Harness engineering for coding agent users

BlogBirgitta BöckelerApr 2, 2026

AI Summary

Agent = Model + Harness. Böckeler's framework separates guides (feedforward controls that prevent problems) from sensors (feedback controls that catch them) as the path to trusting agent-generated code.

Original excerpt

Böckeler — who leads Thoughtworks' AI-assisted delivery practice — gives the harness its own engineering discipline. Her equation: Agent = Model + Harness. You don't control the model, so all your leverage is in the harness, and she splits that leverage into two control types.

Guides are feedforward: linting rules, conventions files, scoped permissions, and prompts that prevent classes of failure before the agent acts. Sensors are feedback: tests, typechecks, review gates, and runtime checks that catch what the guides missed. Trust in agent output is built by layering both, not by hoping the model got better.

Published on Martin Fowler's site — the traditional home of software-practice essays…

Frequently asked questions

What is "Harness engineering for coding agent users" about?

Agent = Model + Harness. Böckeler's framework separates guides (feedforward controls that prevent problems) from sensors (feedback controls that catch them) as the path to trusting agent-generated code.

Who wrote "Harness engineering for coding agent users"?

"Harness engineering for coding agent users" was written by Birgitta Böckeler. It is curated in the Agentic Engineering vault on Burn 451, which covers engineering with ai coding agents.

How can I read more content from Agentic Engineering?

The complete Agentic Engineering reading list is available at burn451.cloud/vault/agentic-engineering. Each article includes an AI-generated summary so you can decide what to read in seconds. Connect the Burn 451 MCP server to Claude or Cursor to query all Agentic Engineering articles as live AI context.

Can I use "Harness engineering for coding agent users" with Claude or Cursor?

Yes. Install the burn-mcp-server npm package and connect it to Claude Desktop, Claude Code, or Cursor. Once connected, your AI can search and reference this article and the full Agentic Engineering vault in real time — no manual copy-paste required.

15 more articles in this vault.

Import the full Agentic Engineering vault to Burn 451 and build your own knowledge base.

Content attributed to the original author (Birgitta Böckeler). Burn 451 curates publicly available writing as a reading index. For removal requests, contact @hawking520.