Customer CLI Input
        │
        ▼
┌─────────────────────┐
│   LangGraph Agent   │  ← ReAct pattern, Claude Haiku (Anthropic API)
│   (crm_agent.py)    │
└──────────┬──────────┘
           │ MCP protocol — stdio transport
           │ Runtime tool discovery via get_tools()
           ▼
┌─────────────────────┐
│    MCP Server       │  ← FastMCP, Python
│    (server.py)      │
│                     │
│  get_customer_      │  ← queries CustomerAccounts table
│  account()          │
│                     │
│  get_open_          │  ← queries SupportTickets table
│  tickets()          │
└──────────┬──────────┘
           │ boto3
           ▼
┌─────────────────────┐
│   AWS DynamoDB      │  ← eu-west-1
│                     │
│ GalaxyTelecom_      │
│ CustomerAccounts    │
│                     │
│ GalaxyTelecom_      │
│ SupportTickets      │
└─────────────────────┘

@server.tool()
def get_customer_account(customer_id: str) -> str:
    """
    Retrieve a Galaxy Telecom customer account from DynamoDB.
    Returns account details including plan, status, and balance due.
    """
    ...

@server.tool()
def get_open_tickets(customer_id: str) -> str:
    """
    Retrieve all open support tickets for a Galaxy Telecom customer.
    Returns a list of tickets with issue type, description, status and priority.
    """
    ...

Customer ID : C001
Message     : Hi, I wanted to check on my account and see if there are any issues.

[MCP] Tools discovered: ['get_customer_account', 'get_open_tickets']

Response: Hi John, I can see your account is overdue with a balance of £47.50.
You have 2 open tickets — a billing query (T001, medium priority) and
broadband dropouts (T002, high priority, in progress with Technical Support)...

Customer ID : C002
Message     : I have been having some signal issues at home, can you help?

Response: Hello Sarah! I can see you're on our EliteMax plan with no balance due.
You've already raised ticket T003 regarding weak 5G signal — an engineer
visit has been requested, marked medium priority...

Customer ID : 99
Message     : I have been having some signal issues at home, can you help?

Response: I'm unable to locate a Galaxy Telecom account associated with
Customer ID 99. The ID may have been entered incorrectly...

langgraph-mcp-aws-dynamodb-agent/
├── agent/
│   ├── __init__.py
│   └── crm_agent.py        # LangGraph ReAct agent — connects to MCP server
├── dynamo/
│   ├── __init__.py
│   └── seed_data.py        # Creates DynamoDB tables and seeds mock CRM data
├── mcp_server/
│   ├── __init__.py
│   └── server.py           # MCP server — exposes CRM tools backed by DynamoDB
├── main.py                 # Interactive CLI entry point
├── requirements.txt
├── .env.example            # Environment variable template
└── .gitignore

# Clone the repository
git clone https://github.com/gayatrianne/langgraph-mcp-aws-dynamodb-agent.git
cd langgraph-mcp-aws-dynamodb-agent

# Create and activate virtual environment
python -m venv venv
venv\Scripts\activate        # Windows
source venv/bin/activate     # macOS/Linux

# Install dependencies
pip install -r requirements.txt

# Configure environment variables
cp .env.example .env
# Edit .env and add your Anthropic API key

# Anthropic
ANTHROPIC_API_KEY=your_key_here

# AWS — credentials come from AWS CLI profile (aws configure)
AWS_REGION=eu-west-1

# DynamoDB table names
CUSTOMER_TABLE=GalaxyTelecom_CustomerAccounts
TICKETS_TABLE=GalaxyTelecom_SupportTickets

# LLM Configuration
CLAUDE_MODEL=claude-haiku-4-5-20251001
CLAUDE_TEMPERATURE=0.3

python dynamo/seed_data.py

python main.py