Basics of Subscriptions
Introduction
Subscriptions allow you to push real-time updates from your data sources to clients, making them ideal for building reactive applications without constant polling.
Subscriptions are in beta and are free to use during this period.
Configuration
You can enable subscriptions on your GraphQL API in the following ways:
New Hasura DDN project
If you're starting fresh, set up a Hasura DDN project using the quickstart guide. After adding your
models to the supergraph using the ddn model add command, subscription capabilities
are automatically generated! For further customization, you can edit the metadata.
Existing Hasura DDN project
To enable subscriptions in an existing DDN project, use the following CLI command:
ddn codemod upgrade-graphqlconfig-subscriptions
This command updates the local metadata files, adding subscription-specific configurations. After running this, create a supergraph build and test the subscriptions on the API. For further customization, you can edit the metadata.
Metadata configuration
You can configure the overall usage of subscriptions in your GraphQL API using
the GraphQlConfig object in your
metadata.
Additionally, you can customize individual subscriptions by modifying the
SubscriptionGraphQlDefinition field on any
model's selectUniques, selectMany, or aggregate fields.
Learn more
Subscriptions are supported for the following queries:
