NEW290922
declarativeNetRequest modifyHeaders doesn't support custom headers 
https://bugs.webkit.org/show_bug.cgi?id=290922
Summary declarativeNetRequest modifyHeaders doesn't support custom headers
Jeff Johnson
Reported 2025-04-02 07:46:14 PDT
Created attachment 474805 [details] Example extension background.js Unlike Chrome and Firefox, Safari doesn't support custom headers with declarativeNetRequest modifyHeaders. Attached is a sample web extension demonstrating the issue. The extension gives the following error: "Invalid call to declarativeNetRequest.updateDynamicRules(). The 'addRules' value is invalid, because an error with rule at index 0: Rule with id 1 is invalid. The header `Foo` is not recognized." Another, tangential issue is that updateDynamicRules throws an exception, caught in my try-catch block, rather than rejecting the promise that's supposed to be returned by updateDynamicRules.
Attachments
Example extension background.js (1.92 KB, application/x-javascript)
2025-04-02 07:46 PDT, Jeff Johnson 		no flags
Details
Sample extension manifest.json (398 bytes, application/json)
2025-04-02 07:46 PDT, Jeff Johnson 		no flags
Details
1-star App Store review of Safari extension (40.76 KB, image/png)
2026-03-19 04:21 PDT, Jeff Johnson 		no flags
Details
View All Add attachment proposed patch, testcase, etc.
Jeff Johnson
Comment 1 2025-04-02 07:46:32 PDT
Created attachment 474806 [details] Sample extension manifest.json
Radar WebKit Bug Importer
Comment 2 2025-04-02 07:46:55 PDT
<rdar://problem/148430468>
Timothy Hatcher
Comment 3 2025-06-13 12:02:51 PDT
*** Bug 293576 has been marked as a duplicate of this bug. ***
Pas
Comment 4 2025-10-30 10:26:20 PDT
bump. I hope this can get fixed soon
Jeff Johnson
Comment 5 2026-03-19 04:21:32 PDT
Created attachment 478722 [details] 1-star App Store review of Safari extension Attached is a screenshot of a 1-star App Store user review that my Safari extension received due to this bug.
brief
Comment 6 2026-07-07 14:56:57 PDT
Adding my support for a fix to this one too.
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