If you’ve been running AG2 (formerly AutoGen) and haven’t touched it since before this month, there’s a good chance your upgrade path just changed shape entirely. AG2 hit its v1.0.0 milestone days ago, and the framework has now shipped v1.0.2 — a rapid pair of follow-up releases that flesh out the new protocol-driven architecture. Here’s what actually changed, confirmed directly against the official GitHub release notes.

The Big Picture: What “v1.0” Actually Means

Per the official AG2 v1.0.0 release notes: “AG2 v1 is here! The protocol-driven framework we started building as autogen.beta in v0.12 is now the mainline framework, and the classic framework has moved to its own repository.”

This is not a routine version bump. The release notes are explicit that v1.0 is not a drop-in upgrade: “The agent model, orchestration, and imports are different. Install autogen or pin the classic distribution rather than tracking ag2>=1.0, and your existing code keeps working unchanged.”

In other words, if you’re currently running ConversableAgent, GroupChat, or initiate_chat — the API surface most AutoGen/AG2 users have built on for years — none of that is going away, but it now lives in a separate, maintenance-mode repository: ag2ai/ag2-classic, with its own documentation at classic.docs.ag2.ai. It’s still installable and still receives security and critical bug fixes. It just isn’t where new feature development happens anymore.

If you have existing production code on the classic API, the safe move is: keep pinning the classic distribution. Don’t blindly bump to ag2>=1.0 expecting your old code to still work — it won’t, per the release notes’ own explicit warning.

What’s New in the Protocol-Driven Mainline

The new AG2 mainline is built around external agent protocols rather than an internal conversation loop. The headline addition in v1.0.0 is ACP (Agent Client Protocol) support, described in the release notes as: “First-class support for driving external CLI coding agents (Claude Code, Codex, OpenCode, Gemini CLI, and others) as Agents over Agent Client Protocol (ACP)! … together with an MCP tool gateway that exposes AG2 tools to those agents.”

That’s a meaningful capability if your team already has investment in specific CLI coding agents and wants to orchestrate them from AG2 rather than reimplementing their behavior natively.

What Changed in v1.0.1 and v1.0.2

Two fast-follow releases have already landed since v1.0.0, per the official GitHub releases page:

v1.0.1 was a compatibility-driven patch: “MCP 2.0 has been released and is a breaking change. Releasing AG2 1.0.1, which pins mcp to <2, until compatibility is implemented.” If you’re using AG2’s MCP integration, this matters — don’t let your mcp dependency float past 2.0 until AG2 confirms compatibility.

v1.0.2 adds several concrete protocol-surface improvements, confirmed via the official release notes:

  • Kilo Code support — “add Kilo Code support and model selection to ACP configurations” (PR #3101), meaning ACP configs can now select which model an external coding agent uses.
  • User-defined A2A extensions — “support user-defined A2A extensions” (PR #3116), letting you extend agent-to-agent protocol behavior.
  • gRPC TLS for A2A — “add gRPC TLS support for secure agent communication” (PR #3138), for teams that need encrypted transport between agents.
  • Serving an AG2 Agent over ACP — “serve an AG2 Agent over ACP” (PR #3139), meaning the direction now works both ways: AG2 can drive external ACP agents and expose its own agents over ACP for others to drive.
  • Driving remote ACP agents over HTTP/WebSocket — including answering agent questions and an ACP protocol version bump to 0.12 (PR #3146).
  • Middleware describe() — middleware components can now report their own configuration (PR #3120), useful for debugging composed middleware stacks.

How to Approach the Upgrade

Based strictly on what’s confirmed in the official release notes:

  1. Check your current install. If you depend on ConversableAgent, GroupChat, or initiate_chat, you’re on the classic API surface. Pin to the ag2-classic distribution explicitly rather than letting ag2 float to >=1.0.
  2. If you’re building new agent orchestration, the mainline ag2 package (v1.0.2) is where ACP, A2A, and MCP-gateway work is happening. Read the migration notes in the v1.0.0 release before porting any classic code — the release notes describe the agent model and orchestration as fundamentally different, not just renamed.
  3. If you use AG2’s MCP integration, make sure your mcp package version is pinned appropriately — AG2 pinned mcp<2 in v1.0.1 specifically because MCP 2.0 introduced breaking changes AG2 hadn’t yet adapted to.
  4. If you want to drive Claude Code, Codex, OpenCode, or Gemini CLI from AG2, the ACP integration added in v1.0.0 and expanded in v1.0.2 (Kilo Code support, remote HTTP/WebSocket driving) is the feature to look at — check the official docs at docs.ag2.ai for the exact configuration syntax, since specific config keys aren’t reproduced in the release notes text itself.

We’re not fabricating exact CLI commands or config file syntax here beyond what’s directly quoted from the GitHub release notes above — for the precise ACP configuration schema, consult AG2’s official documentation before wiring this into a production pipeline.

Sources

  1. AG2 Releases — Official GitHub (v1.0.0, v1.0.1, v1.0.2)

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