grantex-adk 0.1.0

Google ADK integration for the Grantex delegated authorization protocol — scope-enforced agent tools

grantex-adk

Google Agent Development Kit (ADK) integration for the Grantex delegated authorization protocol — scope-enforced agent tools.

Wrap any function with Grantex grant token verification so your agents can only use tools they've been authorized for.

Install

pip install grantex-adk

You also need the Google ADK installed (it's a peer dependency):

pip install google-adk

Quick start

from grantex_adk import create_grantex_tool
from google.adk import Agent

# Create a scope-enforced tool from any function
read_calendar = create_grantex_tool(
    name="read_calendar",
    description="Read upcoming calendar events",
    grant_token=grant_token,       # JWT from Grantex authorization flow
    required_scope="calendar:read",
    func=get_calendar_events,      # your function
)

# Google ADK uses plain functions as tools — just pass them directly
agent = Agent(
    model="gemini-2.0-flash",
    name="assistant",
    tools=[read_calendar],
)

If the grant token doesn't include the required scope, create_grantex_tool raises a PermissionError immediately — the tool is never created.

API reference

create_grantex_tool()

Creates a plain function with the correct __name__ and __doc__ for ADK tool discovery, with offline scope enforcement.

Parameter	Type	Description
name	str	Tool name (becomes __name__)
description	str	Tool description (becomes __doc__)
grant_token	str	JWT grant token from Grantex
required_scope	str	Scope that must be present in the token
func	Callable[..., str]	The function to wrap

get_tool_scopes()

Returns the scopes embedded in a grant token (offline, no network call).

decode_jwt_payload()

Decodes the payload of a JWT without verifying the signature. Useful for inspecting token claims.

Requirements

• Python 3.9+
• grantex >= 0.1.0
• google-adk >= 0.2.0 (peer dependency)

License

Apache-2.0