docs: document advanced_feature_flags_dedup_per_session config option#15765
Merged
dustinbyrne merged 2 commits intomasterfrom Mar 18, 2026
Merged
docs: document advanced_feature_flags_dedup_per_session config option#15765dustinbyrne merged 2 commits intomasterfrom
dustinbyrne merged 2 commits intomasterfrom
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- Add to JS SDK advanced config table - Add troubleshooting entry for missing experiment exposures - Add section in exposures docs on ensuring exposures for returning users
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Vale prose linter → found 3 errors, 49 warnings, 1 suggestions in your markdown Full report → Copy the linter results into an LLM to batch-fix issues. Linter being weird? Update the rules!
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| Line | Severity | Message | Rule |
|---|---|---|---|
| 11:234 | warning | Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept. | PostHogBase.ProductNames |
| 17:45 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 62:63 | warning | Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept. | PostHogBase.ProductNames |
| 66:30 | warning | Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept. | PostHogBase.ProductNames |
| 72:113 | warning | Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept. | PostHogBase.ProductNames |
| 86:36 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 116:5 | warning | 'Why SRM matters' heading should be in sentence case, and product names should be capitalized. | PostHogBase.SentenceCase |
| 145:117 | error | Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash. | PostHogBase.EnDash |
| 147:5 | warning | 'What to do if SRM is detected' heading should be in sentence case, and product names should be capitalized. | PostHogBase.SentenceCase |
| 178:38 | warning | Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept. | PostHogBase.ProductNames |
contents/docs/experiments/troubleshooting.mdx — 0 errors, 9 warnings, 0 suggestions
| Line | Severity | Message | Rule |
|---|---|---|---|
| 14:4 | warning | 'Have a question? Ask PostHog AI' heading should be in sentence case, and product names should be capitalized. | PostHogBase.SentenceCase |
| 20:53 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 22:111 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 43:21 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 45:217 | warning | Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept. | PostHogBase.ProductNames |
| 49:18 | warning | Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept. | PostHogBase.ProductNames |
| 51:57 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 82:14 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 100:48 | warning | Capitalize 'Experimentation' for PostHog's product. Use 'experimentation' for the general industry concept. | PostHogBase.ProductNames |
contents/docs/libraries/js/config.mdx — 2 errors, 31 warnings, 1 suggestions
| Line | Severity | Message | Rule |
|---|---|---|---|
| 20:136 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 42:242 | warning | 'pageleave' is a possible misspelling. | PostHogBase.Spelling |
| 48:205 | warning | Capitalize 'Surveys' for PostHog's product. Use 'surveys' for the general industry concept. | PostHogBase.ProductNames |
| 48:308 | warning | Capitalize 'Surveys' for PostHog's product. Use 'surveys' for the general industry concept. | PostHogBase.ProductNames |
| 50:213 | warning | Capitalize 'Logs' for PostHog's product. Use 'logs' for the general industry concept. | PostHogBase.ProductNames |
| 52:233 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 53:270 | warning | Capitalize 'Surveys' for PostHog's product. Use 'surveys' for the general industry concept. | PostHogBase.ProductNames |
| 54:448 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 54:500 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 54:565 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 60:263 | warning | 'googlebot' is a possible misspelling. | PostHogBase.Spelling |
| 61:239 | suggestion | Address the reader directly. Use 'you' instead of 'the user'. | PostHogDocs.DirectAddress |
| 76:68 | warning | 'autocapture's' is a possible misspelling. | PostHogBase.Spelling |
| 82:187 | warning | 'textarea' is a possible misspelling. | PostHogBase.Spelling |
| 87:16 | warning | 'rageclick' is a possible misspelling. | PostHogBase.Spelling |
| 106:216 | warning | Capitalize 'Surveys' for PostHog's product. Use 'surveys' for the general industry concept. | PostHogBase.ProductNames |
| 106:255 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 107:178 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 108:152 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 108:170 | warning | Capitalize 'Surveys' for PostHog's product. Use 'surveys' for the general industry concept. | PostHogBase.ProductNames |
| 108:236 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 108:254 | warning | Capitalize 'Surveys' for PostHog's product. Use 'surveys' for the general industry concept. | PostHogBase.ProductNames |
| 108:291 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 109:208 | warning | Capitalize 'Experiments' for PostHog's product. Use 'experiments' for the general industry concept. | PostHogBase.ProductNames |
| 110:130 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 112:125 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 112:390 | error | Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash. | PostHogBase.EnDash |
| 114:118 | warning | 'params' is a possible misspelling. | PostHogBase.Spelling |
| 115:482 | error | Hi, Andy here... use an en dash ( – ) with spaces. On Mac, holding down the Option and hyphen key will give you an en dash. | PostHogBase.EnDash |
| 122:244 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 136:125 | warning | 'gzip' is a possible misspelling. | PostHogBase.Spelling |
| 137:7 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'Feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 137:50 | warning | Capitalize 'Feature Flags' for PostHog's product. Use 'feature flags' for the general industry concept. | PostHogBase.ProductNames |
| 138:63 | warning | Capitalize 'Surveys' for PostHog's product. Use 'surveys' for the general industry concept. | PostHogBase.ProductNames |
marandaneto
approved these changes
Mar 16, 2026
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Problem
The new
advanced_feature_flags_dedup_per_sessionconfig option in posthog-js (PostHog/posthog-js#3241) needs documentation so users know it exists and when to use it.The core issue:
$feature_flag_calledevents are deduplicated globally — once cached for a flag+value, they don't fire again unlessidentify/resetis called. If a user checked a flag before an experiment launched, the experiment never sees their exposure.Changes
contents/docs/libraries/js/config.mdx— Addedadvanced_feature_flags_dedup_per_sessionto the advanced configuration table with a description linking to experiments and exposures docs.contents/docs/experiments/troubleshooting.mdx— New section "Why are returning users not showing as exposed to my experiment?" explaining the dedup caching issue and how to fix it.contents/docs/experiments/exposures.mdx— New section "Ensuring exposures for returning users" explaining the dedup behavior and the config option, placed before the custom exposure events section.