Updates
Change log for the Harness Engineering handbook
Last Updated
June 13, 2026
Operating Principles
- Evidence first: Record source publication dates and read dates.
- Interpretation first: Track how new information changes the handbook's view.
- Separate structure and interpretation: Distinguish editing changes from conceptual changes.
- Maintain a watchlist: Do not rely on one person's update memory.
External Sources to Watch
| Source | What to watch | Cadence |
|---|---|---|
| OpenAI Harness Engineering | repo structure, observability, cleanup view | Quarterly |
| OpenAI Agents SDK / API Changelog | model-native harness, sandbox, MCP, skills, open-source harness, Secure MCP | Monthly |
| OpenAI Codex docs | hooks, remote connection, approval, MCP/security, plugin operations | Monthly |
| Anthropic Harness / Managed Agents / auto mode | planner/evaluator/load-bearing, session-harness-sandbox split, permission classifier | Monthly |
| Anthropic domain agent templates | skills/connectors/subagents/approval-flow packaging | Quarterly |
| Toss harness article | organizational adoption, domain/HITL interpretation | Semiannual |
| gstack | roles, QA/ship flow, install patterns | Monthly |
| revfactory/harness | harness generation and team architecture | Monthly |
Change Log
2026-06-13
Structure Changes
- Review and refresh round: fixed a locale-leaking cross-read link in
index.mdx(bare/books/agent-orchestration-patterns→/ko/books/agent-orchestration-patterns, annotated as Korean) so it no longer 308-redirects out of the English edition. - Bumped
index.mdxupdatedAtto 2026-06-13.
Interpretation Changes
- None. No conceptual or interpretive change to the handbook in this round.
Affected Chapters
index.mdx
Evidence Links
- N/A (editorial/link-hygiene change only)
2026-05-23
Structure Changes
- Created English edition under
apps/handbook/content/books/en/harness-engineering. - Added 23 English MDX pages and
meta.json. - Added English home catalog override for
harness-engineering. - Reflected OpenAI Agents SDK, Codex remote/hooks, Secure MCP Tunnel, and OpenAI Developers plugin.
- Reflected Anthropic Managed Agents, Claude Code auto mode, and financial agents.
- Reflected latest gstack and revfactory/harness README interpretation from the Korean baseline update.
- Added verification and update appendix pages.
Interpretation Changes
- Previous view: a harness is a team work system made of repo structure, docs, evaluation, approval, and operations.
- Updated view: that remains true, but 2026 product changes show more harness elements becoming standard primitives: MCP, skills, sandbox, hooks, remote approvals, open-source harnesses, plugins, session logs, and permission classifiers.
- Additional view: Anthropic Managed Agents and auto mode move harness design beyond evaluation loops into durable session, stateless harness, sandbox/hands, credential boundary, and classifier policy design.
- Additional view: Anthropic financial agents and OpenAI Developers plugin show domain templates and provider setup becoming rollout surfaces.
Affected Chapters
index.mdxfoundations.mdxrepo-readable-systems.mdxfive-elements.mdxengineering-mechanics.mdxevaluation-loops.mdxcase-studies.mdxcase-openai.mdxcase-anthropic.mdxcase-toss.mdxcase-gstack.mdxcase-revfactory.mdxdomain-playbooks.mdxscenario-frontend-team.mdxscenario-platform-team.mdxscenario-payments-team.mdxscenario-ai-product-team.mdxmake-it-yours.mdxteam-rollout.mdxchecklist.mdxoperations.mdxverification.mdxupdates.mdxapps/handbook/lib/home-server.ts
Evidence Links
- https://openai.com/ko-KR/index/harness-engineering/
- https://openai.com/index/the-next-evolution-of-the-agents-sdk/
- https://openai.com/index/work-with-codex-from-anywhere/
- https://developers.openai.com/api/docs/changelog
- https://developers.openai.com/api/docs/guides/agents
- https://developers.openai.com/api/docs/guides/agents/sandboxes
- https://developers.openai.com/codex/hooks
- https://developers.openai.com/codex/remote-connections
- https://developers.openai.com/learn/developers-codex-plugin
- https://www.anthropic.com/engineering/harness-design-long-running-apps
- https://www.anthropic.com/engineering/claude-code-auto-mode
- https://code.claude.com/docs/en/permission-modes
- https://code.claude.com/docs/en/auto-mode-config
- https://www.anthropic.com/engineering/managed-agents
- https://platform.claude.com/docs/en/managed-agents/overview
- https://platform.claude.com/docs/en/managed-agents/mcp-connector
- https://www.anthropic.com/news/finance-agents
- https://toss.tech/article/harness-for-team-productivity
- https://github.com/garrytan/gstack
- https://github.com/revfactory/harness
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