Metadata API Reference: Scheduled Triggers

Introduction

Scheduled Triggers are used to invoke webhooks based on a timestamp or cron.

Supported from

The Metadata API is supported for versions v2.0.0 and above and replaces the older schema/Metadata API.

create_cron_trigger

create_cron_trigger is used to create a new cron trigger.

POST /v1/metadata HTTP/1.1
Content-Type: application/json
X-Hasura-Role: admin

{
    "type" : "create_cron_trigger",
    "args" : {
        "name": "sample_cron",
        "webhook": "https://httpbin.org/post",
        "schedule":  "* * * * *",
        "payload": {
            "key1": "value1",
            "key2": "value2"
        },
        "include_in_metadata":false,
        "comment":"sample_cron comment"
    }
}

Args syntax

Key	Required	Schema	Description
name	true	TriggerName	Name of the cron trigger
webhook	true	WebhookURL	URL of the webhook
schedule	true	Cron Expression	Cron expression at which the trigger should be invoked.
payload	false	JSON	Any JSON payload which will be sent when the webhook is invoked.
headers	false	[HeaderFromValue | HeaderFromEnv]	List of headers to be sent with the webhook
retry_conf	false	RetryConfST	Retry configuration if scheduled invocation delivery fails
include_in_metadata	true	Boolean	Flag to indicate whether a trigger should be included in the metadata. When a cron trigger is included in the metadata, the user will be able to export it when the Metadata of the graphql-engine is exported.
comment	false	Text	Custom comment.
replace	false	Bool	When replace is set to true, the cron trigger will be updated(if exists) and when it's false or the field is omitted, then a new cron trigger will be created.
request_transform	false	RequestTransformation	Attaches a Request Transformation to the cron trigger.
response_transform	false	ResponseTransformation	Attaches a Request Transformation to the cron trigger.

Supported from

Scheduled Triggers are supported from versions v1.3.0 and above.

delete_cron_trigger

delete_cron_trigger is used to delete an existing cron trigger. The scheduled events associated with the cron trigger will also be deleted.

POST /v1/metadata HTTP/1.1
Content-Type: application/json
X-Hasura-Role: admin

{
    "type" : "delete_cron_trigger",
    "args" : {
        "name": "sample_cron"
    }
}

Args syntax

Key	Required	Schema	Description
name	true	TriggerName	Name of the cron trigger

Supported from

Scheduled Triggers are supported from versions v1.3.0 and above.

create_scheduled_event

create_scheduled_event is used to create a scheduled event.

POST /v1/metadata HTTP/1.1
Content-Type: application/json
X-Hasura-Role: admin

{
    "type": "create_scheduled_event",
    "args": {
        "webhook": "https://httpbin.org/post",
        "schedule_at": "2019-09-09T22:00:00Z",
        "payload": {
            "key1": "value1",
            "key2": "value2"
        },
        "headers": [{
            "name":"header-key",
            "value":"header-value"
        }],
        "comment": "sample scheduled event comment"
    }
}

Upon creating a scheduled event successfully, this API will return the event_id in the response.

HTTP/1.1 200 OK
Content-Type: application/json

{
    "message": "success",
    "event_id": "b918cd10-8853-4e66-91b8-81b5cd16e44b"
}

Args syntax

Key	Required	Schema	Description
webhook	true	WebhookURL	URL of the webhook
schedule_at	true	Timestamp (ISO8601 format)	The time at which the invocation should be invoked.
payload	false	JSON	Any JSON payload which will be sent when the webhook is invoked.
headers	false	[HeaderFromValue | HeaderFromEnv]	List of headers to be sent with the webhook
retry_conf	false	RetryConfST	Retry configuration if scheduled event delivery fails
comment	false	Text	Custom comment.

Supported from

Scheduled Triggers are supported from versions v1.3.0 and above.

delete_scheduled_event

delete_scheduled_event is used to delete an existing scheduled event (one-off or cron).

POST /v1/metadata HTTP/1.1
Content-Type: application/json
X-Hasura-Role: admin

{
    "type" : "delete_scheduled_event",
    "args" : {
        "type": "one_off",
        "event_id": "b918cd10-8853-4e66-91b8-81b5cd16e44b"
    }
}

Args syntax

Key	Required	Schema	Description
type	true	one_off | cron	Type of the Event Trigger.
event_id	true	UUID	The id of the scheduled event.

Supported from

Scheduled Triggers are supported from versions v1.3.0 and above.

get_cron_triggers

get_cron_triggers fetches all the cron triggers from the metadata. This API also returns the cron triggers which have include_in_metadata set to false, and thus are not exported in the export_metadata API.

POST /v1/metadata HTTP/1.1
Content-Type: application/json
X-Hasura-Role: admin

{
    "type" : "get_cron_triggers",
    "args" : {}
}

get_scheduled_events

get_scheduled_events provides a way to retrieve cron/one-off scheduled events present in the graphql-engine.

POST /v1/metadata HTTP/1.1
Content-Type: application/json
X-Hasura-Role: admin

{
    "type" : "get_scheduled_events",
    "args" : {
      "type": "cron",
      "trigger_name": "daily_trigger",
      "limit": 10,
      "offset": 0,
      "status": [
        "scheduled",
        "delivered"
      ],
      "get_rows_count": false
    }
}

POST /v1/metadata HTTP/1.1
Content-Type: application/json
X-Hasura-Role: admin

{
    "type" : "get_scheduled_events",
    "args" : {
      "type": "one_off",
      "limit": 10,
      "offset": 0,
      "get_rows_count": true
    }
}

Args Syntax

Key	Required	Schema	Description
type	true	one_off | cron	Type of the Scheduled Trigger.
trigger_name	only when type is cron	String	Name of the cron trigger
limit	false	Integer	Maximum number of events to be returned in one API call.
offset	false	Integer	Starting point from where the rows need to be returned.
get_rows_count	false	Boolean	Flag to indicate whether number of rows returned should be included in the response.
status	false	[ScheduledEventStatus]	Filter scheduled events by the status

get_scheduled_event_invocations

get_scheduled_event_invocations provides a way to retrieve the scheduled event invocations of a specific scheduled event or a cron trigger.

POST /v1/metadata HTTP/1.1
Content-Type: application/json
X-Hasura-Role: admin

{
    "type": "get_scheduled_event_invocations",
    "args": {
        "type": "cron",
        "trigger_name": "daily_trigger",
        "limit": 10,
        "offset": 0
    }
}

POST /v1/metadata HTTP/1.1
Content-Type: application/json
X-Hasura-Role: admin

{
    "type" : "get_scheduled_event_invocations",
    "args" : {
      "type": "one_off",
      "limit": 10,
      "offset": 0,
      "get_rows_count": true
    }
}

Args Syntax

Key	Required	Schema	Description
type	true	one_off | cron	Type of the Scheduled Trigger.
trigger_name	only when type is cron	String	Name of the cron trigger
event_id	false	String	Getting invocations of the specified event
limit	false	Integer	Maximum number of events to be returned in one API call.
offset	false	Integer	Starting point from where the rows need to be returned.
get_rows_count	false	Boolean	Flag to indicate whether number of rows returned should be included in the response.