The Harness Engineering Handbook
The canonical, long-form corpus on harness engineering — chapters from definition and taxonomy to memory, evaluation, orchestration, security and governance. The single source of truth for the domain, consumable by humans and AI agents.
- 01HRN-001Foundations
Harness Engineering: Definition and Overview
Harness Engineering is the discipline of building reliable agentic systems for enterprise environments — the engineered scaffolding of memory, tools, orchestration, observability, evaluation, governance, and security that surrounds the model.
- 02HRN-002Foundations
A Brief History of Harness Engineering
How the field moved from prompt engineering to tool use to agents to harnesses, and why the engineered scaffolding around the model became its own discipline.
- 03HRN-003Foundations
The Harness Taxonomy
A structured taxonomy of the harness — memory, tools, planning, orchestration, observability, evaluation, governance, and security — naming each component, its responsibility, and how the parts compose into a reliable agentic system.
- 04HRN-004Foundations
Harness Engineering Principles
The core engineering principles of the harness — reliability over capability, determinism boundaries, observability-first, evidence-first, defense in depth, least authority, graceful degradation, and idempotent actuation — that hold across every component.
- 05HRN-005Memory
Memory in Agentic Systems
How the harness governs what the model sees and remembers — working, short-term, and long-term memory; the context window as a budget; retrieval, compression, and deliberate forgetting.
- 06HRN-006Observability
Observability for Agentic Systems
How to make a non-deterministic, multi-step agent inspectable — traces and spans, token and cost accounting, evaluation hooks, and deterministic replay — so the system can be debugged, measured, and trusted.
- 07HRN-007Evaluation
Evaluation of Agentic Systems
How to measure whether an agent is actually good and getting better — offline and online evaluation, golden sets, LLM-as-judge, regression suites, and task-completion metrics — turning agent development from craft into engineering.
- 08HRN-008Governance
Governance within the Harness
Governance is an engineered harness layer that enforces policy, approvals, and guardrails at runtime, turning enterprise AI obligations into executable controls that gate every agent action.
- 09HRN-009Planning
Planning and Goal Management
Planning and goal management is the harness layer that decomposes goals into executable plans, represents and tracks plan state, and replans under failure, making agent autonomy directed rather than reactive.
- 10HRN-010Orchestration
Orchestration
Orchestration is the harness layer that drives execution—single vs multi-agent topologies, supervisor/worker delegation, routing, state machines, and durable workflows—turning a plan into reliable, resumable action.
- 11HRN-011Security
Security for Agentic Systems
Security for agentic systems is the harness layer that defends against prompt injection, sandboxes tools and permissions, prevents data exfiltration, and enforces agent identity and least privilege across every action.
- 12HRN-012Case Studies
Case Studies in Harness Engineering
Three representative, anonymized composite case studies showing how harness layers—memory, planning, orchestration, governance, security, observability—combine end-to-end to make enterprise agents reliable.
- 13HRN-013Reference
Glossary
A canonical glossary of Harness Engineering and agentic-systems terminology—harness, agent, tool, orchestration, evaluation, span, RAG, MCP, guardrail, and more—with crisp, citable definitions.
- 14HRN-014Reference
Bibliography
A curated, themed reading list for Harness Engineering—agents and orchestration, evaluation, security, governance and standards, and protocols—covering foundational papers, industry writeups, and regulatory frameworks.