How AEAs talk to each other - interaction protocols
Although one can imagine scenarios where single AEAs pursue their goals in isolation without interacting with other AEAs, there is no doubt that by working together, AEAs have the potential of achieving much more, especially when taking into account agents' heterogeneity, specialisations, and differing and often complimentary local views of the environment.
Interactions in the AEA world are in the form of communication. This is influenced by established practices in the field of multi-agent systems and the prominent speech-act theory which suggests that a communicative expression is not only about transferring information from the speaker to the hearer, but that there may be meanings and commitments beyond the statement's appearance. Therefore, speech may more suitably be considered as action. For example, "I hereby appoint you as chairman" is not just a sequence of words, but an action done by the speaker with wide-ranging consequences for the hearer and any other audience to that sentence.
Interaction protocols are thus possible communication scenarios between agents or agent components (specifically, skills and connections).
There are multiple types of interactions an AEA can have:
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AEA-to-AEA interactions. You can find some examples in the demo section.
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Interactions between an AEA's internal components.
Usually, an interaction involves three types of framework packages: skills, protocols and connections.
Example 1: negotiation
The generic buyer/seller skills use the fetchai/fipa protocol which defines the negotiation dialogue between two AEAs. The fetchai/generic_buyer and fetchai/generic_seller skills implement specific strategies for engaging in such negotiations, by providing the logic for producing negotiation messages to be sent, handling negotiation messages received. The fetchai/p2p_libp2p connection is then used for connecting to the agent communication network enabling two AEAs with these skills to deliver negotiation messages to each other.
Example 2: AEA <> web client
In the http connection guide we demonstrate how an AEA with an http server connection (e.g. fetchai/http_server) receives http payloads from web clients, translates them to messages conforming with the fetchai/http protocol and passes it to a skill (e.g. fetchai/http_echo) to process. The fetchai/http protocol in this case is used for communication between the connection and the skill.
Example 3 : AEA <> 3rd party server
The fetchai/http_client connection can be used to make requests to third party servers. In this case, a skill containing the logic for the production of http requests would create messages conforming with the fetchai/http protocol and sends it to the fetchai/http_client connection which in turn translates it into http payload and sends it to the destination server.
Note that in general, third party SDKs can be wrapped in a connection and shared with other developers as a package. Often this also involves creating a custom protocol to enforce the type of interactions permitted between skills and the connection wrapping the SDK.
Next steps
Recommended
We recommend you continue with the next step in the 'Getting Started' series:
Relevant deep-dives
Most AEA development focuses on developing the Skills and Protocols necessary for an AEA to deliver against its economic objectives and implement interaction protocols.
Understanding Protocols is core to developing your own agent. You can learn more about the Protocols agents use to communicate with each other and how they are created in the following section:
Most of an AEA developer's time is spent on Skill development. Skills are the core business logic components of an AEA. Check out the following guide to learn more:
In most cases, one of the available Connection packages can be used. Occasionally, you might develop your own Connection: