#gstack development

#Commands

bun install          # install dependencies
bun test             # run free tests (browse + snapshot + skill validation)
bun run test:evals   # run paid evals: LLM judge + E2E (diff-based, ~$4/run max)
bun run test:evals:all  # run ALL paid evals regardless of diff
bun run test:gate    # run gate-tier tests only (CI default, blocks merge)
bun run test:periodic  # run periodic-tier tests only (weekly cron / manual)
bun run test:e2e     # run E2E tests only (diff-based, ~$3.85/run max)
bun run test:e2e:all # run ALL E2E tests regardless of diff
bun run eval:select  # show which tests would run based on current diff
bun run dev <cmd>    # run CLI in dev mode, e.g. bun run dev goto https://example.com
bun run build        # gen docs + compile binaries
bun run gen:skill-docs  # regenerate SKILL.md files from templates
bun run skill:check  # health dashboard for all skills
bun run dev:skill    # watch mode: auto-regen + validate on change
bun run eval:list    # list all eval runs from ~/.gstack-dev/evals/
bun run eval:compare # compare two eval runs (auto-picks most recent)
bun run eval:summary # aggregate stats across all eval runs

test:evals requires ANTHROPIC_API_KEY. Codex E2E tests (test/codex-e2e.test.ts) use Codex's own auth from ~/.codex/ config — no OPENAI_API_KEY env var needed. E2E tests stream progress in real-time (tool-by-tool via --output-format stream-json --verbose). Results are persisted to ~/.gstack-dev/evals/ with auto-comparison against the previous run.

Diff-based test selection: test:evals and test:e2e auto-select tests based on git diff against the base branch. Each test declares its file dependencies in test/helpers/touchfiles.ts. Changes to global touchfiles (session-runner, eval-store, touchfiles.ts itself) trigger all tests. Use EVALS_ALL=1 or the :all script variants to force all tests. Run eval:select to preview which tests would run.

Two-tier system: Tests are classified as gate or periodic in E2E_TIERS (in test/helpers/touchfiles.ts). CI runs only gate tests (EVALS_TIER=gate); periodic tests run weekly via cron or manually. Use EVALS_TIER=gate or EVALS_TIER=periodic to filter. When adding new E2E tests, classify them:

1. Safety guardrail or deterministic functional test? -> gate
2. Quality benchmark, Opus model test, or non-deterministic? -> periodic
3. Requires external service (Codex, Gemini)? -> periodic

#Testing

bun test             # run before every commit — free, <2s
bun run test:evals   # run before shipping — paid, diff-based (~$4/run max)

bun test runs skill validation, gen-skill-docs quality checks, and browse integration tests. bun run test:evals runs LLM-judge quality evals and E2E tests via claude -p. Both must pass before creating a PR.

#Project structure

gstack/
├── browse/          # Headless browser CLI (Playwright)
│   ├── src/         # CLI + server + commands
│   │   ├── commands.ts  # Command registry (single source of truth)
│   │   └── snapshot.ts  # SNAPSHOT_FLAGS metadata array
│   ├── test/        # Integration tests + fixtures
│   └── dist/        # Compiled binary
├── scripts/         # Build + DX tooling
│   ├── gen-skill-docs.ts  # Template → SKILL.md generator
│   ├── resolvers/   # Template resolver modules (preamble, design, review, etc.)
│   ├── skill-check.ts     # Health dashboard
│   └── dev-skill.ts       # Watch mode
├── test/            # Skill validation + eval tests
│   ├── helpers/     # skill-parser.ts, session-runner.ts, llm-judge.ts, eval-store.ts
│   ├── fixtures/    # Ground truth JSON, planted-bug fixtures, eval baselines
│   ├── skill-validation.test.ts  # Tier 1: static validation (free, <1s)
│   ├── gen-skill-docs.test.ts    # Tier 1: generator quality (free, <1s)
│   ├── skill-llm-eval.test.ts   # Tier 3: LLM-as-judge (~$0.15/run)
│   └── skill-e2e-*.test.ts       # Tier 2: E2E via claude -p (~$3.85/run, split by category)
├── qa-only/         # /qa-only skill (report-only QA, no fixes)
├── plan-design-review/  # /plan-design-review skill (report-only design audit)
├── design-review/    # /design-review skill (design audit + fix loop)
├── ship/            # Ship workflow skill
├── review/          # PR review skill
├── plan-ceo-review/ # /plan-ceo-review skill
├── plan-eng-review/ # /plan-eng-review skill
├── autoplan/        # /autoplan skill (auto-review pipeline: CEO → design → eng)
├── benchmark/       # /benchmark skill (performance regression detection)
├── canary/          # /canary skill (post-deploy monitoring loop)
├── codex/           # /codex skill (multi-AI second opinion via OpenAI Codex CLI)
├── land-and-deploy/ # /land-and-deploy skill (merge → deploy → canary verify)
├── office-hours/    # /office-hours skill (YC Office Hours — startup diagnostic + builder brainstorm)
├── investigate/     # /investigate skill (systematic root-cause debugging)
├── retro/           # Retrospective skill (includes /retro global cross-project mode)
├── bin/             # CLI utilities (gstack-repo-mode, gstack-slug, gstack-config, etc.)
├── document-release/ # /document-release skill (post-ship doc updates)
├── cso/             # /cso skill (OWASP Top 10 + STRIDE security audit)
├── design-consultation/ # /design-consultation skill (design system from scratch)
├── design-shotgun/  # /design-shotgun skill (visual design exploration)
├── connect-chrome/  # /connect-chrome skill (headed Chrome with side panel)
├── design/          # Design binary CLI (GPT Image API)
│   ├── src/         # CLI + commands (generate, variants, compare, serve, etc.)
│   ├── test/        # Integration tests
│   └── dist/        # Compiled binary
├── extension/       # Chrome extension (side panel + activity feed + CSS inspector)
├── lib/             # Shared libraries (worktree.ts)
├── docs/designs/    # Design documents
├── setup-deploy/    # /setup-deploy skill (one-time deploy config)
├── .github/         # CI workflows + Docker image
│   ├── workflows/   # evals.yml (E2E on Ubicloud), skill-docs.yml, actionlint.yml
│   └── docker/      # Dockerfile.ci (pre-baked toolchain + Playwright/Chromium)
├── setup            # One-time setup: build binary + symlink skills
├── SKILL.md         # Generated from SKILL.md.tmpl (don't edit directly)
├── SKILL.md.tmpl    # Template: edit this, run gen:skill-docs
├── ETHOS.md         # Builder philosophy (Boil the Lake, Search Before Building)
└── package.json     # Build scripts for browse

#SKILL.md workflow

SKILL.md files are generated from .tmpl templates. To update docs:

1. Edit the .tmpl file (e.g. SKILL.md.tmpl or browse/SKILL.md.tmpl)
2. Run bun run gen:skill-docs (or bun run build which does it automatically)
3. Commit both the .tmpl and generated .md files

To add a new browse command: add it to browse/src/commands.ts and rebuild. To add a snapshot flag: add it to SNAPSHOT_FLAGS in browse/src/snapshot.ts and rebuild.

Merge conflicts on SKILL.md files: NEVER resolve conflicts on generated SKILL.md files by accepting either side. Instead: (1) resolve conflicts on the .tmpl templates and scripts/gen-skill-docs.ts (the sources of truth), (2) run bun run gen:skill-docs to regenerate all SKILL.md files, (3) stage the regenerated files. Accepting one side's generated output silently drops the other side's template changes.

#Platform-agnostic design

Skills must NEVER hardcode framework-specific commands, file patterns, or directory structures. Instead:

1. Read CLAUDE.md for project-specific config (test commands, eval commands, etc.)
2. If missing, AskUserQuestion — let the user tell you or let gstack search the repo
3. Persist the answer to CLAUDE.md so we never have to ask again

This applies to test commands, eval commands, deploy commands, and any other project-specific behavior. The project owns its config; gstack reads it.

#Writing SKILL templates

SKILL.md.tmpl files are prompt templates read by Claude, not bash scripts. Each bash code block runs in a separate shell — variables do not persist between blocks.

Rules:

• Use natural language for logic and state. Don't use shell variables to pass state between code blocks. Instead, tell Claude what to remember and reference it in prose (e.g., "the base branch detected in Step 0").
• Don't hardcode branch names. Detect main/master/etc dynamically via gh pr view or gh repo view. Use {{BASE_BRANCH_DETECT}} for PR-targeting skills. Use "the base branch" in prose, <base> in code block placeholders.
• Keep bash blocks self-contained. Each code block should work independently. If a block needs context from a previous step, restate it in the prose above.
• Express conditionals as English. Instead of nested if/elif/else in bash, write numbered decision steps: "1. If X, do Y. 2. Otherwise, do Z."

#Browser interaction

When you need to interact with a browser (QA, dogfooding, cookie setup), use the /browse skill or run the browse binary directly via $B <command>. NEVER use mcp__claude-in-chrome__* tools — they are slow, unreliable, and not what this project uses.

#Vendored symlink awareness

When developing gstack, .claude/skills/gstack may be a symlink back to this working directory (gitignored). This means skill changes are live immediately — great for rapid iteration, risky during big refactors where half-written skills could break other Claude Code sessions using gstack concurrently.

Check once per session: Run ls -la .claude/skills/gstack to see if it's a symlink or a real copy. If it's a symlink to your working directory, be aware that:

• Template changes + bun run gen:skill-docs immediately affect all gstack invocations
• Breaking changes to SKILL.md.tmpl files can break concurrent gstack sessions
• During large refactors, remove the symlink (rm .claude/skills/gstack) so the global install at ~/.claude/skills/gstack/ is used instead

Prefix setting: Skill symlinks use either short names (qa -> gstack/qa) or namespaced (gstack-qa -> gstack/qa), controlled by skill_prefix in ~/.gstack/config.yaml. When vendoring into a project, run ./setup after symlinking to create the per-skill symlinks with your preferred naming. Pass --no-prefix or --prefix to skip the interactive prompt.

For plan reviews: When reviewing plans that modify skill templates or the gen-skill-docs pipeline, consider whether the changes should be tested in isolation before going live (especially if the user is actively using gstack in other windows).

#Compiled binaries — NEVER commit browse/dist/ or design/dist/

The browse/dist/ and design/dist/ directories contain compiled Bun binaries (browse, find-browse, design, ~58MB each). These are Mach-O arm64 only — they do NOT work on Linux, Windows, or Intel Macs. The ./setup script already builds from source for every platform, so the checked-in binaries are redundant. They are tracked by git due to a historical mistake and should eventually be removed with git rm --cached.

NEVER stage or commit these files. They show up as modified in git status because they're tracked despite .gitignore — ignore them. When staging files, always use specific filenames (git add file1 file2) — never git add . or git add -A, which will accidentally include the binaries.

#Commit style

Always bisect commits. Every commit should be a single logical change. When you've made multiple changes (e.g., a rename + a rewrite + new tests), split them into separate commits before pushing. Each commit should be independently understandable and revertable.

Examples of good bisection:

• Rename/move separate from behavior changes
• Test infrastructure (touchfiles, helpers) separate from test implementations
• Template changes separate from generated file regeneration
• Mechanical refactors separate from new features

When the user says "bisect commit" or "bisect and push," split staged/unstaged changes into logical commits and push.

#Community PR guardrails

When reviewing or merging community PRs, always AskUserQuestion before accepting any commit that:

1. Touches ETHOS.md — this file is Garry's personal builder philosophy. No edits from external contributors or AI agents, period.
2. Removes or softens promotional material — YC references, founder perspective, and product voice are intentional. PRs that frame these as "unnecessary" or "too promotional" must be rejected.
3. Changes Garry's voice — the tone, humor, directness, and perspective in skill templates, CHANGELOG, and docs are not generic. PRs that rewrite voice to be more "neutral" or "professional" must be rejected.

Even if the agent strongly believes a change improves the project, these three categories require explicit user approval via AskUserQuestion. No exceptions. No auto-merging. No "I'll just clean this up."

#CHANGELOG + VERSION style

VERSION and CHANGELOG are branch-scoped. Every feature branch that ships gets its own version bump and CHANGELOG entry. The entry describes what THIS branch adds — not what was already on main.

When to write the CHANGELOG entry:

• At /ship time (Step 5), not during development or mid-branch.
• The entry covers ALL commits on this branch vs the base branch.
• Never fold new work into an existing CHANGELOG entry from a prior version that already landed on main. If main has v0.10.0.0 and your branch adds features, bump to v0.10.1.0 with a new entry — don't edit the v0.10.0.0 entry.

Key questions before writing:

1. What branch am I on? What did THIS branch change?
2. Is the base branch version already released? (If yes, bump and create new entry.)
3. Does an existing entry on this branch already cover earlier work? (If yes, replace it with one unified entry for the final version.)

Merging main does NOT mean adopting main's version. When you merge origin/main into a feature branch, main may bring new CHANGELOG entries and a higher VERSION. Your branch still needs its OWN version bump on top. If main is at v0.13.8.0 and your branch adds features, bump to v0.13.9.0 with a new entry. Never jam your changes into an entry that already landed on main. Your entry goes on top because your branch lands next.

After merging main, always check:

• Does CHANGELOG have your branch's own entry separate from main's entries?
• Is VERSION higher than main's VERSION?
• Is your entry the topmost entry in CHANGELOG (above main's latest)? If any answer is no, fix it before continuing.

After any CHANGELOG edit that moves, adds, or removes entries, immediately run grep "^## \[" CHANGELOG.md and verify the full version sequence is contiguous with no gaps or duplicates before committing. If a version is missing, the edit broke something. Fix it before moving on.

CHANGELOG.md is for users, not contributors. Write it like product release notes:

• Lead with what the user can now do that they couldn't before. Sell the feature.
• Use plain language, not implementation details. "You can now..." not "Refactored the..."
• Never mention TODOS.md, internal tracking, eval infrastructure, or contributor-facing details. These are invisible to users and meaningless to them.
• Put contributor/internal changes in a separate "For contributors" section at the bottom.
• Every entry should make someone think "oh nice, I want to try that."
• No jargon: say "every question now tells you which project and branch you're in" not "AskUserQuestion format standardized across skill templates via preamble resolver."

#AI effort compression

When estimating or discussing effort, always show both human-team and CC+gstack time:

Completeness is cheap. Don't recommend shortcuts when the complete implementation is a "lake" (achievable) not an "ocean" (multi-quarter migration). See the Completeness Principle in the skill preamble for the full philosophy.

#Search before building

Before designing any solution that involves concurrency, unfamiliar patterns, infrastructure, or anything where the runtime/framework might have a built-in:

1. Search for "{runtime} {thing} built-in"
2. Search for "{thing} best practice {current year}"
3. Check official runtime/framework docs

Three layers of knowledge: tried-and-true (Layer 1), new-and-popular (Layer 2), first-principles (Layer 3). Prize Layer 3 above all. See ETHOS.md for the full builder philosophy.

#Local plans

Contributors can store long-range vision docs and design documents in ~/.gstack-dev/plans/. These are local-only (not checked in). When reviewing TODOS.md, check plans/ for candidates that may be ready to promote to TODOs or implement.

#E2E eval failure blame protocol

When an E2E eval fails during /ship or any other workflow, never claim "not related to our changes" without proving it. These systems have invisible couplings — a preamble text change affects agent behavior, a new helper changes timing, a regenerated SKILL.md shifts prompt context.

Required before attributing a failure to "pre-existing":

1. Run the same eval on main (or base branch) and show it fails there too
2. If it passes on main but fails on the branch — it IS your change. Trace the blame.
3. If you can't run on main, say "unverified — may or may not be related" and flag it as a risk in the PR body

"Pre-existing" without receipts is a lazy claim. Prove it or don't say it.

#Long-running tasks: don't give up

When running evals, E2E tests, or any long-running background task, poll until completion. Use sleep 180 && echo "ready" + TaskOutput in a loop every 3 minutes. Never switch to blocking mode and give up when the poll times out. Never say "I'll be notified when it completes" and stop checking — keep the loop going until the task finishes or the user tells you to stop.

The full E2E suite can take 30-45 minutes. That's 10-15 polling cycles. Do all of them. Report progress at each check (which tests passed, which are running, any failures so far). The user wants to see the run complete, not a promise that you'll check later.

#E2E test fixtures: extract, don't copy

NEVER copy a full SKILL.md file into an E2E test fixture. SKILL.md files are 1500-2000 lines. When claude -p reads a file that large, context bloat causes timeouts, flaky turn limits, and tests that take 5-10x longer than necessary.

Instead, extract only the section the test actually needs:

// BAD — agent reads 1900 lines, burns tokens on irrelevant sections
fs.copyFileSync(path.join(ROOT, 'ship', 'SKILL.md'), path.join(dir, 'ship-SKILL.md'));

// GOOD — agent reads ~60 lines, finishes in 38s instead of timing out
const full = fs.readFileSync(path.join(ROOT, 'ship', 'SKILL.md'), 'utf-8');
const start = full.indexOf('## Review Readiness Dashboard');
const end = full.indexOf('\n---\n', start);
fs.writeFileSync(path.join(dir, 'ship-SKILL.md'), full.slice(start, end > start ? end : undefined));

Also when running targeted E2E tests to debug failures:

• Run in foreground (bun test ...), not background with & and tee
• Never pkill running eval processes and restart — you lose results and waste money
• One clean run beats three killed-and-restarted runs

#Deploying to the active skill

The active skill lives at ~/.claude/skills/gstack/. After making changes:

1. Push your branch
2. Fetch and reset in the skill directory: cd ~/.claude/skills/gstack && git fetch origin && git reset --hard origin/main
3. Rebuild: cd ~/.claude/skills/gstack && bun run build

Or copy the binaries directly:

• cp browse/dist/browse ~/.claude/skills/gstack/browse/dist/browse
• cp design/dist/design ~/.claude/skills/gstack/design/dist/design