From c1430c363c2fbec118fed75ebb26c723dcba913f Mon Sep 17 00:00:00 2001
From: Manoel Aranda Neto <marandaneto@gmail.com>
Date: Mon, 20 Apr 2026 15:08:56 +0200
Subject: [PATCH 1/3] fix: trim whitespace from API keys and host config

---
 lib/posthog/client.rb       | 21 ++++++++++++++++++++-
 spec/posthog/client_spec.rb | 26 ++++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/lib/posthog/client.rb b/lib/posthog/client.rb
index 74e4dab..b8068e5 100644
--- a/lib/posthog/client.rb
+++ b/lib/posthog/client.rb
@@ -74,7 +74,9 @@ def _decrement_instance_count(api_key)
     def initialize(opts = {})
       symbolize_keys!(opts)
 
-      opts[:host] ||= 'https://app.posthog.com'
+      opts[:api_key] = normalize_string_option(opts[:api_key])
+      opts[:personal_api_key] = normalize_string_option(opts[:personal_api_key], blank_as_nil: true)
+      opts[:host] = normalize_host_option(opts[:host])
 
       @queue = Queue.new
       @api_key = opts[:api_key]
@@ -102,6 +104,7 @@ def initialize(opts = {})
       @personal_api_key = opts[:personal_api_key]
 
       check_api_key!
+      logger.error('api_key is empty after trimming whitespace; check your project API key') if @api_key == ''
 
       # Warn when multiple clients are created with the same API key (can cause dropped events)
       unless opts[:test_mode] || opts[:disable_singleton_warning]
@@ -585,6 +588,22 @@ def check_api_key!
       raise ArgumentError, 'API key must be initialized' if @api_key.nil?
     end
 
+    def normalize_string_option(value, blank_as_nil: false)
+      return value unless value.is_a?(String)
+
+      normalized = value.strip
+      return nil if blank_as_nil && normalized.empty?
+
+      normalized
+    end
+
+    def normalize_host_option(host)
+      normalized = normalize_string_option(host)
+      return 'https://app.posthog.com' if normalized.nil? || normalized.empty?
+
+      normalized
+    end
+
     def ensure_worker_running
       return if worker_running?
 
diff --git a/spec/posthog/client_spec.rb b/spec/posthog/client_spec.rb
index 28ce781..9ca14e6 100644
--- a/spec/posthog/client_spec.rb
+++ b/spec/posthog/client_spec.rb
@@ -16,6 +16,7 @@ module PostHog
       allow(logger).to receive(:warn)
       allow(logger).to receive(:info)
       allow(logger).to receive(:debug)
+      allow(logger).to receive(:error)
     end
 
     describe '#initialize' do
@@ -37,6 +38,31 @@ module PostHog
         expect { Client.new api_key: API_KEY, skip_ssl_verification: true }.to_not raise_error
       end
 
+      it 'trims whitespace-sensitive options' do
+        client = Client.new(
+          api_key: " \n#{API_KEY}\t ",
+          personal_api_key: " \n\t ",
+          host: " \nhttps://eu.i.posthog.com/\t ",
+          test_mode: true
+        )
+
+        expect(client.instance_variable_get(:@api_key)).to eq(API_KEY)
+        expect(client.instance_variable_get(:@personal_api_key)).to be_nil
+        expect(client.instance_variable_get(:@feature_flags_poller).instance_variable_get(:@host)).to eq('https://eu.i.posthog.com/')
+      end
+
+      it 'defaults a blank host after trimming whitespace' do
+        client = Client.new(api_key: API_KEY, host: " \n\t ", test_mode: true)
+
+        expect(client.instance_variable_get(:@feature_flags_poller).instance_variable_get(:@host)).to eq('https://app.posthog.com')
+      end
+
+      it 'logs when the api_key is empty after trimming whitespace' do
+        Client.new(api_key: " \n\t ", test_mode: true)
+
+        expect(logger).to have_received(:error).with(include('api_key is empty after trimming whitespace'))
+      end
+
       context 'singleton warning' do
         before do
           # Stub HTTP to allow creating clients without test_mode (which triggers the warning)

From f1173797e098eb92f6b96afb26f4a7f3685a73db Mon Sep 17 00:00:00 2001
From: Manoel Aranda Neto <marandaneto@gmail.com>
Date: Mon, 20 Apr 2026 17:23:35 +0200
Subject: [PATCH 2/3] fix: default host to https://us.i.posthog.com

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 lib/posthog/client.rb                      |   4 +-
 lib/posthog/defaults.rb                    |   2 +-
 spec/posthog/client_spec.rb                |  38 ++++----
 spec/posthog/feature_flag_error_spec.rb    |   4 +-
 spec/posthog/feature_flag_spec.rb          | 104 ++++++++++-----------
 spec/posthog/flag_definition_cache_spec.rb |   2 +-
 spec/posthog/flags_spec.rb                 |  26 +++---
 7 files changed, 90 insertions(+), 90 deletions(-)

diff --git a/lib/posthog/client.rb b/lib/posthog/client.rb
index b8068e5..2f8cd9f 100644
--- a/lib/posthog/client.rb
+++ b/lib/posthog/client.rb
@@ -59,7 +59,7 @@ def _decrement_instance_count(api_key)
     #   on the calling thread. Useful in forking environments like Sidekiq
     #   and Resque. Defaults to +false+.
     # @option opts [Proc] :on_error Handles error calls from the API.
-    # @option opts [String] :host Fully qualified hostname of the PostHog server. Defaults to `https://app.posthog.com`
+    # @option opts [String] :host Fully qualified hostname of the PostHog server. Defaults to `https://us.i.posthog.com`
     # @option opts [Integer] :feature_flags_polling_interval How often to poll for feature flag definition changes.
     #   Measured in seconds, defaults to 30.
     # @option opts [Integer] :feature_flag_request_timeout_seconds How long to wait for feature flag evaluation.
@@ -599,7 +599,7 @@ def normalize_string_option(value, blank_as_nil: false)
 
     def normalize_host_option(host)
       normalized = normalize_string_option(host)
-      return 'https://app.posthog.com' if normalized.nil? || normalized.empty?
+      return 'https://us.i.posthog.com' if normalized.nil? || normalized.empty?
 
       normalized
     end
diff --git a/lib/posthog/defaults.rb b/lib/posthog/defaults.rb
index 1d918d7..2fdcef2 100644
--- a/lib/posthog/defaults.rb
+++ b/lib/posthog/defaults.rb
@@ -5,7 +5,7 @@ module Defaults
     MAX_HASH_SIZE = 50_000
 
     module Request
-      HOST = 'app.posthog.com'
+      HOST = 'us.i.posthog.com'
       PORT = 443
       PATH = '/batch/'
       SSL = true
diff --git a/spec/posthog/client_spec.rb b/spec/posthog/client_spec.rb
index 9ca14e6..a0c630b 100644
--- a/spec/posthog/client_spec.rb
+++ b/spec/posthog/client_spec.rb
@@ -3,7 +3,7 @@
 require 'spec_helper'
 
 module PostHog
-  flags_endpoint = 'https://app.posthog.com/flags/?v=2'
+  flags_endpoint = 'https://us.i.posthog.com/flags/?v=2'
 
   RSpec::Support::ObjectFormatter.default_instance.max_formatted_output_length = nil
 
@@ -33,7 +33,7 @@ module PostHog
       end
 
       it 'handles skip_ssl_verification' do
-        expect(PostHog::Transport).to receive(:new).with({ api_host: 'https://app.posthog.com',
+        expect(PostHog::Transport).to receive(:new).with({ api_host: 'https://us.i.posthog.com',
                                                            skip_ssl_verification: true })
         expect { Client.new api_key: API_KEY, skip_ssl_verification: true }.to_not raise_error
       end
@@ -54,7 +54,7 @@ module PostHog
       it 'defaults a blank host after trimming whitespace' do
         client = Client.new(api_key: API_KEY, host: " \n\t ", test_mode: true)
 
-        expect(client.instance_variable_get(:@feature_flags_poller).instance_variable_get(:@host)).to eq('https://app.posthog.com')
+        expect(client.instance_variable_get(:@feature_flags_poller).instance_variable_get(:@host)).to eq('https://us.i.posthog.com')
       end
 
       it 'logs when the api_key is empty after trimming whitespace' do
@@ -66,8 +66,8 @@ module PostHog
       context 'singleton warning' do
         before do
           # Stub HTTP to allow creating clients without test_mode (which triggers the warning)
-          stub_request(:post, 'https://app.posthog.com/batch/').to_return(status: 200, body: '{}')
-          stub_request(:get, %r{https://app\.posthog\.com/api/feature_flag/}).to_return(status: 200, body: '{}')
+          stub_request(:post, 'https://us.i.posthog.com/batch/').to_return(status: 200, body: '{}')
+          stub_request(:get, %r{https://us\.i\.posthog\.com/api/feature_flag/}).to_return(status: 200, body: '{}')
         end
 
         it 'warns when multiple clients are created with the same API key' do
@@ -278,7 +278,7 @@ module PostHog
 
         stub_request(
           :get,
-          'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+          'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
         ).to_return(status: 200, body: api_feature_flag_res.to_json)
         stub_request(:post, flags_endpoint)
           .to_return(status: 200, body: flags_response.to_json)
@@ -323,7 +323,7 @@ module PostHog
 
         stub_request(
           :get,
-          'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+          'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
         ).to_return(status: 200, body: api_feature_flag_res.to_json)
         stub_request(:post, flags_endpoint)
           .to_return(status: 200, body: flags_response.to_json)
@@ -348,7 +348,7 @@ module PostHog
                                                'off-feature' => false } }
         stub_request(
           :get,
-          'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+          'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
         ).to_return(status: 200, body: {}.to_json)
         stub_request(:post, flags_endpoint)
           .to_return(status: 200, body: flags_response.to_json)
@@ -373,7 +373,7 @@ module PostHog
 
         stub_request(
           :get,
-          'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+          'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
         ).to_return(status: 401, body: { 'error' => 'not authorized' }.to_json)
         stub_request(:post, flags_endpoint)
           .to_return(status: 200, body: flags_response.to_json)
@@ -390,7 +390,7 @@ module PostHog
         expect(properties['$feature/beta-feature']).to eq('random-variant')
         expect(properties['$active_feature_flags']).to eq(['beta-feature'])
 
-        assert_not_requested :get, 'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        assert_not_requested :get, 'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       end
 
       it 'manages memory well when sending feature flags' do
@@ -414,7 +414,7 @@ module PostHog
         }
         stub_request(
           :get,
-          'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+          'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
         ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
         stub_const('PostHog::Defaults::MAX_HASH_SIZE', 10)
@@ -482,7 +482,7 @@ module PostHog
 
         stub_request(
           :get,
-          'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+          'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
         ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
         stub_const('PostHog::Defaults::MAX_HASH_SIZE', 10)
@@ -639,7 +639,7 @@ module PostHog
 
         stub_request(
           :get,
-          'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+          'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
         ).to_return(status: 200, body: api_feature_flag_res.to_json)
         stub_request(:post, flags_endpoint)
           .to_return(status: 200, body: flags_response.to_json)
@@ -677,7 +677,7 @@ module PostHog
 
         stub_request(
           :get,
-          'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+          'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
         ).to_return(status: 200, body: api_feature_flag_res.to_json)
         stub_request(:post, flags_endpoint)
           .to_return(status: 200, body: flags_response.to_json)
@@ -703,7 +703,7 @@ module PostHog
       it 'ignores feature flags with invalid send_feature_flags parameter' do
         stub_request(
           :get,
-          'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+          'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
         ).to_return(status: 200, body: { flags: [] }.to_json)
         c = Client.new(api_key: API_KEY, personal_api_key: API_KEY, test_mode: true)
 
@@ -741,7 +741,7 @@ module PostHog
         }
         stub_request(
           :get,
-          'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+          'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
         ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
         # This should NOT be called because only_evaluate_locally is true
@@ -793,7 +793,7 @@ module PostHog
         }
         stub_request(
           :get,
-          'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+          'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
         ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
         # This should NOT be called because only_evaluate_locally is true
@@ -844,7 +844,7 @@ module PostHog
         }
         stub_request(
           :get,
-          'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+          'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
         ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
         # This SHOULD be called because only_evaluate_locally is explicitly false
@@ -1186,7 +1186,7 @@ def run
         # Mock response for api/feature_flag
         stub_request(
           :get,
-          'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+          'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
         ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
         # Mock response for `/flags`
diff --git a/spec/posthog/feature_flag_error_spec.rb b/spec/posthog/feature_flag_error_spec.rb
index 716cf74..9a20385 100644
--- a/spec/posthog/feature_flag_error_spec.rb
+++ b/spec/posthog/feature_flag_error_spec.rb
@@ -4,8 +4,8 @@
 
 module PostHog
   describe 'Feature Flag Error Tracking' do
-    let(:flags_endpoint) { 'https://app.posthog.com/flags/?v=2' }
-    let(:feature_flag_endpoint) { 'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
+    let(:flags_endpoint) { 'https://us.i.posthog.com/flags/?v=2' }
+    let(:feature_flag_endpoint) { 'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
     let(:client) { Client.new(api_key: API_KEY, personal_api_key: API_KEY, test_mode: true) }
 
     before do
diff --git a/spec/posthog/feature_flag_spec.rb b/spec/posthog/feature_flag_spec.rb
index 1f72000..9f5a4c3 100644
--- a/spec/posthog/feature_flag_spec.rb
+++ b/spec/posthog/feature_flag_spec.rb
@@ -6,7 +6,7 @@
 module PostHog
   RSpec::Support::ObjectFormatter.default_instance.max_formatted_output_length = nil
 
-  flags_endpoint = 'https://app.posthog.com/flags/?v=2'
+  flags_endpoint = 'https://us.i.posthog.com/flags/?v=2'
 
   describe 'local evaluation' do
     it 'evaluates person properties' do
@@ -38,7 +38,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       # shouldn't call flags
@@ -89,7 +89,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       # shouldn't call flags
@@ -177,7 +177,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -252,7 +252,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -373,7 +373,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -435,7 +435,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -495,7 +495,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -554,7 +554,7 @@ module PostHog
       # We don't go to `/flags` if local eval is enabled and the flag is not in list of all flag definitions
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -573,7 +573,7 @@ module PostHog
       # TRICKY: Pretty hard to simulate a timeout using sleep with WebMock, so we'll just raise an error
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_raise(Net::ReadTimeout)
 
       stub_request(:post, flags_endpoint)
@@ -620,7 +620,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -686,7 +686,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -758,7 +758,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -780,7 +780,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -832,7 +832,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -883,7 +883,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -933,7 +933,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res_updated.to_json)
 
       # force reload to simulate poll interval
@@ -978,7 +978,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -1037,7 +1037,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -1088,7 +1088,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -1150,7 +1150,7 @@ module PostHog
 
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint).to_return(status: 400)
@@ -2039,7 +2039,7 @@ module PostHog
 
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       # shouldn't call `/flags`
@@ -3086,7 +3086,7 @@ module PostHog
 
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       # shouldn't call `/flags`
@@ -4174,7 +4174,7 @@ module PostHog
 
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: { 'flags' => flag_res }.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -4193,7 +4193,7 @@ module PostHog
     it 'get all flags and payloads with fallback and empty local flags' do
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: { 'flags' => [] }.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -4270,7 +4270,7 @@ module PostHog
 
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: { 'flags' => flag_res }.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -4326,7 +4326,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: { 'flags' => [basic_flag, disabled_flag] }.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -4366,7 +4366,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: { 'flags' => [basic_flag_res] }.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -4387,7 +4387,7 @@ module PostHog
     it 'evaluates boolean feature flags with `/flags`' do
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: { 'flags' => [] }.to_json)
       stub_request(:post, flags_endpoint)
         .to_return(status: 200, body: { 'featureFlags' => {},
@@ -4436,7 +4436,7 @@ module PostHog
 
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: { flags: [multivariate_flag] }.to_json)
       stub_request(:post, flags_endpoint)
         .to_return(status: 200, body: { featureFlagPayloads: { 'first-variant' => { b: 'json' } } }.to_json)
@@ -4468,11 +4468,11 @@ module PostHog
       mock_decrypted_payload = '"super secret payload in plaintext"'
       stub_request(
         :get,
-        "https://app.posthog.com/api/projects/@current/feature_flags/#{encrypted_payload_flag_key}/remote_config?token=testsecret"
+        "https://us.i.posthog.com/api/projects/@current/feature_flags/#{encrypted_payload_flag_key}/remote_config?token=testsecret"
       ).to_return(status: 200, body: mock_decrypted_payload)
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: { flags: [] }.to_json)
 
       c = Client.new(api_key: API_KEY, personal_api_key: API_KEY, test_mode: true)
@@ -4506,7 +4506,7 @@ module PostHog
 
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: { 'flags' => flag_res }.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -4556,7 +4556,7 @@ module PostHog
 
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -4568,7 +4568,7 @@ module PostHog
 
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 400, body: { 'error' => 'went_wrong!' }.to_json)
 
       # force reload to simulate poll interval
@@ -4609,17 +4609,17 @@ module PostHog
 
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       # Add the exact stub for the `/flags` endpoint as recommended in the error
-      stub_request(:post, 'https://app.posthog.com/flags/?v=2').with(
+      stub_request(:post, 'https://us.i.posthog.com/flags/?v=2').with(
         body: '{"distinct_id":"distinct_id","groups":{},"person_properties":{"distinct_id":"distinct_id","region":"USA"},"group_properties":{},"token":"testsecret"}', # rubocop:disable Layout/LineLength
         headers: {
           'Accept' => '*/*',
           'Accept-Encoding' => 'gzip;q=1.0,deflate;q=0.6,identity;q=0.3',
           'Content-Type' => 'application/json',
-          'Host' => 'app.posthog.com',
+          'Host' => 'us.i.posthog.com',
           'User-Agent' => "posthog-ruby#{PostHog::VERSION}"
         }
       ).to_return(status: 200, body: '{"featureFlags": {}}', headers: {})
@@ -4632,7 +4632,7 @@ module PostHog
       # Now simulate quota limit with 402 response
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 402, body: { error: 'quota_limit_exceeded' }.to_json)
 
       # Force reload to simulate poll interval
@@ -4692,11 +4692,11 @@ module PostHog
 
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       # Mock API response - user is in the static cohort
-      stub_request(:post, 'https://app.posthog.com/flags/?v=2')
+      stub_request(:post, 'https://us.i.posthog.com/flags/?v=2')
         .to_return(status: 200, body: {
           'featureFlags' => { 'multi-condition-flag' => 'set-1' }
         }.to_json)
@@ -4749,11 +4749,11 @@ module PostHog
 
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       # Mock API response - user is in the static cohort
-      stub_request(:post, 'https://app.posthog.com/flags/?v=2')
+      stub_request(:post, 'https://us.i.posthog.com/flags/?v=2')
         .to_return(status: 200, body: {
           'featureFlags' => { 'multi-condition-flag' => 'variant-1' },
           'featureFlagPayloads' => { 'multi-condition-flag' => '{"message": "from-api"}' }
@@ -4773,7 +4773,7 @@ module PostHog
   end
 
   describe 'get_feature_flag_result' do
-    let(:flags_endpoint) { 'https://app.posthog.com/flags/?v=2' }
+    let(:flags_endpoint) { 'https://us.i.posthog.com/flags/?v=2' }
 
     it 'returns a FeatureFlagResult with flag value and payload' do
       api_feature_flag_res = {
@@ -4792,7 +4792,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint).to_return(status: 400)
@@ -4827,7 +4827,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: { 'flags' => [multivariate_flag] }.to_json)
 
       stub_request(:post, flags_endpoint).to_return(status: 400)
@@ -4861,7 +4861,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint).to_return(status: 400)
@@ -4895,7 +4895,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint).to_return(status: 400)
@@ -4926,7 +4926,7 @@ module PostHog
       }
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: api_feature_flag_res.to_json)
 
       stub_request(:post, flags_endpoint).to_return(status: 400)
@@ -4949,7 +4949,7 @@ module PostHog
     it 'returns nil when flag evaluation returns nil' do
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: { 'flags' => [] }.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -4965,7 +4965,7 @@ module PostHog
     it 'falls back to remote evaluation when needed' do
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: { 'flags' => [] }.to_json)
 
       stub_request(:post, flags_endpoint)
@@ -4994,7 +4994,7 @@ module PostHog
     it 'includes request_id and evaluated_at from remote evaluation in event' do
       stub_request(
         :get,
-        'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
+        'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true'
       ).to_return(status: 200, body: { 'flags' => [] }.to_json)
 
       stub_request(:post, flags_endpoint)
diff --git a/spec/posthog/flag_definition_cache_spec.rb b/spec/posthog/flag_definition_cache_spec.rb
index 2aba7d1..511c381 100644
--- a/spec/posthog/flag_definition_cache_spec.rb
+++ b/spec/posthog/flag_definition_cache_spec.rb
@@ -85,7 +85,7 @@ def provider.shutdown; end
 
   describe 'flag definition cache integration' do
     let(:provider) { MockCacheProvider.new }
-    let(:local_eval_url) { 'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
+    let(:local_eval_url) { 'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
 
     # Sample flag data with string keys (simulating JSON deserialization from cache)
     let(:sample_flags_data) do
diff --git a/spec/posthog/flags_spec.rb b/spec/posthog/flags_spec.rb
index b7771ec..41b9b40 100644
--- a/spec/posthog/flags_spec.rb
+++ b/spec/posthog/flags_spec.rb
@@ -5,8 +5,8 @@
 
 module PostHog
   describe 'FeatureFlagsPoller#get_flags' do
-    let(:flags_endpoint) { 'https://app.posthog.com/flags/?v=2' }
-    let(:feature_flag_endpoint) { 'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
+    let(:flags_endpoint) { 'https://us.i.posthog.com/flags/?v=2' }
+    let(:feature_flag_endpoint) { 'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
     let(:client) { Client.new(api_key: API_KEY, personal_api_key: API_KEY, test_mode: true) }
     let(:poller) { client.instance_variable_get(:@feature_flags_poller) }
     let(:flags_v3_response) do
@@ -23,7 +23,7 @@ module PostHog
             'Accept' => '*/*',
             'Accept-Encoding' => 'gzip;q=1.0,deflate;q=0.6,identity;q=0.3',
             'Authorization' => 'Bearer testsecret',
-            'Host' => 'app.posthog.com',
+            'Host' => 'us.i.posthog.com',
             'User-Agent' => "posthog-ruby#{PostHog::VERSION}"
           }
         )
@@ -334,7 +334,7 @@ module PostHog
 
   describe 'Client#get_feature_flag' do
     let(:client) { Client.new(api_key: API_KEY, personal_api_key: nil, test_mode: true) }
-    let(:flags_endpoint) { 'https://app.posthog.com/flags/?v=2' }
+    let(:flags_endpoint) { 'https://us.i.posthog.com/flags/?v=2' }
     let(:flags_v4_response) do
       JSON.parse(File.read(File.join(__dir__, 'fixtures', 'test-flags-v4.json')), symbolize_names: true)
     end
@@ -365,8 +365,8 @@ module PostHog
   end
 
   describe 'FeatureFlagsPoller#get_remote_config_payload' do
-    let(:remote_config_endpoint) { 'https://app.posthog.com/api/projects/@current/feature_flags/test-flag/remote_config?token=testsecret' }
-    let(:feature_flag_endpoint) { 'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
+    let(:remote_config_endpoint) { 'https://us.i.posthog.com/api/projects/@current/feature_flags/test-flag/remote_config?token=testsecret' }
+    let(:feature_flag_endpoint) { 'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
     let(:client) { Client.new(api_key: 'testsecret', personal_api_key: 'personal_key', test_mode: true) }
     let(:poller) { client.instance_variable_get(:@feature_flags_poller) }
 
@@ -387,7 +387,7 @@ module PostHog
             'Accept-Encoding' => 'gzip;q=1.0,deflate;q=0.6,identity;q=0.3',
             'Content-Type' => 'application/json',
             'Authorization' => 'Bearer personal_key',
-            'Host' => 'app.posthog.com',
+            'Host' => 'us.i.posthog.com',
             'User-Agent' => "posthog-ruby#{PostHog::VERSION}"
           }
         )
@@ -680,7 +680,7 @@ module PostHog
     end
 
     describe 'integration with feature flags' do
-      let(:feature_flag_endpoint) { 'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
+      let(:feature_flag_endpoint) { 'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
       let(:client) { Client.new(api_key: 'testsecret', personal_api_key: 'personal_key', test_mode: true) }
       let(:poller) { client.instance_variable_get(:@feature_flags_poller) }
 
@@ -781,8 +781,8 @@ module PostHog
   end
 
   describe 'Flag dependencies' do
-    let(:flags_endpoint) { 'https://app.posthog.com/flags/?v=2' }
-    let(:feature_flag_endpoint) { 'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
+    let(:flags_endpoint) { 'https://us.i.posthog.com/flags/?v=2' }
+    let(:feature_flag_endpoint) { 'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
     let(:client) { Client.new(api_key: API_KEY, personal_api_key: API_KEY, test_mode: true) }
     let(:poller) { client.instance_variable_get(:@feature_flags_poller) }
 
@@ -794,7 +794,7 @@ module PostHog
             'Accept' => '*/*',
             'Accept-Encoding' => 'gzip;q=1.0,deflate;q=0.6,identity;q=0.3',
             'Authorization' => 'Bearer testsecret',
-            'Host' => 'app.posthog.com',
+            'Host' => 'us.i.posthog.com',
             'User-Agent' => "posthog-ruby#{PostHog::VERSION}"
           }
         )
@@ -1529,7 +1529,7 @@ def stub_feature_flags(flags)
 
     before do
       # Stub the initial feature flag definitions request
-      stub_request(:get, 'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true')
+      stub_request(:get, 'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true')
         .to_return(status: 200, body: { flags: [] }.to_json)
     end
 
@@ -1621,7 +1621,7 @@ def stub_feature_flags(flags)
   end
 
   describe 'FeatureFlagsPoller ETag support' do
-    let(:feature_flag_endpoint) { 'https://app.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
+    let(:feature_flag_endpoint) { 'https://us.i.posthog.com/api/feature_flag/local_evaluation?token=testsecret&send_cohorts=true' }
     let(:client) { Client.new(api_key: API_KEY, personal_api_key: API_KEY, test_mode: true) }
     let(:poller) { client.instance_variable_get(:@feature_flags_poller) }
 

From c543d07b75be5955032cf3d585fb7f5afd86190f Mon Sep 17 00:00:00 2001
From: Manoel Aranda Neto <marandaneto@gmail.com>
Date: Mon, 20 Apr 2026 17:25:07 +0200
Subject: [PATCH 3/3] chore: add release changeset

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 .changeset/trim-whitespace-default-host.md | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 .changeset/trim-whitespace-default-host.md

diff --git a/.changeset/trim-whitespace-default-host.md b/.changeset/trim-whitespace-default-host.md
new file mode 100644
index 0000000..42166a9
--- /dev/null
+++ b/.changeset/trim-whitespace-default-host.md
@@ -0,0 +1,5 @@
+---
+'posthog-ruby': patch
+---
+
+Trim whitespace from `api_key`, `personal_api_key`, and `host` config values, and default `host` to `https://us.i.posthog.com`.