AEA Quick Start¶
If you want to create Autonomous Economic Agents (AEAs) that can act independently of constant user input and autonomously execute actions to achieve their objective, you can use the AEA framework.
This example will take you through a simple AEA to familiarise you with the basics of the framework.
Echo Skill Demo¶
This is a simple demo that introduces you to the main components of an AEA.
The fastest way to have your first AEA is to fetch one that already exists!
To learn more about the folder structure of an AEA project read on here.
Alternatively: step by step install:
Create a new AEA
First, create a new AEA project and enter it.
Add the stub connection
Second, add the stub connection to the project.
Add the echo skill
Third, add the echo skill to the project.
This copies the fetchai/echo:0.20.6 skill code containing the "behaviours", and "handlers" into the project, ready to run. The identifier of the skill fetchai/echo:0.20.6 consists of the name of the author of the skill, followed by the skill name and its version.
Echo Skill¶
Just like humans, AEAs can have skills to achieve their tasks. As an agent developer, you can create skills to add to your own AEAs. You can also choose to publish your skills so others add them to their AEAs. More details on skills can be found on this page .
The above agent has an echo skill, fetched from the registry, which simply echoes any messages it receives back to its sender.
Communication via Envelopes and Messages¶
AEAs use envelopes containing messages for communication. To learn more, check out the next section.
Stub Connection¶
Besides skills, AEAs may have one or more connections enabling them to interface with entities in the outside world. For example, an HTTP client connection allows an AEA to communicate with HTTP servers. To read more about connections see this page.
In this demo, we use the stub connection (fetchai/stub0.15.0) to send envelopes to and receive envelopes from the AEA.
A stub connection provides an I/O reader and writer. It uses two files for communication: one for incoming envelopes and the other for outgoing envelopes.
The AEA waits for a new envelope posted to the file my_first_aea/input_file, and adds a response to the file my_first_aea/output_file.
The format of each envelope is the following:
For example:
Install AEA Dependencies¶
Add and Create a Private Key¶
All AEAs need a private key to run. Add one now:
Run the AEA¶
Run the AEA.
You will see the echo skill running in the terminal window (an output similar to the one below).
_ _____ _
/ \ | ____| / \
/ _ \ | _| / _ \
/ ___ \ | |___ / ___ \
/_/ \_\|_____|/_/ \_\
v1.1.1
Starting AEA 'my_first_aea' in 'async' mode ...
info: Echo Handler: setup method called.
info: Echo Behaviour: setup method called.
info: [my_first_aea]: Start processing messages...
info: Echo Behaviour: act method called.
info: Echo Behaviour: act method called.
info: Echo Behaviour: act method called.
...
The framework first calls the setup methods in the skill's Handler and Behaviour classes in that order; after which it repeatedly calls the act method of Behaviour class. This is the main agent loop in action.
Add a Message to the Input File¶
You can send the AEA a message wrapped in an envelope using the CLI's interact command.
From a different terminal and same directory (ensure you are in the same virtual environment: pipenv shell):
You can now send messages to this AEA via an interactive tool by typing anything into the prompt and hitting enter twice (once to send the message and once more to check for a response).
Let us send hello to this AEA (type hello and press enter twice). In the original terminal, you will see the Echo Handler dealing with this envelope and its contained message. You should see an output similar to the one below but with a different dialogue_reference.
info: Echo Behaviour: act method called.
info: Echo Handler: message=Message(dialogue_reference=('1', '') message_id=1 target=0 performative=bytes content=b'hello'), sender=my_first_aea_interact
info: Echo Behaviour: act method called.
info: Echo Behaviour: act method called.
Manual approach:
Optionally, from a different terminal and same directory (i.e. the my_first_aea project), you can send the AEA a message wrapped in an envelope via the input file.
echo 'my_first_aea,sender_aea,fetchai/default:1.0.0,\x12\x10\x08\x01\x12\x011*\t*\x07\n\x05hello,' >> input_file
You will see the Echo Handler dealing with the envelope and responding with the same message to the output_file, and also decoding the Base64 encrypted message in this case.
info: Echo Behaviour: act method called.
Echo Handler: message=Message(sender=sender_aea,to=my_first_aea,content=b'hello',dialogue_reference=('1', ''),message_id=1,performative=bytes,target=0), sender=sender_aea
info: Echo Behaviour: act method called.
info: Echo Behaviour: act method called.
Note, due to the dialogue reference having to be incremented, you can only send the above envelope once! This approach does not work in conjunction with the aea interact command.
Stop the AEA¶
You can stop an AEA by pressing CTRL C.
Once you do, you should see the AEA being interrupted and then calling the teardown() methods:
info: Echo Behaviour: act method called.
info: Echo Behaviour: act method called.
^C my_first_aea interrupted!
my_first_aea stopping ...
info: Echo Handler: teardown method called.
info: Echo Behaviour: teardown method called.
Write a Test for the AEA¶
We can write an end-to-end test for the AEA utilising helper classes provided by the framework.
Writing tests:
The following test class replicates the preceding demo and tests its correct behaviour. The AEATestCase classes are a tool for AEA developers to write useful end-to-end tests of their AEAs.
First, get the packages directory from the AEA repository (execute from the working directory which contains the my_first_aea folder):
Then write the test:
import signal
import time
from aea.common import Address
from aea.mail.base import Envelope
from aea.protocols.base import Message
from aea.protocols.dialogue.base import Dialogue
from packages.fetchai.protocols.default.dialogues import DefaultDialogue, DefaultDialogues
from packages.fetchai.protocols.default.message import DefaultMessage
from packages.fetchai.protocols.default.serialization import DefaultSerializer
from aea.test_tools.test_cases import AEATestCase
class TestEchoSkill(AEATestCase):
"""Test that echo skill works."""
def test_echo(self):
"""Run the echo skill sequence."""
process = self.run_agent()
is_running = self.is_running(process)
assert is_running, "AEA not running within timeout!"
# add sending and receiving envelope from input/output files
sender_aea = "sender_aea"
def role_from_first_message(
message: Message, receiver_address: Address
) -> Dialogue.Role:
return DefaultDialogue.Role.AGENT
dialogues = DefaultDialogues(sender_aea, role_from_first_message)
message_content = b"hello"
message = DefaultMessage(
performative=DefaultMessage.Performative.BYTES,
dialogue_reference=dialogues.new_self_initiated_dialogue_reference(),
content=message_content,
)
sent_envelope = Envelope(
to=self.agent_name,
sender=sender_aea,
protocol_id=message.protocol_id,
message=DefaultSerializer().encode(message),
)
self.send_envelope_to_agent(sent_envelope, self.agent_name)
time.sleep(2.0)
received_envelope = self.read_envelope_from_agent(self.agent_name)
assert sent_envelope.to == received_envelope.sender
assert sent_envelope.sender == received_envelope.to
assert sent_envelope.protocol_id == received_envelope.protocol_id
received_message = DefaultMessage.serializer.decode(received_envelope.message)
assert message.content == received_message.content
check_strings = (
"Echo Handler: setup method called.",
"Echo Behaviour: setup method called.",
"Echo Behaviour: act method called.",
"content={}".format(message_content),
)
missing_strings = self.missing_from_output(process, check_strings)
assert (
missing_strings == []
), "Strings {} didn't appear in agent output.".format(missing_strings)
assert (
self.is_successfully_terminated()
), "Echo agent wasn't successfully terminated."
Place the above code into a file test.py in your AEA project directory (the same level as the aea-config.yaml file).
To run, execute the following:
Delete the AEA¶
Delete the AEA from the parent directory (cd .. to go to the parent directory).
Next Steps¶
To gain an understanding of the core components of the framework, please continue to the next page:
For more demos, use cases or step-by-step guides, please check the following: