diff --git a/.ci/samples_test/run_samples_tests.sh b/.ci/samples_test/run_samples_tests.sh
new file mode 100644
index 0000000000..81a7732950
--- /dev/null
+++ b/.ci/samples_test/run_samples_tests.sh
@@ -0,0 +1,181 @@
+#!/bin/bash
+# Copyright 2026 Google LLC
+# 
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+# 
+#      http://www.apache.org/licenses/LICENSE-2.0
+# 
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -e
+
+# Configuration
+SAMPLES_ROOT="docs/en/samples/pre_post_processing"
+SQL_FILE=".ci/samples_test/setup_hotels_sample.sql"
+TABLE_NAME="hotels_samples"
+VERSION=$(cat ./cmd/version.txt)
+
+# Process IDs & Logs
+PROXY_PID=""
+TOOLBOX_PID=""
+PROXY_LOG="cloud_sql_proxy.log"
+TOOLBOX_LOG="toolbox_server.log"
+
+install_system_packages() {
+  echo "Installing system packages..."
+  apt-get update && apt-get install -y \
+    postgresql-client \
+    python3-venv \
+    wget \
+    gettext-base  \
+    netcat-openbsd
+}
+
+start_cloud_sql_proxy() {
+  echo "Starting Cloud SQL Proxy..."
+  wget -q "https://storage.googleapis.com/cloud-sql-connectors/cloud-sql-proxy/v2.10.0/cloud-sql-proxy.linux.amd64" -O /usr/local/bin/cloud-sql-proxy
+  chmod +x /usr/local/bin/cloud-sql-proxy
+  cloud-sql-proxy "${CLOUD_SQL_INSTANCE}" > "$PROXY_LOG" 2>&1 &
+  PROXY_PID=$!
+
+  # Health check (Idea 3)
+  for i in {1..30}; do
+    if nc -z 127.0.0.1 5432; then
+      echo "Cloud SQL Proxy is up and running."
+      return
+    fi
+    sleep 1
+  done
+  echo "ERROR: Cloud SQL Proxy failed to start. Logs:"
+  cat "$PROXY_LOG"
+  exit 1
+}
+
+setup_toolbox() {
+  echo "Setting up Toolbox server..."
+  TOOLBOX_YAML="/tools.yaml"
+  echo "${TOOLS_YAML_CONTENT}" > "$TOOLBOX_YAML"
+  wget -q "https://storage.googleapis.com/genai-toolbox/v${VERSION}/linux/amd64/toolbox" -O "/toolbox"
+  chmod +x "/toolbox"
+  /toolbox --tools-file "$TOOLBOX_YAML" > "$TOOLBOX_LOG" 2>&1 &
+  TOOLBOX_PID=$!
+  
+  # Health check (Idea 3)
+  for i in {1..15}; do
+    if nc -z 127.0.0.1 5000; then
+      echo "Toolbox server is up and running."
+      return
+    fi
+    sleep 1
+  done
+  echo "ERROR: Toolbox server failed to start. Logs:"
+  cat "$TOOLBOX_LOG"
+  exit 1
+}
+
+setup_db_table() {
+  echo "Setting up database table $TABLE_NAME..."
+  export TABLE_NAME
+  envsubst < "$SQL_FILE" | psql -h 127.0.0.1 -p 5432 -U "$DB_USER" -d "$DATABASE_NAME"
+}
+
+run_python_sample() {
+  local dir=$1
+  local orch_name=$(basename "$dir")
+  echo "--- Testing Python sample: $orch_name ---"
+  
+  (
+    cd "$dir"
+    python3 -m venv .venv
+    source .venv/bin/activate
+    pip install -q -r requirements.txt pytest
+    
+    # Idea 5: Use native pytest instead of shell grep
+    echo "Running native pytest for $orch_name..."
+    export ORCH_NAME="$orch_name"
+    export PYTHONPATH="../../" # Path to docs/en/samples/pre_post_processing
+    pytest ../agent_test.py
+    local exit_code=$?
+    
+    if [ $exit_code -ne 0 ]; then
+      echo "ERROR: Pytest failed for $orch_name"
+      exit $exit_code
+    fi
+    
+    echo "SUCCESS: $orch_name"
+    rm -rf .venv
+  )
+}
+
+run_js_sample() {
+  local dir=$1
+  local orch_name=$(basename "$dir")
+  echo "--- Testing JS sample: $orch_name ---"
+  (
+    cd "$dir"
+    npm install -q
+    node agent.js > output.log 2>&1
+    local exit_code=$?
+
+    if [ $exit_code -ne 0 ]; then
+      echo "ERROR: JS Sample failed for $orch_name"
+      cat output.log
+      exit $exit_code
+    fi
+
+    echo "SUCCESS: $orch_name"
+    rm -rf node_modules output.log
+  )
+}
+
+cleanup() {
+  echo "Cleaning up background processes..."
+  [ -n "$TOOLBOX_PID" ] && kill "$TOOLBOX_PID" || true
+  [ -n "$PROXY_PID" ] && kill "$PROXY_PID" || true
+}
+trap cleanup EXIT
+
+# Execution Flow
+install_system_packages
+start_cloud_sql_proxy
+
+export PGHOST=127.0.0.1
+export PGPORT=5432
+export PGPASSWORD="$DB_PASSWORD"
+export GOOGLE_API_KEY="$GOOGLE_API_KEY"
+
+setup_toolbox
+setup_db_table
+
+# Arguments
+TARGET_LANG=$1
+
+# Discovery and run samples
+echo "Discovering samples in $SAMPLES_ROOT for language: ${TARGET_LANG:-all}"
+
+# Run Python samples
+if [[ -z "$TARGET_LANG" || "$TARGET_LANG" == "python" ]]; then
+    find "$SAMPLES_ROOT/python" -name "agent.py" | while read -r agent_file; do
+        run_python_sample "$(dirname "$agent_file")"
+    done
+fi
+
+# Run JS samples
+if [[ -z "$TARGET_LANG" || "$TARGET_LANG" == "js" ]]; then
+    find "$SAMPLES_ROOT/js" -name "agent.js" | while read -r agent_file; do
+        run_js_sample "$(dirname "$agent_file")"
+    done
+fi
+
+# Run Go samples
+if [[ -z "$TARGET_LANG" || "$TARGET_LANG" == "go" ]]; then
+    find "$SAMPLES_ROOT/go" -name "agent.go" | while read -r agent_file; do
+        echo "Go testing coming soon..."
+    done
+fi
diff --git a/.ci/samples_test/samples.integration.cloudbuild.yaml b/.ci/samples_test/samples.integration.cloudbuild.yaml
new file mode 100644
index 0000000000..b8fc111148
--- /dev/null
+++ b/.ci/samples_test/samples.integration.cloudbuild.yaml
@@ -0,0 +1,52 @@
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+steps:
+  - name: "${_IMAGE}"
+    id: "samples-test"
+    entrypoint: "bash"
+    args:
+      - -c
+      - |
+        set -ex
+        chmod +x .ci/samples_test/run_samples_tests.sh
+        .ci/samples_test/run_samples_tests.sh ${_LANG}
+    env:
+      - "CLOUD_SQL_INSTANCE=${_CLOUD_SQL_INSTANCE}"
+      - "GCP_PROJECT=${_GCP_PROJECT}"
+      - "DATABASE_NAME=${_DATABASE_NAME}"
+      - "DB_USER=${_DB_USER}"
+    secretEnv: ["TOOLS_YAML_CONTENT", "GOOGLE_API_KEY", "DB_PASSWORD"]
+
+availableSecrets:
+  secretManager:
+    - versionName: projects/${_GCP_PROJECT}/secrets/${_TOOLS_YAML_SECRET}/versions/5
+      env: "TOOLS_YAML_CONTENT"
+    - versionName: projects/${_GCP_PROJECT_NUMBER}/secrets/${_API_KEY_SECRET}/versions/latest
+      env: "GOOGLE_API_KEY"
+    - versionName: projects/${_GCP_PROJECT}/secrets/${_DB_PASS_SECRET}/versions/latest
+      env: "DB_PASSWORD"
+artifacts:
+  objects:
+    location: "gs://${_LOG_BUCKET}/samples-tests/$BUILD_ID"
+    paths: ["*.log"]
+
+timeout: 1200s
+substitutions:
+  _LANG: "python"
+  _IMAGE: "python:3.11"
+  _LOG_BUCKET: "toolbox-test-logs"
+
+options:
+  logging: CLOUD_LOGGING_ONLY
diff --git a/.ci/samples_test/setup_hotels_sample.sql b/.ci/samples_test/setup_hotels_sample.sql
new file mode 100644
index 0000000000..6480789baf
--- /dev/null
+++ b/.ci/samples_test/setup_hotels_sample.sql
@@ -0,0 +1,28 @@
+-- Copyright 2025 Google LLC
+-- 
+-- Licensed under the Apache License, Version 2.0 (the "License");
+-- you may not use this file except in compliance with the License.
+-- You may obtain a copy of the License at
+-- 
+--      http://www.apache.org/licenses/LICENSE-2.0
+-- 
+-- Unless required by applicable law or agreed to in writing, software
+-- distributed under the License is distributed on an "AS IS" BASIS,
+-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+-- See the License for the specific language governing permissions and
+-- limitations under the License.
+
+TRUNCATE TABLE $TABLE_NAME;
+
+INSERT INTO $TABLE_NAME (id, name, location, price_tier, checkin_date, checkout_date, booked)
+VALUES
+  (1, 'Hilton Basel', 'Basel', 'Luxury', '2024-04-22', '2024-04-20', B'0'),
+  (2, 'Marriott Zurich', 'Zurich', 'Upscale', '2024-04-14', '2024-04-21', B'0'),
+  (3, 'Hyatt Regency Basel', 'Basel', 'Upper Upscale', '2024-04-02', '2024-04-20', B'0'),
+  (4, 'Radisson Blu Lucerne', 'Lucerne', 'Midscale', '2024-04-24', '2024-04-05', B'0'),
+  (5, 'Best Western Bern', 'Bern', 'Upper Midscale', '2024-04-23', '2024-04-01', B'0'),
+  (6, 'InterContinental Geneva', 'Geneva', 'Luxury', '2024-04-23', '2024-04-28', B'0'),
+  (7, 'Sheraton Zurich', 'Zurich', 'Upper Upscale', '2024-04-27', '2024-04-02', B'0'),
+  (8, 'Holiday Inn Basel', 'Basel', 'Upper Midscale', '2024-04-24', '2024-04-09', B'0'),
+  (9, 'Courtyard Zurich', 'Zurich', 'Upscale', '2024-04-03', '2024-04-13', B'0'),
+  (10, 'Comfort Inn Bern', 'Bern', 'Midscale', '2024-04-04', '2024-04-16', B'0');
\ No newline at end of file
diff --git a/docs/en/samples/pre_post_processing/python/langchain/__init__.py b/docs/en/samples/pre_post_processing/python/langchain/__init__.py
new file mode 100644
index 0000000000..3ad6377894
--- /dev/null
+++ b/docs/en/samples/pre_post_processing/python/langchain/__init__.py
@@ -0,0 +1 @@
+# Empty init for package resolution