attic-mcp

Attic

MCP server for Attic Capital. It gives any MCP client the public Attic API: weekly top-5 market reports for rare coins, sports cards, collector cars, and fine art, across 14 pillars, plus gatherings, Creators episodes, and site articles.

Headlines are public. Attic Beyond (the Beyond the Headlines layer, object dossiers, and Market Strength indexes) needs an API key, sent as X-Attic-Key. The paid tier will be sold through Stripe. This server does not take payment and does not ship checkout code. Until that exists, a key issued by Attic Capital is enough.

The wrapped API is OpenAPI 0.1.17. Answers cite atticcapital.com. Article output is the short excerpt only. This server never downloads an article body.

Install

Requires Node.js 18 or newer.

npx -y attic-mcp

attic-mcp was free on the npm registry on 20 October 2026. Until it is published, run from a checkout:

npm install
npm run build
node dist/stdio.js

Optional Beyond key:

export ATTIC_API_KEY="your-key"

Or a JSON file (--config attic.config.json) with apiKey, baseUrl, timeoutMs, retries, and cacheTtlMs. See attic.config.example.json. Precedence is request header, then --api-key, then ATTIC_API_KEY, then the file.

Reports are weekly. Responses are cached for 15 minutes by default (ATTIC_CACHE_TTL_MS). Requests time out after 12 seconds and retry twice on 429, 5xx, and network errors.

Claude Desktop

claude_desktop_config.json:

{
  "mcpServers": {
    "attic": {
      "command": "npx",
      "args": ["-y", "attic-mcp"],
      "env": {
        "ATTIC_API_KEY": "optional-beyond-key"
      }
    }
  }
}

Leave out env if you only want public Headlines, articles, episodes, and gatherings.

Cursor

.cursor/mcp.json or the global MCP config:

{
  "mcpServers": {
    "attic": {
      "command": "npx",
      "args": ["-y", "attic-mcp"]
    }
  }
}

A repo-root .mcp.json is included for directory crawlers that look for that filename.

VS Code

.vscode/mcp.json:

{
  "servers": {
    "attic": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "attic-mcp"]
    }
  }
}

ChatGPT and other remote clients

Run the Streamable HTTP transport and give the client the /mcp URL.

npm run build
ATTIC_PORT=8787 node dist/http.js

Health check: http://127.0.0.1:8787/health

MCP endpoint: http://127.0.0.1:8787/mcp

In ChatGPT, add a custom connector (developer mode) and paste the public HTTPS URL of /mcp. For Beyond, set the request header X-Attic-Key. Authorization: Bearer <key> is accepted too. The server forwards either value as X-Attic-Key and does not log it.

Deploy steps are in PUBLISHING.md. Nothing in this repo is deployed for you.

What you can ask

• What changed in sports cards this week?
• Headlines top 5 for rare coins, pillar The Objects.
• Summarize the latest Attic article and link the page.
• Which Creators episode is about Nolan Ryan?
• Weekly brief for collector cars.

Prompts registered on the server: weekly-market-brief and what-changed-this-week.

Tools

Tool	API	Access
attic_status	GET /status	Public
attic_list_markets	GET /markets	Public
attic_list_pillars	GET /pillars	Public
attic_get_market_report	GET /roster	Headlines public, Beyond paid
attic_get_report_entry	GET /entry	Headlines public, Beyond paid
attic_search	GET /search (query)	Headlines public, layer=beyond paid
attic_list_gatherings	GET /gatherings	Public
attic_get_changes	GET /changes	Headlines public, layer=beyond paid
attic_list_articles	GET /articles	Public excerpts
attic_get_article	GET /article	Public excerpt
attic_list_episodes	GET /episodes	Public
attic_get_episode	GET /episode	Public
attic_get_dossier	GET /dossier	Attic Beyond
attic_get_indexes	GET /indexes	Attic Beyond
attic_comps_status	GET /comps/status	Public
attic_lookup_psa_cert	GET /comps/card/psa	Stub, key required
attic_card_sold_comps	GET /comps/card/sold	Stub, key required
attic_coin_sold_comps	GET /comps/coin/sold	Stub, key required

Resources: attic://markets, attic://markets/{slug}, attic://pillars, attic://pillars/{slug}.

PSA and eBay-sold comps are stubs. PCGS comps are not offered. The tools say so. Do not invent grades or sold prices.

A gated call with no key returns an explanation that the content is Attic Beyond and links to https://atticcapital.com/. It does not surface a bare 401.

Develop

npm install
npm test
npm run build
npx @modelcontextprotocol/inspector --cli node dist/stdio.js --method tools/list

npm test calls the live public API (read-only) and validates server.json against the MCP Registry schema.

Registry

Registry name: com.atticcapital/attic. DNS for atticcapital.com is already verified with the MCP Registry. The npm package is the unscoped attic-mcp.

Listing copy, directory notes, and the exact publish steps are in LISTINGS.md and PUBLISHING.md. Do not publish from a checkout until you mean to.

Privacy

The server stores API responses in memory for the cache TTL. It does not write queries or keys to disk. A key is forwarded only to atticcapital.com as X-Attic-Key.

Contact: https://atticcapital.com/