This guide will take you through the development of a simple skill.
Dependencies
Follow the Preliminaries and Installation sections from the AEA quick start.
Step 1: Setup
We will first create an AEA and add a scaffold skill, which we call my_search.
aea create my_aea && cd my_aea
aea scaffold skill my_search
In the following steps, we replace the scaffolded Behaviour and Handler in my_aea/skills/my_search with our implementation. We will build a simple skill which lets the AEA send a search query to the SOEF search node and process the resulting response.
Step 2: Develop a Behaviour
A Behaviour class contains the business logic specific to initial actions initiated by the AEA rather than reactions to other events.
In this example, we implement a simple search behaviour. Each time, act() gets called by the main agent loop, we will send a search request to the SOEF search node via the P2P communication network.
from typing import cast
from aea.helpers.search.models import Constraint, ConstraintType, Location, Query
from aea.skills.behaviours import TickerBehaviour
from packages.fetchai.protocols.oef_search.message import OefSearchMessage
from packages.fetchai.skills.my_search.dialogues import OefSearchDialogues
DEFAULT_LOCATION = {"longitude": 51.5194, "latitude": 0.1270}
DEFAULT_SEARCH_QUERY = {
"search_key": "seller_service",
"search_value": "generic_service",
"constraint_type": "==",
}
DEFAULT_SEARCH_RADIUS = 5.0
class MySearchBehaviour(TickerBehaviour):
"""This class provides a simple search behaviour."""
def __init__(self, **kwargs):
"""Initialize the search behaviour."""
search_query = kwargs.pop("search_query", DEFAULT_SEARCH_QUERY)
location = kwargs.pop("location", DEFAULT_LOCATION)
agent_location = Location(longitude=location["longitude"], latitude=location["latitude"])
radius = kwargs.pop("search_radius", DEFAULT_SEARCH_RADIUS)
close_to_my_service = Constraint(
"location", ConstraintType("distance", (agent_location, radius))
)
service_key_filter = Constraint(
search_query["search_key"],
ConstraintType(
search_query["constraint_type"], search_query["search_value"],
),
)
self.query = Query([close_to_my_service, service_key_filter])
super().__init__(**kwargs)
self.sent_search_count = 0
def setup(self) -> None:
"""
Implement the setup.
:return: None
"""
self.context.logger.info(
"setting up MySearchBehaviour"
)
def act(self) -> None:
"""
Implement the act.
:return: None
"""
self.sent_search_count += 1
oef_search_dialogues = cast(
OefSearchDialogues, self.context.oef_search_dialogues
)
self.context.logger.info(
"sending search request to OEF search node, search_count={}".format(
self.sent_search_count
)
)
search_request, _ = oef_search_dialogues.create(
counterparty=self.context.search_service_address,
performative=OefSearchMessage.Performative.SEARCH_SERVICES,
query=self.query,
)
self.context.outbox.put_message(message=search_request)
def teardown(self) -> None:
"""
Implement the task teardown.
:return: None
"""
self.context.logger.info(
"tearing down MySearchBehaviour"
)
Searches are proactive and, as such, well placed in a Behaviour. Specifically, we subclass the TickerBehaviour as it allows us to repeatedly search at a defined tick interval.
We place this code in my_aea/skills/my_search/behaviours.py.
Step 3: Develop a Handler
So far, we have tasked the AEA with sending search requests to the SOEF search node. However, we have no way of handling the responses sent to the AEA by the SOEF search node at the moment. The AEA would simply respond to the SOEF search node via the default error skill which sends all unrecognised envelopes back to the sender.
Let us now implement a Handler to deal with the incoming search responses.
from typing import Optional, cast
from aea.protocols.base import Message
from aea.skills.base import Handler
from packages.fetchai.protocols.oef_search.message import OefSearchMessage
from packages.fetchai.skills.my_search.dialogues import (
OefSearchDialogue,
OefSearchDialogues,
)
class MySearchHandler(Handler):
"""This class provides a simple search handler."""
SUPPORTED_PROTOCOL = OefSearchMessage.protocol_id
def __init__(self, **kwargs):
"""Initialize the handler."""
super().__init__(**kwargs)
self.received_search_count = 0
def setup(self) -> None:
"""Set up the handler."""
self.context.logger.info(
"setting up MySearchHandler"
)
def handle(self, message: Message) -> None:
"""
Implement the reaction to a message.
:param message: the message
:return: None
"""
oef_search_msg = cast(OefSearchMessage, message)
# recover dialogue
oef_search_dialogues = cast(
OefSearchDialogues, self.context.oef_search_dialogues
)
oef_search_dialogue = cast(
Optional[OefSearchDialogue], oef_search_dialogues.update(oef_search_msg)
)
if oef_search_dialogue is None:
self._handle_unidentified_dialogue(oef_search_msg)
return
# handle message
if oef_search_msg.performative is OefSearchMessage.Performative.OEF_ERROR:
self._handle_error(oef_search_msg, oef_search_dialogue)
elif oef_search_msg.performative is OefSearchMessage.Performative.SEARCH_RESULT:
self._handle_search(oef_search_msg, oef_search_dialogue)
else:
self._handle_invalid(oef_search_msg, oef_search_dialogue)
def _handle_unidentified_dialogue(self, oef_search_msg: OefSearchMessage) -> None:
"""
Handle an unidentified dialogue.
:param msg: the message
"""
self.context.logger.info(
"received invalid oef_search message={}, unidentified dialogue.".format(
oef_search_msg
)
)
def _handle_error(
self, oef_search_msg: OefSearchMessage, oef_search_dialogue: OefSearchDialogue
) -> None:
"""
Handle an oef search message.
:param oef_search_msg: the oef search message
:param oef_search_dialogue: the dialogue
:return: None
"""
self.context.logger.info(
"received oef_search error message={} in dialogue={}.".format(
oef_search_msg, oef_search_dialogue
)
)
def _handle_search(
self, oef_search_msg: OefSearchMessage, oef_search_dialogue: OefSearchDialogue
) -> None:
"""
Handle the search response.
:param agents: the agents returned by the search
:return: None
"""
self.received_search_count += 1
nb_agents_found = len(oef_search_msg.agents)
self.context.logger.info(
"found number of agents={}, received search count={}".format(
nb_agents_found, self.received_search_count
)
)
self.context.logger.info(
"number of search requests sent={} vs. number of search responses received={}".format(
self.context.behaviours.my_search_behaviour.sent_search_count,
self.received_search_count,
)
)
def _handle_invalid(
self, oef_search_msg: OefSearchMessage, oef_search_dialogue: OefSearchDialogue
) -> None:
"""
Handle an oef search message.
:param oef_search_msg: the oef search message
:param oef_search_dialogue: the dialogue
:return: None
"""
self.context.logger.warning(
"cannot handle oef_search message of performative={} in dialogue={}.".format(
oef_search_msg.performative, oef_search_dialogue,
)
)
def teardown(self) -> None:
"""
Teardown the handler.
:return: None
"""
self.context.logger.info(
"tearing down MySearchHandler"
)
We create a handler which is registered for the oef_search protocol. Whenever it receives a search result, we log the number of agents returned in the search - the agents matching the search query - and update the counter of received searches.
We also implement a trivial check on the difference between the amount of search requests sent and responses received.
Note, how the handler simply reacts to incoming events (i.e. messages). It could initiate further actions, however, they are still reactions to the upstream search event.
Also note, how we have access to other objects in the skill via self.context, the SkillContext.
We place this code in my_aea/skills/my_search/handlers.py.
Step 4: Add dialogues model
We have implemented a behaviour and a handler. We now implement a Model, in particular we implement the Dialogue and Dialogues classes.
from aea.protocols.base import Message
from aea.protocols.dialogue.base import Dialogue as BaseDialogue
from aea.skills.base import Address, Model
from packages.fetchai.protocols.oef_search.dialogues import (
OefSearchDialogue as BaseOefSearchDialogue,
)
from packages.fetchai.protocols.oef_search.dialogues import (
OefSearchDialogues as BaseOefSearchDialogues,
)
OefSearchDialogue = BaseOefSearchDialogue
class OefSearchDialogues(Model, BaseOefSearchDialogues):
"""This class keeps track of all oef_search dialogues."""
def __init__(self, **kwargs) -> None:
"""
Initialize dialogues.
:param agent_address: the address of the agent for whom dialogues are maintained
:return: None
"""
Model.__init__(self, **kwargs)
def role_from_first_message( # pylint: disable=unused-argument
message: Message, receiver_address: Address
) -> BaseDialogue.Role:
"""Infer the role of the agent from an incoming/outgoing first message
:param message: an incoming/outgoing first message
:param receiver_address: the address of the receiving agent
:return: The role of the agent
"""
return BaseOefSearchDialogue.Role.AGENT
BaseOefSearchDialogues.__init__(
self,
self_address=self.context.agent_address,
role_from_first_message=role_from_first_message,
)
We add this code in the file my_aea/skills/my_search/my_model.py, replacing its original content. We then renamce my_aea/skills/my_search/my_model.py to my_aea/skills/my_search/dialogues.py.
Step 5: Create the config file
Based on our skill components above, we create the following config file.
name: my_search
author: fetchai
version: 0.1.0
type: skill
description: A simple search skill utilising the SOEF search node.
license: Apache-2.0
aea_version: '>=0.6.0, <0.7.0'
fingerprint: {}
fingerprint_ignore_patterns: []
contracts: []
protocols:
- fetchai/oef_search:0.6.0
skills: []
behaviours:
my_search_behaviour:
args:
location:
latitude: 0.127
longitude: 51.5194
search_query:
constraint_type: ==
search_key: seller_service
search_value: generic_service
search_radius: 5.0
tick_interval: 5
class_name: MySearchBehaviour
handlers:
my_search_handler:
args: {}
class_name: MySearchHandler
models:
oef_search_dialogues:
args: {}
class_name: OefSearchDialogues
dependencies: {}
Ensure, you replace the author field with your author name! (Run aea init to set or check the author name.)
Importantly, the keys my_search_behaviour and my_search_handler are used in the above handler to access these skill components at runtime via the context. We also set the tick_interval of the TickerBehaviour to 5 seconds.
We place this code in my_aea/skills/my_search/skill.yaml.
Step 6: Update fingerprint
We need to update the fingerprint of our skill next:
aea fingerprint skill fetchai/my_search:0.1.0
Ensure, you use the correct author name to reference your skill (here we use fetchai as the author.)
Step 7: Add the oef protocol and connection
Our AEA does not have the oef protocol yet so let's add it.
aea add protocol fetchai/oef_search:0.6.0
This adds the protocol to our AEA and makes it available on the path packages.fetchai.protocols....
We also need to add the soef and p2p connections and install the AEA's dependencies:
aea add connection fetchai/soef:0.8.0
aea add connection fetchai/p2p_libp2p:0.9.0
aea install
aea config set agent.default_connection fetchai/p2p_libp2p:0.9.0
Finally, in the aea-config.yaml add the following lines:
default_routing:
fetchai/oef_search:0.6.0: fetchai/soef:0.8.0
This will ensure that search requests are processed by the correct connection.
Step 8: Run a service provider AEA
In order to be able to find another AEA when searching, from a different terminal window, we fetch another finished AEA:
aea fetch fetchai/simple_service_registration:0.12.0 && cd simple_service_registration
This AEA will simply register a location service on the SOEF search node so we can search for it.
We first create the private key for the service provider AEA based on the network you want to transact. To generate and add a private-public key pair for Fetch.ai AgentLand use:
aea generate-key fetchai
aea add-key fetchai fetchai_private_key.txt
aea add-key fetchai fetchai_private_key.txt --connection
Then we run the aea:
aea run
Once you see a message of the form My libp2p addresses: ['SOME_ADDRESS'] take note of the address.
Click here to see full code
We use a `TickerBehaviour` to update the service registration at regular intervals. The following code is placed in `behaviours.py`.
from typing import cast
from aea.skills.behaviours import TickerBehaviour
from packages.fetchai.protocols.oef_search.message import OefSearchMessage
from packages.fetchai.skills.simple_service_registration.dialogues import (
OefSearchDialogues,
)
from packages.fetchai.skills.simple_service_registration.strategy import Strategy
DEFAULT_SERVICES_INTERVAL = 30.0
class ServiceRegistrationBehaviour(TickerBehaviour):
"""This class implements a behaviour."""
def __init__(self, **kwargs):
"""Initialise the behaviour."""
services_interval = kwargs.pop(
"services_interval", DEFAULT_SERVICES_INTERVAL
) # type: int
super().__init__(tick_interval=services_interval, **kwargs)
def setup(self) -> None:
"""
Implement the setup.
:return: None
"""
self._register_agent()
self._register_service()
def act(self) -> None:
"""
Implement the act.
:return: None
"""
pass
def teardown(self) -> None:
"""
Implement the task teardown.
:return: None
"""
self._unregister_service()
self._unregister_agent()
def _register_agent(self) -> None:
"""
Register the agent's location.
:return: None
"""
strategy = cast(Strategy, self.context.strategy)
description = strategy.get_location_description()
oef_search_dialogues = cast(
OefSearchDialogues, self.context.oef_search_dialogues
)
oef_search_msg = OefSearchMessage(
performative=OefSearchMessage.Performative.REGISTER_SERVICE,
dialogue_reference=oef_search_dialogues.new_self_initiated_dialogue_reference(),
service_description=description,
)
oef_search_msg.counterparty = self.context.search_service_address
oef_search_dialogues.update(oef_search_msg)
self.context.outbox.put_message(message=oef_search_msg)
self.context.logger.info("registering agent on SOEF.")
def _register_service(self) -> None:
"""
Register the agent's service.
:return: None
"""
strategy = cast(Strategy, self.context.strategy)
description = strategy.get_register_service_description()
oef_search_dialogues = cast(
OefSearchDialogues, self.context.oef_search_dialogues
)
oef_search_msg = OefSearchMessage(
performative=OefSearchMessage.Performative.REGISTER_SERVICE,
dialogue_reference=oef_search_dialogues.new_self_initiated_dialogue_reference(),
service_description=description,
)
oef_search_msg.counterparty = self.context.search_service_address
oef_search_dialogues.update(oef_search_msg)
self.context.outbox.put_message(message=oef_search_msg)
self.context.logger.info("registering service on SOEF.")
def _unregister_service(self) -> None:
"""
Unregister service from the SOEF.
:return: None
"""
strategy = cast(Strategy, self.context.strategy)
description = strategy.get_unregister_service_description()
oef_search_dialogues = cast(
OefSearchDialogues, self.context.oef_search_dialogues
)
oef_search_msg = OefSearchMessage(
performative=OefSearchMessage.Performative.UNREGISTER_SERVICE,
dialogue_reference=oef_search_dialogues.new_self_initiated_dialogue_reference(),
service_description=description,
)
oef_search_msg.counterparty = self.context.search_service_address
oef_search_dialogues.update(oef_search_msg)
self.context.outbox.put_message(message=oef_search_msg)
self.context.logger.info("unregistering service from SOEF.")
def _unregister_agent(self) -> None:
"""
Unregister agent from the SOEF.
:return: None
"""
strategy = cast(Strategy, self.context.strategy)
description = strategy.get_location_description()
oef_search_dialogues = cast(
OefSearchDialogues, self.context.oef_search_dialogues
)
oef_search_msg = OefSearchMessage(
performative=OefSearchMessage.Performative.UNREGISTER_SERVICE,
dialogue_reference=oef_search_dialogues.new_self_initiated_dialogue_reference(),
service_description=description,
)
oef_search_msg.counterparty = self.context.search_service_address
oef_search_dialogues.update(oef_search_msg)
self.context.outbox.put_message(message=oef_search_msg)
self.context.logger.info("unregistering agent from SOEF.")
from aea.helpers.search.generic import (
AGENT_LOCATION_MODEL,
AGENT_REMOVE_SERVICE_MODEL,
AGENT_SET_SERVICE_MODEL,
)
from aea.helpers.search.models import Description, Location
from aea.skills.base import Model
DEFAULT_LOCATION = {"longitude": 51.5194, "latitude": 0.1270}
DEFAULT_SERVICE_DATA = {"key": "seller_service", "value": "generic_service"}
class Strategy(Model):
"""This class defines a strategy for the agent."""
def __init__(self, **kwargs) -> None:
"""
Initialize the strategy of the agent.
:return: None
"""
location = kwargs.pop("location", DEFAULT_LOCATION)
self._agent_location = {
"location": Location(longitude=location["longitude"], latitude=location["latitude"])
}
self._set_service_data = kwargs.pop("service_data", DEFAULT_SERVICE_DATA)
assert (
len(self._set_service_data) == 2
and "key" in self._set_service_data
and "value" in self._set_service_data
), "service_data must contain keys `key` and `value`"
self._remove_service_data = {"key": self._set_service_data["key"]}
super().__init__(**kwargs)
def get_location_description(self) -> Description:
"""
Get the location description.
:return: a description of the agent's location
"""
description = Description(
self._agent_location, data_model=AGENT_LOCATION_MODEL,
)
return description
def get_register_service_description(self) -> Description:
"""
Get the register service description.
:return: a description of the offered services
"""
description = Description(
self._set_service_data, data_model=AGENT_SET_SERVICE_MODEL,
)
return description
def get_unregister_service_description(self) -> Description:
"""
Get the unregister service description.
:return: a description of the to be removed service
"""
description = Description(
self._remove_service_data, data_model=AGENT_REMOVE_SERVICE_MODEL,
)
return description
from aea.protocols.base import Message
from aea.protocols.dialogue.base import Dialogue as BaseDialogue
from aea.protocols.dialogue.base import DialogueLabel as BaseDialogueLabel
from aea.skills.base import Model
from packages.fetchai.protocols.oef_search.dialogues import (
OefSearchDialogue as BaseOefSearchDialogue,
)
from packages.fetchai.protocols.oef_search.dialogues import (
OefSearchDialogues as BaseOefSearchDialogues,
)
OefSearchDialogue = BaseOefSearchDialogue
class OefSearchDialogues(Model, BaseOefSearchDialogues):
"""This class keeps track of all oef_search dialogues."""
def __init__(self, **kwargs) -> None:
"""
Initialize dialogues.
:param agent_address: the address of the agent for whom dialogues are maintained
:return: None
"""
Model.__init__(self, **kwargs)
def role_from_first_message( # pylint: disable=unused-argument
message: Message, receiver_address: Address
) -> BaseDialogue.Role:
"""Infer the role of the agent from an incoming/outgoing first message
:param message: an incoming/outgoing first message
:param receiver_address: the address of the receiving agent
:return: The role of the agent
"""
return BaseOefSearchDialogue.Role.AGENT
BaseOefSearchDialogues.__init__(
self,
self_address=self.context.agent_address,
role_from_first_message=role_from_first_message,
)
from typing import Optional, cast
from aea.configurations.base import ProtocolId
from aea.protocols.base import Message
from aea.skills.base import Handler
from packages.fetchai.protocols.oef_search.message import OefSearchMessage
from packages.fetchai.skills.simple_service_registration.dialogues import (
OefSearchDialogue,
OefSearchDialogues,
)
LEDGER_API_ADDRESS = "fetchai/ledger:0.5.0"
class OefSearchHandler(Handler):
"""This class implements an OEF search handler."""
SUPPORTED_PROTOCOL = OefSearchMessage.protocol_id # type: Optional[ProtocolId]
def setup(self) -> None:
"""Call to setup the handler."""
pass
def handle(self, message: Message) -> None:
"""
Implement the reaction to a message.
:param message: the message
:return: None
"""
oef_search_msg = cast(OefSearchMessage, message)
# recover dialogue
oef_search_dialogues = cast(
OefSearchDialogues, self.context.oef_search_dialogues
)
oef_search_dialogue = cast(
Optional[OefSearchDialogue], oef_search_dialogues.update(oef_search_msg)
)
if oef_search_dialogue is None:
self._handle_unidentified_dialogue(oef_search_msg)
return
# handle message
if oef_search_msg.performative is OefSearchMessage.Performative.OEF_ERROR:
self._handle_error(oef_search_msg, oef_search_dialogue)
else:
self._handle_invalid(oef_search_msg, oef_search_dialogue)
def teardown(self) -> None:
"""
Implement the handler teardown.
:return: None
"""
pass
def _handle_unidentified_dialogue(self, oef_search_msg: OefSearchMessage) -> None:
"""
Handle an unidentified dialogue.
:param msg: the message
"""
self.context.logger.info(
"received invalid oef_search message={}, unidentified dialogue.".format(
oef_search_msg
)
)
def _handle_error(
self, oef_search_msg: OefSearchMessage, oef_search_dialogue: OefSearchDialogue
) -> None:
"""
Handle an oef search message.
:param oef_search_msg: the oef search message
:param oef_search_dialogue: the dialogue
:return: None
"""
self.context.logger.info(
"received oef_search error message={} in dialogue={}.".format(
oef_search_msg, oef_search_dialogue
)
)
def _handle_invalid(
self, oef_search_msg: OefSearchMessage, oef_search_dialogue: OefSearchDialogue
) -> None:
"""
Handle an oef search message.
:param oef_search_msg: the oef search message
:param oef_search_dialogue: the dialogue
:return: None
"""
self.context.logger.warning(
"cannot handle oef_search message of performative={} in dialogue={}.".format(
oef_search_msg.performative, oef_search_dialogue,
)
)
name: simple_service_registration
author: fetchai
version: 0.4.0
type: skill
description: The simple service registration skills is a skill to register a service.
license: Apache-2.0
aea_version: '>=0.6.0, <0.7.0'
fingerprint:
__init__.py: QmNkZAetyctaZCUf6ACxP5onGWsSxu2hjSNoFmJ3ta6Lta
behaviours.py: QmRr1oe3zWKyPcktzKP4BiKqjCqmKjEDdLUQhn1JzNm4nD
dialogues.py: QmayFh6ytPefJng5ENTUg46zsd6guHCZSsG3Cc2sy3xz6y
handlers.py: QmViyyV5KvR3kkLEMpvDfqH5QtHowTbnpDxRYnKABpVvpC
strategy.py: Qmdp6LCPZSnnyfM4EdRDTGZPqwxiJ3A1jsc3oF2Hv4m5Mv
fingerprint_ignore_patterns: []
contracts: []
protocols:
- fetchai/oef_search:0.6.0
skills: []
behaviours:
service:
args:
services_interval: 30
class_name: ServiceRegistrationBehaviour
handlers:
oef_search:
args: {}
class_name: OefSearchHandler
models:
oef_search_dialogues:
args: {}
class_name: OefSearchDialogues
strategy:
args:
location:
latitude: 0.127
longitude: 51.5194
service_data:
key: seller_service
value: generic_service
class_name: Strategy
dependencies: {}
Step 9: Run the Search AEA
First, create the private key for the search AEA based on the network you want to transact. To generate and add a private-public key pair for Fetch.ai AgentLand use:
aea generate-key fetchai
aea add-key fetchai fetchai_private_key.txt
aea add-key fetchai fetchai_private_key.txt --connection
Then, update the configuration of the buyer AEA's p2p connection (in vendor/fetchai/connections/p2p_libp2p/connection.yaml) replace the following:
config:
delegate_uri: 127.0.0.1:11001
entry_peers: ['SOME_ADDRESS']
local_uri: 127.0.0.1:9001
log_file: libp2p_node.log
public_uri: 127.0.0.1:9001
where SOME_ADDRESS is replaced accordingly.
We can then launch our AEA.
aea run
We can see that the AEA sends search requests to the SOEF search node and receives search responses from the SOEF search node. The search response returns one or more agents (the service provider and potentially other agents which match the query).
We stop the AEA with CTRL + C.
Next steps
Recommended
We recommend you continue with the next step in the 'Getting Started' series:
Relevant deep-dives
We hope this step by step introduction has helped you develop your own skill. We are excited to see what you will build.