Check for Retry-After reposonse header when receiving 429 responses from the server (eclipse-openvsx#1637)

* fix: check for Retry-After reposonse header for rate limiting

* add changelog entry

Author: netomi

webui/CHANGELOG.md

@@ -8,6 +8,10 @@ This change log covers only the frontend library (webui) of Open VSX.
 
 - Switch from webpack to vite for building the bundle ([#1399](https://github.com/eclipse/openvsx/pull/1399))
 
+### Fixed
+
+- Check `Retry-After` http header when receiving `429` responses from the server ([#1637](https://github.com/eclipse/openvsx/pull/1637))
+
 ## [v0.18.0] (Feb. 2026)
 
 ### Added

webui/src/server-request.ts

@@ -73,7 +73,11 @@ export async function sendRequest<Res>(req: ServerAPIRequest, retry: boolean = t
                 throw new Error(`Unsupported type ${req.headers['Accept']}`);
         }
     } else if (response.status === 429) {
-        const retrySeconds = response.headers.get('X-Rate-Limit-Retry-After-Seconds') ?? '0';
+        // if the server uses the bucket4j starter config
+        const retryAfterSeconds = response.headers.get('X-Rate-Limit-Retry-After-Seconds');
+        // if the server uses the dynamic rate limiting config
+        const retryAfter = response.headers.get('Retry-After');
+        const retrySeconds = retryAfterSeconds ?? retryAfter ?? '0';
         const jitter = Math.floor(Math.random() * 100);
         const timeoutMillis = ((Number(retrySeconds) + 1) * 1000) + jitter;
         return new Promise<ServerAPIRequest>(resolve => setTimeout(resolve, timeoutMillis, req))