# How good of a deal is this car?

DealScore grades a used car's asking price against live market comps — grade, short brief, and risks.

- HTML: https://cardealscore.com/
- Markdown: https://cardealscore.com/index.md
- API docs: https://cardealscore.com/docs/api
- Auth: https://cardealscore.com/auth.md
- llms.txt: https://cardealscore.com/llms.txt

## For humans

Use the web form at https://cardealscore.com/. Live scores require sign-in and share a Free meter of 40 scored deals per month with REST and MCP. Only coverage: scored counts. Paste a listing URL to prefill fields, or optional listing text, or send year/make/model or VIN, asking price, and mileage. ZIP is optional if you want local comps. Facebook Marketplace and Craigslist URLs are refused. Grades use dealer-market comps. A private-party ask may grade lower.

## For agents

MCP Streamable HTTP: https://cardealscore.com/api/mcp

OAuth is the default connect path. Add the URL and sign in in the browser:

```json
{
  "mcpServers": {
    "dealscore": {
      "url": "https://cardealscore.com/api/mcp"
    }
  }
}
```

API keys remain for curl/scripts:

```json
{
  "mcpServers": {
    "dealscore": {
      "url": "https://cardealscore.com/api/mcp",
      "headers": { "x-api-key": "YOUR_KEY" }
    }
  }
}
```

Tools: score_deal, explain_grade, health.

REST:

- `POST https://cardealscore.com/api/score` — grade a deal
- `POST https://cardealscore.com/api/explain` — map delta_pct to a grade
- `GET https://cardealscore.com/api/health` — health (no auth)

Auth: MCP clients use OAuth (browser consent). REST and scripts use `x-api-key` or `Authorization: Bearer` with an API key. Live homepage scores need sign-in and share the Free meter. [Sign in to create an API key](https://cardealscore.com/login). Email magic link — no password. Manage keys at https://cardealscore.com/keys. Live scores share a Free meter of 40 scored deals per month. Sign in on the homepage before live scoring. Details: https://cardealscore.com/docs/api#get-a-key See https://cardealscore.com/auth.md.

Discovery:

- https://cardealscore.com/.well-known/mcp/server-card.json
- https://cardealscore.com/.well-known/oauth-protected-resource
- https://cardealscore.com/.well-known/oauth-authorization-server
- https://cardealscore.com/.well-known/api-catalog
- https://cardealscore.com/.well-known/agent-skills/index.json

## Guides

- [How grades work](https://cardealscore.com/guides/how-deal-grades-work)
- [Is this car a good deal?](https://cardealscore.com/guides/is-this-car-a-good-deal)
- [Score by VIN](https://cardealscore.com/guides/vin-deal-score)
- [Score a car deal with an agent](https://cardealscore.com/guides/score-a-car-deal-with-an-agent)

## Limits

- No Facebook Marketplace or Craigslist URL fetch. A listing URL or pasted text is allowed. Grades use dealer-market comps. A private-party ask may grade lower.
- Production uses live dealer comps; thin data returns `coverage: cannot_score`
- Comps are request-scoped only
- Free meter: 40 scored deals per month per user. Homepage, REST, and MCP share one counter. Over-cap is an error, never a silent mock.