chore: add breaking change detector #1

	name: Breaking Change Detector

	on:
	pull_request:
	branches:
	- main
	paths:
	- 'src/**'

	jobs:
	check-api:
	runs-on: ubuntu-latest
	steps:
	- name: Checkout code
	uses: actions/checkout@v4
	with:
	fetch-depth: 0 # Crucial for griffe.load_git to access the main branch history

	- name: Set up Python
	uses: actions/setup-python@v5
	with:
	python-version: '3.10'

	- name: Install Griffe
	run: pip install griffe

	- name: Run Breaking Change Detection
	shell: python
	run: \|
	import sys
	import griffe
	from griffe import find_breaking_changes, load, load_git

	# 1. Load the current PR version from the local source
	# The adk-python source is located in src/google/adk
	try:
	new_api = load("src/google/adk")

	# 2. Load the 'main' version for comparison
	# Griffe will look at the main branch's version of the package
	old_api = load_git("google.adk", ref="main")

	# 3. Detect and explain breaking changes
	breakages = list(find_breaking_changes(old_api, new_api))

	if breakages:
	print(f"::error::Found {len(breakages)} breaking changes!")
	for breakage in breakages:
	# .explain() provides a human-readable reason for the breakage
	print(breakage.explain())
	sys.exit(1)

	print("No breaking changes detected.")
	except Exception as e:
	print(f"::warning::Breaking change detection failed: {e}")
	# We don't exit 1 here to prevent CI failure if the tool itself crashes

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