Introduction

Omnihedron is a high-performance Rust rewrite of @subql/query — the GraphQL query service for SubQuery Network indexers.

The original TypeScript service uses PostGraphile to auto-generate a full GraphQL API from a live PostgreSQL schema at runtime. Omnihedron replicates that behaviour entirely in Rust, producing an identical external API while handling high concurrent load across all CPU cores.

Why a rewrite?

The Rust version handles the same queries with lower latency and higher throughput, especially under concurrent load.

What it does

PostgreSQL database (populated by a SubQuery indexer)
       ↓
  omnihedron starts up
       ↓
  Introspects tables, columns, types, relations
       ↓
  Builds a full GraphQL API automatically
       ↓
  Serves queries over HTTP

No one writes the GraphQL schema by hand. It is generated at runtime from whatever is in the database. Add a table to Postgres and a GraphQL API for it appears automatically.

Key features

• Dynamic schema generation — full GraphQL API built at runtime from PostgreSQL introspection
• PostGraphile-compatible — same naming, cursors, nodeId, filters, ordering, aggregates
• Schema hot reload — LISTEN/NOTIFY triggers automatic schema rebuild without downtime
• Historical queries — blockHeight and timestamp arguments for versioned table data
• Connection pooling — deadpool-postgres with configurable pool size
• Selective SQL — only columns referenced in the GraphQL query are fetched
• Read replica support — DB_HOST_READ for separating read traffic

Stack