Why am I still getting Access-Control-Allow-Origin header errors in my Express API when preflight requests return a 204 status code?
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The searches the AI actually ran for this prompt.
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Why am I still getting Access-Control-Allow-Origin header errors in my Express API when preflight requests return a 204 status code?
1 real search · 1 real-search pass
Express cors middleware official documentation preflight application-level middleware errors Access-Control-Allow-OriginGoogle ↗
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Badge and edge weight = share of passes that produced the query. Hover a query for its intent and routing format.
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Google's semantic query class for every sub-query: what kind of answer each search is after, simulated vs real.
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Classes come from the query-classifier (a local Laya model). 1 of 1 calls are low-confidence (under 50%) — hover a query in the table to see its confidence.
Searches and sources
ChatGPT1 real searches · gpt-6
Express cors middleware official documentation preflight application-level middleware errors Access-Control-Allow-Origin Google ↗
- cors middleware · expressjs.com
- Cross-Origin Resource Sharing (CORS) - HTTP · developer.mozilla.org
- Access-Control-Allow-Origin header - HTTP · developer.mozilla.org
- CORS errors - HTTP · developer.mozilla.org
- Reason: CORS header 'Access-Control-Allow-Origin' missing - HTTP · developer.mozilla.org