From e0098f35e93604417f5b30a3371d1f6a649c54f9 Mon Sep 17 00:00:00 2001
From: Dustin Byrne <dustin@posthog.com>
Date: Wed, 7 Oct 2026 15:22:42 -0400
Subject: [PATCH] fix(flags): support JSON 3 response parsing

---
 .changeset/json3-response-parsing.md | 6 ++++++
 lib/posthog/feature_flags.rb         | 2 +-
 spec/posthog/flags_spec.rb           | 8 ++++++++
 3 files changed, 15 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/json3-response-parsing.md

diff --git a/.changeset/json3-response-parsing.md b/.changeset/json3-response-parsing.md
new file mode 100644
index 0000000..1b5d91a
--- /dev/null
+++ b/.changeset/json3-response-parsing.md
@@ -0,0 +1,6 @@
+---
+"posthog-ruby": patch
+"posthog-rails": patch
+---
+
+Fix feature flag and remote config response parsing with JSON 3, restoring remote flag evaluation and local definition loading.
diff --git a/lib/posthog/feature_flags.rb b/lib/posthog/feature_flags.rb
index f56ed91..97592cf 100644
--- a/lib/posthog/feature_flags.rb
+++ b/lib/posthog/feature_flags.rb
@@ -1477,7 +1477,7 @@ def _request(uri, request_object, timeout = nil, include_etag: false, retry_stat
 
           # Parse response body to hash
           begin
-            response = JSON.parse(res.body, { symbolize_names: true })
+            response = JSON.parse(res.body, symbolize_names: true)
             # Only add status (and etag if requested) if response is a hash
             extra_fields = { status: status_code }
             extra_fields[:etag] = etag if include_etag
diff --git a/spec/posthog/flags_spec.rb b/spec/posthog/flags_spec.rb
index d0f3408..98c2ab9 100644
--- a/spec/posthog/flags_spec.rb
+++ b/spec/posthog/flags_spec.rb
@@ -491,6 +491,14 @@ module PostHog
       JSON.parse(File.read(File.join(__dir__, 'fixtures', 'test-flags-v4.json')), symbolize_names: true)
     end
     describe '#get_feature_flag' do
+      it 'parses flag responses with keyword JSON options' do
+        body = { featureFlags: { 'enabled-flag' => true }, featureFlagPayloads: {} }.to_json
+        stub_request(:post, flags_endpoint).to_return(status: 200, body: body)
+        expect(JSON).to receive(:parse).with(body, symbolize_names: true).and_call_original
+
+        expect(client.get_feature_flag('enabled-flag', 'test-distinct-id')).to eq(true)
+      end
+
       it 'calls the $feature_flag_called event with additional properties' do
         stub_request(:post, flags_endpoint)
           .to_return(status: 200, body: flags_v4_response.to_json)