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Netlify Edge Functions: injecting CORS on rewrite paths and split testing
Edge handlers run Deno; set headers on both success and error branches before returning to the client.
1 min read
netlifyedgecors
Deploy previews
Preview URLs change per PR—automate allowlist updates or use wildcard subdomains with strict validation.
Split tests may route users to different backends; keep CORS consistent across variants.
Limits
CPU time caps can truncate slow origin lookups—cache allowlists at the edge KV when available.
Monitor function logs for OPTIONS volume spikes after frontend releases.