Handling Messages

What happens when an agent receives a message?

Context passed to every agent provides a list of messages in the agent's inbox in the messages field. Here we can iterate through the list of messages sent to the agent and make some decisions.

context {
    messages(): [
    /*  
        Any messages sent to the given agent on this step.
        If the agent wants to preserve access to these on future steps,
        they'll need to store them in their own state.
    */
    ],
    /* other context values to come. */
}

It's best to think of the messages field like a mailbox.

• When sending a message, we put the message in the outbox under the messages field on state.

• When receiving a message, it will show up in our inbox, under the messages field on context.

Notice the distinction. Context is immutable and any accidental changes made to it will not propagate.

Handling the messages here would be pretty simple - just iterating through the messages array in context.

const behavior = (state, context) => {
    for (const message in context.messages()) {
        ...
    }
    
    // OR
    
    context.messages().forEach(m => {
        ...
    })
}

def behavior(state, context):
    for message in context.messages():
        ...

The messages that an agent receives are only available on the timestep they received them. context.messages() is cleared between timesteps, so an agent will need to store the messages on their state if they want to preserve a message.