Google ADK: Gemini Models with MCP Support

The Google ADK backend uses Google’s Agent Development Kit (google-adk package) with Gemini models. It provides native MCP support and custom tool bridging.

Overview

  • Status: Beta
  • Provider support: Google (Gemini models), LiteLLM
  • Built-in tools: google_search, code_execution
  • MCP support: Yes (native via McpToolset — stdio, SSE, HTTP transports)
  • Session management: InMemoryRunner with per-session state

Configuration

Terminal window
export POCKETPAW_AGENT_BACKEND="google_adk"
export POCKETPAW_GOOGLE_API_KEY="..."

The backend also reads GOOGLE_API_KEY from the environment.

Backend-Specific Settings

SettingEnv VariableDefaultDescription
google_adk_providerPOCKETPAW_GOOGLE_ADK_PROVIDERgoogleProvider: google or litellm
google_adk_modelPOCKETPAW_GOOGLE_ADK_MODEL"" (auto)Gemini model to use
google_adk_max_turnsPOCKETPAW_GOOGLE_ADK_MAX_TURNS0 (unlimited)Max tool-use turns per query

Using with LiteLLM

LiteLLM support lets you use non-Gemini models with Google ADK’s tooling and MCP integration:

Terminal window
export POCKETPAW_AGENT_BACKEND="google_adk"
export POCKETPAW_GOOGLE_ADK_PROVIDER="litellm"
export POCKETPAW_LITELLM_API_BASE="http://localhost:4000"
export POCKETPAW_LITELLM_MODEL="openai/gpt-4o"

Built-in Tools

ADK ToolPolicy Mapping
google_searchbrowser
code_executionshell

PocketPaw’s custom tools are wrapped as ADK FunctionTool objects via the build_adk_function_tools() bridge in tool_bridge.py. This uses signature introspection to convert PocketPaw tool definitions into ADK-compatible functions.

MCP Integration

Google ADK has native MCP support via McpToolset. PocketPaw loads configured MCP servers and passes them to the ADK agent:

  • stdio transport for local MCP servers
  • SSE transport for HTTP-based MCP servers
  • HTTP transport for REST-based MCP servers

MCP tools are subject to the same tool policy system as other tools.

How It Works

  1. PocketPaw creates a LlmAgent with the system prompt, tools, and MCP servers
  2. An InMemoryRunner manages session state
  3. Messages are sent via the runner’s async interface
  4. The ADK handles multi-turn tool calling with Gemini
  5. Responses stream back as AgentEvent objects

Installation

Terminal window
pip install pocketpaw[google-adk]

This installs google-adk>=1.0.0 as an optional dependency.

Info

Replaces Gemini CLI: This backend replaced the earlier gemini_cli backend. If your config still uses gemini_cli, PocketPaw will automatically redirect to google_adk.

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Last updated: April 29, 2026
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