fix(server): honor versioned local property matching

.changeset/quiet-booleans-match.md

@@ -0,0 +1,6 @@
+---
+"posthog": patch
+"posthog-server": patch
+---
+
+Retain `property_matching_version` in local-evaluation definitions and shared caches. Server-side local evaluation now uses explicit boolean matching for version 2, preserves legacy matching for missing/1, and keeps one definition snapshot through group, cohort, and dependency evaluation and version-only refreshes. In-flight remote evaluations retain their response errors and request metadata when definitions refresh, without repopulating the new result cache.

posthog-server/src/main/java/com/posthog/server/PostHogFlagDefinitionCacheProvider.kt

@@ -25,7 +25,9 @@ public interface PostHogFlagDefinitionCacheProvider {
      * Return cached flag definitions, or null when the cache is empty or unavailable.
      *
      * The data should use the shared local-evaluation definitions shape returned by PostHog's
-     * `/flags/definitions` endpoint: `flags`, `group_type_mapping`, and `cohorts`.
+     * `/flags/definitions` endpoint: `flags`, `group_type_mapping`, `cohorts`, and
+     * `property_matching_version`. Preserve the matching version with the definitions;
+     * older entries without it use legacy property matching.
      */
     public fun getFlagDefinitions(): CompletionStage<Map<String, Any?>?>
 

posthog-server/src/main/java/com/posthog/server/internal/FlagEvaluator.kt

@@ -26,6 +26,7 @@ import java.util.regex.PatternSyntaxException
  */
 internal class FlagEvaluator(
     private val config: PostHogConfig,
+    private val propertyMatchingVersion: Int? = null,
 ) {
     companion object {
         private const val LONG_SCALE = 0xFFFFFFFFFFFFFFF.toDouble()
@@ -240,7 +241,11 @@ internal class FlagEvaluator(
         propertyValue: Any?,
         overrideValue: Any?,
     ): Boolean {
-        if (isTruthyOrFalsyPropertyValue(propertyValue)) {
+        // Empty filters retain recursive ALL truthiness in both matching versions.
+        if (propertyValue is List<*> && propertyValue.isEmpty()) {
+            return isTruthyPropertyValue(overrideValue)
+        }
+        if (propertyMatchingVersion != 2 && isTruthyOrFalsyPropertyValue(propertyValue)) {
             return isTruthyPropertyValue(propertyValue) == isTruthyPropertyValue(overrideValue)
         }
 

posthog-server/src/main/java/com/posthog/server/internal/PostHogFeatureFlagCache.kt

@@ -53,7 +53,7 @@ internal class PostHogFeatureFlagCache(
         requestId: String? = null,
         evaluatedAt: Long? = null,
         error: String? = null,
-    ) {
+    ): FeatureFlagCacheEntry {
         val currentTime = System.currentTimeMillis()
         val entry =
             FeatureFlagCacheEntry(
@@ -66,6 +66,7 @@ internal class PostHogFeatureFlagCache(
             )
 
         cache[key] = entry
+        return entry
     }
 
     /**