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Hasura target

Send GraphQL queries to Hasura.

The Hasura target can handle two types of events: a raw request for Hasura that consists of a JSON payload, and passing a premade query with the parameters in a key/value array.

With tmctl:

tmctl create target hasura --endpoint <endpoint>

On Kubernetes:


apiVersion: v1
kind: Secret
  name: hasuratargetadminsecret
type: Opaque

Example with a predefined query

kind: HasuraTarget
 name: hasuratarget

  endpoint: '' # Target Hasura instance
    - name: MyQuery
      query: "query MyQuery($person_id: Int) { foo(where: {id: {_eq: $person_id}} ) { id name } }"

If required, the admin token or a JWT token can be specified for queries that require authorized access. Lastly, if a particular role is required, a defaultRole can be defined.

  • Admin Token for Hasura: An admin secret or JWT to communicate with Hasura as discussed in Admin Secret or JWT.
  • Hasura Server URL: URL endpoint to communicate with Hasura.
  • Default Role: Specify the Hasura user role to use when querying Hasura.
  • Pre-canned Queries: A key/value pair of predefined queries available for CloudEvents to specify.

You can test the Target by sending it an event using curl.

Example of sending a raw query:

curl -v http://localhost:8080 \
 -X POST \
 -H "Content-Type: application/json" \
 -H "Ce-Specversion: 1.0" \
 -H "Ce-Type: org.graphql.query.raw" \
 -H "Ce-Source: awesome/instance" \
 -H "Ce-Id: aabbccdd11223344" \
 -d '{
  "query": "query MyQuery { foo { id name } }",
  "operationName": "MyQuery",
  "variables": {}

To make use of the pre-defined query, the Ce-Subject will need to specify the specific query, and the Ce-Type must match org.graphql.query or org.graphql.query.raw. The resulting payload must be an object of keys and string values.

Example of sending a predefined query:

curl -v http://localhost:8080 \
 -X POST \
 -H "Content-Type: application/json" \
 -H "Ce-Specversion: 1.0" \
 -H "Ce-Type: org.graphql.query" \
 -H "Ce-Source: awesome/instance" \
 -H "Ce-Subject: MyQuery" \
 -H "Ce-Id: aabbccdd11223344" \
 -d '{"person_id": "5"}'

The Hasura target accepts the following event types.


Events of this type are raw GraphQL queries intended to be submitted directly to Hasura.

This type expects a JSON payload with the following properties:

Name Type Comment
query string The GraphQL to run against the Hasura server
operationName string The query name specified in the query attribute
variables map[string]string Key/value pairs of variables with the key defined in the query

The response event will have the ce-type attribute set to org.graphql.query.result and ce-source attribute set to the Target's endpoint.


Events of this type leverage the pre-defined query defined when the Target is created. In addition to the ce-type, the ce-subject must be set to the name of the pre-defined query, otherwise the event will not be processed by the Target.

The JSON payload for this type must consist of a string dictionary where the keys correspond to the variables defined in the query, and key's value is passed as a string.

The response event will have the ce-type attribute set to org.graphql.query.result and ce-source attribute set to the Target's endpoint.

See the Kubernetes object reference for more details.


The Hasura base URL acting as the endpoint is a requirement. In addition, either an admin token or JWT token may be required to grant permission to the target tables hosted by Hasura.

If using JWT, you may choose to add an optional user role to invoke the queries as.

Authentication and authorization will be considered out of scope for the target guide, but can be found in the Hasura Guide

For more information about using Hasura and GraphQL, please refer to the Hasura and GraphQL documentation.