A2A Jakarta 1.0.0.CR1 is released!

By Kabir Khan | June 11, 2026

I am pleased to announce the 1.0.0.CR1 release of A2A Jakarta (formerly the A2A Java SDK for Jakarta).

This release supports version 1.0 of the A2A Protocol Specification and is built on top of a2a-java 1.0.0.Final, whose highlights are covered in its release announcement.

This post also covers the highlights from the 1.0.0.Beta1 release, which did not have its own announcement.

New Repository Name and Coordinates

The repository has been renamed from wildfly-extras/a2a-java-sdk-server-jakarta to wildfly-extras/a2a-jakarta. Alongside this, the Maven artifact IDs and Java package names have been simplified:

Artifact IDs now use the a2a-jakarta- prefix instead of a2a-java-sdk-jakarta-. For example, a2a-java-sdk-jakarta-jsonrpc becomes a2a-jakarta-jsonrpc.
Java packages now use org.wildfly.a2a.jakarta as the root package.
The groupId remains org.wildfly.a2a.

If you are upgrading from a previous release, you will need to update your Maven dependencies and Java imports accordingly. For example, to use the JSON-RPC module:

<dependency>
    <groupId>org.wildfly.a2a</groupId>
    <artifactId>a2a-jakarta-jsonrpc</artifactId>
    <version>1.0.0.CR1</version>
</dependency>

v0.3 Protocol Compatibility Layer

The headline feature of this release is a compatibility layer for version 0.3 of the A2A Protocol. As the protocol evolved from v0.3 to v1.0, there were significant breaking changes. The compatibility layer lets you support v0.3 clients without maintaining a separate codebase.

The key design principle is that you only need a single AgentExecutor implementation. The compatibility layer intercepts incoming v0.3 requests, converts them to v1.0 format, and delegates to your existing executor. This means you write your agent logic once against the v1.0 API, and v0.3 support comes for free.

There are three deployment modes:

Standalone v0.3

If you need to deploy an application that only speaks v0.3, use the compat-0.3 modules instead of the v1.0 ones. The dependency names follow the same pattern with a compat-0.3 prefix:

org.wildfly.a2a:a2a-jakarta-compat-0.3-jsonrpc and a2a-jakarta-compat-0.3-jsonrpc-web for JSON-RPC
org.wildfly.a2a:a2a-jakarta-compat-0.3-grpc for gRPC
org.wildfly.a2a:a2a-jakarta-compat-0.3-rest and a2a-jakarta-compat-0.3-rest-web for REST

Multiversion (v0.3 + v1.0)

The most interesting mode is serving both protocol versions from the same deployment. To do this, you add the v0.3 compat dependencies alongside your v1.0 ones, plus the multiversion dispatching modules (a2a-jakarta-compat-0.3-multiversion-jsonrpc and a2a-jakarta-compat-0.3-multiversion-rest). These modules register JAX-RS resources that inspect incoming requests and route them to the correct protocol handler — v0.3 requests go through the compatibility conversion layer while v1.0 requests are handled directly. You can see how the project’s own TCK sets this up with a Maven profile in the tck/pom.xml.

As with the other modes, only a single AgentExecutor is needed. The one additional requirement is that you provide agent cards for both protocol versions — typically one is your "real" card and the other is either a stub or derived from it. See the README for detailed instructions and examples.

Agent Card Compatibility

When serving both protocol versions, the v1.0 AgentCard is what clients receive. To ensure v0.3 clients can parse it, the card needs some backward-compatibility fields. You can either set these manually or use the Compat03Fields.addCompat03FieldsIfAvailable() utility method.

Other Highlights

a2a-java 1.0.0.Final — We are now aligned with the final release of the upstream a2a-java SDK.
gRPC Feature Pack 0.2.0 — Upgraded to the latest WildFly gRPC Feature Pack.
WildFly 40 — The TCK now runs on WildFly 40.
CI on Windows — The CI pipeline now runs on both Linux and Windows.

Get Involved

If you have any issues with the project, please open an issue. Also, pull requests are welcome!