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IsaacEldridge merged 11 commits into from
Jan 7, 2026
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W-20130488 add context to a2a protocol flow #545

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897687c
Add A2A Protocol details and non-supported features to af-agent-netwo…
IsaacEldridge Dec 18, 2025
76d9f34
Enhance documentation in af-project-files.adoc by adding a reference …
IsaacEldridge Dec 18, 2025
ee95291
Fix typo in af-agent-networks.adoc by correcting "as aserver" to "as …
IsaacEldridge Dec 18, 2025
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Update af-agent-networks.adoc to clarify A2A protocol usage by replac…
IsaacEldridge Jan 5, 2026
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IsaacEldridge Jan 6, 2026
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IsaacEldridge Jan 6, 2026
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Refine explanation in af-agent-networks.adoc regarding ID generation …
IsaacEldridge Jan 6, 2026
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IsaacEldridge Jan 6, 2026
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Remove the streaming section from af-agent-networks.adoc to streamlin…
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Merge branch 'latest' into W-20130488-ACB--A2A-Protocol-flow-ie
IsaacEldridge Jan 7, 2026
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38 changes: 33 additions & 5 deletions modules/ROOT/pages/af-agent-networks.adoc
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Expand Up @@ -60,6 +60,39 @@ These servers will be published to Exchange.
The asset might also be published to Exchange.
. An asset that has been added to this agent network project from Exchange.

== A2A Protocol

The Agent2Agent (A2A) Protocol governs agent-to-agent communication. This protocol powers orchestration, observability, and governance features in agent networks. MuleSoft supports v0.3.0 of the A2A Protocol Specification.

=== Context and Task ID Scoping in Agent Networks

In MuleSoft agent networks, the brokers receiving a request always generate a `contextId` and `taskId`. These IDs define the state and scope of a specific conversation between two agents. A `taskId` is always matched to a `contextId`, but a `contextId` can exist without a `taskId`.

In a multi-agent network, a client sends a request to Broker_1 and Broker_1 generates the necessary IDs for that request. When Broker_1 sends a new request to the next broker or non-broker agent in line, that broker or non-broker agent establishes a unique `contextID` and `taskID` for the new request.

NOTE: It is not mandatory for non-broker agents to generate a `contextId` and `taskId` when receiving requests from a client.

Consider a network with a client and two brokers (1 and 2).

* The IDs used between the client and Broker_1 are independent of the IDs used between Broker_1 and Broker_2.
* When Broker_1 delegates a task to Broker_2, Broker 2 (acting as a server) generates its own `contextId` and `taskId`.
* Broker_1 is responsible for maintaining a mapping between its own upstream `taskId` (used to respond to its client) and the downstream `taskId` it's tracking with Broker_2.
* If Broker_2 requires more information (if it returns `status: input-required`), it provides a `contextId` and `taskId` to Broker_1. Broker_1 uses these IDs to provide the requested input to Broker_2. The client never sees Broker_2's internal IDs.

[cols="1,1,1", options="header"]
|===
| Relationship | Role | Logic
| Client -> Broker_1 | Broker_1 is server | Generates `contextID_1` and `taskID_1` for the client.
| Agent A -> Broker_2 | Broker_2 is server | Generates `contextID_2` and `taskID_2` for Broker_1.
| Network broker | Broker_1 | Broker_1 maps `contextID_1` and `taskID_1` to `contextID_2` and `taskID_2`.
|===

For more information, see https://a2a-protocol.org/v0.3.0/topics/life-of-a-task/#group-related-interactions[Life of a Task - Group Related Interactions].

=== Non-Supported Features

Agent network doesn't support streaming with Server-Sent Events (SSE).

== Considerations

Agent networks have these considerations.
Expand All @@ -69,11 +102,6 @@ Agent networks have these considerations.
** Basic
** Client Credentials
** Anypoint Client Credentials
* A2A specification 0.3.0 is supported. Brokers use the A2A protocol to accept requests to reach other agents.
* These A2A features aren't available.
** Task History
** Push Notifications Config
** Streaming
* Text-based prompts and responses are supported. Image and binary message/artifact types aren't supported.
* All LLM models in your agent network project must support structured responses in JSON format. For example, a `gpt4.1` model is supported; a `gpt4` model isn't.
* These LLMs are supported.
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2 changes: 1 addition & 1 deletion modules/ROOT/pages/af-project-files.adoc
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Expand Up @@ -494,7 +494,7 @@ Use these properties to handle error scenarios. Define these properties within t

`agents`

Reference agents defined in a different agent network, or another agent used in your company. Any agent is valid, as long as it supports A2A as its communication protocol.
Reference agents defined in a different agent network, or another agent used in your company. Any agent is valid, as long as it supports A2A as its communication protocol. For more information, see xref:af-agent-networks.adoc#a2a-protocol[]

Example

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