Harness engineering
Practice of changing the instructions, tools and checks around an AI agent in response to its mistakes, intended to make later runs less likely to repeat them.
In plain language
When an agent gets something wrong, change the setup that let it happen.
In a sentence
- The team used harness engineering to add a check after the coding agent repeatedly omitted a required field.
- Their harness engineering work put the build instructions where the agent reads them before each task.
Usage note
The account below names the practice without claiming to have coined the phrase, so it does not settle who did.
Harness engineering
An origin source records where a term or practice came from. Mitchell Hashimoto described the practice under that name in February 2026, writing that he did not know of an accepted industry term for it.
Not to be confused with
- Test harness
A test harness is the stubs and drivers needed to execute a test suite. Improving an agent's operating setup can involve tests, instructions and tools beyond the test runner.
Why it matters
Repairing one answer leaves the setup unchanged. Changing the setup can help later runs detect the same mistake.
See also
- Coding agent
AI agent configured for software tasks that inspects a repository, changes code and runs development tools in an attempt to resolve a requested issue.
- Test harness
Collection of supporting code, namely stubs and drivers, needed to execute a test suite, which forms part of a test environment rather than the whole of it.
- Audit dimension
Category of previously observed failure that Orbyt checks across proposed changes, with a defined subject and a result that may report or block.
Cite this term.
CC BY 4.0, attribution required.
Orbyt Labs, Harness engineering (AI Glossary), Nov 6, 2026. https://
Orbyt Labs Glossaries (Nov 6, 2026), https://
Last updated .