2026-05-02 - “Upstream Sent Too Large a Header” Error Fixed¶
Release¶
AgileData.io - No More Cryptic Errors: Oversized Response Headers Resolved
Some users were encountering an “upstream sent too large a header” error after a recent dependency update. This has been fixed — AgileData now correctly handles large HTTP response headers without returning a 502 error to the browser.
The issue was traced to the Link header in API responses growing beyond the limit that the upstream proxy expects. A recent package update changed how response headers were assembled, causing the header to accumulate more content than intended. The fix trims the header back to within safe limits.
What was happening:
Certain API responses were generating an oversized Link response header
The proxy layer rejected these responses with a 502 “upstream sent too large a header” error
Issue appeared after a dependency update changed response header assembly behaviour
What this means for you:
The cryptic 502 error no longer appears during normal use
Pages and API calls that were affected now load reliably
No action needed on your end — this was a server-side fix
Last Refreshed¶
Doc Refreshed: 2026-05-02