, with sold counts, median prices, days-to-sell.
- predict_price_with_comparables: AI price prediction with the comparables used to derive it.
- get_car_history: complete listing history by VIN.
- decode_vin_neovin: full VIN specs, options, packages, trim via NeoVIN.
- get_server_info: server metadata and tool catalog.

### Data MCP tools (UK)
- search_uk_active_cars: UK live listings search.
- search_uk_recent_cars: UK recently sold or expired listings.

## Plans and pricing
- Current plans and per-endpoint rate cards: https://developers.marketcheck.com/ (pricing section)
- Per-call prices, machine-readable (agentic commerce feed): https://developers.marketcheck.com/acp-feed.json

## Core pages
- [Developer portal home](https://developers.marketcheck.com/): product overview, pricing, sign-up.
- [MCP overview](https://developers.marketcheck.com/mcp): tools, connect flows for Claude, ChatGPT, Cursor, coding assistants.
- [Sign up](https://developers.marketcheck.com/sign-up): create a free account and get an API key.

## Legal
- [Terms of Service](https://developers.marketcheck.com/terms)
- [Privacy Policy](https://developers.marketcheck.com/privacy)

## Contact
- api@marketcheck.com, or the contact options on the portal home page.