Updated headers for GitHub Copilot Extension requests

On March 31, 2025, GitHub Copilot Extensions will require an updated header format for agent requests. Both updated and previous versions of the request headers will be supported until then. These headers denote requests that come from GitHub and enable your extension to communicate with GitHub.

Updated headers:
– X-GitHub-Public-Key-Identifier
– X-GitHub-Public-Key-Signature

Previous headers, to be deprecated on March 31, 2025:
– Github-Public-Key-Identifier
– Github-Public-Key-Signature

Please update your relevant checks to the correct headers by March 31, 2025 for a consistent experience and to avoid breaking changes. To learn more, visit this page.

Linux arm64 hosted runners now available for free in public repositories (Public Preview)

Now in public preview, Linux arm64 hosted runners are available for free in public repositories. Following the release of arm64 larger hosted runners in June, this offering now extends to the open source-community. Powered by the Cobalt 100-based processors, these 4 vCPU runners can deliver up to a 40% performance boost compared to Microsoft Azure’s previous generation of Arm-based VMs, providing a power-efficient compute layer for your workloads. Arm-native developers can now build, test and deploy entirely within the arm64 architecture without the need for virtualization on your Actions runs.

How to use the runners

To leverage the arm64 hosted runners, add the following labels in your public repository workflow runs:
– ubuntu-24.04-arm
– ubuntu-22.04-arm

Please note that these labels will not work in private repositories, and the workflow will fail if added. All runs in public repositories will adhere to our standard runners usage limits, with maximum concurrencies based on your plan type. While the arm64 runners are in public preview, you may experience longer queue times during peak usage hours.

Images

In partnership with Arm, GitHub provides the Ubuntu VM images for these runners, helping customers with a seamless start to building on Arm. To view the list of installed software, give feedback, or report issues with the image, visit the partner-runner-images repository.

Get started today!

To get started, simply add one of the new labels to theruns-on syntax in your public Actions workflow file. For more information on arm64 runners and how to use them, see our documentation and join the conversation in the community discussion.

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Copilot Users Can Ask About A Failed Actions Job [GA]

The ability to ask Copilot chat about Actions job failures is now Generally Available. You can now press “Explain Error” from the PR mergebox or the Actions Job Page to kick off a conversation with Copilot about why a job failed and what steps can be taken to resolve the issue.

Mergebox
Within the mergebox, you can select the “More actions” option for a failing check and click “Explain Error” as seen below:

Screenshot of Explain Error in the mergebox of a PR
This will open Copilot chat and ask Copilot about this particular job.

Actions Job Page
You can go to the Job page for a failing job and press the “Explain Error” button next to the search bar for logs as seen below:

Screenshot of Explain Error in the Actions job page

This will open Copilot chat and ask Copilot about this job.

Who has access to this capability?

“Explain Error” can only analyze one job at a time. It is available on all Copilot tiers, but does consume a chat message to use. See the Copilot subscriptions page for more information on limits per tier.

Join the discussion within the GitHub Community.

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