# Notes — Kogen From the work # Notes Practical findings from building Kogen. - 31 October 2026 ## [Build your own harness](https://kogen.dev/notes/2026-10-31/build-your-own-harness/) Why we're building a harness around Kogen's workflow, what the newer Codex comparisons show, and which changes haven't helped. [Read the note](https://kogen.dev/notes/2026-10-31/build-your-own-harness/) - 30 October 2026 ## [Tuning macOS for development](https://kogen.dev/notes/2026-10-30/tuning-macos-for-development/) What I changed on my Mac after slow Kogen builds led me to Spotlight, fseventsd, XProtect and automatic Xcode updates. [Read the note](https://kogen.dev/notes/2026-10-30/tuning-macos-for-development/) - 30 October 2026 ## [Why I fork my ChatGPT conversations](https://kogen.dev/notes/2026-10-30/why-i-fork-my-chatgpt-conversations/) Organized project files already save me from repeating workflows. Forking a prepared conversation lets the next task reuse the reading too; caching was what led me to investigate it. [Read the note](https://kogen.dev/notes/2026-10-30/why-i-fork-my-chatgpt-conversations/) - 27 October 2026 ## [How much spec does an agent need?](https://kogen.dev/notes/2026-10-27/how-much-spec-does-an-agent-need/) What our benchmarks taught us about giving coding agents a useful target and checking what they build. [Read the note](https://kogen.dev/notes/2026-10-27/how-much-spec-does-an-agent-need/) - 26 October 2026 ## [Don't get locked in](https://kogen.dev/notes/2026-10-26/dont-get-locked-in/) I've moved between Claude and Codex. I want the skills and setup I build to move with me when a model, subscription or harness stops fitting my work. [Read the note](https://kogen.dev/notes/2026-10-26/dont-get-locked-in/) - 1 October 2026 ## [Jev this, Jev that](https://kogen.dev/notes/2026-10-01/jev-this-jev-that/) The boring Jev uses I've found in Kogen: reading an agent's notes and checking requirements before coding. [Read the note](https://kogen.dev/notes/2026-10-01/jev-this-jev-that/) - 22 September 2026 ## [Check what your agent actually receives](https://kogen.dev/notes/2026-09-22/check-what-your-agent-actually-receives/) In Optimum Codegen, 31 rules we had written for the build agents reached them as one. Here is what broke the delivery, why nothing caught it, and how to check your own setup. [Read the note](https://kogen.dev/notes/2026-09-22/check-what-your-agent-actually-receives/) - 21 September 2026 ## [Replacing Codex without replacing Kogen](https://kogen.dev/notes/2026-09-21/replacing-codex-without-replacing-kogen/) I want to try other coding agents without handing them Kogen's checks, review, history, and definition of finished. [Read the note](https://kogen.dev/notes/2026-09-21/replacing-codex-without-replacing-kogen/) - 20 September 2026 ## [I don't want AGENTS.md](https://kogen.dev/notes/2026-09-20/i-dont-want-agents-md/) One repository-wide instruction file cannot fit agents with different jobs, and sharing its filename does not standardize how tools interpret it. [Read the note](https://kogen.dev/notes/2026-09-20/i-dont-want-agents-md/) - 19 September 2026 ## [Make no mistakes](https://kogen.dev/notes/2026-09-19/make-no-mistakes/) Preventable mistakes enter an agent-led Build through ambiguity. Make the decisions explicit enough to inspect and check. [Read the note](https://kogen.dev/notes/2026-09-19/make-no-mistakes/) - 18 September 2026 ## [Making the offline check fast enough to keep running](https://kogen.dev/notes/2026-09-18/making-the-offline-check-fast-enough-to-keep-running/) A slow verification step gets deferred or skipped. Here's how Kogen kept its check fast without cutting what it verifies. [Read the note](https://kogen.dev/notes/2026-09-18/making-the-offline-check-fast-enough-to-keep-running/) - 17 September 2026 ## [The agent said it ran the checks](https://kogen.dev/notes/2026-09-17/the-agent-said-it-ran-the-checks/) A Stop hook makes declared checks part of finishing instead of trusting an agent to report that it ran them. [Read the note](https://kogen.dev/notes/2026-09-17/the-agent-said-it-ran-the-checks/) - 16 September 2026 ## [My Codex is not Kogen's Codex](https://kogen.dev/notes/2026-09-16/kogen-managed-codex-runtime/) Kogen pins a tested Codex version and runs it with its own settings and login, separate from mine. [Read the note](https://kogen.dev/notes/2026-09-16/kogen-managed-codex-runtime/) - 15 September 2026 ## [codex exec can exit 0 after failed checks](https://kogen.dev/notes/2026-09-15/codex-exec-can-exit-0-after-failed-checks/) Codex can exhaust its attempts to fix a failing check while the surrounding codex exec process still exits successfully. [Read the note](https://kogen.dev/notes/2026-09-15/codex-exec-can-exit-0-after-failed-checks/) - 14 September 2026 ## [Markdown for agents. HTML for humans.](https://kogen.dev/notes/2026-09-14/markdown-for-agents-html-for-humans/) The source stays Markdown. Astro templates turn it into a website, so I don't hand-write HTML on every report. [Read the note](https://kogen.dev/notes/2026-09-14/markdown-for-agents-html-for-humans/) - 13 September 2026 ## [You don’t need Astra](https://kogen.dev/notes/2026-09-13/you-dont-need-astra/) I tried cheaper models on the same Kogen build. They finished the job too. [Read the note](https://kogen.dev/notes/2026-09-13/you-dont-need-astra/) - 12 September 2026 ## [Don’t let the coding agent grade its own work](https://kogen.dev/notes/2026-09-12/dont-let-the-coding-agent-grade-its-own-work/) Why Kogen lets the Developer run focused tests but reserves final verification for automated machinery. [Read the note](https://kogen.dev/notes/2026-09-12/dont-let-the-coding-agent-grade-its-own-work/) - 11 September 2026 ## [How to turn off Codex terminal animations](https://kogen.dev/notes/2026-09-11/turn-off-codex-terminal-animations/) The setting for a calmer Codex terminal—and what a small startup comparison showed. [Read the note](https://kogen.dev/notes/2026-09-11/turn-off-codex-terminal-animations/) --- Canonical page: https://kogen.dev/notes