Cross-vendor · Autonomous · CI-gated

The workshop where software builds itself.

ystack is a small, autonomous coding team. You set the north star; yshifu breaks it into PR-sized pieces and debates each with a cross-vendor reviewer, then a coder builds them while a second reviewer checks every change. You stay above the diff.

Being forged in private. A public release is on the way.
YouNorth star
yshifu · ClaudePlan
CodexDebate
Coder · ClaudeBuild
CodexReview
CI greenMerge
one continuous loop — it returns, it never ends

Two cross-vendor checks — Codex debates the plan, then reviews the code. Revision rounds cap at ~3; genuinely stuck work escalates to a human.

The team

Four roles, two altitudes. You talk to one.

You set the north star and talk only to yshifu, the manager. At each altitude, Claude proposes or builds and a different vendor — Codex — checks the work. The reviewers are read-only: they can object, never merge.

Direction the issue is the message bus
Manager Claude

yshifu

Your single interface. Breaks the north star into PR-sized issues — one concern each — and drives the loop end to end. Files issues, never code.

Plan reviewer Codex · OpenAI

The Debater

Debates each proposal against the north star before any code is written. Proactive work ships only on consensus — veto-only, defaulting to drop.

Delivery the pull request is the message bus
Coder Claude

The Builder

A fresh subagent per issue. Branches, builds, and opens the pull request — then revises it against the review until it converges.

Code reviewer Codex · OpenAI

The Reviewer

The cross-vendor second opinion on every change. Comments only — it can object, but it can never merge. CI is the hard gate behind it.

Claude and Codex never talk directly. The issue and the pull request are the message bus.

Why it's built this way

Autonomy that rests on ground truth, not hope.

01

Cross-vendor by design

Claude proposes and builds; Codex checks — at both altitudes, the plan and the code. Different architectures mean decorrelated blind spots: a reviewer that's valuable because it's another mind, not a second copy.

02

You stay above the diff

Judgment lives at the direction, not the change. You approve a north star; the team pursues it. You stop reviewing every diff.

03

CI is the hard gate

Nothing merges unless the tests are green. Ground truth comes first; the diverse reviewer is the second line, not the first.

04

Safety rails, not trust falls

The reviewer is read-only. Merges are gated and SHA-pinned. Rounds are capped. When the team is stuck, it escalates to a human.

In practice

How one change ships, end to end.

The loop isn't a diagram — it's the path every change takes. Here's a single iteration, from your direction to a merged, SHA-pinned diff.

  1. You · Direction

    You set the direction

    You approve a north star, or hand yshifu a one-liner. That's the whole interface — you stay above the diff from here on.

  2. yshifu · ClaudeCodex debates

    yshifu drafts a PR-sized issue

    yshifu breaks the work into one concern — roughly 300–400 lines. For proactive work, Codex debates the plan first and it proceeds only on consensus: veto-only, defaulting to drop. User-directed work is gated by your approval of the drafted spec.

  3. Coder · Claude

    A fresh coder builds it

    A new subagent picks up the issue, branches off an up-to-date base, implements the one concern, and opens the pull request.

  4. Codex · OpenAICodex reviews

    Codex reviews the diff

    The cross-vendor second opinion reads the code — comments only, never merges. The coder revises across capped rounds (~3); genuinely stuck work escalates to a human rather than grinding on.

  5. CI green · Merge

    CI is the hard gate; yshifu merges

    Nothing lands until the tests are green. yshifu merges only a clean, low-risk PR — SHA-pinned to the exact head Codex reviewed.

This page was built this way.

What you get

A team you can adopt — and one that can rebuild itself.

ystack isn't a bespoke script wired to one project. It's a product you point at your own repo, and a system captured entirely as files.

Outcome 01

Adopt the team

Point it at your own repo, set your conventions in a CLAUDE.md, and give it a north star. The prompts and tooling are parameterized — no hardcoded names — so what you get is an autonomous, cross-vendor coding team, not a one-off script.

Outcome 02

It can rebuild itself

The whole team is captured as files — prompts, scripts, and a restore-critical manifest that CI enforces on every change. It's a full backup: if the live setup is ever lost, you reconstruct the team straight from the repo.

Who it's for Solo developers and small teams who want to stay above the diff — keeping cross-vendor review and CI as hard guardrails, instead of hand-reviewing every change.

The workshop

ystack is being forged.

The workshop is taking shape. We're still deciding how it ships — check back, and it'll be here.