Seneschal Data API

Free, public REST + Model Context Protocol server exposing real-time and historical DeFi liquidation telemetry for Aave, Morpho, Spark and Compound on Ethereum mainnet, plus block-builder market share data from the operator's own slot-by-slot shadow recorder.

Two paid tiers sit on top, both billed per call over x402 micropayments (USDC on Base — no account, no API key):

• Private Watch (flagship) — give us a Monero or Zcash view key and a webhook URL; we watch the chain on our own full nodes and POST you an HMAC-signed event for every inbound payment. Credit-metered ($0.02/day + $0.005/call), so small receivers pay pennies and you never run a node. Drive it from the API, the MCP tools, or the WalletConnect control panel.
• Premium data — expected-value-ranked liquidation opportunities, per-builder bid distributions, and Penny Oracle atomic single-fact endpoints (DeFi + Monero/Zcash) from $0.001/call.

Watches can also be topped up natively in XMR or ZEC (we quote an amount, you pay on-chain, our view-key scanner credits the watch — no bridge, no custodian). All paid routes carry the x402 Bazaar discovery extension and settle through the Coinbase CDP facilitator, so agents can find and pay them via CDP discovery search, Agentic.Market and x402.eco without any pre-baked integration.

The payment engine itself (x402 paywall, view-key watching, credit meters, MCP tools) is the open-source, brand-neutral payments-gateway — embed it to charge for your own services.

Live endpoints

Rate limit: 120 requests/min/IP at the REST host. The MCP host pipelines requests over a single transport so the same limit applies per session.

Quick start

REST

curl 'https://api.seneschal.space/v1/liquidations/atrisk?max_hf=1.05&min_debt_usd=1000'

MCP — Claude Desktop / Cursor / Continue

Add this to your MCP client config (e.g. ~/.cursor/mcp.json):

{
  "mcpServers": {
    "seneschal-data": {
      "url": "https://mcp.seneschal.space/"
    }
  }
}

This server is published to the official MCP Registry as io.github.Rotwang9000/seneschal-data (see server.json), so MCP-aware clients and aggregators can discover it automatically.

Eighteen tools become available to your agent — free read tools, plus paid tools that hand back the exact URL + body to settle over x402:

REST endpoints

Full details, parameter tables, and worked examples at https://docs.seneschal.space.

Why this exists

Seneschal operates an Ethereum block builder (extra_data = Seneschal/0.1) and a vertically-integrated liquidation searcher. The searcher already tracks ~500 Morpho borrowers, 1,300+ Spark borrowers, every Aave V3 mainnet position with non-trivial debt, and the winning builder of every slot since May 2026. Nobody else publishes this combination, so we expose it.

Two protocols, one backend:

• REST API — dashboards, monitoring tools, anything that speaks HTTP.
• MCP server — AI agents (Claude, Cursor, Continue, etc.) using the Model Context Protocol.

Local dev

git clone https://github.com/Rotwang9000/seneschal-data-api
cd seneschal-data-api
npm install
SENESCHAL_MEV_LOGS_DB=/path/to/your-mev-data.sqlite \
SENESCHAL_MORPHO_BORROWERS=/path/to/morpho-borrowers.json \
SENESCHAL_SPARK_BORROWERS=/path/to/spark-borrowers.json \
SENESCHAL_SHADOW_BLOCKS=/path/to/shadow-blocks.jsonl \
  node bin/rest.mjs
# in another shell:
curl http://127.0.0.1:8810/v1/health

Docker

A Dockerfile is provided for self-hosting the MCP server:

docker build -t seneschal-data-api .
docker run -p 8811:8811 -v /path/to/your-data:/data seneschal-data-api
# point your MCP client at http://localhost:8811/

The data sources are SQLite + JSONL files written by the Seneschal bot. Schemas are documented in src/db.js; if you have your own writer producing the same shapes you can point this server at it.

Tests

npm test

539 jest tests covering the query layer (in-memory SQLite fixtures), the Fastify REST routes (via fastify.inject), the MCP server (both in-process via InMemoryTransport and end-to-end via StreamableHTTPClientTransport), the x402 paywall + bazaar-discovery wiring, the Private Watch credit meter / poller / surge pricing, and the ops watchdog. Plus test/live-smoke.mjs which exercises the live mcp.seneschal.space endpoint over Streamable HTTP.

Architecture

services/data-api/   ← this repository
├── bin/
│   ├── rest.mjs                  systemd entry — Fastify REST listener
│   └── mcp.mjs                   systemd entry — MCP HTTP listener
├── src/
│   ├── config.js                 env-driven config (ports, paths, limits)
│   ├── db.js                     better-sqlite3 read-only handle + JSON cache
│   ├── queries.js                pure functions used by both REST and MCP
│   ├── rest-server.js            Fastify app: `buildApp()` for tests, `start()` for prod
│   └── mcp-server.js             McpServer + StreamableHTTPServerTransport
├── docs/                         public docs served at docs.seneschal.space
└── test/                         queries / rest-server / mcp-server tests

Shared design rule: both REST and MCP layers are thin wrappers around queries.js. Any new endpoint goes in queries.js first (with tests), then both wrappers in the same commit.

Premium tier (x402 paywall)

src/queries-premium.js plus src/x402.js add per-call payment to a small family of /v1/premium/* endpoints (and seneschal_premium_* MCP tools). The paywall is off unless the operator sets X402_RECIPIENT_ADDRESS. Once set, unsigned requests get HTTP 402 with machine-readable payment requirements, and an x402 facilitator settles a signed EIP-3009 transferWithAuthorization for USDC on Base mainnet.

Configure

Free metadata endpoint (zero cost, no signature required):

curl https://api.seneschal.space/v1/paywall

returns the live network/recipient/price/route table so agents can budget a session before opening a paid request.

Support

• Per-call payments (preferred for agents): pay $0.05 USDC on Base to call GET /v1/premium/opportunities. See /v1/paywall for the live recipient + rails.
• GitHub Sponsors: the Sponsor button at the top of the repo (.github/FUNDING.yml).
• Direct tips: ETH / BTC addresses are surfaced on stats.seneschal.space once the operator sets SENESCHAL_DONATE_ETH / SENESCHAL_DONATE_BTC.
• Questions / allow-list bumps: Telegram @OrknetP.

Seneschal runs on a single Helsinki box; every cent helps keep it online.

License

MIT — see LICENSE.

Operator contact

Seneschal is a single-operator Ethereum block builder and searcher running an rbuilder fork from a co-located server in Helsinki. Builder on-chain extra_data is Seneschal/0.1. Contact @OrknetP on Telegram (checked periodically).