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Digital Underground MCP server

Which MCP servers are Digital Underground's own, from the official registry and from asking its own domain, whether they answer, and what they offer. A program checked each of these, nobody copied them from a product page.

read 2026-10-28

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Whose server it is
  • Registry namecom.digitalundergroundstore/marketplaceverified in the MCP registry

The registry name sits under digitalundergroundstore.com. The registry only lets a publisher use that namespace after proving control of the domain through DNS or HTTP.

When we asked itchecked 2026-10-28
  • Stateanswerschecked 2026-10-28
  • Tools4
  • Server calls itselfdigital-underground-marketplace
  • Server version1.0.0
  • Protocol version2025-06-18

On 2026-10-28 the server answered initialize and tools/list without a sign-in. First answer in 253 ms.

Should an agent connect itNot proven either way yet
  • Whether its tools do the product's job has not been judged yet.

Once connected

  • Parameters are untyped or undescribed in 4 of 4 tools: check arguments before calling.

Said by rules from the measurements above. The likely first call is a model's pick from the tool list; read its description before relying on it.

Measured dailydaily checks: 7, the first on 2026-10-28
  • INITE MCP score95 of 100answers 100 · definitions 83 · context 100 · connects 100
  • Answered100% of days7 of 7 daily checks
  • Median first answer131 ms
  • Space in an agent's context≈ 640 tokensthe definitions of all its tools (4), which an agent carries on every turn
  • Tool definitionsB · 83 of 100
  • Typed results0 of 4 toolsdeclared outputSchema: results come typed, read once
  • Parameters without a description: in 4 of 4

What an agent can do with it

  • not sure · submit an indie app by pasting its URL
  • not sure · review autofilled listing details before publishing
  • not sure · share a maker profile link in a bio

Each of the product's use cases, put to Jev against this server's tool list: can an agent do it with these tools?

Worth a look

None of the five warning signs in these definitions.

A program checks the server once a day: initialize and tools/list, no model. Tokens are the definitions' length at about four characters a token. The grade averages six checks of every tool's name, description, schema and annotations; it says how well the tools are described, not whether they work. The score weighs what was measured and nothing else: answering (25%), doing the product's job (25%), definitions (20%), context (10%), use (10%) and how readily a client connects (10%). A part that was not measured is left out, and a hidden instruction caps the score at 40. The state of vendors' MCP servers: method and numbers →

Tools it offers4 tools · read 2026-10-28
  • search_listings

    Search approved products on the Digital Underground Developer Marketplace (apps, AI tools, books, templates by independent makers). Returns summaries with links. Checkout happens on each maker's own site.

  • get_listing

    Get full public details (including the long description) of one approved listing by its id (cm_...).

  • submit_listing

    Submit the user's own product to the marketplace. Requires the creator's API key (duk_..., from the Creator dashboard -> API keys; never guess one). Free. Every submission is screened automatically and goes live once it passes; flagged…

  • get_my_listing_status

    Check the review status (pending, approved, rejected) of one of the user's own listings. Requires their API key.

How to connect

Add the server to your MCP client config. Claude Desktop, Cursor and most other clients read this shape:

{
  "mcpServers": {
    "marketplace": {
      "type": "http",
      "url": "https://digitalundergroundstore.com/mcp"
    }
  }
}

Add it

Claude Code, in a terminal

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

Add to CursorAdd to VS Code

claude.ai, ChatGPT and other clients: add https://digitalundergroundstore.com/mcp as a custom connector in the settings.

OpenAPI spec

4 paths, read 2026-10-28. Open the spec ↗

Each line is something a program found when it went looking: the registry entry, the server's own answer, a spec that parses. A missing line means we did not find it, not that it does not exist.