> For the complete documentation index, see [llms.txt](https://dzhelezov.gitbook.io/hydra/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dzhelezov.gitbook.io/hydra/hydra-indexer-gateway.md).

# Hydra Indexer Gateway

Hydra Indexer Gateway is a GraphQL server exposing the indexed Substrate data (primarily, extrinsics and events), indexed by Hydra Indexer.

## Installation

The project is built using [Warthog](https://github.com/goldcaddy77/warthog) library.

### Local development

For local development, first inspect `env.yml` and generate a dev `.env` file using run `yarn config:dev`. Then the server can be run with `yarn start:dev`

### Production/Docker

For production a pre-built Docker image in recommended. The following environment variables must be set:

| Variable                       | Description                                                       |
| ------------------------------ | ----------------------------------------------------------------- |
| WARTHOG\_STARTER\_DB\_DATABASE | Indexer database name                                             |
| WARTHOG\_STARTER\_DB\_HOST     | Indexer database host                                             |
| WARTHOG\_STARTER\_DB\_PORT     | Indexer database port                                             |
| WARTHOG\_STARTER\_DB\_USERNAME | User to access the indexer database                               |
| WARTHOG\_STARTER\_DB\_PASSWORD | User password                                                     |
| WARTHOG\_STARTER\_REDIS\_URI   | Redis connection string (must be the same as used by the Indexer) |
| PORT                           | Port at which the GraphQL server will listen for connections      |