Harness Engineering

Observation

agent = model + harness

harness = everything around model

References

• https://openai.com/index/harness-engineering/

• https://martinfowler.com/articles/harness-engineering.html

• https://www.langchain.com/blog/improving-deep-agents-with-harness-engineering

• https://www.langchain.com/blog/the-anatomy-of-an-agent-harness

• https://developers.redhat.com/articles/2026/04/07/harness-engineering-structured-workflows-ai-assisted-development

• https://www.anthropic.com/engineering/effective-harnesses-for-long-running-agents

OpenSource Projects

• earendil-works/pi
• openai/codex
• zed-industries/zed