As Xander Moffatt recently shared in Improving Canvas Infrastructure with a Content Delivery Network (CDN), we are putting AWS CloudFront in front of Canvas in order to improve speed and reliability. During continued testing, we discovered an additional change that affects API response headers, and we want to make sure you're aware before the production rollout begins.
What's different now?
In my May 2024 post, I shared that Canvas API response headers would transition to lowercase. However, CloudFront normalizes HTTP/1.1 response header names to Title Case (e.g., Link, Content-Type) rather than the lowercase format we previously communicated. If your integration connects via HTTP/2, headers will remain lowercase as required by the HTTP/2 specification. However, if your integration uses HTTP/1.1, you will now receive Title Case headers.
As I mentioned in the original post, RFC 9110 states that "field names are case-insensitive," so clients should not rely on header names matching any particular case. If you updated your integration to explicitly check for lowercase headers based on our earlier guidance, you may need to revisit that logic – or better yet, ensure your code handles headers case-insensitively.
How do I validate my integration?
This behavior is already active in both the Beta and Test environments. If your tool functions as expected in Beta and Test, you may safely assume it handles header capitalization correctly.
Note: You may want to monitor any third-party tools or integrations you utilize, to ensure that they behave correctly as well.
What is the timeline?
We will begin gradually rolling out CloudFront to production instances as part of the February 25, 2026 Canvas deploy.
What if I encounter issues?
If this change affects you in any way, you have options:
- Before your instance migrates: Contact your CSM to be added to the exclusion list, and we will delay CloudFront deployment for your instance.
- After your instance migrates: Contact your CSM, and we will roll your instance back while you make necessary updates.
Please see Xander's post for full details on the CloudFront migration and other potential impacts.
Thank you for your patience as we work to make Canvas faster, more reliable, and more secure. We appreciate you being part of this journey with us!
