feat(plugins): Add RateLimitPlugin for global request rate limiting

Add a new RateLimitPlugin that enforces global rate limiting across all
LLM models using a sliding window algorithm. The plugin blocks (waits)
when the rate limit is exceeded, ensuring requests are processed within
the configured limit.

Key features:
- Global rate limiting (default 15 QPM) across all models
- Sliding window algorithm for accurate tracking
- Automatic blocking when limit exceeded (no errors thrown)
- Thread-safe with asyncio locks
- Automatic cleanup of expired timestamps

Example usage:
```python
from google.adk.plugins import RateLimitPlugin

runner = Runner(
    agents=[agent],
    plugins=[RateLimitPlugin(max_requests_per_minute=15)]
)
```

.github/ISSUE_TEMPLATE/bug_report.md

@@ -19,7 +19,7 @@ Steps to reproduce the behavior:
 1. Install '...'
 2. Run '....'
 3. Open '....'
-4. Provide error or stacktrace
+4. Provie error or stacktrace
 
 **Expected behavior**
 A clear and concise description of what you expected to happen.

CHANGELOG.md

@@ -79,8 +79,6 @@
 * Fix issue with MCP tools throwing an error ([1a4261a](https://github.com/google/adk-python/commit/1a4261ad4b66cdeb39d39110a086bd6112b17516))
 * Remove redundant `format` field from LiteLLM content objects ([489c39d](https://github.com/google/adk-python/commit/489c39db01465e38ecbc2c7f32781c349b8cddc9))
 * Update the contribution analysis tool to use original write mode ([54db3d4](https://github.com/google/adk-python/commit/54db3d4434e0706b83a589fa2499d11d439a6e4e))
-* Fix agent evaluations detailed output rows wrapping issue([4284c61](https://github.com/google/adk-python/commit/4284c619010b8246c1ecaa011f14b6cc9de512dd))
-* Update dependency version constraints to be based on PyPI versions([0b1784e](https://github.com/google/adk-python/commit/0b1784e0e493a0e2df1edfe37e5ed5f4247e7d9d))
 
 ### Improvements
 
@@ -99,14 +97,13 @@
 * Add sample agent for VertexAiCodeExecutor ([edfe553](https://github.com/google/adk-python/commit/edfe5539421d196ca4da14d3a37fac7b598f8c8d))
 * Adds a new sample agent that demonstrates how to integrate PostgreSQL databases using the Model Context Protocol (MCP) ([45a2168](https://github.com/google/adk-python/commit/45a2168e0e6773e595ecfb825d7e4ab0a38c3a38))
 * Add example for using ADK with Fast MCP sampling ([d3796f9](https://github.com/google/adk-python/commit/d3796f9b33251d28d05e6701f11e80f02a2a49e1))
-* Refactor gepa sample code and clean-up user demo colab([63353b2](https://github.com/google/adk-python/commit/63353b2b74e23e97385892415c5a3f2a59c3504f))
 
 ## [1.17.0](https://github.com/google/adk-python/compare/v1.16.0...v1.17.0) (2025-10-22)
 
 ### Features
 
 * **[Core]**
-  * Add a service registry to provide a generic way to register custom service implementations to be used in FastAPI server. See [short instruction](https://github.com/google/adk-python/discussions/3175#discussioncomment-14745120). ([391628f](https://github.com/google/adk-python/commit/391628fcdc7b950c6835f64ae3ccab197163c990))
+  * Add a service registry to provide a generic way to register custom service implementations to be used in FastAPI server. See short instruction [here](https://github.com/google/adk-python/discussions/3175#discussioncomment-14745120). ([391628f](https://github.com/google/adk-python/commit/391628fcdc7b950c6835f64ae3ccab197163c990))
   * Add the ability to rewind a session to before a previous invocation ([9dce06f](https://github.com/google/adk-python/commit/9dce06f9b00259ec42241df4f6638955e783a9d1))
   * Support resuming a parallel agent with multiple branches paused on tool confirmation requests ([9939e0b](https://github.com/google/adk-python/commit/9939e0b087094038b90d86c2fd35c26dd63f1157))
   * Support content union as static instruction ([cc24d61](https://github.com/google/adk-python/commit/cc24d616f80c0eba2b09239b621cf3d176f144ea))
@@ -173,8 +170,9 @@
 * Set default for `bypass_multi_tools_limit` to False for GoogleSearchTool and VertexAiSearchTool ([6da7274](https://github.com/google/adk-python/commit/6da727485898137948d72906d86d78b6db6331ac))
 * Add more clear instruction to the doc updater agent about one PR for each recommended change ([b21d0a5](https://github.com/google/adk-python/commit/b21d0a50d610407be2f10b73a91274840ffdfe18))
 * Add a guideline to avoid content deletion ([16b030b](https://github.com/google/adk-python/commit/16b030b2b25a9b0b489e47b4b148fc4d39aeffcb))
-* Add a sample agent for the `ReflectAndRetryToolPlugin` ([9b8a4aa](https://github.com/google/adk-python/commit/9b8a4aad6fe65ef37885e5c3368d2799a2666534))
+* Add an sample agent for the `ReflectAndRetryToolPlugin` ([9b8a4aa](https://github.com/google/adk-python/commit/9b8a4aad6fe65ef37885e5c3368d2799a2666534))
 * Improve error message when adk web is run in wrong directory ([4a842c5](https://github.com/google/adk-python/commit/4a842c5a1334c3ee01406f796651299589fe12ab))
+* Add an sample agent for the `ReflectAndRetryToolPlugin` ([9b8a4aa](https://github.com/google/adk-python/commit/9b8a4aad6fe65ef37885e5c3368d2799a2666534))
 * Add span for context caching handling and new cache creation ([a2d9f13](https://github.com/google/adk-python/commit/a2d9f13fa1d31e00ba9493fba321ca151cdd9366))
 * Disable the scheduled execution for issue triage workflow ([bae2102](https://github.com/google/adk-python/commit/bae21027d9bd7f811bed638ecce692262cb33fe5))
 * Correct the callback signatures ([fa84bcb](https://github.com/google/adk-python/commit/fa84bcb5756773eadff486b99c9bd416b4faa9c6))
@@ -204,7 +202,7 @@
   * Add `dry_run` functionality to BigQuery `execute_sql` tool ([960eda3](https://github.com/google/adk-python/commit/960eda3d1f2f46dc93a365eb3de03dc3483fe9bb))
   * Add BigQuery analyze_contribution tool ([4bb089d](https://github.com/google/adk-python/commit/4bb089d386d4e8133e9aadbba5c42d31ff281cf6))
   * Spanner ADK toolset supports customizable template SQL and parameterized SQL ([da62700](https://github.com/google/adk-python/commit/da62700d739cb505149554962a8bcfb30f9428cc))
-  * Support OAuth2 client credentials grant type ([5c6cdcd](https://github.com/google/adk-python/commit/5c6cdcd197a6780fc86d9183fa208f78c8a975d9))
+  * Support Oauth2 client credentials grant type ([5c6cdcd](https://github.com/google/adk-python/commit/5c6cdcd197a6780fc86d9183fa208f78c8a975d9))
   * Add `ReflectRetryToolPlugin` to reflect from errors and retry with different arguments when tool errors ([e55b894](https://github.com/google/adk-python/commit/e55b8946d6a2e01aaf018d6a79d11d13c5286152))
   * Support using `VertexAiSearchTool` built-in tool with other tools in the same agent ([4485379](https://github.com/google/adk-python/commit/4485379a049a5c84583a43c85d444ea1f1ba6f12))
   * Support using google search built-in tool with other tools in the same agent ([d3148da](https://github.com/google/adk-python/commit/d3148dacc97f0a9a39b6d7a9640f7b7b0d6f9a6c))
@@ -285,7 +283,7 @@
   * Add endpoint to generate memory from session ([2595824](https://github.com/google/adk-python/commit/25958242db890b4d2aac8612f7f7cfbb561727fa))
 * **[Tools]**
   * Add Google Maps Grounding Tool to ADK ([6b49391](https://github.com/google/adk-python/commit/6b493915469ecb42068e24818ab547b0856e4709))
-  * **MCP:** Initialize tool_name_prefix in MCPToolset ([86dea5b](https://github.com/google/adk-python/commit/86dea5b53ac305367283b7e353b60d0f4515be3b))
+  * **MCP:** Initialize tool_name_prefix in MCPToolse ([86dea5b](https://github.com/google/adk-python/commit/86dea5b53ac305367283b7e353b60d0f4515be3b))
 * **[Evals]**
   * Data model for storing App Details and data model for steps ([01923a9](https://github.com/google/adk-python/commit/01923a9227895906ca8ae32712d65b178e2cd7d5))
   * Adds Rubric based final response evaluator ([5a485b0](https://github.com/google/adk-python/commit/5a485b01cd64cb49735e13ebd5e7fa3da02cd85f))
@@ -352,7 +350,7 @@
 * Fix discussion answering github action workflow to escape the quote in the discussion content JSON [43c9681](https://github.com/google/adk-python/commit/43c96811da891a5b0c9cf1be525665e65f346a13)
 * Send full MIME types for image/video/pdf in get_content [e45c3be](https://github.com/google/adk-python/commit/e45c3be23895b5ec68908ad9ee19bd622dcbd003)
 * Fix flaky unit tests: tests/unittests/flows/llm_flows/test_functions_simple.py [b92b288](https://github.com/google/adk-python/commit/b92b288c978a9b3d1a76c8bcb96cc8f439ce610b)
-* Make UT of a2a consistent about how tests should be skipped when python version < 3.10 [98b0426](https://github.com/google/adk-python/commit/98b0426cd2dc5e28014ead22b22dbf50d42d0a9a)
+* Make UT of a2a consistent about how tests should be skipped when python verison < 3.10 [98b0426](https://github.com/google/adk-python/commit/98b0426cd2dc5e28014ead22b22dbf50d42d0a9a)
 
 ### Improvements
 
@@ -443,7 +441,7 @@ with Bigtable for building AI Agent applications(experimental feature) ([a953807
 * Using base event's invocation id when merge multiple function response event ([279e4fe](https://github.com/google/adk-python/commit/279e4fedd0b1c0d1499c0f9a4454357af7da490e))
 * Avoid crash when there is no candidates_token_count, which is Optional ([22f34e9](https://github.com/google/adk-python/commit/22f34e9d2c552fbcfa15a672ef6ff0c36fa32619))
 * Fix the packaging version comparison logic in adk cli ([a2b7909](https://github.com/google/adk-python/commit/a2b7909fc36e7786a721f28e2bf75a1e86ad230d))
-* Add Spanner admin scope to Spanner tool default OAuth scopes ([b66054d](https://github.com/google/adk-python/commit/b66054dd0d8c5b3d6f6ad58ac1fbd8128d1da614))
+* Add Spanner admin scope to Spanner tool default Oauth scopes ([b66054d](https://github.com/google/adk-python/commit/b66054dd0d8c5b3d6f6ad58ac1fbd8128d1da614))
 * Fixes SequentialAgent.config_type type hint ([8a9a271](https://github.com/google/adk-python/commit/8a9a271141678996c9b84b8c55d4b539d011391c))
 * Fixes the host in the ansi bracket of adk web ([cd357bf](https://github.com/google/adk-python/commit/cd357bf5aeb01f1a6ae2a72349a73700ca9f1ed2))
 * Add spanner tool name prefix ([a27927d](https://github.com/google/adk-python/commit/a27927dc8197c391c80acb8b2c23d610fba2f887))
@@ -455,7 +453,7 @@ with Bigtable for building AI Agent applications(experimental feature) ([a953807
 * Update `openai` dependency version, based on correct OPENAI release ([bb8ebd1](https://github.com/google/adk-python/commit/bb8ebd15f90768b518cd0e21a59b269e30d6d944))
 * Add the missing license header for core_callback_config init file ([f8fd6a4](https://github.com/google/adk-python/commit/f8fd6a4f09ab520b8ecdbd8f9fe48228dbff7ebe))
 * Creates yaml_utils.py in utils to allow adk dump yaml in the same style ([1fd58cb](https://github.com/google/adk-python/commit/1fd58cb3633992cd88fa7e09ca6eda0f9b34236f))
-* Return explicit None type for DELETE endpoints ([f03f167](https://github.com/google/adk-python/commit/f03f1677790c0a9e59b6ba6f46010d0b7b64be50))
+* Return explict None type for DELETE endpoints ([f03f167](https://github.com/google/adk-python/commit/f03f1677790c0a9e59b6ba6f46010d0b7b64be50))
 * Add _config suffix to all yaml-based agent examples ([43f302c](https://github.com/google/adk-python/commit/43f302ce1ab53077ee8f1486d5294540678921e6))
 * Rename run related method and request to align with the conventions ([ecaa7b4](https://github.com/google/adk-python/commit/ecaa7b4c9847b478c7cdc37185b1525f733bb403))
 * Update models in samples/ folder to be gemini 2.0+ ([6c217ba](https://github.com/google/adk-python/commit/6c217bad828edf62b41ec06b168f8a6cb7ece2ed))
@@ -480,7 +478,7 @@ with Bigtable for building AI Agent applications(experimental feature) ([a953807
 
 ### Bug Fixes
 
-* A2A RPC URL got overridden by host and port param of adk api server ([52284b1](https://github.com/google/adk-python/commit/52284b1bae561e0d6c93c9d3240a09f210551b97))
+* A2A RPC URL got overriden by host and port param of adk api server ([52284b1](https://github.com/google/adk-python/commit/52284b1bae561e0d6c93c9d3240a09f210551b97))
 * Aclose all async generators to fix OTel tracing context ([a30c63c](https://github.com/google/adk-python/commit/a30c63c5933a770b960b08a6e2f8bf13eece8a22))
 * Use PreciseTimestamp for create and update time in database session service to improve precision ([585141e](https://github.com/google/adk-python/commit/585141e0b7dda20abb024c7164073862c8eea7ae))
 * Ignore AsyncGenerator return types in function declarations ([e2518dc](https://github.com/google/adk-python/commit/e2518dc371fe77d7b30328d8d6f5f864176edeac))
@@ -508,7 +506,7 @@ with Bigtable for building AI Agent applications(experimental feature) ([a953807
 * Group FastAPI endpoints with tags ([c323de5](https://github.com/google/adk-python/commit/c323de5c692223e55372c3797e62d4752835774d))
 * Allow implementations to skip defining a close method on Toolset ([944e39e](https://github.com/google/adk-python/commit/944e39ec2a7c9ad7f20c08fd66bf544de94a23d7))
 * Add sample agent to test support of output_schema and tools at the same time for gemini model ([f2005a2](https://github.com/google/adk-python/commit/f2005a20267e1ee8581cb79c37aa55dc8e18c0ea))
-* Add GitHub workflow config for uploading ADK docs to knowledge store ([5900273](https://github.com/google/adk-python/commit/59002734559d49a46940db9822b9c5f490220a8c))
+* Add Github workflow config for uploading ADK docs to knowledge store ([5900273](https://github.com/google/adk-python/commit/59002734559d49a46940db9822b9c5f490220a8c))
 * Update ADK Answering agent to reference doc site instead of adk-docs repo ([b5a8bad](https://github.com/google/adk-python/commit/b5a8bad170e271b475385dac440c7983ed207df8))
 
 ### Documentation

CONTRIBUTING.md

@@ -145,7 +145,7 @@ part before or alongside your code PR.
 
 3.  **Create and activate a virtual environment:**
 
-    **NOTE**: ADK supports Python 3.10+. Python 3.11 and above is strongly
+    **NOTE**: ADK supports Python 3.9+. Python 3.11 and above is strongly
     recommended.
 
     Create a workspace venv using uv.

README.md

@@ -17,8 +17,7 @@
       Important Links:
       <a href="https://google.github.io/adk-docs/">Docs</a>,
       <a href="https://github.com/google/adk-samples">Samples</a>,
-      <a href="https://github.com/google/adk-java">Java ADK</a>,
-      <a href="https://github.com/google/adk-go">Go ADK</a> &
+      <a href="https://github.com/google/adk-java">Java ADK</a> &
       <a href="https://github.com/google/adk-web">ADK Web</a>.
     </h3>
 </html>
@@ -33,7 +32,7 @@ deployment-agnostic, and compatible with other frameworks.
 
 ## 🔥 What's new
 
-- **Custom Service Registration**: Add a service registry to provide a generic way to register custom service implementations to be used in FastAPI server. See [short instruction](https://github.com/google/adk-python/discussions/3175#discussioncomment-14745120). ([391628f](https://github.com/google/adk-python/commit/391628fcdc7b950c6835f64ae3ccab197163c990))
+- **Custom Service Registration**: Add a service registry to provide a generic way to register custom service implementations to be used in FastAPI server. See short instruction [here](https://github.com/google/adk-python/discussions/3175#discussioncomment-14745120). ([391628f](https://github.com/google/adk-python/commit/391628fcdc7b950c6835f64ae3ccab197163c990))
 
 - **Rewind**: Add the ability to rewind a session to before a previous invocation ([9dce06f](https://github.com/google/adk-python/commit/9dce06f9b00259ec42241df4f6638955e783a9d1)).
 

contributing/samples/adk_agent_builder_assistant/__init__.py

@@ -18,10 +18,9 @@ This package provides an intelligent assistant for building multi-agent systems
 using YAML configurations. It can be used directly as an agent or integrated
 with ADK tools and web interfaces.
 """
-from __future__ import annotations
 
 from . import agent  # Import to make agent.root_agent available
-from .adk_agent_builder_assistant import AgentBuilderAssistant
+from .agent_builder_assistant import AgentBuilderAssistant
 
 __all__ = [
     'AgentBuilderAssistant',

contributing/samples/adk_agent_builder_assistant/agent.py

@@ -13,9 +13,8 @@
 # limitations under the License.
 
 """Agent Builder Assistant instance for ADK web testing."""
-from __future__ import annotations
 
-from .adk_agent_builder_assistant import AgentBuilderAssistant
+from .agent_builder_assistant import AgentBuilderAssistant
 
 # Create the agent instance using the factory
 # The root_agent variable is what ADK looks for when loading agents

contributing/samples/adk_agent_builder_assistant/agent_builder_assistant.py

@@ -0,0 +1,216 @@
+# 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.
+
+"""Agent factory for creating Agent Builder Assistant with embedded schema."""
+
+from pathlib import Path
+from typing import Callable
+from typing import Optional
+from typing import Union
+
+from google.adk.agents import LlmAgent
+from google.adk.agents.readonly_context import ReadonlyContext
+from google.adk.models import BaseLlm
+from google.adk.tools import AgentTool
+from google.adk.tools import FunctionTool
+from google.genai import types
+
+from .sub_agents.google_search_agent import create_google_search_agent
+from .sub_agents.url_context_agent import create_url_context_agent
+from .tools.cleanup_unused_files import cleanup_unused_files
+from .tools.delete_files import delete_files
+from .tools.explore_project import explore_project
+from .tools.read_config_files import read_config_files
+from .tools.read_files import read_files
+from .tools.search_adk_knowledge import search_adk_knowledge
+from .tools.search_adk_source import search_adk_source
+from .tools.write_config_files import write_config_files
+from .tools.write_files import write_files
+from .utils import load_agent_config_schema
+
+
+class AgentBuilderAssistant:
+  """Agent Builder Assistant factory for creating configured instances."""
+
+  @staticmethod
+  def create_agent(
+      model: Union[str, BaseLlm] = "gemini-2.5-flash",
+      working_directory: Optional[str] = None,
+  ) -> LlmAgent:
+    """Create Agent Builder Assistant with embedded ADK AgentConfig schema.
+
+    Args:
+      model: Model to use for the assistant (default: gemini-2.5-flash)
+      working_directory: Working directory for path resolution (default: current
+        working directory)
+
+    Returns:
+      Configured LlmAgent with embedded ADK AgentConfig schema
+    """
+    # Load full ADK AgentConfig schema directly into instruction context
+    instruction = AgentBuilderAssistant._load_instruction_with_schema(model)
+
+    # TOOL ARCHITECTURE: Hybrid approach using both AgentTools and FunctionTools
+    #
+    # Why use sub-agents for built-in tools?
+    # - ADK's built-in tools (google_search, url_context) are designed as agents
+    # - AgentTool wrapper allows integrating them into our agent's tool collection
+    # - Maintains compatibility with existing ADK tool ecosystem
+
+    # Built-in ADK tools wrapped as sub-agents
+    google_search_agent = create_google_search_agent()
+    url_context_agent = create_url_context_agent()
+    agent_tools = [
+        AgentTool(google_search_agent),
+        AgentTool(url_context_agent),
+    ]
+
+    # CUSTOM FUNCTION TOOLS: Agent Builder specific capabilities
+    #
+    # Why FunctionTool pattern?
+    # - Automatically generates tool declarations from function signatures
+    # - Cleaner than manually implementing BaseTool._get_declaration()
+    # - Type hints and docstrings become tool descriptions automatically
+
+    # Core agent building tools
+    custom_tools = [
+        FunctionTool(read_config_files),  # Read/parse multiple YAML configs
+        FunctionTool(
+            write_config_files
+        ),  # Write/validate multiple YAML configs
+        FunctionTool(explore_project),  # Analyze project structure
+        # File management tools (multi-file support)
+        FunctionTool(read_files),  # Read multiple files
+        FunctionTool(write_files),  # Write multiple files
+        FunctionTool(delete_files),  # Delete multiple files
+        FunctionTool(cleanup_unused_files),
+        # ADK source code search (regex-based)
+        FunctionTool(search_adk_source),  # Search ADK source with regex
+        # ADK knowledge search
+        FunctionTool(search_adk_knowledge),  # Search ADK knowledge base
+    ]
+
+    # Combine all tools
+    all_tools = agent_tools + custom_tools
+
+    # Create agent directly using LlmAgent constructor
+    agent = LlmAgent(
+        name="agent_builder_assistant",
+        description=(
+            "Intelligent assistant for building ADK multi-agent systems "
+            "using YAML configurations"
+        ),
+        instruction=instruction,
+        model=model,
+        tools=all_tools,
+        generate_content_config=types.GenerateContentConfig(
+            max_output_tokens=8192,
+        ),
+    )
+
+    return agent
+
+  @staticmethod
+  def _load_schema() -> str:
+    """Load ADK AgentConfig.json schema content and format for YAML embedding."""
+
+    # CENTRALIZED ADK AGENTCONFIG SCHEMA LOADING: Use common utility function
+    # This avoids duplication across multiple files and provides consistent
+    # ADK AgentConfig schema loading with caching and error handling.
+    schema_content = load_agent_config_schema(
+        raw_format=True,  # Get as JSON string
+    )
+
+    # Format as indented code block for instruction embedding
+    #
+    # Why indentation is needed:
+    # - The ADK AgentConfig schema gets embedded into instruction templates using .format()
+    # - Proper indentation maintains readability in the final instruction
+    # - Code block markers (```) help LLMs recognize this as structured data
+    #
+    # Example final instruction format:
+    #   "Here is the ADK AgentConfig schema:
+    #   ```json
+    #     {"type": "object", "properties": {...}}
+    #   ```"
+    lines = schema_content.split("\n")
+    indented_lines = ["  " + line for line in lines]  # 2-space indent
+    return "```json\n" + "\n".join(indented_lines) + "\n  ```"
+
+  @staticmethod
+  def _load_instruction_with_schema(
+      model: Union[str, BaseLlm],
+  ) -> Callable[[ReadonlyContext], str]:
+    """Load instruction template and embed ADK AgentConfig schema content."""
+    instruction_template = (
+        AgentBuilderAssistant._load_embedded_schema_instruction_template()
+    )
+    schema_content = AgentBuilderAssistant._load_schema()
+
+    # Get model string for template replacement
+    model_str = (
+        str(model)
+        if isinstance(model, str)
+        else getattr(model, "model_name", str(model))
+    )
+
+    # Return a function that accepts ReadonlyContext and returns the instruction
+    def instruction_provider(context: ReadonlyContext) -> str:
+      # Extract project folder name from session state
+      project_folder_name = AgentBuilderAssistant._extract_project_folder_name(
+          context
+      )
+
+      # Fill the instruction template with all variables
+      instruction_text = instruction_template.format(
+          schema_content=schema_content,
+          default_model=model_str,
+          project_folder_name=project_folder_name,
+      )
+      return instruction_text
+
+    return instruction_provider
+
+  @staticmethod
+  def _extract_project_folder_name(context: ReadonlyContext) -> str:
+    """Extract project folder name from session state using resolve_file_path."""
+    from .utils.resolve_root_directory import resolve_file_path
+
+    session_state = context._invocation_context.session.state
+
+    # Use resolve_file_path to get the full resolved path for "."
+    # This handles all the root_directory resolution logic consistently
+    resolved_path = resolve_file_path(".", session_state)
+
+    # Extract the project folder name from the resolved path
+    project_folder_name = resolved_path.name
+
+    # Fallback to "project" if we somehow get an empty name
+    if not project_folder_name:
+      project_folder_name = "project"
+
+    return project_folder_name
+
+  @staticmethod
+  def _load_embedded_schema_instruction_template() -> str:
+    """Load instruction template for embedded ADK AgentConfig schema mode."""
+    template_path = Path(__file__).parent / "instruction_embedded.template"
+
+    if not template_path.exists():
+      raise FileNotFoundError(
+          f"Instruction template not found at {template_path}"
+      )
+
+    with open(template_path, "r", encoding="utf-8") as f:
+      return f.read()

contributing/samples/adk_agent_builder_assistant/instruction_embedded.template

@@ -75,9 +75,6 @@ Always reference this schema when creating configurations to ensure compliance.
 - **CRITICAL TIMING**: Ask for model selection IMMEDIATELY after determining LlmAgent is needed, BEFORE presenting any design
 - **MANDATORY CONFIRMATION**: Say "Please confirm what model you want to use" - do NOT assume or suggest defaults
 - **EXAMPLES**: "gemini-2.5-flash", "gemini-2.5-pro", etc.
-- **ALLOWED MODELS ONLY**: Only mention or propose "gemini-2.5-flash" or
-  "gemini-2.5-pro". Treat any request for gemini-1.5-* or older models as
-  unsupported and redirect to one of the 2.5 options.
 - **RATIONALE**: Only LlmAgent requires model specification; workflow agents do not
 - **DEFAULT MODEL**: If user says "use default" or "proceed with default model", use: {default_model}
   * This is the actual model name, NOT the literal string "default"

contributing/samples/adk_agent_builder_assistant/sub_agents/__init__.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 """Sub-agents for Agent Builder Assistant."""
-from __future__ import annotations
 
 from .google_search_agent import create_google_search_agent
 from .url_context_agent import create_url_context_agent

contributing/samples/adk_agent_builder_assistant/sub_agents/google_search_agent.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 """Sub-agent for Google Search functionality."""
-from __future__ import annotations
 
 from google.adk.agents import LlmAgent
 from google.adk.tools import google_search

contributing/samples/adk_agent_builder_assistant/sub_agents/url_context_agent.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 """Sub-agent for URL context fetching functionality."""
-from __future__ import annotations
 
 from google.adk.agents import LlmAgent
 from google.adk.tools import url_context

contributing/samples/adk_agent_builder_assistant/tools/__init__.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 """Tools for Agent Builder Assistant."""
-from __future__ import annotations
 
 from .cleanup_unused_files import cleanup_unused_files
 from .delete_files import delete_files

contributing/samples/adk_agent_builder_assistant/tools/cleanup_unused_files.py

@@ -14,9 +14,10 @@
 
 """Cleanup unused files tool for Agent Builder Assistant."""
 
-from __future__ import annotations
-
 from typing import Any
+from typing import Dict
+from typing import List
+from typing import Optional
 
 from google.adk.tools.tool_context import ToolContext
 
@@ -25,11 +26,11 @@ from ..utils.resolve_root_directory import resolve_file_paths
 
 
 async def cleanup_unused_files(
-    used_files: list[str],
+    used_files: List[str],
     tool_context: ToolContext,
-    file_patterns: list[str] | None = None,
-    exclude_patterns: list[str] | None = None,
-) -> dict[str, Any]:
+    file_patterns: Optional[List[str]] = None,
+    exclude_patterns: Optional[List[str]] = None,
+) -> Dict[str, Any]:
   """Identify and optionally delete unused files in project directories.
 
   This tool helps clean up unused tool files when agent configurations change.

contributing/samples/adk_agent_builder_assistant/tools/delete_files.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 """File deletion tool for Agent Builder Assistant."""
-from __future__ import annotations
 
 from datetime import datetime
 from pathlib import Path

contributing/samples/adk_agent_builder_assistant/tools/explore_project.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 """Project explorer tool for analyzing structure and suggesting file paths."""
-from __future__ import annotations
 
 from pathlib import Path
 from typing import Any

contributing/samples/adk_agent_builder_assistant/tools/query_schema.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 """ADK AgentConfig schema query tool for dynamic schema information access."""
-from __future__ import annotations
 
 from typing import Any
 from typing import Dict

contributing/samples/adk_agent_builder_assistant/tools/read_config_files.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 """Configuration file reader tool for existing YAML configs."""
-from __future__ import annotations
 
 from pathlib import Path
 from typing import Any

contributing/samples/adk_agent_builder_assistant/tools/read_files.py

@@ -13,7 +13,6 @@
 # limitations under the License.
 
 """File reading tool for Agent Builder Assistant."""
-from __future__ import annotations
 
 from pathlib import Path
 from typing import Any