Lilambd Data for Agents

What it is

Connect an agent

The MCP server speaks JSON-RPC 2.0 over POST (methods initialize, ping, tools/list, tools/call). It exposes list_apis plus one tool per API, named by the ids in the table below. Tool arguments: route (for example "/search"), params (object of query strings) and sample (true for the free preview). For paid calls over MCP, put the x402 v2 payload in _meta["x402/payment"].

Claude Desktop

Either add https://api.lilambd.com/mcp as a custom connector in Settings, or bridge it in claude_desktop_config.json:

{
  "mcpServers": {
    "lilambd": {
      "command": "npx",
      "args": ["-y", "mcp-remote", "https://api.lilambd.com/mcp"]
    }
  }
}

Cursor

~/.cursor/mcp.json (global) or .cursor/mcp.json (project):

{
  "mcpServers": {
    "lilambd": {
      "url": "https://api.lilambd.com/mcp"
    }
  }
}

Any MCP client or plain curl

# Streamable HTTP, JSON-RPC 2.0 over POST
curl -s https://api.lilambd.com/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/list"}'

# Free 3-row preview through MCP
curl -s https://api.lilambd.com/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{
        "name":"airports",
        "arguments":{"route":"/nearby","params":{"lat":"35.68","lon":"139.76"},"sample":true}}}'

Without MCP

# Plain HTTP: free preview
curl -s 'https://api.lilambd.com/units/convert?value=100&from=degF&to=degC&sample=1'

# Paid call: first response is HTTP 402 with a PAYMENT-REQUIRED header
# (x402 v2, scheme exact, network eip155:8453, USDC). Sign it, then retry
# with a PAYMENT-SIGNATURE header. Any x402 client does this for you.
curl -si 'https://api.lilambd.com/units/convert?value=100&from=degF&to=degC'

Clients without an x402 wallet can still use tools/list, list_apis, samples and the always-free routes. Paid calls need an x402-capable client.

Discovery files

• llms.txt: short index for language models (llms-full.txt has every route, parameter, price, licence and source)
• openapi.json: OpenAPI 3.1, every route with parameters and x-payment-info
• /.well-known/x402: x402 v2 payment requirements per resource
• /meta: sources, licence, data date and refresh for every API
• MCP Registry name: io.github.Veniwol-Li-Lambd/lilambd-data

Finished answers

One call returns a finished, sourced answer instead of raw rows. USDC on Base via x402. Add ?sample=1 for a free preview.

APIs

Prices are USDC per call on Base. "sample" opens a free 3-row preview over plain HTTP.

If a person may be in crisis, call /koyomi/helplines (free) first. Travel-meds, pet-entry and exposure answers are facts with cited sources, not medical, veterinary, legal or security advice. No personal records are served.

Free datasets

Bulk files for training, analysis and offline use on Hugging Face and Kaggle:

• World Signals (daily) CC BY 4.0
• World Seeds CC BY-SA 4.0
• Japan DPC Hospitals CC BY 4.0
• Japan by Prefecture CC BY 4.0
• World Markets CDLA-Permissive 2.0
• World Marketplaces CDLA-Permissive 2.0
• World Earth Surface Ledger CC BY 4.0
• World Ground Ledger CC BY 4.0
• World Hazard Ledger CC BY 4.0
• World Prices Long Record CC BY 4.0
• World Biodiversity Cells CC BY-NC 4.0 (non-commercial)
• World Science (papers by field x country x year) CC0 1.0
• Machine Economy Daily Census CC BY 4.0
• security-daily
• world-pulse-daily

Game and sound assets built from the same sources are on itch.io.