How to Create a Subgraph

Introduction

You can easily create subgraphs using the CLI and — for cloud projects — the Hasura DDN console. By default, the CLI will generate an app subgraph when a new project is initialized.

In your local metadata

Within a local project directory, run the following:

ddn subgraph init <subgraph-name>

You can verify this by identifying the new subdirectory in your project with the subgraph's name.

Then, add the subgraph to your supergraph's config file:

ddn subgraph add <subgraph-name> --subgraph ./<subgraph-name>/subgraph.yaml --target-supergraph ./supergraph.yaml

This will add the new subgraph to your supergraph.yaml:

kind: Supergraph
version: v2
definition:
  subgraphs:
    - globals/subgraph.yaml
    - app/subgraph.yaml
    - <subgraph-name>/subgraph.yaml

On a cloud project

By default, when a cloud project is initialized, any subgraphs present in your supergraph configuration will be initialized as well. However, to explicitly add a new subgraph to a cloud project — such as when iterating on an existing project — follow these steps:

Using the CLI

The folowing will create a new subgraph on the current context's cloud project:

ddn project subgraph create <subgraph-name>

Using the console

Under Settings > Subgraphs click + Create New Subgraph.

Subgraph mapping

Be careful of mismatching subgraphs between your local metadata and a cloud project: if you create a subgraph locally and add it to your supergraph configuration without also creating the subgraph on your cloud project, cloud builds will fail.

To resolve this, ensure that when you create a local subgraph in your metadata, you also create the companion subgraph on the cloud project.

Next steps

• Check out an end-to-end tutorial for working with multiple subgraphs
• Learn how to work with multiple subgraphs in a project