Update integration.cloudbuild.yaml

## Description

Response is being re-assigned

## PR Checklist

> Thank you for opening a Pull Request! Before submitting your PR, there
are a
> few things you can do to make sure it goes smoothly:

- [ ] Make sure you reviewed

[CONTRIBUTING.md](https://github.com/googleapis/genai-toolbox/blob/main/CONTRIBUTING.md)
- [ ] Make sure to open an issue as a

[bug/issue](https://github.com/googleapis/genai-toolbox/issues/new/choose)
  before writing your code! That way we can discuss the change, evaluate
  designs, and agree on the general idea
- [ ] Ensure the tests and linter pass
- [ ] Code coverage does not decrease (if any source code was changed)
- [ ] Appropriate docs were updated (if necessary)
- [ ] Make sure to add `!` if this involve a breaking change

🛠️ Fixes #<issue_number_goes_here>

.ci/quickstart_test/go.integration.cloudbuild.yaml

@@ -1,47 +0,0 @@
-# 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.
-
-steps:
-  - name: 'golang:1.25.1'
-    id: 'go-quickstart-test'
-    entrypoint: 'bash'
-    args:
-      # The '-c' flag tells bash to execute the following string as a command.
-      # The 'set -ex' enables debug output and exits on error for easier troubleshooting.
-      - -c
-      - |
-        set -ex
-        export VERSION=$(cat ./cmd/version.txt)
-        chmod +x .ci/quickstart_test/run_go_tests.sh
-        .ci/quickstart_test/run_go_tests.sh
-    env:
-      - 'CLOUD_SQL_INSTANCE=${_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/${_TOOLS_YAML_SECRET}/versions/7
-    env: 'TOOLS_YAML_CONTENT'
-  - versionName: projects/${_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'
-
-timeout: 1000s
-
-options:
-  logging: CLOUD_LOGGING_ONLY

.ci/quickstart_test/js.integration.cloudbuild.yaml

@@ -1,47 +0,0 @@
-# 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.
-
-steps:
-  - name: 'node:22'
-    id: 'js-quickstart-test'
-    entrypoint: 'bash'
-    args:
-      # The '-c' flag tells bash to execute the following string as a command.
-      # The 'set -ex' enables debug output and exits on error for easier troubleshooting.
-      - -c
-      - |
-        set -ex
-        export VERSION=$(cat ./cmd/version.txt)
-        chmod +x .ci/quickstart_test/run_js_tests.sh
-        .ci/quickstart_test/run_js_tests.sh
-    env:
-      - 'CLOUD_SQL_INSTANCE=${_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/${_TOOLS_YAML_SECRET}/versions/6
-    env: 'TOOLS_YAML_CONTENT'
-  - versionName: projects/${_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'
-
-timeout: 1000s
-
-options:
-  logging: CLOUD_LOGGING_ONLY

.ci/quickstart_test/py.integration.cloudbuild.yaml

@@ -1,47 +0,0 @@
-# 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.
-
-steps:
-  - name: 'gcr.io/google.com/cloudsdktool/cloud-sdk:537.0.0'
-    id: 'python-quickstart-test'
-    entrypoint: 'bash'
-    args:
-      # The '-c' flag tells bash to execute the following string as a command.
-      # The 'set -ex' enables debug output and exits on error for easier troubleshooting.
-      - -c
-      - |
-        set -ex
-        export VERSION=$(cat ./cmd/version.txt)
-        chmod +x .ci/quickstart_test/run_py_tests.sh
-        .ci/quickstart_test/run_py_tests.sh
-    env:
-      - 'CLOUD_SQL_INSTANCE=${_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'
-
-timeout: 1000s
-
-options:
-  logging: CLOUD_LOGGING_ONLY

.ci/quickstart_test/run_go_tests.sh

@@ -1,125 +0,0 @@
-# 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.
-
-#!/bin/bash
-
-set -e
-
-TABLE_NAME="hotels_go"
-QUICKSTART_GO_DIR="docs/en/getting-started/quickstart/go"
-SQL_FILE=".ci/quickstart_test/setup_hotels_sample.sql"
-
-PROXY_PID=""
-TOOLBOX_PID=""
-
-install_system_packages() {
-  apt-get update && apt-get install -y \
-    postgresql-client \
-    wget \
-    gettext-base  \
-    netcat-openbsd
-}
-
-start_cloud_sql_proxy() {
-  wget "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 "${CLOUD_SQL_INSTANCE}" &
-  PROXY_PID=$!
-
-  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 "Cloud SQL Proxy failed to start within the timeout period."
-  exit 1
-}
-
-setup_toolbox() {
-  TOOLBOX_YAML="/tools.yaml"
-  echo "${TOOLS_YAML_CONTENT}" > "$TOOLBOX_YAML"
-  if [ ! -f "$TOOLBOX_YAML" ]; then echo "Failed to create tools.yaml"; exit 1; fi
-  wget "https://storage.googleapis.com/genai-toolbox/v${VERSION}/linux/amd64/toolbox" -O "/toolbox"
-  chmod +x "/toolbox"
-  /toolbox --tools-file "$TOOLBOX_YAML" &
-  TOOLBOX_PID=$!
-  sleep 2
-}
-
-setup_orch_table() {
-  export TABLE_NAME
-  envsubst < "$SQL_FILE" | psql -h "$PGHOST" -p "$PGPORT" -U "$DB_USER" -d "$DATABASE_NAME"
-}
-
-run_orch_test() {
-  local orch_dir="$1"
-  local orch_name
-  orch_name=$(basename "$orch_dir")
-
-  if [ "$orch_name" == "openAI" ]; then
-      echo -e "\nSkipping framework '${orch_name}': Temporarily excluded."
-      return
-  fi
-
-  (
-    set -e
-    setup_orch_table
-
-    echo "--- Preparing module for $orch_name ---"
-    cd "$orch_dir"
-
-    if [ -f "go.mod" ]; then
-      go mod tidy
-    fi
-
-    cd ..
-
-    export ORCH_NAME="$orch_name"
-
-    echo "--- Running tests for $orch_name ---"
-    go test -v ./...
-  )
-}
-
-cleanup_all() {
-  echo "--- Final cleanup: Shutting down processes and dropping table ---"
-  if [ -n "$TOOLBOX_PID" ]; then
-    kill $TOOLBOX_PID || true
-  fi
-  if [ -n "$PROXY_PID" ]; then
-    kill $PROXY_PID || true
-  fi
-}
-trap cleanup_all EXIT
-
-# Main script execution
-install_system_packages
-start_cloud_sql_proxy
-
-export PGHOST=127.0.0.1
-export PGPORT=5432
-export PGPASSWORD="$DB_PASSWORD"
-export GOOGLE_API_KEY="$GOOGLE_API_KEY"
-
-setup_toolbox
-
-for ORCH_DIR in "$QUICKSTART_GO_DIR"/*/; do
-  if [ ! -d "$ORCH_DIR" ]; then
-    continue
-  fi
-  run_orch_test "$ORCH_DIR"
-done

.ci/quickstart_test/run_js_tests.sh

@@ -1,125 +0,0 @@
-# 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.
-
-#!/bin/bash
-
-set -e
-
-TABLE_NAME="hotels_js"
-QUICKSTART_JS_DIR="docs/en/getting-started/quickstart/js"
-SQL_FILE=".ci/quickstart_test/setup_hotels_sample.sql"
-
-# Initialize process IDs to empty at the top of the script
-PROXY_PID=""
-TOOLBOX_PID=""
-
-install_system_packages() {
-  apt-get update && apt-get install -y \
-    postgresql-client \
-    wget \
-    gettext-base  \
-    netcat-openbsd
-}
-
-start_cloud_sql_proxy() {
-  wget "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 "${CLOUD_SQL_INSTANCE}" &
-  PROXY_PID=$!
-
-  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 "Cloud SQL Proxy failed to start within the timeout period."
-  exit 1
-}
-
-setup_toolbox() {
-  TOOLBOX_YAML="/tools.yaml"
-  echo "${TOOLS_YAML_CONTENT}" > "$TOOLBOX_YAML"
-  if [ ! -f "$TOOLBOX_YAML" ]; then echo "Failed to create tools.yaml"; exit 1; fi
-  wget "https://storage.googleapis.com/genai-toolbox/v${VERSION}/linux/amd64/toolbox" -O "/toolbox"
-  chmod +x "/toolbox"
-  /toolbox --tools-file "$TOOLBOX_YAML" &
-  TOOLBOX_PID=$!
-  sleep 2
-}
-
-setup_orch_table() {
-  export TABLE_NAME
-  envsubst < "$SQL_FILE" | psql -h "$PGHOST" -p "$PGPORT" -U "$DB_USER" -d "$DATABASE_NAME"
-}
-
-run_orch_test() {
-  local orch_dir="$1"
-  local orch_name
-  orch_name=$(basename "$orch_dir")
-
-  (
-    set -e
-    echo "--- Preparing environment for $orch_name ---"
-    setup_orch_table
-
-    cd "$orch_dir"
-    echo "Installing dependencies for $orch_name..."
-    if [ -f "package-lock.json" ]; then
-      npm ci
-    else
-      npm install
-    fi
-
-    cd ..
-
-    echo "--- Running tests for $orch_name ---"
-    export ORCH_NAME="$orch_name"
-    node --test quickstart.test.js
-
-    echo "--- Cleaning environment for $orch_name ---"
-    rm -rf "${orch_name}/node_modules"
-  )
-}
-
-cleanup_all() {
-  echo "--- Final cleanup: Shutting down processes and dropping table ---"
-  if [ -n "$TOOLBOX_PID" ]; then
-    kill $TOOLBOX_PID || true
-  fi
-  if [ -n "$PROXY_PID" ]; then
-    kill $PROXY_PID || true
-  fi
-}
-trap cleanup_all EXIT
-
-# Main script execution
-install_system_packages
-start_cloud_sql_proxy
-
-export PGHOST=127.0.0.1
-export PGPORT=5432
-export PGPASSWORD="$DB_PASSWORD"
-export GOOGLE_API_KEY="$GOOGLE_API_KEY"
-
-setup_toolbox
-
-for ORCH_DIR in "$QUICKSTART_JS_DIR"/*/; do
-  if [ ! -d "$ORCH_DIR" ]; then
-    continue
-  fi
-  run_orch_test "$ORCH_DIR"
-done

.ci/quickstart_test/run_py_tests.sh

@@ -1,115 +0,0 @@
-# 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.
-
-#!/bin/bash
-
-set -e
-
-TABLE_NAME="hotels_python"
-QUICKSTART_PYTHON_DIR="docs/en/getting-started/quickstart/python"
-SQL_FILE=".ci/quickstart_test/setup_hotels_sample.sql"
-
-PROXY_PID=""
-TOOLBOX_PID=""
-
-install_system_packages() {
-  apt-get update && apt-get install -y \
-    postgresql-client \
-    python3-venv \
-    wget \
-    gettext-base  \
-    netcat-openbsd
-}
-
-start_cloud_sql_proxy() {
-  wget "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 "${CLOUD_SQL_INSTANCE}" &
-  PROXY_PID=$!
-
-  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 "Cloud SQL Proxy failed to start within the timeout period."
-  exit 1
-}
-
-setup_toolbox() {
-  TOOLBOX_YAML="/tools.yaml"
-  echo "${TOOLS_YAML_CONTENT}" > "$TOOLBOX_YAML"
-  if [ ! -f "$TOOLBOX_YAML" ]; then echo "Failed to create tools.yaml"; exit 1; fi
-  wget "https://storage.googleapis.com/genai-toolbox/v${VERSION}/linux/amd64/toolbox" -O "/toolbox"
-  chmod +x "/toolbox"
-  /toolbox --tools-file "$TOOLBOX_YAML" &
-  TOOLBOX_PID=$!
-  sleep 2
-}
-
-setup_orch_table() {
-  export TABLE_NAME
-  envsubst < "$SQL_FILE" | psql -h "$PGHOST" -p "$PGPORT" -U "$DB_USER" -d "$DATABASE_NAME"
-}
-
-run_orch_test() {
-  local orch_dir="$1"
-  local orch_name
-  orch_name=$(basename "$orch_dir")
-  (
-    set -e
-    setup_orch_table
-    cd "$orch_dir"
-    local VENV_DIR=".venv"
-    python3 -m venv "$VENV_DIR"
-    source "$VENV_DIR/bin/activate"
-    pip install -r requirements.txt
-    echo "--- Running tests for $orch_name ---"
-    cd ..
-    ORCH_NAME="$orch_name" pytest
-    rm -rf "$VENV_DIR"
-  )
-}
-
-cleanup_all() {
-  echo "--- Final cleanup: Shutting down processes and dropping table ---"
-  if [ -n "$TOOLBOX_PID" ]; then
-    kill $TOOLBOX_PID || true
-  fi
-  if [ -n "$PROXY_PID" ]; then
-    kill $PROXY_PID || true
-  fi
-}
-trap cleanup_all EXIT
-
-# Main script execution
-install_system_packages
-start_cloud_sql_proxy
-
-export PGHOST=127.0.0.1
-export PGPORT=5432
-export PGPASSWORD="$DB_PASSWORD"
-export GOOGLE_API_KEY="$GOOGLE_API_KEY"
-
-setup_toolbox
-
-for ORCH_DIR in "$QUICKSTART_PYTHON_DIR"/*/; do
-  if [ ! -d "$ORCH_DIR" ]; then
-    continue
-  fi
-  run_orch_test "$ORCH_DIR"
-done

.ci/universal/integration.cloudbuild.yaml

@@ -0,0 +1,59 @@
+# 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: "${_IMAGE}"
+    id: "universal-test"
+    entrypoint: "bash"
+    args:
+      - -c
+      - |
+        set -ex
+        chmod +x .ci/universal/run_tests.sh
+        .ci/universal/run_tests.sh
+    env:
+      - "CLOUD_SQL_INSTANCE=${_CLOUD_SQL_INSTANCE}"
+      - "GCP_PROJECT=${_GCP_PROJECT}"
+      - "DATABASE_NAME=${_DATABASE_NAME}"
+      - "DB_USER=${_DB_USER}"
+      - "TARGET_ROOT=${_TARGET_ROOT}"
+      - "TARGET_LANG=${_TARGET_LANG}"
+      - "TABLE_NAME=${_TABLE_NAME}"
+      - "SQL_FILE=${_SQL_FILE}"
+      - "AGENT_FILE_PATTERN=${_AGENT_FILE_PATTERN}"
+    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"
+
+
+timeout: 1200s
+
+substitutions:
+  _TARGET_LANG: "python"
+  _IMAGE: "python:3.11"
+  _TARGET_ROOT: "docs/en/getting-started/quickstart/python"
+  _TABLE_NAME: "hotels_python"
+  _SQL_FILE: ".ci/universal/setup_hotels.sql"
+  _AGENT_FILE_PATTERN: "quickstart.py"
+  _LOG_BUCKET: "toolbox-test-logs"
+
+options:
+  logging: CLOUD_LOGGING_ONLY

.ci/universal/run_tests.sh

@@ -0,0 +1,173 @@
+#!/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 (from Environment Variables) ---
+# TARGET_ROOT: The directory to search for tests (e.g., docs/en/getting-started/quickstart/js)
+# TARGET_LANG: python, js, go
+# TABLE_NAME: Database table name to use
+# SQL_FILE: Path to the SQL setup file
+# AGENT_FILE_PATTERN: Filename to look for (e.g., quickstart.js or agent.py)
+
+VERSION=$(cat ./cmd/version.txt)
+
+# Process IDs & Logs
+PROXY_PID=""
+TOOLBOX_PID=""
+PROXY_LOG="cloud_sql_proxy.log"
+TOOLBOX_LOG="toolbox_server.log"
+
+install_system_packages() {
+  echo "Installing system packages..."
+  apt-get update && apt-get install -y \
+    postgresql-client \
+    wget \
+    gettext-base  \
+    netcat-openbsd
+    
+  if [[ "$TARGET_LANG" == "python" ]]; then
+    apt-get install -y python3-venv
+  fi
+}
+
+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=$!
+
+  # Health Check
+  for i in {1..30}; do
+    if nc -z 127.0.0.1 5432; then
+      echo "Cloud SQL Proxy is up and running."
+      return
+    fi
+    sleep 1
+  done
+  echo "ERROR: Cloud SQL Proxy failed to start. Logs:"
+  cat "$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
+  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 using $SQL_FILE..."
+  export TABLE_NAME
+  envsubst < "$SQL_FILE" | psql -h 127.0.0.1 -p 5432 -U "$DB_USER" -d "$DATABASE_NAME"
+}
+
+run_python_test() {
+  local dir=$1
+  local name=$(basename "$dir")
+  echo "--- Running Python Test: $name ---"
+  (
+    cd "$dir"
+    python3 -m venv .venv
+    source .venv/bin/activate
+    pip install -q -r requirements.txt pytest
+    
+    cd ..
+    # If there is a pytest file in the parent directory (like agent_test.py or quickstart_test.py)
+    # we use it. Otherwise we just run the agent.
+    local test_file=$(find . -maxdepth 1 -name "*test.py" | head -n 1)
+    if [ -n "$test_file" ]; then
+        echo "Found native test: $test_file. Running pytest..."
+        export ORCH_NAME="$name"
+        export PYTHONPATH="../" 
+        pytest "$test_file"
+    else
+        echo "No native test found. running agent directly..."
+        export PYTHONPATH="../"
+        python3 "${name}/${AGENT_FILE_PATTERN}"
+    fi
+    rm -rf "${name}/.venv"
+  )
+}
+
+run_js_test() {
+  local dir=$1
+  local name=$(basename "$dir")
+  echo "--- Running JS Test: $name ---"
+  (
+    cd "$dir"
+    if [ -f "package-lock.json" ]; then npm ci -q; else npm install -q; fi
+    
+    cd ..
+    # Looking for a JS test file in the parent directory
+    local test_file=$(find . -maxdepth 1 -name "*test.js" | head -n 1)
+    if [ -n "$test_file" ]; then
+        echo "Found native test: $test_file. Running node --test..."
+        export ORCH_NAME="$name"
+        node --test "$test_file"
+    else
+        echo "No native test found. running agent directly..."
+        node "${name}/${AGENT_FILE_PATTERN}"
+    fi
+    rm -rf "${name}/node_modules"
+  )
+}
+
+cleanup() {
+  echo "Cleaning up background processes..."
+  [ -n "$TOOLBOX_PID" ] && kill "$TOOLBOX_PID" || true
+  [ -n "$PROXY_PID" ] && kill "$PROXY_PID" || true
+}
+trap cleanup EXIT
+
+# --- Execution ---
+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
+
+echo "Scanning $TARGET_ROOT for tests with pattern $AGENT_FILE_PATTERN..."
+
+find "$TARGET_ROOT" -name "$AGENT_FILE_PATTERN" | while read -r agent_file; do
+    sample_dir=$(dirname "$agent_file")
+    if [[ "$TARGET_LANG" == "python" ]]; then
+        run_python_test "$sample_dir"
+    elif [[ "$TARGET_LANG" == "js" ]]; then
+        run_js_test "$sample_dir"
+    fi
+done

docs/en/getting-started/quickstart/js/genkit/quickstart.js

@@ -53,7 +53,7 @@ export async function main() {
 
   for (const query of queries) {
     conversationHistory.push({ role: "user", content: [{ text: query }] });
-    const response = await ai.generate({
+    let response = await ai.generate({
       messages: conversationHistory,
       tools: tools,
     });

docs/en/how-to/invoke_tool.md

@@ -13,12 +13,12 @@ The `invoke` command allows you to invoke tools defined in your configuration di
 
 {{< notice tip >}}
 **Keep configurations minimal:** The `invoke` command initializes *all* resources (sources, tools, etc.) defined in your configuration files during execution. To ensure fast response times, consider using a minimal configuration file containing only the tools you need for the specific invocation.
-{{< notice tip >}}
+{{< /notice >}}
 
-## Prerequisites
+## Before you begin
 
-- You have the `toolbox` binary installed or built.
-- You have a valid tool configuration file (e.g., `tools.yaml`).
+1. Make sure you have the `toolbox` binary installed or built.
+2. Make sure you have a valid tool configuration file (e.g., `tools.yaml`).
 
 ## Basic Usage
 

internal/server/api.go

@@ -19,6 +19,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"strings"
 
 	"github.com/go-chi/chi/v5"
 	"github.com/go-chi/chi/v5/middleware"
@@ -234,10 +235,8 @@ func toolInvokeHandler(s *Server, w http.ResponseWriter, r *http.Request) {
 	params, err := parameters.ParseParams(tool.GetParameters(), data, claimsFromAuth)
 	if err != nil {
 		// If auth error, return 401
-		errMsg := fmt.Sprintf("error parsing authenticated parameters from ID token: %w", err)
-		var clientServerErr *util.ClientServerError
-		if errors.As(err, &clientServerErr) && clientServerErr.Code == http.StatusUnauthorized {
-			s.logger.DebugContext(ctx, errMsg)
+		if errors.Is(err, util.ErrUnauthorized) {
+			s.logger.DebugContext(ctx, fmt.Sprintf("error parsing authenticated parameters from ID token: %s", err))
 			_ = render.Render(w, r, newErrResponse(err, http.StatusUnauthorized))
 			return
 		}
@@ -260,49 +259,34 @@ func toolInvokeHandler(s *Server, w http.ResponseWriter, r *http.Request) {
 
 	// Determine what error to return to the users.
 	if err != nil {
-		var tbErr util.ToolboxError
+		errStr := err.Error()
+		var statusCode int
 
-		if errors.As(err, &tbErr) {
-			switch tbErr.Category() {
-			case util.CategoryAgent:
-				// Agent Errors -> 200 OK
-				s.logger.DebugContext(ctx, fmt.Sprintf("Tool invocation agent error: %v", err))
-				_ = render.Render(w, r, newErrResponse(err, http.StatusOK))
-				return
+		// Upstream API auth error propagation
+		switch {
+		case strings.Contains(errStr, "Error 401"):
+			statusCode = http.StatusUnauthorized
+		case strings.Contains(errStr, "Error 403"):
+			statusCode = http.StatusForbidden
+		}
 
-			case util.CategoryServer:
-				// Server Errors -> Check the specific code inside
-				var clientServerErr *util.ClientServerError
-				statusCode := http.StatusInternalServerError // Default to 500
-
-				if errors.As(err, &clientServerErr) {
-					if clientServerErr.Code != 0 {
-						statusCode = clientServerErr.Code
-					}
-				}
-
-				// Process auth error
-				if statusCode == http.StatusUnauthorized || statusCode == http.StatusForbidden {
-					if clientAuth {
-						// Token error, pass through 401/403
-						s.logger.DebugContext(ctx, fmt.Sprintf("Client credentials lack authorization: %v", err))
-						_ = render.Render(w, r, newErrResponse(err, statusCode))
-						return
-					}
-					// ADC/Config error, return 500
-					statusCode = http.StatusInternalServerError
-				}
-
-				s.logger.ErrorContext(ctx, fmt.Sprintf("Tool invocation server error: %v", err))
+		if statusCode == http.StatusUnauthorized || statusCode == http.StatusForbidden {
+			if clientAuth {
+				// Propagate the original 401/403 error.
+				s.logger.DebugContext(ctx, fmt.Sprintf("error invoking tool. Client credentials lack authorization to the source: %v", err))
 				_ = render.Render(w, r, newErrResponse(err, statusCode))
 				return
 			}
-		} else {
-			// Unknown error -> 500
-			s.logger.ErrorContext(ctx, fmt.Sprintf("Tool invocation unknown error: %v", err))
-			_ = render.Render(w, r, newErrResponse(err, http.StatusInternalServerError))
+			// ADC lacking permission or credentials configuration error.
+			internalErr := fmt.Errorf("unexpected auth error occured during Tool invocation: %w", err)
+			s.logger.ErrorContext(ctx, internalErr.Error())
+			_ = render.Render(w, r, newErrResponse(internalErr, http.StatusInternalServerError))
 			return
 		}
+		err = fmt.Errorf("error while invoking tool: %w", err)
+		s.logger.DebugContext(ctx, err.Error())
+		_ = render.Render(w, r, newErrResponse(err, http.StatusBadRequest))
+		return
 	}
 
 	resMarshal, err := json.Marshal(res)

internal/server/mcp.go

@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"strings"
 	"sync"
 	"time"
 
@@ -443,17 +444,15 @@ func httpHandler(s *Server, w http.ResponseWriter, r *http.Request) {
 		code := rpcResponse.Error.Code
 		switch code {
 		case jsonrpc.INTERNAL_ERROR:
-			// Map Internal RPC Error (-32603) to HTTP 500
 			w.WriteHeader(http.StatusInternalServerError)
 		case jsonrpc.INVALID_REQUEST:
-			var clientServerErr *util.ClientServerError
-			if errors.As(err, &clientServerErr) {
-				switch clientServerErr.Code {
-				case http.StatusUnauthorized:
-					w.WriteHeader(http.StatusUnauthorized)
-				case http.StatusForbidden:
-					w.WriteHeader(http.StatusForbidden)
-				}
+			errStr := err.Error()
+			if errors.Is(err, util.ErrUnauthorized) {
+				w.WriteHeader(http.StatusUnauthorized)
+			} else if strings.Contains(errStr, "Error 401") {
+				w.WriteHeader(http.StatusUnauthorized)
+			} else if strings.Contains(errStr, "Error 403") {
+				w.WriteHeader(http.StatusForbidden)
 			}
 		}
 	}

internal/server/mcp/v20241105/method.go

@@ -21,6 +21,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"strings"
 
 	"github.com/googleapis/genai-toolbox/internal/prompts"
 	"github.com/googleapis/genai-toolbox/internal/server/mcp/jsonrpc"
@@ -123,11 +124,7 @@ func toolsCallHandler(ctx context.Context, id jsonrpc.RequestId, resourceMgr *re
 	}
 	if clientAuth {
 		if accessToken == "" {
-			return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, "missing access token in the 'Authorization' header", nil), util.NewClientServerError(
-				"missing access token in the 'Authorization' header",
-				http.StatusUnauthorized,
-				nil,
-			)
+			return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, "missing access token in the 'Authorization' header", nil), util.ErrUnauthorized
 		}
 	}
 
@@ -175,11 +172,7 @@ func toolsCallHandler(ctx context.Context, id jsonrpc.RequestId, resourceMgr *re
 	// Check if any of the specified auth services is verified
 	isAuthorized := tool.Authorized(verifiedAuthServices)
 	if !isAuthorized {
-		err = util.NewClientServerError(
-			"unauthorized Tool call: Please make sure you specify correct auth headers",
-			http.StatusUnauthorized,
-			nil,
-		)
+		err = fmt.Errorf("unauthorized Tool call: Please make sure your specify correct auth headers: %w", util.ErrUnauthorized)
 		return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, err.Error(), nil), err
 	}
 	logger.DebugContext(ctx, "tool invocation authorized")
@@ -201,44 +194,30 @@ func toolsCallHandler(ctx context.Context, id jsonrpc.RequestId, resourceMgr *re
 	// run tool invocation and generate response.
 	results, err := tool.Invoke(ctx, resourceMgr, params, accessToken)
 	if err != nil {
-		var tbErr util.ToolboxError
-
-		if errors.As(err, &tbErr) {
-			switch tbErr.Category() {
-			case util.CategoryAgent:
-				// MCP - Tool execution error
-				// Return SUCCESS but with IsError: true
-				text := TextContent{
-					Type: "text",
-					Text: err.Error(),
-				}
-				return jsonrpc.JSONRPCResponse{
-					Jsonrpc: jsonrpc.JSONRPC_VERSION,
-					Id:      id,
-					Result:  CallToolResult{Content: []TextContent{text}, IsError: true},
-				}, nil
-
-			case util.CategoryServer:
-				// MCP Spec - Protocol error
-				// Return JSON-RPC ERROR
-				var clientServerErr *util.ClientServerError
-				rpcCode := jsonrpc.INTERNAL_ERROR // Default to Internal Error (-32603)
-
-				if errors.As(err, &clientServerErr) {
-					if clientServerErr.Code == http.StatusUnauthorized || clientServerErr.Code == http.StatusForbidden {
-						if clientAuth {
-							rpcCode = jsonrpc.INVALID_REQUEST
-						} else {
-							rpcCode = jsonrpc.INTERNAL_ERROR
-						}
-					}
-				}
-				return jsonrpc.NewError(id, rpcCode, err.Error(), nil), err
+		errStr := err.Error()
+		// Missing authService tokens.
+		if errors.Is(err, util.ErrUnauthorized) {
+			return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, err.Error(), nil), err
+		}
+		// Upstream auth error
+		if strings.Contains(errStr, "Error 401") || strings.Contains(errStr, "Error 403") {
+			if clientAuth {
+				// Error with client credentials should pass down to the client
+				return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, err.Error(), nil), err
 			}
-		} else {
-			// Unknown error -> 500
+			// Auth error with ADC should raise internal 500 error
 			return jsonrpc.NewError(id, jsonrpc.INTERNAL_ERROR, err.Error(), nil), err
 		}
+
+		text := TextContent{
+			Type: "text",
+			Text: err.Error(),
+		}
+		return jsonrpc.JSONRPCResponse{
+			Jsonrpc: jsonrpc.JSONRPC_VERSION,
+			Id:      id,
+			Result:  CallToolResult{Content: []TextContent{text}, IsError: true},
+		}, nil
 	}
 
 	content := make([]TextContent, 0)

internal/server/mcp/v20250326/method.go

@@ -21,6 +21,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"strings"
 
 	"github.com/googleapis/genai-toolbox/internal/prompts"
 	"github.com/googleapis/genai-toolbox/internal/server/mcp/jsonrpc"
@@ -123,11 +124,7 @@ func toolsCallHandler(ctx context.Context, id jsonrpc.RequestId, resourceMgr *re
 	}
 	if clientAuth {
 		if accessToken == "" {
-			return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, "missing access token in the 'Authorization' header", nil), util.NewClientServerError(
-				"missing access token in the 'Authorization' header",
-				http.StatusUnauthorized,
-				nil,
-			)
+			return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, "missing access token in the 'Authorization' header", nil), util.ErrUnauthorized
 		}
 	}
 
@@ -175,11 +172,7 @@ func toolsCallHandler(ctx context.Context, id jsonrpc.RequestId, resourceMgr *re
 	// Check if any of the specified auth services is verified
 	isAuthorized := tool.Authorized(verifiedAuthServices)
 	if !isAuthorized {
-		err = util.NewClientServerError(
-			"unauthorized Tool call: Please make sure you specify correct auth headers",
-			http.StatusUnauthorized,
-			nil,
-		)
+		err = fmt.Errorf("unauthorized Tool call: Please make sure your specify correct auth headers: %w", util.ErrUnauthorized)
 		return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, err.Error(), nil), err
 	}
 	logger.DebugContext(ctx, "tool invocation authorized")
@@ -201,45 +194,31 @@ func toolsCallHandler(ctx context.Context, id jsonrpc.RequestId, resourceMgr *re
 	// run tool invocation and generate response.
 	results, err := tool.Invoke(ctx, resourceMgr, params, accessToken)
 	if err != nil {
-		var tbErr util.ToolboxError
-
-		if errors.As(err, &tbErr) {
-			switch tbErr.Category() {
-			case util.CategoryAgent:
-				// MCP - Tool execution error
-				// Return SUCCESS but with IsError: true
-				text := TextContent{
-					Type: "text",
-					Text: err.Error(),
-				}
-				return jsonrpc.JSONRPCResponse{
-					Jsonrpc: jsonrpc.JSONRPC_VERSION,
-					Id:      id,
-					Result:  CallToolResult{Content: []TextContent{text}, IsError: true},
-				}, nil
-
-			case util.CategoryServer:
-				// MCP Spec - Protocol error
-				// Return JSON-RPC ERROR
-				var clientServerErr *util.ClientServerError
-				rpcCode := jsonrpc.INTERNAL_ERROR // Default to Internal Error (-32603)
-
-				if errors.As(err, &clientServerErr) {
-					if clientServerErr.Code == http.StatusUnauthorized || clientServerErr.Code == http.StatusForbidden {
-						if clientAuth {
-							rpcCode = jsonrpc.INVALID_REQUEST
-						} else {
-							rpcCode = jsonrpc.INTERNAL_ERROR
-						}
-					}
-				}
-				return jsonrpc.NewError(id, rpcCode, err.Error(), nil), err
+		errStr := err.Error()
+		// Missing authService tokens.
+		if errors.Is(err, util.ErrUnauthorized) {
+			return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, err.Error(), nil), err
+		}
+		// Upstream auth error
+		if strings.Contains(errStr, "Error 401") || strings.Contains(errStr, "Error 403") {
+			if clientAuth {
+				// Error with client credentials should pass down to the client
+				return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, err.Error(), nil), err
 			}
-		} else {
-			// Unknown error -> 500
+			// Auth error with ADC should raise internal 500 error
 			return jsonrpc.NewError(id, jsonrpc.INTERNAL_ERROR, err.Error(), nil), err
 		}
+		text := TextContent{
+			Type: "text",
+			Text: err.Error(),
+		}
+		return jsonrpc.JSONRPCResponse{
+			Jsonrpc: jsonrpc.JSONRPC_VERSION,
+			Id:      id,
+			Result:  CallToolResult{Content: []TextContent{text}, IsError: true},
+		}, nil
 	}
+
 	content := make([]TextContent, 0)
 
 	sliceRes, ok := results.([]any)

internal/server/mcp/v20250618/method.go

@@ -21,6 +21,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"strings"
 
 	"github.com/googleapis/genai-toolbox/internal/prompts"
 	"github.com/googleapis/genai-toolbox/internal/server/mcp/jsonrpc"
@@ -116,12 +117,7 @@ func toolsCallHandler(ctx context.Context, id jsonrpc.RequestId, resourceMgr *re
 	}
 	if clientAuth {
 		if accessToken == "" {
-			errMsg := "missing access token in the 'Authorization' header"
-			return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, errMsg, nil), util.NewClientServerError(
-				errMsg,
-				http.StatusUnauthorized,
-				nil,
-			)
+			return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, "missing access token in the 'Authorization' header", nil), util.ErrUnauthorized
 		}
 	}
 
@@ -169,11 +165,7 @@ func toolsCallHandler(ctx context.Context, id jsonrpc.RequestId, resourceMgr *re
 	// Check if any of the specified auth services is verified
 	isAuthorized := tool.Authorized(verifiedAuthServices)
 	if !isAuthorized {
-		err = util.NewClientServerError(
-			"unauthorized Tool call: Please make sure you specify correct auth headers",
-			http.StatusUnauthorized,
-			nil,
-		)
+		err = fmt.Errorf("unauthorized Tool call: Please make sure your specify correct auth headers: %w", util.ErrUnauthorized)
 		return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, err.Error(), nil), err
 	}
 	logger.DebugContext(ctx, "tool invocation authorized")
@@ -195,44 +187,29 @@ func toolsCallHandler(ctx context.Context, id jsonrpc.RequestId, resourceMgr *re
 	// run tool invocation and generate response.
 	results, err := tool.Invoke(ctx, resourceMgr, params, accessToken)
 	if err != nil {
-		var tbErr util.ToolboxError
-
-		if errors.As(err, &tbErr) {
-			switch tbErr.Category() {
-			case util.CategoryAgent:
-				// MCP - Tool execution error
-				// Return SUCCESS but with IsError: true
-				text := TextContent{
-					Type: "text",
-					Text: err.Error(),
-				}
-				return jsonrpc.JSONRPCResponse{
-					Jsonrpc: jsonrpc.JSONRPC_VERSION,
-					Id:      id,
-					Result:  CallToolResult{Content: []TextContent{text}, IsError: true},
-				}, nil
-
-			case util.CategoryServer:
-				// MCP Spec - Protocol error
-				// Return JSON-RPC ERROR
-				var clientServerErr *util.ClientServerError
-				rpcCode := jsonrpc.INTERNAL_ERROR // Default to Internal Error (-32603)
-
-				if errors.As(err, &clientServerErr) {
-					if clientServerErr.Code == http.StatusUnauthorized || clientServerErr.Code == http.StatusForbidden {
-						if clientAuth {
-							rpcCode = jsonrpc.INVALID_REQUEST
-						} else {
-							rpcCode = jsonrpc.INTERNAL_ERROR
-						}
-					}
-				}
-				return jsonrpc.NewError(id, rpcCode, err.Error(), nil), err
+		errStr := err.Error()
+		// Missing authService tokens.
+		if errors.Is(err, util.ErrUnauthorized) {
+			return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, err.Error(), nil), err
+		}
+		// Upstream auth error
+		if strings.Contains(errStr, "Error 401") || strings.Contains(errStr, "Error 403") {
+			if clientAuth {
+				// Error with client credentials should pass down to the client
+				return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, err.Error(), nil), err
 			}
-		} else {
-			// Unknown error -> 500
+			// Auth error with ADC should raise internal 500 error
 			return jsonrpc.NewError(id, jsonrpc.INTERNAL_ERROR, err.Error(), nil), err
 		}
+		text := TextContent{
+			Type: "text",
+			Text: err.Error(),
+		}
+		return jsonrpc.JSONRPCResponse{
+			Jsonrpc: jsonrpc.JSONRPC_VERSION,
+			Id:      id,
+			Result:  CallToolResult{Content: []TextContent{text}, IsError: true},
+		}, nil
 	}
 
 	content := make([]TextContent, 0)

internal/server/mcp/v20251125/method.go

@@ -21,6 +21,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"strings"
 
 	"github.com/googleapis/genai-toolbox/internal/prompts"
 	"github.com/googleapis/genai-toolbox/internal/server/mcp/jsonrpc"
@@ -116,11 +117,7 @@ func toolsCallHandler(ctx context.Context, id jsonrpc.RequestId, resourceMgr *re
 	}
 	if clientAuth {
 		if accessToken == "" {
-			return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, "missing access token in the 'Authorization' header", nil), util.NewClientServerError(
-				"missing access token in the 'Authorization' header",
-				http.StatusUnauthorized,
-				nil,
-			)
+			return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, "missing access token in the 'Authorization' header", nil), util.ErrUnauthorized
 		}
 	}
 
@@ -168,11 +165,7 @@ func toolsCallHandler(ctx context.Context, id jsonrpc.RequestId, resourceMgr *re
 	// Check if any of the specified auth services is verified
 	isAuthorized := tool.Authorized(verifiedAuthServices)
 	if !isAuthorized {
-		err = util.NewClientServerError(
-			"unauthorized Tool call: Please make sure you specify correct auth headers",
-			http.StatusUnauthorized,
-			nil,
-		)
+		err = fmt.Errorf("unauthorized Tool call: Please make sure your specify correct auth headers: %w", util.ErrUnauthorized)
 		return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, err.Error(), nil), err
 	}
 	logger.DebugContext(ctx, "tool invocation authorized")
@@ -194,44 +187,29 @@ func toolsCallHandler(ctx context.Context, id jsonrpc.RequestId, resourceMgr *re
 	// run tool invocation and generate response.
 	results, err := tool.Invoke(ctx, resourceMgr, params, accessToken)
 	if err != nil {
-		var tbErr util.ToolboxError
-
-		if errors.As(err, &tbErr) {
-			switch tbErr.Category() {
-			case util.CategoryAgent:
-				// MCP - Tool execution error
-				// Return SUCCESS but with IsError: true
-				text := TextContent{
-					Type: "text",
-					Text: err.Error(),
-				}
-				return jsonrpc.JSONRPCResponse{
-					Jsonrpc: jsonrpc.JSONRPC_VERSION,
-					Id:      id,
-					Result:  CallToolResult{Content: []TextContent{text}, IsError: true},
-				}, nil
-
-			case util.CategoryServer:
-				// MCP Spec - Protocol error
-				// Return JSON-RPC ERROR
-				var clientServerErr *util.ClientServerError
-				rpcCode := jsonrpc.INTERNAL_ERROR // Default to Internal Error (-32603)
-
-				if errors.As(err, &clientServerErr) {
-					if clientServerErr.Code == http.StatusUnauthorized || clientServerErr.Code == http.StatusForbidden {
-						if clientAuth {
-							rpcCode = jsonrpc.INVALID_REQUEST
-						} else {
-							rpcCode = jsonrpc.INTERNAL_ERROR
-						}
-					}
-				}
-				return jsonrpc.NewError(id, rpcCode, err.Error(), nil), err
+		errStr := err.Error()
+		// Missing authService tokens.
+		if errors.Is(err, util.ErrUnauthorized) {
+			return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, err.Error(), nil), err
+		}
+		// Upstream auth error
+		if strings.Contains(errStr, "Error 401") || strings.Contains(errStr, "Error 403") {
+			if clientAuth {
+				// Error with client credentials should pass down to the client
+				return jsonrpc.NewError(id, jsonrpc.INVALID_REQUEST, err.Error(), nil), err
 			}
-		} else {
-			// Unknown error -> 500
+			// Auth error with ADC should raise internal 500 error
 			return jsonrpc.NewError(id, jsonrpc.INTERNAL_ERROR, err.Error(), nil), err
 		}
+		text := TextContent{
+			Type: "text",
+			Text: err.Error(),
+		}
+		return jsonrpc.JSONRPCResponse{
+			Jsonrpc: jsonrpc.JSONRPC_VERSION,
+			Id:      id,
+			Result:  CallToolResult{Content: []TextContent{text}, IsError: true},
+		}, nil
 	}
 
 	content := make([]TextContent, 0)

internal/tools/bigquery/bigqueryconversationalanalytics/bigqueryconversationalanalytics.go

@@ -184,7 +184,7 @@ func (t Tool) Invoke(ctx context.Context, resourceMgr tools.SourceProvider, para
 	if source.UseClientAuthorization() {
 		// Use client-side access token
 		if accessToken == "" {
-			return nil, util.NewClientServerError("tool is configured for client OAuth but no token was provided in the request header", http.StatusUnauthorized, nil)
+			return nil, fmt.Errorf("tool is configured for client OAuth but no token was provided in the request header: %w", util.ErrUnauthorized)
 		}
 		tokenStr, err = accessToken.ParseBearerToken()
 		if err != nil {

internal/tools/tools.go

@@ -17,7 +17,6 @@ package tools
 import (
 	"context"
 	"fmt"
-	"net/http"
 	"slices"
 	"strings"
 
@@ -81,7 +80,7 @@ type AccessToken string
 func (token AccessToken) ParseBearerToken() (string, error) {
 	headerParts := strings.Split(string(token), " ")
 	if len(headerParts) != 2 || strings.ToLower(headerParts[0]) != "bearer" {
-		return "", util.NewClientServerError("authorization header must be in the format 'Bearer <token>'", http.StatusUnauthorized, nil)
+		return "", fmt.Errorf("authorization header must be in the format 'Bearer <token>': %w", util.ErrUnauthorized)
 	}
 	return headerParts[1], nil
 }

internal/util/errors.go

@@ -1,61 +0,0 @@
-// 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.
-package util
-
-import "fmt"
-
-type ErrorCategory string
-
-const (
-	CategoryAgent  ErrorCategory = "AGENT_ERROR"
-	CategoryServer ErrorCategory = "SERVER_ERROR"
-)
-
-// ToolboxError is the interface all custom errors must satisfy
-type ToolboxError interface {
-	error
-	Category() ErrorCategory
-}
-
-// Agent Errors return 200 to the sender
-type AgentError struct {
-	Msg   string
-	Cause error
-}
-
-func (e *AgentError) Error() string { return e.Msg }
-
-func (e *AgentError) Category() ErrorCategory { return CategoryAgent }
-
-func (e *AgentError) Unwrap() error { return e.Cause }
-
-func NewAgentError(msg string, cause error) *AgentError {
-	return &AgentError{Msg: msg, Cause: cause}
-}
-
-// ClientServerError returns 4XX/5XX error code
-type ClientServerError struct {
-	Msg   string
-	Code  int
-	Cause error
-}
-
-func (e *ClientServerError) Error() string { return fmt.Sprintf("%s: %v", e.Msg, e.Cause) }
-
-func (e *ClientServerError) Category() ErrorCategory { return CategoryServer }
-
-func (e *ClientServerError) Unwrap() error { return e.Cause }
-
-func NewClientServerError(msg string, code int, cause error) *ClientServerError {
-	return &ClientServerError{Msg: msg, Code: code, Cause: cause}
-}

internal/util/parameters/parameters.go

@@ -19,7 +19,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"net/http"
 	"reflect"
 	"regexp"
 	"slices"
@@ -119,7 +118,7 @@ func parseFromAuthService(paramAuthServices []ParamAuthService, claimsMap map[st
 		}
 		return v, nil
 	}
-	return nil, util.NewClientServerError("missing or invalid authentication header", http.StatusUnauthorized, nil)
+	return nil, fmt.Errorf("missing or invalid authentication header: %w", util.ErrUnauthorized)
 }
 
 // CheckParamRequired checks if a parameter is required based on the required and default field.

internal/util/util.go

@@ -17,6 +17,7 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"net/http"
@@ -187,3 +188,5 @@ func InstrumentationFromContext(ctx context.Context) (*telemetry.Instrumentation
 	}
 	return nil, fmt.Errorf("unable to retrieve instrumentation")
 }
+
+var ErrUnauthorized = errors.New("unauthorized")