Use messages, channels, and arguments intentionally

Overview

AgentConfiguration.Args tunes an instance. AgentMessage.Args carries per-turn metadata. For Operations Desk, RequestId is a useful application argument; the signed-in principal must come from the Host. Response() retains the routing relationship, while telemetry uses explicit trace fields.

Separate lasting settings from one-turn context

AgentConfiguration.Args belongs to the instance and can configure behavior across turns. AgentMessage.Args accompanies one message. RequestId=SR-1042 is useful per-turn context for a request page; a plugin's default endpoint is an instance setting. A model can help interpret a request, but trusted code should validate the request ID and authorize access before touching the record.

Correlation is not conversation content

Channel can tell your application that a turn came from operations-desk. Routing and trace fields connect the reply and telemetry to the incoming work. These values are not instructions to include in the answer. Use message.Response() to preserve the reply relationship, and inspect Args in trusted code instead of forcing users to repeat every machine-readable value in prose.

Construct the message envelope

1. Send RequestId=SR-1042 in AgentMessage.Args and read it defensively with TryGetValue. Give the request a meaningful application MessageType.
2. Branch on Channel only for presentation capabilities, such as text-only A2A output versus a Surface card. Do not infer permission from that branch.
3. Pass large structured application data through the documented Data/file contract rather than flattening secrets or entire documents into arguments.

var request = new AgentMessage
{
    ToHandle = "assistant",
    Message = "Investigate this service request.",
    MessageType = "request.investigate",
    Channel = "operations-desk",
    Args = new() { ["RequestId"] = "SR-1042" }
};

// Inside OnMessage: metadata is not authorization.
message.Args?.TryGetValue("RequestId", out var requestId);
var response = message.Response();

var message = new AgentMessage
{
    Message = "Process order",
    State = new() { ["priority"] = "high", ["source"] = "web-api" },
    Args = new() { ["orderId"] = "ORD-123" },
};

public override async Task<AgentMessage> OnMessage(AgentMessage message)
{
    var response = message.Response();

    if (message.Channel == "a2a")
    {
        // A2A groups related turns by contextId, and carries any caller-supplied metadata
        // (Copilot Studio puts its conversation history there) as raw JSON.
        var contextId = message.Args?.GetValueOrDefault("A2A:ContextId");
        var callerMetadata = message.Args?.GetValueOrDefault("A2A:Metadata");
    }

    response.Message = "...";
    return response;
}

Go deeper

Explore the related documentation.

• FabrCore Agents
• FabrCore Communication
• FabrCore Agent Framework
• Message Metadata