docs/reference/api/actors.md

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Actors

Dapr provides native, cross-platform and cross-language virtual actor capabilities. Besides the language specific Dapr SDKs, a developer can invoke an actor using the API endpoints below.

Specifications for user service code calling to Dapr

Invoke Actor Method

Invokes a method on an actor.

HTTP Request

POST/GET/PUT/DELETE http://localhost:<daprPort>/v1.0/actors/<actorType>/<actorId>/method/<method>

HTTP Response Codes

Code Description
200 Request successful
500 Request failed
404 Actor not found

URL Parameters

Parameter Description
daprPort The Dapr port.
actorType The actor type.
actorId The actor ID.
method The name of the method to invoke.

Example of invoking a method on an actor:

curl -X POST http://localhost:3500/v1.0/actors/stormtrooper/50/method/shoot \
  -H "Content-Type: application/json"

Example of invoking a method on an actor with a payload:

curl -X POST http://localhost:3500/v1.0/actors/x-wing/33/method/fly \
  -H "Content-Type: application/json"
  -d '{
        "destination": "Hoth"
      }'

The response from the remote endpoint will be returned in the request body.

Actor State Changes - Transaction

Persists the changed to the state for an actor as a multi-item transaction.

Note that this operation is dependant on a state store that supports multi-item transactions.

HTTP Request

POST/PUT http://localhost:<daprPort>/v1.0/actors/<actorType>/<actorId>/state

HTTP Response Codes

Code Description
201 Request successful
500 Request failed
404 Actor not found

URL Parameters

Parameter Description
daprPort The Dapr port.
actorType The actor type.
actorId The actor ID.
curl -X POST http://localhost:3500/v1.0/actors/stormtrooper/50/state \
  -H "Content-Type: application/json"
  -d '[
       {
         "operation": "upsert",
         "request": {
           "key": "key1",
           "value": "myData"
         }
       },
       {
         "operation": "delete",
         "request": {
           "key": "key2"
         }
       }
      ]'

Get Actor State

Gets the state for an actor using a specified key.

HTTP Request

GET http://localhost:<daprPort>/v1.0/actors/<actorType>/<actorId>/state/<key>

HTTP Response Codes

Code Description
200 Request successful
500 Request failed
404 Actor not found

URL Parameters

Parameter Description
daprPort The Dapr port.
actorType The actor type.
actorId The actor ID.
key The key for the state value.
curl http://localhost:3500/v1.0/actors/stormtrooper/50/state/location \
  -H "Content-Type: application/json"

The above command returns the state:

{
  "location": "Alderaan"
}

Create Actor Reminder

Creates a persistent reminder for an actor.

HTTP Request

POST,PUT http://localhost:<daprPort>/v1.0/actors/<actorType>/<actorId>/reminders/<name>

Body:

The following specifies a dueTime of 3 seconds and a period of 7 seconds.

{
  "dueTime":"0h0m3s0ms",
  "period":"0h0m7s0ms"
}

A dueTime of 0 means to fire immediately. The following body means to fire immediately, then every 9 seconds.

{
  "dueTime":"0h0m0s0ms",
  "period":"0h0m9s0ms"
}

To configure the reminder to fire once only, the period should be set to empty string. The following specifies a dueTime of 3 seconds with a period of empty string, which means the reminder will fire in 3 seconds and then never fire again.

{
  "dueTime":"0h0m3s0ms",
  "period":""
}

HTTP Response Codes

Code Description
200 Request successful
500 Request failed
404 Actor not found

URL Parameters

Parameter Description
daprPort The Dapr port.
actorType The actor type.
actorId The actor ID.
name The name of the reminder to create.
curl http://localhost:3500/v1.0/actors/stormtrooper/50/reminders/checkRebels \
  -H "Content-Type: application/json"
-d '{
      "data": "someData",
      "dueTime": "1m",
      "period": "20s"
    }'

Get Actor Reminder

Gets a reminder for an actor.

HTTP Request

GET http://localhost:<daprPort>/v1.0/actors/<actorType>/<actorId>/reminders/<name>

HTTP Response Codes

Code Description
200 Request successful
500 Request failed
404 Actor not found

URL Parameters

Parameter Description
daprPort The Dapr port.
actorType The actor type.
actorId The actor ID.
name The name of the reminder to get.
curl http://localhost:3500/v1.0/actors/stormtrooper/50/reminders/checkRebels \
  "Content-Type: application/json"

The above command returns the reminder:

{
  "dueTime": "1s",
  "period": "5s",
  "data": "0",
}

Delete Actor Reminder

Deletes a reminder for an actor.

HTTP Request

DELETE http://localhost:<daprPort>/v1.0/actors/<actorType>/<actorId>/reminders/<name>

HTTP Response Codes

Code Description
200 Request successful
500 Request failed
404 Actor not found

URL Parameters

Parameter Description
daprPort The Dapr port.
actorType The actor type.
actorId The actor ID.
name The name of the reminder to delete.
curl http://localhost:3500/v1.0/actors/stormtrooper/50/reminders/checkRebels \
  -X "Content-Type: application/json"

Create Actor Timer

Creates a timer for an actor.

HTTP Request

POST,PUT http://localhost:<daprPort>/v1.0/actors/<actorType>/<actorId>/timers/<name>

Body:

The following specifies a dueTime of 3 seconds and a period of 7 seconds.

{
  "dueTime":"0h0m3s0ms",
  "period":"0h0m7s0ms"
}

A dueTime of 0 means to fire immediately. The following body means to fire immediately, then every 9 seconds.

{
  "dueTime":"0h0m0s0ms",
  "period":"0h0m9s0ms"
}

HTTP Response Codes

Code Description
200 Request successful
500 Request failed
404 Actor not found

URL Parameters

Parameter Description
daprPort The Dapr port.
actorType The actor type.
actorId The actor ID.
name The name of the timer to create.
curl http://localhost:3500/v1.0/actors/stormtrooper/50/timers/checkRebels \
    -H "Content-Type: application/json"
-d '{
      "data": "someData",
      "dueTime": "1m",
      "period": "20s",
      "callback": "myEventHandler"
    }'

Delete Actor Timer

Deletes a timer for an actor.

HTTP Request

DELETE http://localhost:<daprPort>/v1.0/actors/<actorType>/<actorId>/timers/<name>

HTTP Response Codes

Code Description
200 Request successful
500 Request failed
404 Actor not found

URL Parameters

Parameter Description
daprPort The Dapr port.
actorType The actor type.
actorId The actor ID.
name The name of the timer to delete.
curl http://localhost:3500/v1.0/actors/stormtrooper/50/timers/checkRebels \
  -X "Content-Type: application/json"

Specifications for Dapr calling to user service code

Get Registered Actors

Gets the registered actors in Dapr.

HTTP Request

GET http://localhost:<appPort>/dapr/config

HTTP Response Codes

Code Description
200 Request successful
500 Request failed

URL Parameters

Parameter Description
appPort The application port.

Example of getting the registered actors:

curl -X GET http://localhost:3000/dapr/config \
  -H "Content-Type: application/json"

The above command returns the config (all fields are optional):

Parameter Description
entities The actor types this app supports.
actorIdleTimeout Specifies how long to wait before deactivating an idle actor. An actor is idle if no actor method calls and no reminders have fired on it.
actorScanInterval A duration which specifies how often to scan for actors to deactivate idle actors. Actors that have been idle longer than the actorIdleTimeout will be deactivated.
drainOngoingCallTimeout A duration used when in the process of draining rebalanced actors. This specifies how long to wait for the current active actor method to finish. If there is no current actor method call, this is ignored.
drainRebalancedActors A bool. If true, Dapr will wait for drainOngoingCallTimeout to allow a current actor call to complete before trying to deactivate an actor. If false, do not wait.
{
  "entities":["actorType1", "actorType2"],
  "actorIdleTimeout": "1h",
  "actorScanInterval": "30s",
  "drainOngoingCallTimeout": "30s",
  "drainRebalancedActors": true
}

Activate Actor

Activates an actor.

HTTP Request

POST http://localhost:<appPort>/actors/<actorType>/<actorId>

HTTP Response Codes

Code Description
200 Request successful
500 Request failed
404 Actor not found

URL Parameters

Parameter Description
appPort The application port.
actorType The actor type.
actorId The actor ID.

Example of activating an actor:

curl -X POST http://localhost:3000/actors/stormtrooper/50 \
  -H "Content-Type: application/json"

Deactivate Actor

Deactivates an actor.

HTTP Request

DELETE http://localhost:<appPort>/actors/<actorType>/<actorId>

HTTP Response Codes

Code Description
200 Request successful
500 Request failed
404 Actor not found

URL Parameters

Parameter Description
appPort The application port.
actorType The actor type.
actorId The actor ID.

Example of deactivating an actor:

curl -X DELETE http://localhost:3000/actors/stormtrooper/50 \
  -H "Content-Type: application/json"

Invoke Actor method

Invokes a method for an actor.

HTTP Request

PUT http://localhost:<appPort>/actors/<actorType>/<actorId>/method/<methodName>

HTTP Response Codes

Code Description
200 Request successful
500 Request failed
404 Actor not found

URL Parameters

Parameter Description
appPort The application port.
actorType The actor type.
actorId The actor ID.
methodName The name of the method to invoke.

Example of invoking a method for an actor:

curl -X POST http://localhost:3000/actors/stormtrooper/50/method/performAction \
  -H "Content-Type: application/json"

Invoke Reminder

Invokes a reminder for an actor.

HTTP Request

PUT http://localhost:<appPort>/actors/<actorType>/<actorId>/method/remind/<reminderName>

HTTP Response Codes

Code Description
200 Request successful
500 Request failed
404 Actor not found

URL Parameters

Parameter Description
appPort The application port.
actorType The actor type.
actorId The actor ID.
reminderName The name of the reminder to invoke.

Example of invoking a reminder for an actor:

curl -X POST http://localhost:3000/actors/stormtrooper/50/method/remind/checkRebels \
  -H "Content-Type: application/json"

Invoke Timer

Invokes a timer for an actor.

HTTP Request

PUT http://localhost:<appPort>/actors/<actorType>/<actorId>/method/timer/<timerName>

HTTP Response Codes

Code Description
200 Request successful
500 Request failed
404 Actor not found

URL Parameters

Parameter Description
appPort The application port.
actorType The actor type.
actorId The actor ID.
timerName The name of the timer to invoke.

Example of invoking a timer for an actor:

curl -X POST http://localhost:3000/actors/stormtrooper/50/method/timer/checkRebels \
  -H "Content-Type: application/json"

Querying Actor State Externally

In order to promote visibility into the state of an actor and allow for complex scenarios such as state aggregation, Dapr saves actor state in external databases.

As such, it is possible to query for an actor state externally by composing the correct key or query. The state namespace created by Dapr for actors is composed of the following items:

  • Dapr ID - Represents the unique ID given to the Dapr application.
  • Actor Type - Represents the type of the actor.
  • Actor ID - Represents the unique ID of the actor instance for an actor type.
  • Key - A key for the specific state value. An actor ID can hold multiple state keys.

The following example shows how to construct a key for the state of an actor instance under the myapp Dapr ID namespace: myapp-cat-hobbit-food

In the example above, we are getting the value for the state key food, for the actor ID hobbit with an actor type of cat, under the Dapr ID namespace of myapp.