I’m the author of agent-contracts, a Python library that explores a contract-based approach to structuring LangGraph agents.

When building larger LangGraph-based systems, I kept running into the same issues: - node responsibilities becoming implicit - state dependencies spreading across the graph - routing logic getting harder to reason about - refactoring feeling increasingly risky

agent-contracts is an attempt to make these boundaries explicit. Each node declares a contract that describes: - which parts of the state it reads and writes - what external services it depends on - when it should run, using rule-based conditions with optional LLM hints

From these contracts, the LangGraph structure can be assembled in a more predictable and inspectable way.

This is still early-stage and experimental. I’m mainly interested in feedback on the design trade-offs and whether this mental model resonates with others building complex agent systems.