# How Kenton Varda actually uses coding agents

Cloudflare Workers, Cap'n Proto

**If you take one thing:** `plans/ in the repo`, checked in for code review. the agent-written plan is committed beside the code, so reviewers and later prompts work from the same document.

- **Agent:** Claude Code (cli) ([source, 2025-08-03](https://github.com/cloudflare/cloudflare-os/commit/895dd83e4ef3bfd640612f4ec8e4f59bebacc3f7))
- **Agent:** Cloudflare OS (web) ([source, 2026-08-28](https://github.com/cloudflare/cloudflare-os/pull/384))
- **Model:** Fable 5.1 ([source, 2026-09-14](https://github.com/cloudflare/cloudflare-os/pull/492))
- **Model:** Sol ([source, 2026-09-14](https://github.com/cloudflare/cloudflare-os/pull/492))
- **Review:** Sol reviews every commit; he reviews the plan and the code ([source, 2026-08-19](https://github.com/cloudflare/cloudflare-os/pull/275))
- **Harness:** Plan first, review it, then implement; one PR split into reviewable commits ([source, 2026-08-06](https://news.ycombinator.com/item?id=49191519))
- **Rules file:** AGENTS.md (181 lines, now team-shared), began as his CLAUDE.md ([source, 2025-08-10](https://github.com/cloudflare/cloudflare-os/commit/cc0bb85a6a511e670684474e315ee97b470efbf1))
- **Skills:** write-gatekeeper ([source, 2026-03-21](https://github.com/cloudflare/cloudflare-os/tree/dd8b5c9e28593cf2595dec4a9862e1b645e5ca61/.agents/skills/write-gatekeeper))
- **MCP servers:** playwright ([source, 2025-08-10](https://github.com/cloudflare/cloudflare-os/commit/5c0e1a44882113853724a18347998f1076356499))

## In their words

> Generated by Claude Code based on my instructions.

> This pull request was created entirely by my Cloudflare OS agent: https://github.com/kentonv/lanparty/pull/10

> Plan written by Fable 5.1, reviewed by me and Astra (Astra's review was mostly stupid, though). Each code commit written by Fable 5.1, reviewed by Sol.

> Each code commit written by Fable 5.1, reviewed by Sol.

> The code was almost entirely written by Fable with Sol acting as code reviewer at each step. I am pretty happy with the code I've reviewed but need to spend a bit more time looking before un-drafting this.


Archetype (our label): Purist. Newest source: 2026-09-14.
Card: https://www.prehistoriq.com/stacks/kentonv/ · Data: https://github.com/prehistoriq/stacks/blob/main/data/stacks/kentonv.json