What it does The MCP Buyer-Seller-Broker is a decentralized AI agent system that enables agents to autonomously negotiate, transact, and make decisions on behalf of humans. Agents represent buyers, sellers, and brokers—each with their own goals, preferences, and memory. Using Model Context Protocol (MCP) and Claude 3.5 Sonnet via AWS Bedrock, the agents share context, evaluate options, and collaboratively reach agreements. Our initial use case is ticket brokering, but the architecture supports any transactional flow.
🛠️ How we built it We used a fully serverless AWS stack:
Amazon API Gateway: Entry point for agent communication
AWS Lambda (Python 3.13): Agent logic, prompting, memory fetch
DynamoDB: AgentRegistry and ProductRegistry
Amazon S3: Storage for FAISS vector index (semantic memory)
FAISS (via Lambda Layer): Vector search for memory/context retrieval
Titan Embeddings v2: Embeds agent profiles and offers
Claude 3.5 Sonnet via Bedrock: Core LLM for decision-making
Jupyter Notebook: For local agent simulation and development
Agents follow structured prompting via MCP, which defines shared context schemas and interaction flow between agent types.
🧗 Challenges we ran into Cold start limits for Lambda with FAISS
Prompt stability with Claude across agent types
Ensuring negotiation flows don’t loop or stall
Memory vectorization and retrieval accuracy
Designing MCP as both a communication protocol and logic layer
Orchestrating multi-agent coordination in real time
🏆 Accomplishments that we're proud of Created a functional MCP agent bridge with real memory and vector search
Enabled Claude to simulate multi-agent negotiation with persistent context
Built a full buyer-seller-broker chain using only AWS serverless resources
Maintained modularity so new agent roles can be added with minimal effort
Reduced cost and complexity by leveraging Bedrock and Titan embeddings
📚 What we learned Structured prompts with embedded memory yield far better results
Serverless design scales beautifully—but requires thoughtful cold start management
Claude 3.5 Sonnet is strong at reasoning, but semantic clarity is critical
Vector search is invaluable for maintaining long-term memory across agents
Defining interaction protocols (MCP) creates reusable, interpretable systems
🔮 What's next for MCP Buyer-Seller-Broker Support multi-party negotiations (e.g., auctions, bundles, add-ons)
Add agent personality traits and risk profiles
Move toward real-time chat interface with human input
Integrate event-driven workflows via AWS EventBridge or Step Functions
Expand to new verticals like real estate, freelance hiring, and logistics
Publish a developer SDK for third-party AI agent integration
Built With
- amazon-web-services
- claude
- faiss
- lambda
- titan
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