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LaunchDarkly feature flags: JavaScript SDK bootstrap, streaming endpoints, and CORS for client-side evaluation
Client-side SDKs call LaunchDarkly edge endpoints; corporate proxies sometimes block streams that resemble long-polling CORS preflights.
1 min read
launchdarklyfeature-flagscors
Targeting rules
User context attributes may include PII—hash or tokenize before sending from the browser.
Flag variations should never embed secrets readable by end users.
Relay proxy
Self-hosted relay can consolidate CORS configuration for many SPAs behind one domain.
Monitor relay CPU when many browser tabs open streaming connections.