JetBrains backs open AI coding standard that could gnaw at VS Code dominance

Google and Zed have already adopted ACP – will Microsoft now follow?

JetBrains has joined Google and Zed Industries in adopting the fledgling Agent Client Protocol (ACP), a standard for how AI agents interact with code editors and integrated development environments (IDEs).

The idea is that coding agents that support ACP will get automatic integration with editors. In the absence of a standard, developers building coding agents have to create separate add-ins for each editor they support, or rely on a command-line interface (CLI) that works in the terminal, independent of any specific editor.

Google told us that using Gemini CLI alone means that "developers constantly switch between the command line... and their IDE for coding, which is inefficient and breaks concentration." This problem led the team toward a collaboration with Zed in developing IDE integration, which evolved into the ACP standard, designed to work with any editor that implements it.

The Rust-based Zed has a small market share, whereas JetBrains is second only to Microsoft, whose Visual Studio Code (VS Code) and Visual Studio are the first and second most popular IDEs, according to most surveys.

JetBrains has stated that it will now support ACP and is collaborating with Zed on developing the protocol. The company highlights the top benefit as "no vendor lock-in" since developers will be able to use their preferred coding assistant from any IDE that supports the protocol.

Microsoft is the beneficiary of a familiar winner-takes-all pattern with VS Code, which is used by over 75 percent of developers, according to a recent survey. The VS Code marketplace has over 80,000 extensions, whereas JetBrains invites users to "search 10,000 extensions," and the vendor-neutral Open VSX Registry has just under 7,000.

ACP will not solve VS Code extension lock-in on its own, but it could benefit competing IDEs in the hot area of coding agent support. A key question is whether VS Code itself will support ACP. There is an open issue designated "under discussion" and assigned to Microsoft engineer Rob Lourens. Lourens said on GitHub that "this is interesting, but I don't plan to implement it right away."

The Rust-based Zed has a small market share, whereas JetBrains is second only to Microsoft, whose Visual Studio Code (VS Code) and Visual Studio are the first and second most popular IDEs

There might also be some benefit to Microsoft in implementing ACP since the company also provides Visual Studio, its Windows-only IDE, which has a different extension model than VS Code. Via ACP, compatible coding agents would work with both products.

It is early days for ACP, described on GitHub as "still under heavy development." There is, however, support for the Emacs and Neovim editors via extensions, and some progress on ACP for Eclipse.

Developers may also hope that ACP will make coding agent integration more reliable. The official VS Code plugin for Gemini Code Assist is the subject of many complaints such as "most of the time hangs" and "extension has huge memory leak." A new Gemini CLI extension in preview looks more promising, though with limited features. ®