Wildfly A2A Feature Pack

:toc: = WildFly A2A Feature Pack

WARNING: This is an unsupported experimental POC implementation. Use with caution.

A WildFly feature pack implementing the open-standard Agent2Agent (A2A) Protocol to enable universal interoperability and seamless collaboration between AI agents across diverse frameworks and vendors.

== Building

WARNING: To pass all tests, a gRPC Feature Pack with fix for https://github.com/wildfly-extras/wildfly-grpc-feature-pack/issues/430 is required. Thus, temporarily use an unrelease version compiled from the main branch.

First, clone and build the https://github.com/wildfly-extras/wildfly-grpc-feature-pack[wildfly-grpc-feature-pack]:

[source,bash]

git clone https://github.com/wildfly-extras/wildfly-grpc-feature-pack.git cd wildfly-grpc-feature-pack ./mvnw install -DskipTests

Then, build the A2A feature pack:

[source,bash]

git clone https://github.com/rhusar/wildfly-a2a-feature-pack.git cd wildfly-a2a-feature-pack ./mvnw install -DskipTests

== Provisioning with Maven

Use the wildfly-maven-plugin to provision WildFly with the A2A feature pack.

=== A2A Server with All Transports (JSON-RPC, gRPC, REST)

For gRPC support, include the https://github.com/wildfly-extras/wildfly-grpc-feature-pack[wildfly-grpc-feature-pack]:

[source,xml]

== Layers

The feature pack provides the following Galleon layers:

|=== |Layer |Description

|a2a |Base layer with A2A subsystem |a2a-client-jsonrpc |A2A client with JSON-RPC 2.0 over HTTP transport |a2a-client-grpc |A2A client with gRPC binary protocol transport |a2a-client-http-json |A2A client with RESTful HTTP/JSON transport |a2a-server-jsonrpc |A2A server with JSON-RPC 2.0 over HTTP transport |a2a-server-grpc |A2A server with gRPC binary protocol transport |a2a-server-http-json |A2A server with RESTful HTTP/JSON transport |===

Server layers include both the A2A SDK transport module and the Jakarta EE implementation. Client layers include only the SDK transport module.

== Running Integration Tests

Based on https://github.com/wildfly-extras/a2a-java-sdk-server-jakarta[a2a-java-sdk-server-jakarta] testing approach.

[source,bash]

mvn clean install # All tests mvn clean test -pl testsuite/integration/jsonrpc # JSON-RPC only mvn clean test -pl testsuite/integration/grpc # gRPC only mvn clean test -pl testsuite/integration/http-json # HTTP-JSON only

== Running the TCK

The feature pack includes a TCK (Test Compatibility Kit) module that runs the official A2A protocol TCK against WildFly.

=== Prerequisites

• Java 17 (or newer)
• Maven 3.9 (or newer)
• Python 3.11 (or newer) with uv package manager

=== Build and Run TCK

1. Build the feature pack:

[source,bash]

mvn clean install

1. Build and provision the TCK server:

[source,bash]

mvn package -pl tck -am

. Start the WildFly server:

[source,bash]

SUT_JSONRPC_URL=http://localhost:8080 SUT_GRPC_URL=http://localhost:9555 SUT_REST_URL=http://localhost:8080 tck/target/wildfly/bin/standalone.sh --stability=preview

. Clone and set up the A2A TCK:

[source,bash]

git clone https://github.com/a2aproject/a2a-tck.git cd a2a-tck pip install uv uv pip install -e .

. Run the TCK:

[source,bash]

TCK_STREAMING_TIMEOUT=4.0 SUT_JSONRPC_URL=http://localhost:8080 SUT_GRPC_URL=http://localhost:9555 SUT_REST_URL=http://localhost:8080 uv run ./run_tck.py --sut-url http://localhost:8080 --category all --transports jsonrpc,grpc,rest --compliance-report report.json

. Stop the server:

[source,bash]

mvn wildfly:shutdown -pl tck

TCK Endpoints Reference

• JSON-RPC: http://localhost:8080
• REST (HTTP-JSON): http://localhost:8080
• gRPC: localhost:9555 (gRPC endpoint provisioned by the FP runs on separate Netty-back port)

== Resources

• https://a2aprotocol.ai/[A2A Protocol] - Official A2A protocol specification
• https://github.com/a2aproject/A2A[A2A] - Reference implementation of the A2A protocol
• https://github.com/a2aproject/a2a-java[a2a-java] - Java SDK for A2A protocol
• https://github.com/a2aproject/a2a-tck[a2a-tck] - Official A2A protocol TCK
• https://github.com/wildfly-extras/a2a-java-sdk-server-jakarta[a2a-java-sdk-server-jakarta] - Jakarta EE server implementation of A2A Java SDK
• https://github.com/wildfly-extras/wildfly-ai-feature-pack[wildfly-ai-feature-pack] - WildFly feature pack for AI/LLM integration (langchain4j)