Mem0 FastAPI Integration Patterns

Purpose: Provide complete Mem0 integration templates, memory service patterns, user tracking implementations, and conversation persistence strategies for building FastAPI applications with intelligent AI memory.

Activation Triggers:

• Integrating Mem0 memory layer into FastAPI
• Building chat applications with conversation history
• Implementing user context and personalization
• Adding memory to AI agents
• Creating stateful AI interactions
• User preference management

Key Resources:

• templates/memory_service.py – Complete Mem0 service implementation
• templates/memory_middleware.py – Request-scoped memory middleware
• templates/memory_client.py – Mem0 client configuration
• templates/memory_routes.py – API routes for memory operations
• scripts/setup-mem0.sh – Mem0 installation and configuration
• scripts/test-memory.sh – Memory service testing utility
• examples/chat_with_memory.py – Complete chat implementation
• examples/user_preferences.py – User preference management

Core Mem0 Integration

1. Client Configuration

Template: templates/memory_client.py

Workflow:

from mem0 import Memory, AsyncMemory, MemoryClient
from mem0.configs.base import MemoryConfig

# Hosted Mem0 Platform
client = MemoryClient(api_key=settings.MEM0_API_KEY)

# Self-Hosted Configuration
config = MemoryConfig(
    vector_store={
        "provider": "qdrant",
        "config": {
            "host": settings.QDRANT_HOST,
            "port": settings.QDRANT_PORT,
            "api_key": settings.QDRANT_API_KEY
        }
    },
    llm={
        "provider": "openai",
        "config": {
            "model": "gpt-4",
            "api_key": settings.OPENAI_API_KEY
        }
    },
    embedder={
        "provider": "openai",
        "config": {
            "model": "text-embedding-3-small",
            "api_key": settings.OPENAI_API_KEY
        }
    }
)
memory = AsyncMemory(config)

2. Memory Service Pattern

Template: templates/memory_service.py

Key Operations:

class MemoryService:
    async def add_conversation(
        user_id: str,
        messages: List[Dict[str, str]],
        metadata: Optional[Dict] = None
    ) -> Dict

    async def search_memories(
        query: str,
        user_id: str,
        limit: int = 5
    ) -> List[Dict]

    async def get_user_summary(user_id: str) -> Dict

    async def add_user_preference(
        user_id: str,
        preference: str,
        category: str = "general"
    ) -> bool

Initialization:

@asynccontextmanager
async def lifespan(app: FastAPI):
    # Startup
    memory_service = MemoryService()
    app.state.memory_service = memory_service
    yield
    # Shutdown

Memory Patterns

1. Conversation Persistence

When to use: Chat applications, conversational AI

Template: templates/memory_service.py#add_conversation

async def add_conversation(
    self,
    user_id: str,
    messages: List[Dict[str, str]],
    metadata: Optional[Dict[str, Any]] = None
) -> Optional[Dict]:
    enhanced_metadata = {
        "timestamp": datetime.now().isoformat(),
        "conversation_type": "chat",
        **(metadata or {})
    }

    if self.client:
        result = self.client.add(
            messages=messages,
            user_id=user_id,
            metadata=enhanced_metadata
        )
    elif self.memory:
        result = await self.memory.add(
            messages=messages,
            user_id=user_id,
            metadata=enhanced_metadata
        )

    return result

Best for: Chat history, conversation context, multi-turn interactions

2. Semantic Memory Search

When to use: Context retrieval, relevant history lookup

Template: templates/memory_service.py#search_memories

async def search_memories(
    self,
    query: str,
    user_id: str,
    limit: int = 5,
    filters: Optional[Dict] = None
) -> List[Dict]:
    if self.client:
        result = self.client.search(
            query=query,
            user_id=user_id,
            limit=limit
        )
    elif self.memory:
        result = await self.memory.search(
            query=query,
            user_id=user_id,
            limit=limit
        )

    memories = result.get('results', [])
    return memories

Best for: Finding relevant past conversations, context-aware responses

3. User Preference Storage

When to use: Personalization, user settings, behavioral tracking

Template: templates/memory_service.py#add_user_preference

async def add_user_preference(
    self,
    user_id: str,
    preference: str,
    category: str = "general"
) -> bool:
    preference_message = {
        "role": "system",
        "content": f"User preference ({category}): {preference}"
    }

    metadata = {
        "type": "preference",
        "category": category,
        "timestamp": datetime.now().isoformat()
    }

    if self.client:
        self.client.add(
            messages=[preference_message],
            user_id=user_id,
            metadata=metadata
        )
    elif self.memory:
        await self.memory.add(
            messages=[preference_message],
            user_id=user_id,
            metadata=metadata
        )

    return True

Best for: User customization, learning user behavior, preference management

API Routes Integration

1. Memory Management Endpoints

Template: templates/memory_routes.py

from fastapi import APIRouter, Depends, BackgroundTasks
from app.api.deps import get_current_user, get_memory_service
from app.services.memory_service import MemoryService

router = APIRouter()

@router.post("/conversation")
async def add_conversation(
    request: ConversationRequest,
    background_tasks: BackgroundTasks,
    user_id: str = Depends(get_current_user),
    memory_service: MemoryService = Depends(get_memory_service)
):
    # Add to memory in background
    background_tasks.add_task(
        memory_service.add_conversation,
        user_id,
        request.messages,
        request.metadata
    )

    return {
        "status": "success",
        "message": "Conversation added to memory"
    }

@router.post("/search")
async def search_memories(
    request: SearchRequest,
    user_id: str = Depends(get_current_user),
    memory_service: MemoryService = Depends(get_memory_service)
):
    memories = await memory_service.search_memories(
        query=request.query,
        user_id=user_id,
        limit=request.limit
    )

    return {
        "query": request.query,
        "results": memories,
        "count": len(memories)
    }

@router.get("/summary")
async def get_memory_summary(
    user_id: str = Depends(get_current_user),
    memory_service: MemoryService = Depends(get_memory_service)
):
    summary = await memory_service.get_user_summary(user_id)
    return {"user_id": user_id, "summary": summary}

2. Request Models

Template: templates/memory_routes.py#models

from pydantic import BaseModel, Field
from typing import List, Dict, Optional, Any

class ConversationRequest(BaseModel):
    messages: List[Dict[str, str]] = Field(..., description="Conversation messages")
    session_id: Optional[str] = Field(None, description="Session identifier")
    metadata: Optional[Dict[str, Any]] = Field(None, description="Additional metadata")

class SearchRequest(BaseModel):
    query: str = Field(..., description="Search query")
    limit: int = Field(5, ge=1, le=20, description="Number of results")
    filters: Optional[Dict[str, Any]] = Field(None, description="Search filters")

class PreferenceRequest(BaseModel):
    preference: str = Field(..., description="User preference")
    category: str = Field("general", description="Preference category")

Background Task Integration

1. Async Memory Storage

Pattern:

from fastapi import BackgroundTasks

@router.post("/chat")
async def chat(
    request: ChatRequest,
    background_tasks: BackgroundTasks,
    memory_service: MemoryService = Depends(get_memory_service)
):
    # Generate AI response
    response = await ai_service.generate(request.message)

    # Store conversation in background
    background_tasks.add_task(
        memory_service.add_conversation,
        user_id=request.user_id,
        messages=[
            {"role": "user", "content": request.message},
            {"role": "assistant", "content": response}
        ]
    )

    return {"response": response}

Benefits:

• Non-blocking memory operations
• Faster response times
• Graceful failure handling

2. Batch Memory Updates

Pattern:

async def batch_update_memories(
    conversations: List[Conversation],
    memory_service: MemoryService
):
    tasks = [
        memory_service.add_conversation(
            user_id=conv.user_id,
            messages=conv.messages
        )
        for conv in conversations
    ]

    results = await asyncio.gather(*tasks, return_exceptions=True)
    return results

Dependency Injection Pattern

1. Memory Service Dependency

Template: templates/memory_middleware.py#deps

from fastapi import Request

def get_memory_service(request: Request) -> MemoryService:
    """Get memory service from app state"""
    return request.app.state.memory_service

# Usage in routes
@router.get("/")
async def endpoint(
    memory_service: MemoryService = Depends(get_memory_service)
):
    memories = await memory_service.search_memories(...)
    return memories

2. User Context Injection

Pattern:

async def get_user_context(
    user_id: str = Depends(get_current_user),
    memory_service: MemoryService = Depends(get_memory_service)
) -> Dict[str, Any]:
    """Get enriched user context from memory"""
    summary = await memory_service.get_user_summary(user_id)
    return {
        "user_id": user_id,
        "preferences": summary.get("user_preferences", []),
        "total_conversations": summary.get("total_memories", 0)
    }

# Usage
@router.post("/personalized-response")
async def personalized(
    request: QueryRequest,
    context: Dict = Depends(get_user_context)
):
    # Use context for personalized AI response
    pass

Implementation Workflow

Step 1: Setup Mem0

# Install and configure Mem0
./scripts/setup-mem0.sh

Creates:

• Mem0 configuration file
• Environment variable template
• Vector database setup (if self-hosted)

Step 2: Configure Memory Service

Decision tree:

• Hosted Mem0: Use MemoryClient with API key (simple, managed)
• Self-Hosted: Use AsyncMemory with config (full control, cost-effective)
• Hybrid: Support both with fallback logic

Step 3: Integrate with FastAPI Lifespan

Pattern:

from contextlib import asynccontextmanager

@asynccontextmanager
async def lifespan(app: FastAPI):
    # Startup
    memory_service = MemoryService()
    app.state.memory_service = memory_service
    logger.info("Memory service initialized")

    yield

    # Shutdown
    logger.info("Shutting down memory service")

Step 4: Add Memory Routes

Use template: templates/memory_routes.py

Register:

app.include_router(
    memory.router,
    prefix=f"{settings.API_V1_STR}/memory",
    tags=["memory"]
)

Step 5: Test Memory Service

# Run memory service tests
./scripts/test-memory.sh

Tests:

• Add conversation
• Search memories
• Get user summary
• Add preferences
• Error handling

Optimization Strategies

1. Memory Caching

Pattern:

from functools import lru_cache
from datetime import datetime, timedelta

class CachedMemoryService(MemoryService):
    def __init__(self):
        super().__init__()
        self._cache = {}
        self._cache_ttl = timedelta(minutes=5)

    async def search_memories(self, query: str, user_id: str, limit: int = 5):
        cache_key = f"{user_id}:{query}:{limit}"

        if cache_key in self._cache:
            cached_time, cached_result = self._cache[cache_key]
            if datetime.now() - cached_time < self._cache_ttl:
                return cached_result

        result = await super().search_memories(query, user_id, limit)
        self._cache[cache_key] = (datetime.now(), result)
        return result

2. Batch Operations

Pattern:

async def batch_add_conversations(
    conversations: List[Tuple[str, List[Dict]]],
    memory_service: MemoryService
):
    """Add multiple conversations efficiently"""
    tasks = [
        memory_service.add_conversation(user_id, messages)
        for user_id, messages in conversations
    ]
    return await asyncio.gather(*tasks)

3. Error Handling with Fallback

Pattern:

async def resilient_memory_add(
    user_id: str,
    messages: List[Dict],
    memory_service: MemoryService
):
    try:
        return await memory_service.add_conversation(user_id, messages)
    except Exception as e:
        logger.error(f"Memory add failed: {e}")
        # Fallback: Queue for retry or log to backup storage
        await backup_storage.save(user_id, messages)
        return None

Production Best Practices

1. Environment Configuration

Template: .env variables

# Hosted Mem0
MEM0_API_KEY=your_mem0_api_key

# Self-Hosted Configuration
QDRANT_HOST=localhost
QDRANT_PORT=6333
QDRANT_API_KEY=your_qdrant_key
OPENAI_API_KEY=your_openai_key

# Memory Settings
MEMORY_CACHE_TTL_SECONDS=300
MEMORY_SEARCH_LIMIT_DEFAULT=5
MEMORY_SEARCH_LIMIT_MAX=20

2. Monitoring and Logging

Pattern:

import logging
from datetime import datetime

logger = logging.getLogger(__name__)

class MonitoredMemoryService(MemoryService):
    async def add_conversation(self, user_id: str, messages: List[Dict], metadata=None):
        start_time = datetime.now()
        try:
            result = await super().add_conversation(user_id, messages, metadata)
            latency = (datetime.now() - start_time).total_seconds()
            logger.info(f"Memory add success: user={user_id}, latency={latency}s")
            return result
        except Exception as e:
            logger.error(f"Memory add failed: user={user_id}, error={e}")
            raise

3. Rate Limiting

Pattern:

from fastapi import HTTPException
from slowapi import Limiter
from slowapi.util import get_remote_address

limiter = Limiter(key_func=get_remote_address)

@router.post("/search")
@limiter.limit("10/minute")
async def search_memories(request: Request, ...):
    # Rate-limited memory search
    pass

Common Memory Patterns

1. Chat with Memory

Example: examples/chat_with_memory.py

Complete chat implementation with conversation history and context retrieval

Features:

• Automatic conversation storage
• Context-aware responses
• Session management
• Memory search integration

2. User Preference Management

Example: examples/user_preferences.py

User preference tracking and personalization

Features:

• Preference categorization
• Preference retrieval
• Behavioral learning
• Personalized AI responses

3. Multi-User Memory Isolation

Pattern:

async def get_user_memories_isolated(
    user_id: str,
    memory_service: MemoryService
):
    """Ensure memory isolation between users"""
    # All memory operations scoped to user_id
    memories = await memory_service.search_memories(
        query="...",
        user_id=user_id  # Always scoped
    )
    return memories

Vector Database Support

Supported Vector Databases

1. Qdrant (Recommended for Self-Hosted)

vector_store={
    "provider": "qdrant",
    "config": {
        "host": "localhost",
        "port": 6333,
        "api_key": settings.QDRANT_API_KEY
    }
}

2. Pinecone (Fully Managed)

vector_store={
    "provider": "pinecone",
    "config": {
        "api_key": settings.PINECONE_API_KEY,
        "environment": "us-west1-gcp"
    }
}

3. Chroma (Local Development)

vector_store={
    "provider": "chroma",
    "config": {
        "host": "localhost",
        "port": 8000
    }
}

Resources

Scripts:

• setup-mem0.sh – Install and configure Mem0
• test-memory.sh – Test memory service functionality

Templates:

• memory_service.py – Complete MemoryService implementation
• memory_client.py – Mem0 client configuration
• memory_middleware.py – Middleware and dependencies
• memory_routes.py – FastAPI routes for memory operations

Examples:

• chat_with_memory.py – Complete chat with memory
• user_preferences.py – User preference management
• memory_analytics.py – Memory usage analytics

Supported Configurations: Hosted Mem0, Self-Hosted (Qdrant, Pinecone, Chroma) FastAPI Version: 0.100+ Mem0 Version: 0.1.0+ Python Version: 3.9+

Best Practice: Start with hosted Mem0 for simplicity, migrate to self-hosted for cost optimization