Copilot CLI is becoming the default agent harness in GitHub Copilot for JetBrains, and our local harness will be deprecated.
This change provides greater consistency across all GitHub Copilot surfaces and is an important step toward faster feature parity and higher-quality results in GitHub Copilot for JetBrains.
Copilot CLI sessions run independently in the background on your machine and use the Copilot CLI agent harness, while the IDE starts, monitors, and steers them. This is the same architecture used across GitHub Copilot today and adopting it in JetBrains lets us ship the same capabilities to JetBrains developers at a faster pace.
Why we’re making this change
Copilot is not the same product it was a year ago. Agentic coding — long, multi-step sessions that plan, edit, and verify work autonomously — is now the core of the experience, and the harness that runs those sessions matters more than ever.
Until recently, JetBrains has used its own local harness. Maintaining a separate harness meant new capabilities landed in JetBrains later than in other surfaces, and it added a layer we had to keep in sync with the rest of Copilot.
Copilot CLI fixes that. Moving to it as the default harness delivers two concrete benefits:
- Better feature and model parity, faster. New capabilities and models built on Copilot CLI reach JetBrains developers on a similar timeline as our other surfaces, instead of waiting on a separate harness.
- Higher-quality results. Copilot CLI completes coding tasks at a higher quality, so the agent’s plans, edits, and fixes are more reliable.
What’s changing
We are gradually rolling out Copilot CLI as the default agent harness in GitHub Copilot for JetBrains. As this roll out reaches you, Copilot CLI will be selected by default in the agent provider. The local agent harness may be deprecated in a future release; we will share timing when it happens.
What this means for JetBrains developers
Your day-to-day workflow stays familiar — you start, monitor, and respond to agent sessions from the IDE just as you do today.
- Existing local sessions will be converted to Copilot CLI sessions. You do not lose your sessions; they move to the new harness.
- Sessions run in the background. Copilot CLI sessions continue running independently on your machine, which makes them well-suited for running tasks in parallel.
- You stay in control. When a session needs input or permission to act, you respond from within the IDE.
For step-by-step instructions on converting your existing local sessions to Copilot CLI sessions, see Migrate to Copilot CLI in JetBrains.
The bottom line
Your sessions aren’t going away, and your workflow stays familiar. By moving GitHub Copilot for JetBrains to use Copilot CLI as the default harness, you get new features faster and higher-quality results, while existing local sessions are converted automatically. If you have feedback, please open an issue in our Copilot IntelliJ feedback repo or fill out our survey.
using the copilot cli vs local is a terrible experience. i really like the in file diffs, and the ability to actually see changes clearly in local. the copilot CLI loses a ton of transparency, new files miss getting added to git often, and since the new file isnt opened in the IDE, i need to go searching for it, assuming i know its been created. the pop out diff view is annoying to use, and context around changes are harder to find.
the agent has also started to pop out to a "coding agent" that dosnt show any progress...
This has been a regression in real functionality almost serious enough that I am having trouble countenancing paying for a Github Copilot subscription any longer.
It does not help that seemingly around the same time the in-editor diff viewer for seeing and approving agent changes has been removed or stopped working.
Hi Eric, what version are you using where the in-editor diff was not showing? Aside from this issue, are there any other regression that was happening?
I don't think it's worked the way that it originally did since May.
I've got Rider 2026.1.4 with the 1.13.1-251 GH Copilot plugin.
Maybe half the time, when the agent chat makes updates, it will show the box at the bottom of the chat to accept or decline the changes. Once upon a time, this showed the edit diff directly in the text editor window that you had the file open in, and you could approve things line by line.
Now, when a diff is available at all, it opens in the Rider git diff window instead, which is much less...
But then it doesn’t have access to the IDE agent tools, to do things like fix IDE errors (all the ones that appear in the scroll gutter), these include both Jetbrains identified code issues and Sonar issues. Deprecating this is a terrible idea.
Hi Richard, the Copilot CLI agent is different from the Copilot CLI terminal tools. We are basically using the brain behind the Copilot CLI terminal tools, while still adapting to an IDE-native environment. In fact, we intend to add more IDE-native tools integration in the future. Thanks
it does not mean that. There are protocols now for IDE/AI-Agent integration which I expect Github Copilot CLI will be implementing too to integrate with Jetbrains IDEs. There is even already a /ide command for it, but it just doesn’t support Jetbrains IDEs yet. Claude Code already does.
It looks like in CLI mode the Configure tools button is missing. So how do I configure my MCP servers and get the CLI to use them?
Hi Thomas, this was added in the latest release, you should see the configure tools button in Copilot CLI mode in the chat window
Apparently this new harness is not able to use MCPs. Neither configured in IntelliJ nor in Copilot CLI.
Hi Piotr, MCP support was recently added. You can configure it in settings -> customizations (the gears icon top right corner of GitHub Copilot’s chat window)
Will this allow us to add plugins from the marketplace using /plugin marketplace add?
Hi Nishita, we’ve added support for plugins. You can configure it in settings -> customizations (the gears icon top right corner of GitHub Copilot’s chat window)
breaks new sessions?
https://github.com/microsoft/copilot-intellij-feedback/issues/1843