Subgraph to HyperIndex Query Converter

A standalone Rust service that converts The Graph subgraph GraphQL queries to Envio HyperIndex / Hasura GraphQL format and forwards them to a HyperIndex endpoint. Responses are converted back to The Graph subgraph format, making it a transparent proxy that lets existing frontends and clients read from HyperIndex without code changes.

Note: This tool is under active development and is currently in a proof-of-concept stage. It is not yet ready for production use. It will likely work for most common subgraph query patterns but may not cover all edge cases.

What Problem Does This Solve?

When migrating from a subgraph to HyperIndex, existing frontends use The Graph's GraphQL query syntax (e.g. streams(first: 2, orderBy: timestamp)) which is different from HyperIndex's Hasura-based syntax (e.g. Stream(limit: 2, order_by: {timestamp: asc})). This converter acts as a middleware proxy so you can point your existing frontend at it without rewriting all your queries.

See the HyperIndex query conversion guide for a manual reference on the differences.

Who is this for?

Teams migrating from The Graph to HyperIndex who want to keep their existing frontend queries working during the transition, without rewriting all GraphQL calls upfront. Point your frontend at this proxy, migrate your indexer to HyperIndex, and update your queries at your own pace.

Features

• Query conversion: Converts subgraph GraphQL syntax to HyperIndex / Hasura format
• Response conversion: Converts responses back to subgraph format
• HTTP proxy: Forwards converted queries to your HyperIndex endpoint
• Chain-specific endpoint: Automatically adds chainId filters via /chainId/{chain_id}
• Debug endpoint: Inspect converted queries without forwarding (/debug)
• Prometheus metrics: Request latency, error rates, conversion timing
• Filter mapping: Translates all common subgraph filter operators (_gt, _in, _contains, etc.) to Hasura equivalents

API Endpoints

Endpoint	Description
POST /	Convert and forward to HyperIndex (no chain filter)
POST /chainId/{id}	Convert and forward, auto-adds chainId filter
POST /debug	Return converted query without forwarding
GET /metrics	Prometheus metrics

Setup

Prerequisites

• Rust (latest stable)

Install and Run

git clone <repository-url>
cd subgraph-to-hyperindex-query-converter

cp .env.example .env
# Set HYPERINDEX_URL in .env

cargo run

Service starts on http://localhost:3000.

Environment Variables

# Required
HYPERINDEX_URL=https://indexer.hyperindex.xyz/your-deployment/v1/graphql

# Optional
PORT=3000
HTTP_TIMEOUT_SECS=30

Run with Docker

docker build -t subgraph-converter .
docker run -p 3000:3000 --env-file .env subgraph-converter

Example Conversions

Subgraph input:

query {
  streams(first: 2, skip: 10) {
    category
    cliff
    chainId
  }
}

HyperIndex output (at /):

query {
  Stream(limit: 2, offset: 10) {
    category
    cliff
    chainId
  }
}

HyperIndex output (at /chainId/1):

query {
  Stream(limit: 2, offset: 10, where: { chainId: { _eq: "1" } }) {
    category
    cliff
    chainId
  }
}

Filter Conversion Reference

Subgraph Filter	Hasura Equivalent
field: val	field: { _eq: val }
field_not: val	field: { _neq: val }
field_gt: val	field: { _gt: val }
field_gte: val	field: { _gte: val }
field_lt: val	field: { _lt: val }
field_lte: val	field: { _lte: val }
field_in: [...]	field: { _in: [...] }
field_not_in: [...]	field: { _nin: [...] }
field_contains: val	field: { _ilike: "%val%" }
field_starts_with: val	field: { _ilike: "val%" }
field_ends_with: val	field: { _ilike: "%val" }

See the full filter table and known limitations in the source code.

Known Limitations

• Uses string parsing rather than a full GraphQL parser
• orderBy and orderDirection with variables are not supported (Hasura limitation)
• Block/time-travel queries are not supported
• _meta queries only return latest block number
• Default limit should not exceed 1000 unless HyperIndex is configured for higher limits

Documentation

• HyperIndex Docs
• Subgraph to HyperIndex query conversion guide
• Migrate from The Graph to Envio

License

MIT

Support

• Discord community
• Envio Docs