YieldCave MCP server

YieldCave

Machine-readable tokenized-finance data for AI agents: tokenized treasuries, stablecoin yield venues, and tokenized stocks.

YieldCave is an MCP server. Add it to Claude Desktop, Claude Code or Cursor and your agent can answer questions like:

• "What tokenized US treasuries are on Solana right now, and what do they yield?"
• "How much more would $25k earn in the best liquid tokenized treasury than in my 0.4% savings account?"
• "Summarize the tokenized RWA market."
• "Where does USDC earn the most on a collateralized lending market with at least $50M behind it?"
• "Which tokenized NVIDIA token is the most liquid, and is it trading at a premium to the stock?"

It is read-only. It never touches a wallet, never moves money and never recommends. That is the point: an index, not a broker.

Data comes from DefiLlama's public API. No API key is needed.

1. Run it locally (5 minutes)

You need Node 20 or newer (node --version).

cd ~/yieldcave && npm install

See the data in your terminal:

npm run demo

Run the unit tests (no network needed):

npm test

Run the end-to-end checks, which start the real MCP server and call it the way Claude would, over stdio and over HTTP:

npm run smoke && npm run smoke:http

2. Add it to Claude Desktop

Open this file (create it if it does not exist):

~/Library/Application Support/Claude/claude_desktop_config.json

Add YieldCave under mcpServers. If the file already has other servers, add just the "yieldcave" block inside the existing object.

{
  "mcpServers": {
    "yieldcave": {
      "command": "node",
      "args": ["/Users/bjf/yieldcave/src/server.js"]
    }
  }
}

Quit and reopen Claude Desktop. You should see a tools icon with four YieldCave tools. Try: "Use YieldCave to summarize the tokenized treasury market."

3. Add it to Claude Code

claude mcp add yieldcave -- node /Users/bjf/yieldcave/src/server.js

3b. Use it from claude.ai in a browser (hosted version)

YieldCave also runs in the cloud on Supabase, so claude.ai (and anyone else) can reach it without your Mac being on.

https://ccvhvxbqtvqbhexhrjnj.supabase.co/functions/v1/mcp

In claude.ai: Customize → Connectors → Add → Add custom connector → paste that URL, no sign-in. The hosted version serves data from Postgres, which a scheduled job refreshes every hour, and it keeps one snapshot per day. That history powers the fifth tool, rwa_history.

How the hosted version is put together, all inside the supabase/ folder:

supabase/functions/_shared/   the real code: data.js, tools.js, mcp.js (src/ re-exports these)
supabase/functions/mcp/       public MCP endpoint, reads market_latest and snapshots from Postgres
supabase/functions/refresh/   fetches DefiLlama + CoinGecko + quotes, writes market_latest + today's snapshot, fires alerts; needs REFRESH_SECRET header
supabase/functions/enrich/    fills chain metadata for tokenized equities, 15 per run, every 10 minutes
supabase/functions/stripe-webhook/  upgrades/downgrades keys on Stripe events
supabase/functions/site/      serves the landing page (pages.js is generated from site/)
supabase/migrations/          tables (market, snapshots, alerts, api_keys, usage_daily), RLS on, hourly pg_cron job, public site bucket
scripts/                      configure-stripe.sh, publish-site.sh

To redeploy after a change:

supabase functions deploy mcp --no-verify-jwt --use-api && supabase functions deploy refresh --no-verify-jwt --use-api

Check a deployment end to end (tools, history, and an alert that creates, fires, and deletes itself):

Shortened. The full README is on GitHub.