Subgraph Registry MCP server

Subgraph Registry

Agent-friendly semantic classification of all subgraphs on The Graph Network.

Pre-computed index of 15,330 subgraphs with domain classification, protocol type detection, schema fingerprinting, canonical entity mapping, and composite reliability scoring.

What's new in 0.8.0 — three agent-discovery upgrades:

- Semantic search via 384-dim embeddings (semanticsearchsubgraphs)

- Schema evolution tracking with stability days surfaced on every result (getschemachanges)

- OpenAPI 3.1 spec auto-generated for MCP tools + REST routes, served at /.well-known/openapi.json

The Problem

Agents querying The Graph need to discover and select the right subgraph before they can query data. Today this requires 3-4 tool calls (search, check volumes, fetch schema, infer structure) before any real work happens. This registry flips that: agents start with structured knowledge, not a blank slate.

What It Does

1. Crawls all active subgraphs from the Graph Network meta-subgraph
2. Fetches the GraphQL schema for every deployment
3. Extracts contract addresses from each manifest's dataSources and templates — agents can answer "which subgraph indexes contract 0x… on chain X?"
4. Generates a per-subgraph starter GraphQL query from the parsed schema (real top entity, real fields, sensible orderBy) — no more generic boilerplate that doesn't compile against most subgraphs
5. Classifies each subgraph by domain, protocol type, canonical entities, and schema family
6. Scores reliability using on-chain signals (query fees, volume, curation, stake)
7. Returns x402 + legacy query URLs — agents can pay $0.01 USDC on Base per query (no API key) or use a Studio key
8. Publishes as SQLite database + REST API + MCP server + per-subgraph JSON-LD at /.well-known/subgraph/{id}.jsonld for ecosystem crawlers
9. Generates visual dashboards and bot-readable category files (auto-updated with each sync)

Querying with x402 (no API key)

Every result includes queryurlx402 alongside the legacy queryurl. The Graph's public x402 gateway (live since 2026-05-08) accepts $0.01 USDC on Base** per query with zero signup.

// An x402-native agent — discovery to data in two calls
const { recommendations } = await mcp.call("recommend_subgraph", {
  goal: "find DEX trades on Arbitrum",
});
const top = recommendations[0];

// POST your GraphQL query. The first call returns HTTP 402 with a
// base64 `payment-required` header; the x402 client signs the
// EIP-3009 USDC transfer on Base and retries automatically.
const data = await x402Fetch(top.query_url_x402, {
  method: "POST",
  body: JSON.stringify({ query: "{ swaps(first: 5) { id amountUSD } }" }),
});

Pricing manifest returned per subgraph:

{
  "amount_usd": 0.01,
  "asset": "USDC",
  "asset_contract": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
  "chain": "base",
  "network": "eip155:8453",
  "pay_to": "0x79DC34E41B2b591078d3dE222C43EcaaBD52FcCB",
  "scheme": "exact",
  "asset_transfer_method": "eip3009"
}

Client libraries: @graphprotocol/client-x402, x402-fetch, or any generic x402 wrapper.

Registry at a Glance

Shortened. The full README is on GitHub.