MCP Server
Underground Cultural District: developer utilities (UUID, JSON, Base64, hashing, JWT, regex, cron), creative tools and a marketplace of digital goods.
Install
The installation steps are in the documentation below. Documentation
Documentation
From the project's README on GitHub, refreshed weekly. Links open on GitHub.
Contents
@underground-cultural-district/mcp-server — v5.0.0
Maraventano MCP — three brands, one house.
- Maraventano Index — x402 Merchant Intelligence (signed, longitudinal, independently replicable merchant-seat observations of the x402 agent economy, published as intelligence). Operated continuously since April 2026. maraventanoindex.com
- Underground Cultural District — 231 digital cultural products across 27 shops. Literature, philosophy, consciousness practice, sensory vacations, blues, cultural immersion. substratesymposium.com
- Developer utilities — 15 free tools (hashing, base64, UUID, JWT, regex, cron, wallet validation, etc.)
25 tools total. All free MCP overhead. Paid Index endpoints are x402 USDC (Base + Solana).
v5.0.0 — What's new
Six new Maraventano Index tools:
| Tool | What | Pricing |
|---|---|---|
maraventano-index-overview | Signed Index manifest + endpoint directory | FREE |
maraventano-census | Signed longitudinal roster of 250+ x402 operators with class + payment behaviour | FREE headline / $0.50 full |
maraventano-mirror | Your x402 client's Report Card from the merchant seat (verdict ladder + class comparison + diagnostic findings) | FREE preview / $0.25 full |
maraventano-failure-corpus | Classified failure-mode taxonomy with per-signature counts | FREE headline / $0.50 full |
maraventano-conformance-grade | Grade your x402 client A/B/C/D/F/I + 30-day signed SVG badge | FREE grade letter / $0.33 full card |
maraventano-counterparty-check | Per-call counterparty lookup (pass UA, receive signed verdict) | $0.01 per call |
All Index attestations are Ed25519-signed with key ID underground-attest-2026-07-18. Payloads are CC0.
Why this matters
The Index measures what no chain analyst, crawler, or facilitator-side dashboard can see: what actually arrives at a continuously-operated x402 merchant seat. Who knocks, who pays, who only probes, how clients fail, who settles.
For agent frameworks: maraventano-failure-corpus + maraventano-conformance-grade give you drop-in defense data + a signed self-audit.
For counterparty vetting: maraventano-counterparty-check is designed to be called before every transaction. $0.01/call makes it cheap enough to wire into your buy pipeline.
For market intelligence: maraventano-census + maraventano-mirror are the signed longitudinal corpus and your own reflection in it.
Install
npm install @underground-cultural-district/mcp-server
Then add to your Claude Desktop / MCP client config:
{
"mcpServers": {
"maraventano-mcp": {
"command": "npx",
"args": ["-y", "@underground-cultural-district/mcp-server"]
}
}
}
Or run as a hosted HTTP/SSE server:
MCP_PORT=3002 node src/index.js
Endpoints:
GET /sse— SSE transportPOST /mcp— Streamable HTTP transportGET /health— status, version, tool/product countsGET /— JSON manifest
Discovery
- MI methodology: https://maraventanoindex.com/methodology
- MI machine-readable: https://maraventanoindex.com/.well-known/x402
- MI openapi: https://maraventanoindex.com/openapi.json
- MI agent card: https://maraventanoindex.com/.well-known/agent.json
About the Maraventano name
Case-Shiller. Russell. Nielsen. Maraventano.
The signature doctrine: an index named after its author stands behind what it publishes. Operated by Lisa Maraventano since April 2026.
License
MIT (code). CC0 (Index payloads).
Author
Lisa Maraventano · lisamaraventano@gmail.com
Frequently asked questions
What is MCP Server?
Underground Cultural District: developer utilities (UUID, JSON, Base64, hashing, JWT, regex, cron), creative tools and a marketplace of digital goods.
How do I install MCP Server?
Follow the installation steps in its documentation, shown on this page and in its repository.
Is MCP Server open source?
Yes. Its code is on GitHub under the MIT license.
Who maintains MCP Server?
It is published by lisamaraventano-spine. AI.tn lists it but does not maintain or endorse it.
From the community awesome-mcp-servers lists and the project's GitHub repository. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.