AI and MCP

What is contract-driven AI development?

Contract-driven AI development (C-DAD) is a methodology where every tool an AI agent can invoke is governed by a machine-readable contract. The contract defines what the tool accepts, what it returns, and what behavioral constraints hold. The runtime enforces these at call time — not just at documentation time.

The problem it solves

When you give an AI agent access to tools, two things tend to go wrong. First, the agent builds wrong assumptions about what a tool does because the only spec is a natural language description. Second, you have no audit trail — when an agent does something unexpected, you cannot reconstruct exactly what it called and what it got back.

C-DAD solves both. The contract is machine-readable, so the agent gets a precise spec at discovery time. The runtime produces a trace artifact on every call, so every agent action is reconstructable.

What it looks like in practice

  • You write a contract for each business capability: input schema, output schema, preconditions, postconditions
  • You compile the implementation to WASM and register it alongside the contract
  • The agent discovers capabilities via MCP and gets the full schema for each one
  • The runtime enforces contracts on every agent call — invalid inputs are rejected before execution
  • Every call produces a trace artifact you can inspect, store, or alert on

Relation to design-by-contract

C-DAD applies the decades-old design-by-contract idea to AI agent pipelines. Bertrand Meyer's original insight was that software components should specify their obligations and guarantees formally. C-DAD extends that to the interface between a non-deterministic agent and deterministic business logic.

The C-DAD whitepaper

Enrico Piovesan published the C-DAD whitepaper as part of the Traverse project. It covers the methodology in depth — why contracts are necessary for agentic systems, how to structure them, and how Traverse implements enforcement. The whitepaper builds on the Universal Microservices Architecture (UMA) foundation described in the UMA book.