Merge branch 'main' into adk-python-processing

## Description

Trigger has been tested corresponding to local changes. Latest
successful run:
https://pantheon.corp.google.com/cloud-build/builds;region=global/0e7720f6-451c-4a89-8a43-a35131ec90a5;step=0?project=toolbox-testing-438616

Note: After merging, update JS pre and post processing sample testing
trigger.

## 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>

---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Co-authored-by: Anubhav Dhawan <anubhavdhawan@google.com>

.ci/sample_tests/pre_post_processing/go.integration.cloudbuild.yaml

@@ -0,0 +1,57 @@
+# 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: "${_IMAGE}"
+    id: "go-pre-post-processing-test"
+    entrypoint: "bash"
+    args:
+      - -c
+      - |
+        set -ex
+        chmod +x .ci/sample_tests/run_tests.sh
+        .ci/sample_tests/run_tests.sh
+    env:
+      - "CLOUD_SQL_INSTANCE=${_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: "go"
+  _IMAGE: "golang:1.25.1"
+  _TARGET_ROOT: "docs/en/samples/pre_post_processing/go"
+  _TABLE_NAME: "hotels_go_pre_post_processing"
+  _SQL_FILE: ".ci/sample_tests/setup_hotels.sql"
+  _AGENT_FILE_PATTERN: "agent.go"
+
+options:
+  logging: CLOUD_LOGGING_ONLY

.ci/sample_tests/pre_post_processing/js.integration.cloudbuild.yaml

@@ -0,0 +1,57 @@
+# 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: "${_IMAGE}"
+    id: "js-pre-post-processing-test"
+    entrypoint: "bash"
+    args:
+      - -c
+      - |
+        set -ex
+        chmod +x .ci/sample_tests/run_tests.sh
+        .ci/sample_tests/run_tests.sh
+    env:
+      - "CLOUD_SQL_INSTANCE=${_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: "js"
+  _IMAGE: "node:22"
+  _TARGET_ROOT: "docs/en/samples/pre_post_processing/js"
+  _TABLE_NAME: "hotels_js_pre_post_processing"
+  _SQL_FILE: ".ci/sample_tests/setup_hotels.sql"
+  _AGENT_FILE_PATTERN: "agent.js"
+
+options:
+  logging: CLOUD_LOGGING_ONLY

.github/workflows/link_checker.yaml

@@ -0,0 +1,132 @@
+# 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.
+name: Link Checker
+
+on:
+  pull_request:
+permissions:
+  contents: read
+  pull-requests: write
+  issues: write
+
+
+jobs:
+  link-check:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout Repository
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          fetch-depth: 0
+      - name: Identify Changed Files
+        id: changed-files
+        shell: bash
+        run: |
+          git fetch origin main
+          CHANGED_FILES=$(git diff --name-only --diff-filter=ACMRT origin/main...HEAD -- '*.md')
+
+          if [ -z "$CHANGED_FILES" ]; then
+            echo "No markdown files changed. Skipping checks."
+            echo "HAS_CHANGES=false" >> $GITHUB_ENV
+          else
+            echo "--- Changed Files to Scan ---"
+            echo "$CHANGED_FILES"
+            echo "-----------------------------"
+            
+            # FIX: Wrap filenames in quotes to handle spaces
+            FILES_QUOTED=$(echo "$CHANGED_FILES" | sed 's/^/"/;s/$/"/' | tr '\n' ' ')
+            
+            # Write to env using EOF pattern
+            echo "CHECK_FILES<<EOF" >> $GITHUB_ENV
+            echo "$FILES_QUOTED" >> $GITHUB_ENV
+            echo "EOF" >> $GITHUB_ENV
+            echo "HAS_CHANGES=true" >> $GITHUB_ENV
+          fi
+
+
+      - name: Restore lychee cache
+        if: env.HAS_CHANGES == 'true'
+        uses: actions/cache@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5
+        with:
+          path: .lycheecache
+          key: cache-lychee-${{ github.sha }}
+          restore-keys: cache-lychee-
+
+      - name: Link Checker
+        id: lychee-check       
+        if: env.HAS_CHANGES == 'true'
+        uses: lycheeverse/lychee-action@a8c4c7cb88f0c7386610c35eb25108e448569cb0 # v2
+        continue-on-error: true 
+        with:
+          args: >
+            --quiet
+            --no-progress
+            --cache
+            --max-cache-age 1d
+            --exclude '^neo4j\+.*' --exclude '^bolt://.*'
+            ${{ env.CHECK_FILES }}
+          output: lychee-report.md
+          format: markdown
+          fail: true           
+          jobSummary: false    
+          debug: false
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+      - name: Find comment
+        uses: peter-evans/find-comment@b30e6a3c0ed37e7c023ccd3f1db5c6c0b0c23aad # v4
+        id: find-comment
+        with:
+          issue-number: ${{ github.event.pull_request.number }}
+          comment-author: 'github-actions[bot]'
+          body-includes: "## Link Resolution Note"
+
+      - name: Delete comment on success
+        if: steps.lychee-check.outcome == 'success' && steps.find-comment.outputs.comment-id != ''
+        run: |
+          gh api \
+            --method DELETE \
+            -H "Accept: application/vnd.github+json" \
+            /repos/${{ github.repository }}/issues/comments/${{ steps.find-comment.outputs.comment-id }}
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Prepare Report 
+        if: env.HAS_CHANGES == 'true' && steps.lychee-check.outcome == 'failure'
+        run: |
+          echo "## Link Resolution Note" > full-report.md
+          
+          
+          echo "Local links and directory changes work differently on GitHub than on the docsite.You must ensure fixes pass the **GitHub check** and also work with **\`hugo server\`**." >> full-report.md
+          echo "See [Link Checking and Fixing with Lychee](https://github.com/googleapis/genai-toolbox/blob/main/DEVELOPER.md#link-checking-and-fixing-with-lychee) for more details." >> full-report.md          
+          echo "" >> full-report.md 
+          sed -E '/(Redirect|Redirects per input)/d' lychee-report.md >> full-report.md
+
+      - name: Create PR Comment
+        if: env.HAS_CHANGES == 'true' && steps.lychee-check.outcome == 'failure'
+        uses: peter-evans/create-or-update-comment@71345be0265236311c031f5c7866368bd1eff043 # v4
+        with:
+          comment-id: ${{ steps.find-comment.outputs.comment-id }}
+          issue-number: ${{ github.event.pull_request.number }}
+          body-path: full-report.md
+          edit-mode: replace
+
+      - name: Display Failure Report
+        # Run this ONLY if the link checker failed
+        if: steps.lychee-check.outcome == 'failure'
+        run: |
+          # We can now simply output the prepared file to the job summary
+          cat full-report.md >> $GITHUB_STEP_SUMMARY
+          
+          # Fail the job
+          exit 1

.github/workflows/link_checker_workflow.yaml

@@ -1,68 +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.
-name: Link Checker
-
-on:
-  pull_request:
-
-
-jobs:
-  link-check:
-    runs-on: ubuntu-latest
-    steps:
-      - name: Checkout Repository
-        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
-
-      - name: Restore lychee cache
-        uses: actions/cache@cdf6c1fa76f9f475f3d7449005a359c84ca0f306 # v5
-        with:
-          path: .lycheecache
-          key: cache-lychee-${{ github.sha }}
-          restore-keys: cache-lychee-
-
-      - name: Link Checker
-        id: lychee-check       
-        uses: lycheeverse/lychee-action@a8c4c7cb88f0c7386610c35eb25108e448569cb0 # v2
-        continue-on-error: true 
-        with:
-          args: >
-            --quiet
-            --no-progress
-            --cache
-            --max-cache-age 1d
-            --exclude '^neo4j\+.*' --exclude '^bolt://.*'
-            README.md
-            docs/
-          output: lychee-report.md
-          format: markdown
-          fail: true           
-          jobSummary: false    
-          debug: false
-        env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-
-      - name: Display Failure Report
-        # Run this ONLY if the link checker failed
-        if: steps.lychee-check.outcome == 'failure'
-        run: |
-          echo "## Link Resolution Note" >> $GITHUB_STEP_SUMMARY
-          echo "Local links and directory changes work differently on GitHub than on the docsite." >> $GITHUB_STEP_SUMMARY
-          echo "You must ensure fixes pass the **GitHub check** and also work with **\`hugo server\`**." >> $GITHUB_STEP_SUMMARY
-          echo "See [Link Checking and Fixing with Lychee](https://github.com/googleapis/genai-toolbox/blob/main/DEVELOPER.md#link-checking-and-fixing-with-lychee) for more details." >> $GITHUB_STEP_SUMMARY
-          echo "---" >> $GITHUB_STEP_SUMMARY
-
-          echo "### Broken Links Found" >> $GITHUB_STEP_SUMMARY
-          cat ./lychee-report.md >> $GITHUB_STEP_SUMMARY
-
-          exit 1

docs/en/getting-started/colab_quickstart.ipynb

@@ -41,7 +41,7 @@
         "# Getting Started With MCP Toolbox\n",
         "\n",
         "This guide demonstrates how to quickly run\n",
-        "[Toolbox](https://github.com/googleapis/genai-toolbox) end-to-end in Google\n",
+        "[MCP Toolbox](https://github.com/googleapis/genai-toolbox) end-to-end in Google\n",
         "Colab using Python, PostgreSQL, and either [Google\n",
         "GenAI](https://pypi.org/project/google-genai/), [ADK](https://google.github.io/adk-docs/),\n",
         "[Langgraph](https://www.langchain.com/langgraph)\n",
@@ -49,12 +49,12 @@
         "\n",
         "Within this Colab environment, you'll\n",
         "- Set up a `PostgreSQL database`.\n",
-        "- Launch a Toolbox server.\n",
-        "- Connect to Toolbox and develop a sample `Hotel Booking` application.\n",
+        "- Launch an MCP Toolbox server.\n",
+        "- Connect to MCP Toolbox and develop a sample `Hotel Booking` application.\n",
         "\n",
-        "Here is the simplified flow of a Toolbox Application:\n",
+        "Here is the simplified flow of a MCP Toolbox Application:\n",
         "\n",
-        "<img src=\"https://services.google.com/fh/files/misc/toolbox_flow.png\" alt=\"Toolbox Flow\"/>\n",
+        "<img src=\"https://services.google.com/fh/files/misc/toolbox_flow.png\" alt=\"MCP Toolbox Flow\"/>\n",
         "\n"
       ]
     },
@@ -208,12 +208,12 @@
         "id": "EPuheP8DIt3p"
       },
       "source": [
-        "## Step 2: Install and configure Toolbox\n",
+        "## Step 2: Install and configure MCP Toolbox\n",
         "\n",
         "In this section, we will\n",
-        "1. Download the latest version of the toolbox binary.\n",
-        "2. Create a toolbox config file.\n",
-        "3. Start a toolbox server using the config file.\n",
+        "1. Download the latest version of the MCP toolbox binary.\n",
+        "2. Create an MCP toolbox config file.\n",
+        "3. Start an MCP toolbox server using the config file.\n",
         "\n"
       ]
     },
@@ -223,7 +223,7 @@
         "id": "Bl1IeaqZbMYh"
       },
       "source": [
-        "Download the [latest](https://github.com/googleapis/genai-toolbox/releases) version of Toolbox as a binary."
+        "Download the [latest](https://github.com/googleapis/genai-toolbox/releases) version of MCP Toolbox as a binary."
       ]
     },
     {
@@ -284,7 +284,7 @@
         "\n",
         "Our application will leverage these tools to interact with the hotels database.\n",
         "\n",
-        "For detailed configuration options, please refer to the [Toolbox documentation](https://googleapis.github.io/genai-toolbox/getting-started/configure/).\n",
+        "For detailed configuration options, please refer to the [MCP Toolbox documentation](https://googleapis.github.io/genai-toolbox/getting-started/configure/).\n",
         "\n"
       ]
     },
@@ -297,7 +297,7 @@
       "outputs": [],
       "source": [
         "# Create a tools file at runtime.\n",
-        "# You can also upload a tools file and use that to run toolbox.\n",
+        "# You can also upload a tools file and use that to run MCP toolbox.\n",
         "tools_file_name = \"tools.yml\"\n",
         "file_content = f\"\"\"\n",
         "kind: sources\n",
@@ -417,7 +417,7 @@
       },
       "outputs": [],
       "source": [
-        "# Start a toolbox server\n",
+        "# Start an MCP toolbox server\n",
         "! nohup {TOOLBOX_BINARY_PATH} --tools-file {TOOLS_FILE_PATH} -p {SERVER_PORT} > toolbox.log 2>&1 &"
       ]
     },
@@ -429,7 +429,7 @@
       },
       "outputs": [],
       "source": [
-        "# Check if toolbox is running\n",
+        "# Check if MCP toolbox is running\n",
         "!sudo lsof -i :{SERVER_PORT}"
       ]
     },
@@ -439,10 +439,10 @@
         "id": "4yFH4JK7JEAv"
       },
       "source": [
-        "## Step 3: Connect your agent to Toolbox\n",
+        "## Step 3: Connect your agent to MCP Toolbox\n",
         "\n",
         "In this section, you will\n",
-        "1. Establish a connection to the tools by creating a Toolbox client.\n",
+        "1. Establish a connection to the tools by creating an MCP Toolbox client.\n",
         "2. Build an agent that leverages the tools and an LLM for Hotel Booking functionality.\n"
       ]
     },
@@ -495,7 +495,7 @@
         "id": "J46eLkFbNhWq"
       },
       "source": [
-        "> You can either use LangGraph or LlamaIndex to develop a Toolbox based\n",
+        "> You can either use LangGraph or LlamaIndex to develop an MCP Toolbox based\n",
         "> application. Run one of the sections below\n",
         "> - [Connect using Google GenAI](#scrollTo=Fv2-uT4mvYtp)\n",
         "> - [Connect using ADK](#scrollTo=QqRlWqvYNKSo)\n",
@@ -618,7 +618,7 @@
       },
       "outputs": [],
       "source": [
-        "# Install the Toolbox Langchain package\n",
+        "# Install the MCP Toolbox Langchain package\n",
         "!pip install toolbox-langchain --quiet\n",
         "!pip install langgraph --quiet\n",
         "\n",
@@ -679,7 +679,7 @@
         "  # model = ChatGoogleGenerativeAI(model=\"gemini-2.0-flash-001\")\n",
         "  # model = ChatAnthropic(model=\"claude-3-5-sonnet-20240620\")\n",
         "\n",
-        "  # Load the tools from the Toolbox server\n",
+        "  # Load the tools from the MCP Toolbox server\n",
         "  client = ToolboxClient(\"http://127.0.0.1:5000\")\n",
         "  tools = await client.aload_toolset()\n",
         "\n",
@@ -711,7 +711,7 @@
       },
       "outputs": [],
       "source": [
-        "# Install the Toolbox LlamaIndex package\n",
+        "# Install the MCP Toolbox LlamaIndex package\n",
         "!pip install toolbox-llamaindex --quiet\n",
         "\n",
         "# Install the llamaindex llm package\n",
@@ -783,7 +783,7 @@
         "    #   api_key=os.getenv(\"ANTHROPIC_API_KEY\")\n",
         "    # )\n",
         "\n",
-        "    # Load the tools from the Toolbox server\n",
+        "    # Load the tools from the MCP Toolbox server\n",
         "    client = ToolboxClient(\"http://127.0.0.1:5000\")\n",
         "    tools = await client.aload_toolset()\n",
         "\n",
@@ -821,7 +821,7 @@
       },
       "outputs": [],
       "source": [
-        "# Install the Toolbox Core package\n",
+        "# Install the MCP Toolbox Core package\n",
         "!pip install toolbox-core --quiet\n",
         "\n",
         "# Install the Google GenAI package\n",
@@ -999,7 +999,7 @@
         "id": "yatf9YoGclV9"
       },
       "source": [
-        "Executing this will terminate the processes running on the database and Toolbox ports.\n",
+        "Executing this will terminate the processes running on the database and MCP Toolbox ports.\n",
         "\n",
         "This is necessary before re-running the startup cells for these services to prevent `port already in use` errors."
       ]

docs/en/getting-started/local_quickstart.md

@@ -3,7 +3,7 @@ title: "Python Quickstart (Local)"
 type: docs
 weight: 2
 description: >
-  How to get started running Toolbox locally with [Python](https://github.com/googleapis/mcp-toolbox-sdk-python), PostgreSQL, and  [Agent Development Kit](https://google.github.io/adk-docs/),
+  How to get started running MCP Toolbox locally with [Python](https://github.com/googleapis/mcp-toolbox-sdk-python), PostgreSQL, and  [Agent Development Kit](https://google.github.io/adk-docs/),
   [LangGraph](https://www.langchain.com/langgraph), [LlamaIndex](https://www.llamaindex.ai/) or [GoogleGenAI](https://pypi.org/project/google-genai/).
 ---
 
@@ -32,14 +32,14 @@ This guide assumes you have already done the following:
 
 {{< regionInclude "quickstart/shared/database_setup.md" "database_setup" >}}
 
-## Step 2: Install and configure Toolbox
+## Step 2: Install and configure MCP Toolbox
 
 {{< regionInclude "quickstart/shared/configure_toolbox.md" "configure_toolbox" >}}
 
-## Step 3: Connect your agent to Toolbox
+## Step 3: Connect your agent to MCP Toolbox
 
 In this section, we will write and run an agent that will load the Tools
-from Toolbox.
+from MCP Toolbox.
 
 {{< notice tip>}}
 If you prefer to experiment within a Google Colab environment, you can connect
@@ -113,7 +113,7 @@ pip install google-genai
     ```
     <br/>
 
-1. Update `my_agent/agent.py` with the following content to connect to Toolbox:
+1. Update `my_agent/agent.py` with the following content to connect to MCP Toolbox:
     ```py
     {{< regionInclude "quickstart/python/adk/quickstart.py" "quickstart" >}}
     ```

docs/en/getting-started/local_quickstart_go.md

@@ -3,7 +3,7 @@ title: "Go Quickstart (Local)"
 type: docs
 weight: 4
 description: >
-  How to get started running Toolbox locally with [Go](https://github.com/googleapis/mcp-toolbox-sdk-go), PostgreSQL, and orchestration frameworks such as [LangChain Go](https://tmc.github.io/langchaingo/docs/), [GenkitGo](https://genkit.dev/go/docs/get-started-go/), [Go GenAI](https://github.com/googleapis/go-genai) and [OpenAI Go](https://github.com/openai/openai-go).
+  How to get started running MCP Toolbox locally with [Go](https://github.com/googleapis/mcp-toolbox-sdk-go), PostgreSQL, and orchestration frameworks such as [LangChain Go](https://tmc.github.io/langchaingo/docs/), [GenkitGo](https://genkit.dev/go/docs/get-started-go/), [Go GenAI](https://github.com/googleapis/go-genai) and [OpenAI Go](https://github.com/openai/openai-go).
 ---
 
 ## Before you begin
@@ -24,14 +24,14 @@ This guide assumes you have already done the following:
 
 {{< regionInclude "quickstart/shared/database_setup.md" "database_setup" >}}
 
-## Step 2: Install and configure Toolbox
+## Step 2: Install and configure MCP Toolbox
 
 {{< regionInclude "quickstart/shared/configure_toolbox.md" "configure_toolbox" >}}
 
-## Step 3: Connect your agent to Toolbox
+## Step 3: Connect your agent to MCP Toolbox
 
 In this section, we will write and run an agent that will load the Tools
-from Toolbox.
+from MCP Toolbox.
 
 1. Initialize a go module:
 

docs/en/getting-started/local_quickstart_js.md

@@ -3,7 +3,7 @@ title: "JS Quickstart (Local)"
 type: docs
 weight: 3
 description: >
-  How to get started running Toolbox locally with [JavaScript](https://github.com/googleapis/mcp-toolbox-sdk-js), PostgreSQL, and orchestration frameworks such as [LangChain](https://js.langchain.com/docs/introduction/), [GenkitJS](https://genkit.dev/docs/get-started/),  [LlamaIndex](https://ts.llamaindex.ai/) and [GoogleGenAI](https://github.com/googleapis/js-genai).
+  How to get started running MCP Toolbox locally with [JavaScript](https://github.com/googleapis/mcp-toolbox-sdk-js), PostgreSQL, and orchestration frameworks such as [LangChain](https://js.langchain.com/docs/introduction/), [GenkitJS](https://genkit.dev/docs/get-started/),  [LlamaIndex](https://ts.llamaindex.ai/) and [GoogleGenAI](https://github.com/googleapis/js-genai).
 ---
 
 ## Before you begin
@@ -24,14 +24,14 @@ This guide assumes you have already done the following:
 
 {{< regionInclude "quickstart/shared/database_setup.md" "database_setup" >}}
 
-## Step 2: Install and configure Toolbox
+## Step 2: Install and configure MCP Toolbox
 
 {{< regionInclude "quickstart/shared/configure_toolbox.md" "configure_toolbox" >}}
 
-## Step 3: Connect your agent to Toolbox
+## Step 3: Connect your agent to MCP Toolbox
 
 In this section, we will write and run an agent that will load the Tools
-from Toolbox.
+from MCP Toolbox.
 
 1. (Optional) Initialize a Node.js project:
 

docs/en/getting-started/quickstart/go/quickstart_test.go

@@ -1,3 +1,5 @@
+// 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
@@ -9,6 +11,7 @@
 // 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 main
 
 import (

docs/en/samples/pre_post_processing/_index.md

@@ -50,5 +50,30 @@ It is helpful to understand how tool-level processing differs from other scopes:
 - **Model Level**: Intercepts individual calls to the LLM (prompts and responses). Unlike tool-level, this applies globally to all text sent/received, making it better for global PII redaction or token tracking.
 - **Agent Level**: Wraps the high-level execution loop (e.g., a "turn" in the conversation). Unlike tool-level, this envelopes the entire turn (user input to final response), making it suitable for session management or end-to-end auditing.
 
+## Best Practices
+
+### Security & Guardrails
+
+- **Principle of Least Privilege**: Ensure that tools run with the minimum necessary permissions. Middleware is an excellent place to enforce "read-only" modes or verify user identity before executing sensitive actions.
+- **Input Sanitization**: Actively strip potential PII (like credit card numbers or raw emails) from tool arguments before logging them.
+- **Prompt Injection Defense**: Use pre-processing hooks to scan user inputs for known jailbreak patterns or malicious directives before they reach the model or tools.
+
+### Observability & Debugging
+
+- **Structured Logging**: Instead of simple print statements, use structured JSON logging with correlation IDs. This allows you to trace a single user request through multiple agent turns and tool calls.
+- **Logging for Testability**: LLM responses are non-deterministic and may summarize away key details.
+  - **Pattern**: Add explicit logging markers in your post-processing middleware (e.g., `logger.info("ACTION_SUCCESS: <id>")`).
+  - **Benefit**: Your integration tests can grep logs for these stable markers to verify tool success, rather than painfully parsing variable natural language responses.
+
+### Performance & Cost Optimization
+
+- **Token Economy**: Tools often return verbose JSON. Use post-processing to strip unnecessary fields or summarize large datasets *before* returning the result to the LLM's context window. This saves tokens and reduces latency.
+- **Caching**: For read-heavy tools (like "search_knowledge_base"), implement caching middleware to return previous results for identical queries, saving both time and API costs.
+
+### Error Handling
+
+- **Graceful Degradation**: If a tool fails (e.g., API timeout), catch the exception in middleware and return a structured error message to the LLM (e.g., `Error: Database timeout, please try again`).
+- **Self-Correction**: Well-formatted error messages often allow the LLM to understand *why* a call failed and retry it with corrected parameters automatically.
+
 
 ## Samples

docs/en/samples/pre_post_processing/go.md

@@ -0,0 +1,42 @@
+---
+title: "Go"
+type: docs
+weight: 3
+description: >
+  How to add pre- and post- processing to your Agents using Go.
+---
+
+## Prerequisites
+
+This tutorial assumes that you have set up MCP Toolbox with a basic agent as described in the [local quickstart](../../getting-started/local_quickstart_go.md).
+
+This guide demonstrates how to implement these patterns in your Toolbox applications.
+
+## Implementation
+
+{{< tabpane persist=header >}}
+{{% tab header="ADK" text=true %}}
+The following example demonstrates how to use the `beforeToolCallback` and `afterToolCallback` hooks in the ADK `LlmAgent` to implement pre and post processing logic.
+
+```go
+{{< include "go/adk/agent.go" >}}
+```
+
+You can also add model-level (`beforeModelCallback`, `afterModelCallback`) and agent-level (`beforeAgentCallback`, `afterAgentCallback`) hooks to intercept messages at different stages of the execution loop.
+
+For more information, see the [ADK Callbacks documentation](https://google.github.io/adk-docs/callbacks/types-of-callbacks/).{{% /tab %}}
+{{< /tabpane >}}
+
+## Results
+
+The output should look similar to the following.
+
+{{< notice note >}}
+The exact responses may vary due to the non-deterministic nature of LLMs and differences between orchestration frameworks.
+{{< /notice >}}
+
+```
+AI: Booking Confirmed! You earned 500 Loyalty Points with this stay.
+
+AI: Error: Maximum stay duration is 14 days.
+```

docs/en/samples/pre_post_processing/go/adk/agent.go

@@ -0,0 +1,174 @@
+/*
+ * 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 main
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+	"time"
+
+	"github.com/googleapis/mcp-toolbox-sdk-go/tbadk"
+	"google.golang.org/adk/agent"
+	"google.golang.org/adk/agent/llmagent"
+	"google.golang.org/adk/model/gemini"
+	"google.golang.org/adk/runner"
+	"google.golang.org/adk/session"
+	"google.golang.org/adk/tool"
+	"google.golang.org/genai"
+)
+
+const systemPrompt = `You're a helpful hotel assistant. You handle hotel searching, booking and
+cancellations. When the user searches for a hotel, mention it's name, id,
+location and price tier. Always mention hotel ids while performing any
+searches. This is very important for any operations. For any bookings or
+cancellations, please provide the appropriate confirmation. Be sure to
+update checkin or checkout dates if mentioned by the user.
+Don't ask for confirmations from the user.`
+
+var queries = []string{
+	"Book hotel with id 3.",
+	"Update my hotel with id 3 with checkin date 2025-01-04 and checkout date 2025-01-20",
+}
+
+// Pre-processing
+func enforceBusinessRules(ctx tool.Context, tool tool.Tool, args map[string]any) (map[string]any, error) {
+
+	fmt.Printf("POLICY CHECK: Intercepting '%s'\n", tool.Name())
+	if tool.Name() == "update-hotel" {
+		checkinStr, okCheckin := args["checkin_date"].(string)
+		checkoutStr, okCheckout := args["checkout_date"].(string)
+
+		if okCheckin && okCheckout {
+			startDate, errStart := time.Parse("2006-01-02", checkinStr)
+			endDate, errEnd := time.Parse("2006-01-02", checkoutStr)
+			if errStart != nil || errEnd != nil {
+				return nil, nil
+			}
+
+			duration := endDate.Sub(startDate).Hours() / 24
+			if duration > 14 {
+				fmt.Println("BLOCKED: Stay too long")
+				return map[string]any{"Error": "Maximum stay duration is 14 days."}, nil
+			}
+		}
+	}
+	return nil, nil
+}
+
+// Post-processing
+func enrichResponse(ctx tool.Context, tool tool.Tool, args, result map[string]any, err error) (map[string]any, error) {
+	resultStr := fmt.Sprintf("%v", result)
+
+	if tool.Name() == "book-hotel" {
+		if err != nil {
+			return nil, err
+		}
+		if _, ok := result["Error"]; !ok && !strings.Contains(resultStr, "Error") {
+			const loyaltyBonus = 500
+			enrichedResult := fmt.Sprintf("Booking Confirmed!\n You earned %d Loyalty Points with this stay.\n\nSystem Details: %s", loyaltyBonus, resultStr)
+			return map[string]any{"confirmation": enrichedResult}, nil
+		}
+	}
+	return result, nil
+}
+
+func main() {
+	genaiKey := os.Getenv("GOOGLE_API_KEY")
+	toolboxURL := "http://localhost:5000"
+	ctx := context.Background()
+
+	toolboxClient, err := tbadk.NewToolboxClient(toolboxURL)
+	if err != nil {
+		log.Fatalf("Failed to create MCP Toolbox client: %v", err)
+	}
+
+	toolsetName := "my-toolset"
+	mcpTools, err := toolboxClient.LoadToolset(toolsetName, ctx)
+	if err != nil {
+		log.Fatalf("Failed to load MCP toolset '%s': %v\nMake sure your Toolbox server is running.", toolsetName, err)
+	}
+
+	model, err := gemini.NewModel(ctx, "gemini-2.5-flash", &genai.ClientConfig{
+		APIKey: genaiKey,
+	})
+	if err != nil {
+		log.Fatalf("Failed to create model: %v", err)
+	}
+
+	tools := make([]tool.Tool, len(mcpTools))
+	for i := range mcpTools {
+		tools[i] = &mcpTools[i]
+	}
+	llmagent, err := llmagent.New(llmagent.Config{
+		Name:        "hotel_assistant",
+		Model:       model,
+		Description: "Agent to answer questions about hotels.",
+		Instruction: systemPrompt,
+		Tools:       tools,
+		// Add pre- and post- processing hooks
+		BeforeToolCallbacks: []llmagent.BeforeToolCallback{enforceBusinessRules},
+		AfterToolCallbacks:  []llmagent.AfterToolCallback{enrichResponse},
+	})
+	if err != nil {
+		log.Fatalf("Failed to create agent: %v", err)
+	}
+
+	appName := "hotel_assistant"
+	userID := "user-123"
+	sessionService := session.InMemoryService()
+	respSess, err := sessionService.Create(ctx, &session.CreateRequest{
+		AppName: appName,
+		UserID:  userID,
+	})
+	if err != nil {
+		log.Fatalf("Failed to create the session service: %v", err)
+	}
+	sess := respSess.Session
+
+	r, err := runner.New(runner.Config{
+		AppName:        appName,
+		Agent:          llmagent,
+		SessionService: sessionService,
+	})
+	if err != nil {
+		log.Fatalf("Failed to create runner: %v", err)
+	}
+
+	for i, query := range queries {
+		fmt.Printf("\n=== Query %d: %s ===\n", i+1, query)
+		userMsg := genai.NewContentFromText(query, genai.RoleUser)
+		streamingMode := agent.StreamingModeSSE
+
+		runIter := r.Run(ctx, userID, sess.ID(), userMsg, agent.RunConfig{
+			StreamingMode: streamingMode,
+		})
+
+		fmt.Print("AI: ")
+		for event := range runIter {
+			if event != nil && event.Content != nil {
+				for _, p := range event.Content.Parts {
+					fmt.Print(p.Text)
+				}
+			}
+		}
+
+		fmt.Println("\n" + strings.Repeat("-", 80) + "\n")
+	}
+}

docs/en/samples/pre_post_processing/go/adk/go.mod

@@ -0,0 +1,44 @@
+module example.com/adk-agent
+
+go 1.24.4
+
+require (
+	github.com/googleapis/mcp-toolbox-sdk-go v0.5.1
+	google.golang.org/adk v0.3.0
+	google.golang.org/genai v1.43.0
+)
+
+require (
+	cloud.google.com/go v0.123.0 // indirect
+	cloud.google.com/go/auth v0.18.1 // indirect
+	cloud.google.com/go/auth/oauth2adapt v0.2.8 // indirect
+	cloud.google.com/go/compute/metadata v0.9.0 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/felixge/httpsnoop v1.0.4 // indirect
+	github.com/go-logr/logr v1.4.3 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/google/go-cmp v0.7.0 // indirect
+	github.com/google/s2a-go v0.1.9 // indirect
+	github.com/google/safehtml v0.1.0 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/googleapis/enterprise-certificate-proxy v0.3.11 // indirect
+	github.com/googleapis/gax-go/v2 v2.16.0 // indirect
+	github.com/gorilla/websocket v1.5.3 // indirect
+	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.63.0 // indirect
+	go.opentelemetry.io/otel v1.39.0 // indirect
+	go.opentelemetry.io/otel/metric v1.39.0 // indirect
+	go.opentelemetry.io/otel/sdk v1.39.0 // indirect
+	go.opentelemetry.io/otel/trace v1.39.0 // indirect
+	golang.org/x/crypto v0.47.0 // indirect
+	golang.org/x/net v0.49.0 // indirect
+	golang.org/x/oauth2 v0.34.0 // indirect
+	golang.org/x/sys v0.40.0 // indirect
+	golang.org/x/text v0.33.0 // indirect
+	google.golang.org/api v0.263.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20260122232226-8e98ce8d340d // indirect
+	google.golang.org/grpc v1.78.0 // indirect
+	google.golang.org/protobuf v1.36.11 // indirect
+	rsc.io/omap v1.2.0 // indirect
+	rsc.io/ordered v1.1.1 // indirect
+)

docs/en/samples/pre_post_processing/go/adk/go.sum

@@ -0,0 +1,132 @@
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docs/en/samples/pre_post_processing/go/agent_test.go

@@ -0,0 +1,78 @@
+// 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 main
+
+import (
+	"bytes"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestQuickstartSample(t *testing.T) {
+	framework := os.Getenv("ORCH_NAME")
+	if framework == "" {
+		t.Skip("Skipping test: ORCH_NAME environment variable is not set.")
+	}
+
+	t.Logf("--- Testing: %s ---", framework)
+
+	if os.Getenv("GOOGLE_API_KEY") == "" {
+		t.Skipf("Skipping test for %s: GOOGLE_API_KEY environment variable is not set.", framework)
+	}
+
+	sampleDir := filepath.Join(".", framework)
+	if _, err := os.Stat(sampleDir); os.IsNotExist(err) {
+		t.Fatalf("Test setup failed: directory for framework '%s' not found.", framework)
+	}
+
+	cmd := exec.Command("go", "run", ".")
+	cmd.Dir = sampleDir
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	err := cmd.Run()
+	actualOutput := stdout.String()
+
+	if err != nil {
+		t.Fatalf("Script execution failed with error: %v\n--- STDERR ---\n%s", err, stderr.String())
+	}
+	if len(actualOutput) == 0 {
+		t.Fatal("Script ran successfully but produced no output.")
+	}
+
+	goldenKeywords := []string{
+		"AI:",
+		"Loyalty Points",
+		"POLICY CHECK: Intercepting 'update-hotel'",
+	}
+
+	var missingKeywords []string
+	outputLower := strings.ToLower(actualOutput)
+
+	for _, keyword := range goldenKeywords {
+		kw := strings.TrimSpace(keyword)
+		if kw != "" && !strings.Contains(outputLower, strings.ToLower(kw)) {
+			missingKeywords = append(missingKeywords, kw)
+		}
+	}
+
+	if len(missingKeywords) > 0 {
+		t.Fatalf("FAIL: The following keywords were missing from the output: [%s]", strings.Join(missingKeywords, ", "))
+	}
+}

docs/en/samples/pre_post_processing/js.md

@@ -0,0 +1,47 @@
+---
+title: "Javascript"
+type: docs
+weight: 2
+description: >
+  How to add pre- and post- processing to your Agents using JS.
+---
+
+## Prerequisites
+
+This tutorial assumes that you have set up MCP Toolbox with a basic agent as described in the [local quickstart](../../getting-started/local_quickstart_js.md).
+
+This guide demonstrates how to implement these patterns in your Toolbox applications.
+
+## Implementation
+
+{{< tabpane persist=header >}}
+{{% tab header="ADK" text=true %}}
+Coming soon.
+{{% /tab %}}
+{{% tab header="Langchain" text=true %}}
+The following example demonstrates how to use `ToolboxClient` with LangChain's middleware to implement pre- and post- processing for tool calls.
+
+```js
+{{< include "js/langchain/agent.js" >}}
+```
+
+You can also use the `wrapModelCall` hook to intercept messages before and after model calls.
+You can also use [node-style hooks](https://docs.langchain.com/oss/javascript/langchain/middleware/custom#node-style-hooks) to intercept messages at the agent and model level.
+See the [LangChain Middleware documentation](https://docs.langchain.com/oss/javascript/langchain/middleware/custom#tool-call-monitoring) for details on these additional hook types.
+
+{{% /tab %}}
+{{< /tabpane >}}
+
+## Results
+
+The output should look similar to the following.
+
+{{< notice note >}}
+The exact responses may vary due to the non-deterministic nature of LLMs and differences between orchestration frameworks.
+{{< /notice >}}
+
+```
+AI: Booking Confirmed! You earned 500 Loyalty Points with this stay.
+
+AI: Error: Maximum stay duration is 14 days.
+```

docs/en/samples/pre_post_processing/js/agent.test.js

@@ -0,0 +1,91 @@
+// 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.
+
+import { describe, test, before, after } from "node:test";
+import assert from "node:assert/strict";
+
+import path from "path";
+import { fileURLToPath } from "url";
+
+const ORCH_NAME = process.env.ORCH_NAME;
+const __dirname = path.dirname(fileURLToPath(import.meta.url));
+const orchDir = path.join(__dirname, ORCH_NAME);
+const agentPath = path.join(orchDir, "agent.js");
+
+const { main: runAgent } = await import(agentPath);
+
+const GOLDEN_KEYWORDS = [
+  "AI:",
+  "Loyalty Points",
+  "POLICY CHECK: Intercepting 'update-hotel'"
+];
+
+describe(`${ORCH_NAME} Pre/Post Processing Agent`, () => {
+  let capturedOutput = [];
+  let capturedErrors = [];
+  let originalLog;
+  let originalError;
+
+  before(() => {
+    originalLog = console.log;
+    originalError = console.error;
+
+    console.log = (...args) => {
+      const msg = args.map(a => (typeof a === 'object' ? JSON.stringify(a, null, 2) : String(a))).join(' ');
+      capturedOutput.push(msg);
+    };
+    
+    console.error = (...args) => {
+      const msg = args.map(a => (typeof a === 'object' ? JSON.stringify(a, null, 2) : String(a))).join(' ');
+      capturedErrors.push(msg);
+    };
+  });
+
+  after(() => {
+    console.log = originalLog;
+    console.error = originalError;
+  });
+
+  test("runs without errors and outputContainsRequiredKeywords", async () => {
+    capturedOutput = [];
+    capturedErrors = [];
+
+    await runAgent();
+    assert.equal(
+        capturedErrors.length, 
+        0, 
+        `Script produced stderr: ${capturedErrors.join("\n")}`
+    );
+
+    const actualOutput = capturedOutput.join("\n");
+
+    assert.ok(
+      actualOutput.length > 0,
+      "Assertion Failed: Script ran successfully but produced no output."
+    );
+
+    const missingKeywords = [];
+
+    for (const keyword of GOLDEN_KEYWORDS) {
+      if (!actualOutput.includes(keyword)) {
+        missingKeywords.push(keyword);
+      }
+    }
+
+    assert.ok(
+      missingKeywords.length === 0,
+      `Assertion Failed: The following keywords were missing from the output: [${missingKeywords.join(", ")}]`
+    );
+  });
+});

docs/en/samples/pre_post_processing/js/langchain/agent.js

@@ -0,0 +1,109 @@
+import { ToolboxClient } from "@toolbox-sdk/core";
+import { ChatGoogleGenerativeAI } from "@langchain/google-genai";
+import { createAgent, createMiddleware, ToolMessage } from "langchain";
+import { tool } from "@langchain/core/tools";
+import { fileURLToPath } from "url";
+import process from "process";
+
+const systemPrompt = `
+You're a helpful hotel assistant. You handle hotel searching, booking and
+cancellations. When the user searches for a hotel, mention it's name, id,
+location and price tier. Always mention hotel ids while performing any
+searches. This is very important for any operations. For any bookings or
+cancellations, please provide the appropriate confirmation. Be sure to
+update checkin or checkout dates if mentioned by the user.
+Don't ask for confirmations from the user.
+`;
+
+const GOOGLE_API_KEY = process.env.GOOGLE_API_KEY || 'your-api-key'; // Replace it with your API key
+
+const businessRulesMiddleware = createMiddleware({
+  name: "BusinessRules",
+  wrapToolCall: async (request, handler) => {
+    const toolName = request.toolCall.name;
+    const toolArgs = request.toolCall.args;
+    console.log(`POLICY CHECK: Intercepting '${toolName}' running with args ${JSON.stringify(toolArgs)}`);
+    if (toolName === "update-hotel" && toolArgs.checkin_date && toolArgs.checkout_date) {
+      try {
+        const start = new Date(toolArgs.checkin_date);
+        const end = new Date(toolArgs.checkout_date);
+        const duration = (end - start) / (1000 * 60 * 60 * 24); // days
+
+        if (duration > 14) {
+          console.log("BLOCKED: Stay too long");
+          return ToolMessage({content:'Error: Maximum stay duration is 14 days.', status:"error"})
+        }
+      } catch (e) {
+        // Ignore invalid dates
+      }
+    }
+    return handler(request);
+  }
+});
+
+const enrichmentMiddleware = createMiddleware({
+  name: "Enrichment",
+  wrapToolCall: async (request, handler) => {
+    const result = await handler(request);
+    const toolName = request.toolCall.name;
+    
+    let content = result;
+    if (typeof result === 'object' && result !== null && result.content) {
+        content = result.content;
+    }
+    if (toolName === "book-hotel" && typeof content === 'string' && !content.includes("Error")) {
+        const loyaltyBonus = 500;
+        const enrichedContent = `Booking Confirmed!\n You earned ${loyaltyBonus} Loyalty Points with this stay.\n\nSystem Details: ${content}`;
+        if (typeof result === 'object' && result !== null) {
+            result.content = enrichedContent;
+            return result;
+        }
+        return enrichedContent;
+    }
+    return result;
+  }
+});
+
+const queries = [
+  "Book hotel with id 3.",
+  "Update my hotel with id 3 with checkin date 2025-01-18 and checkout date 2025-02-10"
+];
+
+async function main() {
+  const client = new ToolboxClient("http://127.0.0.1:5000");
+  const rawTools = await client.loadToolset("my-toolset");
+  const tools = rawTools
+    .map(t => tool(t, {
+        name: t.getName(),
+        description: t.getDescription(),
+        schema: t.getParamSchema()
+  }));
+
+  const model = new ChatGoogleGenerativeAI({
+    model: "gemini-2.5-flash",
+  });
+
+  const agent = createAgent({ 
+    model: model, 
+    tools: tools, 
+    systemPrompt: systemPrompt, 
+    middleware: [businessRulesMiddleware, enrichmentMiddleware] 
+  });
+
+  for (const query of queries) {
+    console.log(`\nUSER: '${query}'`);
+    const result = await agent.invoke({
+      messages: [
+        { role: "user", content: query},
+      ],
+    });
+    console.log("-".repeat(50));
+    console.log(`AI: ${result.messages[result.messages.length-1].content}`);
+  }
+}
+
+if (process.argv[1] === fileURLToPath(import.meta.url)) {
+  main();
+}
+
+export { main };

docs/en/samples/pre_post_processing/js/langchain/package.json

@@ -0,0 +1,20 @@
+{
+  "name": "langchain",
+  "version": "1.0.0",
+  "description": "LangChain.js sample for pre/post processing",
+  "type": "module",
+  "main": "agent.js",
+  "scripts": {
+    "start": "node agent.js"
+  },
+  "dependencies": {
+    "@langchain/core": "^1.1.26",
+    "@langchain/google-genai": "^2.1.19",
+    "@langchain/google-vertexai": "^2.1.19",
+    "@toolbox-sdk/core": "^0.2.1",
+    "langchain": "^1.2.25",
+    "zod": "^3.23.8"
+  },
+  "author": "",
+  "license": "ISC"
+}

docs/en/samples/pre_post_processing/python.md

@@ -8,7 +8,7 @@ description: >
 
 ## Prerequisites
 
-This tutorial assumes that you have set up Toolbox with a basic agent as described in the [local quickstart](../../getting-started/local_quickstart.md).
+This tutorial assumes that you have set up MCP Toolbox with a basic agent as described in the [local quickstart](../../getting-started/local_quickstart.md).
 
 This guide demonstrates how to implement these patterns in your Toolbox applications.
 
@@ -16,7 +16,14 @@ This guide demonstrates how to implement these patterns in your Toolbox applicat
 
 {{< tabpane persist=header >}}
 {{% tab header="ADK" text=true %}}
-Coming soon.
+The following example demonstrates how to use `ToolboxToolset` with ADK's pre and post processing hooks to implement pre and post processing for tool calls.
+
+```py
+{{< include "python/adk/agent.py" >}}
+```
+You can also add model-level (`before_model_callback`, `after_model_callback`) and agent-level (`before_agent_callback`, `after_agent_callback`) hooks to intercept messages at different stages of the execution loop. 
+
+For more information, see the [ADK Callbacks documentation](https://google.github.io/adk-docs/callbacks/types-of-callbacks/).
 {{% /tab %}}
 {{% tab header="Langchain" text=true %}}
 The following example demonstrates how to use `ToolboxClient` with LangChain's middleware to implement pre- and post- processing for tool calls.
@@ -31,7 +38,11 @@ You can also add model-level (`wrap_model`) and agent-level (`before_agent`, `af
 
 ## Results
 
-The output should look similar to the following. Note that exact responses may vary due to the non-deterministic nature of LLMs and differences between orchestration frameworks.
+The output should look similar to the following.
+
+{{< notice note >}}
+The exact responses may vary due to the non-deterministic nature of LLMs and differences between orchestration frameworks.
+{{< /notice >}}
 
 ```
 AI: Booking Confirmed! You earned 500 Loyalty Points with this stay.

docs/en/samples/pre_post_processing/python/adk/agent.py

@@ -0,0 +1,137 @@
+import asyncio
+from datetime import datetime
+from typing import Any, Dict, Optional
+from copy import deepcopy
+
+from google.adk import Agent
+from google.adk.apps import App
+from google.adk.runners import Runner
+from google.adk.sessions.in_memory_session_service import InMemorySessionService
+from google.adk.tools.tool_context import ToolContext
+from google.genai import types
+from toolbox_adk import CredentialStrategy, ToolboxToolset, ToolboxTool
+
+SYSTEM_PROMPT = """
+  You're a helpful hotel assistant. You handle hotel searching, booking and
+  cancellations. When the user searches for a hotel, mention it's name, id,
+  location and price tier. Always mention hotel ids while performing any
+  searches. This is very important for any operations. For any bookings or
+  cancellations, please provide the appropriate confirmation. Be sure to
+  update checkin or checkout dates if mentioned by the user.
+  Don't ask for confirmations from the user.
+"""
+
+
+# Pre processing
+async def enfore_business_rules(
+    tool: ToolboxTool, args: Dict[str, Any], tool_context: ToolContext
+) -> Optional[Dict[str, Any]]:
+    """
+    Callback fired before a tool is executed.
+    Enforces business logic: Max stay duration is 14 days.
+    """
+    tool_name = tool.name
+    print(f"POLICY CHECK: Intercepting '{tool_name}'")
+
+    if tool_name == "update-hotel" and "checkin_date" in args and "checkout_date" in args:
+        start = datetime.fromisoformat(args["checkin_date"])
+        end = datetime.fromisoformat(args["checkout_date"])
+        duration = (end - start).days
+
+        if duration > 14:
+            print("BLOCKED: Stay too long")
+            return {"result": "Error: Maximum stay duration is 14 days."}
+    return None
+
+
+# Post processing
+async def enrich_response(
+    tool: ToolboxTool,
+    args: Dict[str, Any],
+    tool_context: ToolContext,
+    tool_response: Any,
+) -> Optional[Any]:
+    """
+    Callback fired after a tool execution.
+    Enriches response for successful bookings.
+    """
+    if isinstance(tool_response, dict):
+        result = tool_response.get("result", "")
+    elif isinstance(tool_response, str):
+        result = tool_response
+    else:
+        return None
+
+    tool_name = tool.name
+    if isinstance(result, str) and "Error" not in result:
+        if tool_name == "book-hotel":
+            loyalty_bonus = 500
+            enriched_result = f"Booking Confirmed!\n You earned {loyalty_bonus} Loyalty Points with this stay.\n\nSystem Details: {result}"
+
+            if isinstance(tool_response, dict):
+                modified_response = deepcopy(tool_response)
+                modified_response["result"] = enriched_result
+                return modified_response
+            else:
+                return enriched_result
+    return None
+
+
+async def run_chat_turn(
+    runner: Runner, session_id: str, user_id: str, message_text: str
+):
+    """Executes a single chat turn and prints the interaction."""
+    print(f"\nUSER: '{message_text}'")
+    response_text = ""
+    async for event in runner.run_async(
+        user_id=user_id,
+        session_id=session_id,
+        new_message=types.Content(role="user", parts=[types.Part(text=message_text)]),
+    ):
+        if event.content and event.content.parts:
+            for part in event.content.parts:
+                if part.text:
+                    response_text += part.text
+
+    print(f"AI: {response_text}")
+
+
+async def main():
+    toolset = ToolboxToolset(
+        server_url="http://127.0.0.1:5000",
+        toolset_name="my-toolset",
+        credentials=CredentialStrategy.toolbox_identity(),
+    )
+    tools = await toolset.get_tools()
+    root_agent = Agent(
+        name="root_agent",
+        model="gemini-2.5-flash",
+        instruction=SYSTEM_PROMPT,
+        tools=tools,
+        # add any pre and post processing callbacks
+        before_tool_callback=enfore_business_rules,
+        after_tool_callback=enrich_response,
+    )
+    app = App(root_agent=root_agent, name="my_agent")
+    runner = Runner(app=app, session_service=InMemorySessionService())
+    session_id = "test-session"
+    user_id = "test-user"
+    await runner.session_service.create_session(
+        app_name=app.name, user_id=user_id, session_id=session_id
+    )
+
+    # First turn: Successful booking
+    await run_chat_turn(runner, session_id, user_id, "Book hotel with id 3.")
+    print("-" * 50)
+    # Second turn: Policy violation (stay > 14 days)
+    await run_chat_turn(
+        runner,
+        session_id,
+        user_id,
+        "Book a hotel with id 5 with checkin date 2025-01-18 and checkout date 2025-02-10",
+    )
+    await toolset.close()
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

docs/en/samples/pre_post_processing/python/adk/requirements.txt

@@ -0,0 +1,3 @@
+google-adk[toolbox]==1.23.0
+toolbox-adk==0.5.8
+google-genai==1.62.0