The Four-Layer Agent Stack: When Your Framework Isn't Enough

Short summary

Production agents operate across four layers: models, harnesses, runtimes, and a control plane that orchestrates multi-runtime systems. Most frameworks handle the first three layers, but teams building at scale need a separate control plane to manage session persistence, access controls, cost tracking, and governance across different runtimes. This separation enables code reuse and prevents fragile systems.

• •Four-layer architecture: models → harnesses → runtimes → control plane
• •Frameworks solve orchestration; control planes solve governance and multi-runtime state management
• •Production teams building multi-runtime agents need durable session stores, credential vaults, cost attribution, and structured observability

Generated with AI, which can make mistakes.