Google ADK

Scope-enforced tools using Google Agent Development Kit.

What it does

This example demonstrates the grantex-adk integration by building scope-enforced tools for Google Agent Development Kit (ADK):

1. Register an agent and obtain a grant token via the sandbox flow
2. Create scoped tools using create_grantex_tool — each tool returns a plain function that can be used directly with Google ADK agents (calendar:read, email:send)
3. Invoke tools directly as plain functions (in a full ADK agent, Gemini would select and call these tools)
4. Demonstrate scope enforcement — attempting to create a tool with account:delete (a scope not in the grant) raises a PermissionError
5. Inspect the audit trail to see the logged actions

Prerequisites

• Python 3.9+
• Docker (Docker Desktop or Docker Engine with Compose)

Run

Start the local Grantex stack from the repository root:

docker compose up --build

In a separate terminal, run the example:

cd examples/google-adk
pip install -r requirements.txt
python main.py

Expected output

Agent registered: ag_01HXYZ...
Grant token received, grantId: grnt_01HXYZ...
Tools created: read_calendar, send_email

--- Invoking read_calendar ---
Result: {"events": [{"title": "Team standup", "time": "9:00 AM", "query": "today"}, {"title": "Design review", "time": "2:00 PM", "query": "today"}]}

--- Invoking send_email ---
Result: Email sent successfully: "Meeting summary: standup at 9 AM, design review at 2 PM"

--- Testing scope enforcement ---
Scope check blocked unauthorized tool: Grant token does not include required scope "account:delete". Granted scopes: calendar:read, email:send

--- Audit trail ---
  [success] read_calendar — 2026-02-28T12:00:00.000Z
  [success] send_email — 2026-02-28T12:00:01.000Z

Done! Google ADK integration demo complete.

Environment variables

Variable	Default	Description
GRANTEX_URL	http://localhost:3001	Base URL of the Grantex auth service
GRANTEX_API_KEY	sandbox-api-key-local	API key. Use a sandbox key for auto-approval

Source code

The full source is in examples/google-adk/main.py.