zep-adk 0.2.1

Google ADK integration for Zep

Zep Google ADK Integration

A memory integration package that enables Google ADK agents to leverage Zep's long-term memory platform for persistent conversation storage and context-aware responses.

Installation

pip install zep-adk

Quick Start

Define one agent, shared across all users. Per-user identity is passed via ADK session state.

import os
from google.adk.agents import Agent
from google.adk.runners import Runner
from google.adk.sessions import InMemorySessionService
from zep_cloud.client import AsyncZep
from zep_adk import ZepContextTool, create_after_model_callback

# Initialize Zep client
zep = AsyncZep(api_key=os.getenv("ZEP_API_KEY"))

# One shared agent definition
agent = Agent(
    name="my_agent",
    model="gemini-2.5-flash",
    instruction="You are a helpful assistant with long-term memory.",
    tools=[ZepContextTool(zep_client=zep)],
    after_model_callback=create_after_model_callback(zep_client=zep),
)

session_service = InMemorySessionService()
runner = Runner(agent=agent, app_name="my_app", session_service=session_service)

# Per-user session: user_id → Zep user, session_id → Zep thread
await session_service.create_session(
    app_name="my_app",
    user_id="user_123",          # automatically used as Zep user ID
    session_id="session_abc",    # automatically used as Zep thread ID
    state={
        "zep_first_name": "Jane",
        "zep_last_name": "Smith",
        "zep_email": "[e-mail]",  # optional
    },
)

Session State Keys

Identity is resolved at runtime from ADK session state and session metadata. The ADK user_id is used as the Zep user ID and the session_id is used as the Zep thread ID -- both automatically, no state keys needed.

Set these optional keys when creating a session to enrich the Zep user profile:

Key	Required	Default	Description
zep_first_name	Recommended	"Anonymous"	User's first name. Zep uses this to anchor the user's identity node in the knowledge graph.
zep_last_name	Optional	"User"	User's last name.
zep_email	Optional	None	User's email address.
zep_user_id	Optional	ADK user_id	Override the Zep user ID if it differs from the ADK user ID.
zep_thread_id	Optional	ADK session_id	Override the Zep thread ID if it differs from the ADK session ID.

How It Works

The integration uses two components that work together to give your ADK agent persistent memory:

ZepContextTool

A BaseTool subclass that hooks into ADK's process_llm_request() lifecycle method (the same pattern ADK's own PreloadMemoryTool uses). On every LLM turn it:

1. Extracts the user's latest message from the invocation context.
2. Resolves the user's Zep identity from session state.
3. Persists the message to Zep via thread.add_messages(return_context=True) -- storing the message and retrieving relevant context in a single API call.
4. Injects the returned context (facts, relationships, prior knowledge) into the LLM's system instructions.

The tool is never called by the model directly; it modifies the outgoing LLM request before it is sent.

create_after_model_callback

A factory function that returns an after_model_callback for persisting assistant responses to Zep. This ensures both sides of the conversation are stored in Zep's memory. The callback also resolves the thread ID from session state at runtime.

Both components include per-thread message deduplication to handle ADK's tool-use cycles, where the framework may call hooks multiple times per turn.

Adding Zep to an Existing Agent

If you already have an ADK agent serving all users, adding Zep memory requires only three changes -- no restructuring needed:

1. Add ZepContextTool to your agent's tools list:

from zep_adk import ZepContextTool

agent = Agent(
    name="my_existing_agent",
    model="gemini-2.5-flash",
    instruction="...",
    tools=[your_existing_tool, ZepContextTool(zep_client=zep)],
    after_model_callback=create_after_model_callback(zep_client=zep),
)

2. Include the user's name in session state when creating sessions (you're already creating sessions -- just add the keys):

await session_service.create_session(
    app_name="my_app",
    user_id=user_id,          # automatically used as Zep user ID
    session_id=session_id,    # automatically used as Zep thread ID
    state={
        **your_existing_state,
        "zep_first_name": first_name,
        "zep_last_name": last_name,
    },
)

3. That's it. No factory function, no per-session agent instances.

Features

• Shared-agent architecture -- one Agent definition serves all users
• Session-state-driven identity -- per-user configuration via ADK's standard mechanism
• Single round-trip -- persist messages and retrieve context in one API call
• Lazy resource creation -- Zep user and thread are created on first use
• Per-thread deduplication -- prevents double-persistence during tool-use cycles
• Graceful error handling -- Zep API failures are logged but never crash the agent
• Context injection -- Zep's knowledge graph context is injected as system instructions
• Per-user setup hook -- on_user_created callback for configuring ontology, instructions, and summaries per user
• On-demand graph search -- ZepGraphSearchTool lets the model actively search the knowledge graph
• Configurable graph search -- pin parameters at construction or let the model choose

Configuration

Environment Variables

# Required
export ZEP_API_KEY="your-zep-api-key"
export GOOGLE_API_KEY="your-google-api-key"

Constructor Parameters

ZepContextTool

Parameter	Type	Required	Default	Description
zep_client	AsyncZep	Yes	--	Initialised Zep async client
context_builder	ContextBuilder	No	None	Custom async callable for context retrieval
ignore_roles	list[str]	No	None	Roles to exclude from graph ingestion
on_user_created	UserSetupHook	No	None	Async callback fired once after a new Zep user is created. Use for per-user ontology, custom instructions, or user summary instructions.

create_after_model_callback

Parameter	Type	Required	Default	Description
zep_client	AsyncZep	Yes	--	Initialised Zep async client
assistant_name	str	No	"Assistant"	Display name for the assistant in Zep
ignore_roles	list[str]	No	None	Roles to exclude from graph ingestion

ZepGraphSearchTool

Parameter	Type	Required	Default	Description
zep_client	AsyncZep	Yes	--	Initialised Zep async client
graph_id	str	No	None	Fixed graph ID for shared-graph search
name	str	No	"zep_graph_search"	Tool name visible to the model
description	str	No	(default)	Tool description visible to the model
search_filters	dict	No	None	Zep search filters (constructor-only)
bfs_origin_node_uuids	list[str]	No	None	BFS seed node UUIDs (constructor-only)
**pinned	any	No	--	Pin any search param: scope, reranker, limit, mmr_lambda, center_node_uuid

Examples

See the examples/ directory for complete working examples:

• basic_agent.py -- Full example with fact seeding and memory recall using the shared-agent pattern

Development

Setup

git clone https://github.com/getzep/zep.git
cd integrations/adk/python
make install

Commands

make format      # Format code with ruff
make lint        # Run linting checks
make type-check  # Run mypy type checking
make test        # Run test suite
make all         # Run all checks
make pre-commit  # Development workflow with auto-fixes
make ci          # Strict CI checks

Requirements

• Python 3.11+
• zep-cloud>=3.23.0
• google-adk>=1.0.0

Support

• Zep Documentation
• Google ADK Documentation
• GitHub Issues

License

Apache 2.0 - see LICENSE for details.

Contributing

Contributions are welcome! Please see our Contributing Guide for details.