Skip to content

The method

Harness engineering is what makes AI reliable.

A discipline documented by engineers at martinfowler.com, OpenAI, Anthropic, and Red Hat. VibeManager is the first consumer product built entirely on its principles: the harness is the context, method, memory, and gates around the model.

14.4%

Raw agent, end-to-end tasks

78.2%

Humans, same tasks

When CMU researchers benchmarked an unharnessed GPT-4 agent on realistic multi-step web tasks, it finished 14.41% of them end-to-end. Humans managed 78.24%. Models have improved since, but the gap that remains is exactly what a harness exists to close: not capability, but reliability across steps.

Zhou et al., “WebArena: A Realistic Web Environment for Building Autonomous Agents”, ICLR 2024.

The literature

We didn't invent the idea. We built the product on it.

Four engineering organizations independently documented the same conclusion across 2025–2026: the harness around the model decides whether AI output can be trusted.

martinfowler.com

Harness engineering for coding agent users

Birgitta Böckeler · April 2026

“The term harness has emerged as a shorthand to mean everything in an AI agent except the model itself.” Guides plus feedback sensors let agents self-correct before work reaches a human.

Read the source

OpenAI

Harness engineering: leveraging Codex in an agent-first world

Ryan Lopopolo · February 2026

An OpenAI team shipped ~1M lines of production code agent-first by investing in the harness: docs as a system of record, enforced invariants, feedback loops. “Humans steer. Agents execute.”

Read the source

Anthropic

Effective harnesses for long-running agents

Anthropic Engineering · November 2025

How to design harnesses that let agents work reliably across sessions: initialization, progress files, and checkpoints so state survives beyond a single context window.

Read the source

Red Hat

Harness engineering: structured workflows for AI-assisted development

Marco Rizzi, Red Hat Developer · April 2026

“The more you constrain the solution space, the more predictable the output becomes.” AI writes better code when you design the environment it works in.

Read the source
The method

A team of specialists. Explicit handoffs. No context bleeding.

Six roles, each seeing only what its phase needs. The analyst never guesses at architecture; the builder never re-litigates scope. No agent sees more than it should; no context bleeds between phases.

AnalystProduct ManagerDesignerArchitectLeadBuilder
Raw AI · tries its bestHarnessed · ships
Same AI. The difference is the harness, context, method, memory, and a gate on every rail.
The gates

Gates. Nothing passes a broken one.

Each gate is a checkpoint: the work must exist, parse, and carry the right structure before the line moves. A broken gate stops the line, it never advances on a guess.

  1. Clarify
  2. Plan
  3. Foundation
  4. Ready
  5. Ship
The moat

Every artifact lives in a graph.

The Artifact Dependency Graph is a genuinely new data model for software development: every brief, plan, screen, and story is a node that knows what depends on it. Change one requirement; everything downstream is flagged. Memory, made structural.

The user never sees the harness. They see the result: software that ships.

See the proof

Run your idea on the harness.

Start free in your browser and watch every gate yourself.

No card to start · $10 of usage on us.