# Rasa SDK - Action Server Endpoint (0.0.0)
HTTP API of the action server which is used by Rasa to execute custom actions.
## [operation/call_action](/content/docs/reference/api/pro/action-server-api/#operation/call_action/index.html) Core request to execute a custom action
Rasa Core sends a request to the action server to execute a certain custom action. As a response to the action call from Core, you can modify the tracker, e.g. by setting slots and send responses back to the user.
##### Request Body schema: application/json required
Describes the action to be called and provides information on the current state of the conversation.
| | |
| --- | --- |
| next_action | string
The name of the action which should be executed. |
| sender_id | string
Unique id of the user who is having the current conversation. |
| tracker | object (Tracker)
Conversation tracker which stores the conversation state. |
| domain | object (Domain)
The bot's domain. |
### Responses
**200**
Action was executed successfully.
**400**
Action execution was rejected. This is the same as returning an `ActionExecutionRejected` event.
**500**
The action server encountered an exception while running the action.
post/
Local development action server
http://localhost:5055/webhook/
### Request samples
- Payload
Content type
application/json
```json
{"next_action": "string",
"sender_id": "string",
"tracker": {"sender_id": "default",
"user_id": "usr_a1b2c3d4e5f6",
"current_session_id": "4b3c1e2a-91f0-4d8e-b123-abc123def456",
"slots": [{"slot_name": "slot_value"}],
"latest_message": {"entities": [{"start": 0,
"end": 0,
"value": "string",
"entity": "string",
"confidence": 0}],
"intent": {"confidence": 0.6323,
"name": "greet"},
"intent_ranking": [{"confidence": 0.6323,
"name": "greet"}],
"text": "Hello!",
"message_id": "b2831e73-1407-4ba0-a861-0f30a42a2a5a",
"metadata": {},
"commands": [{"command": "start flow",
"flow": "transfer_money"}],
"flows_from_semantic_search": [["transfer_money",
0.9035494923591614]],
"flows_in_prompt": ["transfer_money"]},
"latest_event_time": 1537645578.314389,
"followup_action": "string",
"paused": false,
"stack": [{"frame_id": "8UJPHH5C",
"flow_id": "transfer_money",
"step_id": "START",
"frame_type": "regular",
"type": "flow"}],
"events": [{"event": "user",
"timestamp": 1774447464.622012,
"metadata": {"session_id": "eed351b9-a996-4bb8-83ea-1d18e7cd4905",
"model_id": "80687713793f4d07957e8e51f73df866",
"assistant_id": "my-assistant"},
"text": "string",
"input_channel": "string",
"message_id": "string",
"parse_data": {"entities": [{"start": 0,
"end": 0,
"value": "string",
"entity": "string",
"confidence": 0}],
"intent": {"confidence": 0.6323,
"name": "greet"},
"intent_ranking": [{"confidence": 0.6323,
"name": "greet"}],
"text": "Hello!",
"message_id": "b2831e73-1407-4ba0-a861-0f30a42a2a5a",
"metadata": {},
"commands": [{"command": "start flow",
"flow": "transfer_money"}],
"flows_from_semantic_search": [["transfer_money",
0.9035494923591614]],
"flows_in_prompt": ["transfer_money"]},
"anonymized_at": "string"}],
"latest_input_channel": "rest",
"latest_action_name": "action_listen",
"latest_action": {"action_name": "string",
"action_text": "string"},
"active_loop": {"name": "restaurant_form"}},
"domain": {"config": {"store_entities_as_slots": false},
"intents": [{"property1": {"use_entities": true},
"property2": {"use_entities": true}}],
"entities": ["person",
"location"],
"slots": {"property1": {"auto_fill": true,
"initial_value": "string",
"type": "string",
"values": ["string"]},
"property2": {"auto_fill": true,
"initial_value": "string",
"type": "string",
"values": ["string"]}},
"responses": {"property1": {"text": "string"},
"property2": {"text": "string"}},
"actions": ["action_greet",
"action_goodbye",
"action_listen"]}}
```
### Response samples
- 200
- 400
Content type
application/json
```json
{"events": [{"event": "user",
"timestamp": 1774447464.622012,
"metadata": {"session_id": "eed351b9-a996-4bb8-83ea-1d18e7cd4905",
"model_id": "80687713793f4d07957e8e51f73df866",
"assistant_id": "my-assistant"},
"text": "string",
"input_channel": "string",
"message_id": "string",
"parse_data": {"entities": [{"start": 0,
"end": 0,
"value": "string",
"entity": "string",
"confidence": 0}],
"intent": {"confidence": 0.6323,
"name": "greet"},
"intent_ranking": [{"confidence": 0.6323,
"name": "greet"}],
"text": "Hello!",
"message_id": "b2831e73-1407-4ba0-a861-0f30a42a2a5a",
"metadata": {},
"commands": [{"command": "start flow",
"flow": "transfer_money"}],
"flows_from_semantic_search": [["transfer_money",
0.9035494923591614]],
"flows_in_prompt": ["transfer_money"]},
"anonymized_at": "string"}],
"responses": [{"text": "string"}]}
```