/indicator — parallel TDD swarm for a new market indicator

Arguments: <data-source> (URL or short description) and <indicator-name>. Prerequisite: read .claude/skills/new-indicator/SKILL.md first — it defines the target pattern, the lockstep pins, and the CI gates. Every step below produces verifiable evidence before the next step starts.

Derive up front and state them: slug (route segment, short), service (kebab-case, used for scan_snapshots.service, service_health, and systemd unit names), Name (PascalCase for components), tab label (UPPERCASE, no em dashes), and the next free migration number (ls scripts/db/migrations | sort | tail -1).

Step 1 — Research subagent (blocking)

Spawn one research subagent (general-purpose; give it WebFetch/curl) to confirm, with evidence pasted back:

• Source: exact URL(s), transport (XML/JSON/CSV/XLSX), auth (must be none or an existing repo credential), and a captured sample saved to scripts/tests/fixtures/<name>_sample.<ext> (this becomes the pytest fixture).
• Schema: field names, units, date keying, history depth, how far back a backfill can go, and any splice/seam issues between historical regimes.
• Update cadence: when the source actually publishes (day of week/month, time, timezone) — this dictates the timer OnCalendar, MAX_AGE_MS, staleness windows, and what freshness copy is honest.
• Licensing: US-government/public-domain data is fine; otherwise confirm terms permit storage + display. Record verdict in the spec. Stop and ask the user if licensing is unclear.
• Data-source priority: note why IB/UW do not already serve this series (repo rule: IB → UW → Yahoo → scrape).

Reject the indicator here if the source needs browser impersonation, scraping behind auth, or has hostile terms.

Step 2 — Spec + failing tests (red)

Write docs/indicators/<slug>.md: signal definition and thresholds, source facts from Step 1, payload shape (scan_time, source_last_modified, current, series[]), migration DDL, API contract (missing object, cache headers, MAX_AGE reasoning), UI spec (strip cells, chart series/axes, presets, copy strings including tooltip), the freshness rail (the <NAME>_REFRESH constant that mirrors the timer's OnCalendar, the <FreshnessRail> mount under the strip with its two testIds, and which payload field feeds asOf), timer cadence, and the exact file checklist per the pattern skill. The countdown is not optional: an indicator with a timer always shows when its source is next sampled, and the spec must name the constant.

Then write the failing tests against the spec (implementation files do not exist yet):

• scripts/tests/test_<name>.py — parse the captured fixture, transforms, payload contract, migration schema pin, conditional-GET/heartbeat behavior, writer arity.
• web/tests/<name>-api.test.ts — dbFirstRead behavior + missing contract.
• web/tests/<name>-panel.test.tsx — loader/empty/strip/chart/chips + NaN guard.

Run all three suites and record the red output. Failing on import/missing-module is the expected red for greenfield files.

Step 3 — Three worktrees, parallel implementers

Partition by ownership so merges are near-disjoint:

Worktree branch	Owns	Its tests
ind/<slug>-ingestion	scripts/fetch_<name>.py, client, migration, scripts/db/writer.py additions, scripts/watchdog/services.py, cloud/services/radon-<name>.{service,timer}, setup-vps.sh array, cloud/tests/test_systemd_services.py	pytest scripts/tests/test_<name>.py + pytest cloud/tests -q
ind/<slug>-api	web/app/api/<name>/route.ts, web/lib/<name>.ts, web/lib/use<Name>.ts, web/lib/serviceHealthWindows.ts entry + its pin test update, web/lib/refreshSchedule.ts <NAME>_REFRESH constant + its web/tests/refresh-schedule.test.ts case (mirrors the timer the ingestion worktree writes; both copy the OnCalendar from the spec)	bunx vitest run --config vitest.config.ts web/tests/<name>-api.test.ts web/tests/service-health-windows.test.ts web/tests/refresh-schedule.test.ts
ind/<slug>-ui	web/components/<Name>Panel.tsx (with the <FreshnessRail> mount), RegimePanel.tsx registration (all four places), web/app/regime/<slug>/page.tsx, web/tests/regime-tab-routes.test.tsx update, web/e2e/<name>-tab.spec.ts	bunx vitest run --config vitest.config.ts web/tests/<name>-panel.test.tsx web/tests/regime-tab-routes.test.tsx

Mechanics:

git worktree add .claude/worktrees/<slug>-ingestion -b ind/<slug>-ingestion HEAD
# same for -api and -ui

Copy the spec + that worktree's failing tests into each worktree, then launch three implementer subagents in parallel, one per worktree. Each prompt must include: the worktree path (work ONLY there), the spec file, the reference implementation to copy (fetch_margin_debt.py / margin-debt/route.ts / MarginDebtPanel.tsx), its ownership list (touch nothing else), the exact test command, and the loop contract: run tests → fix → rerun until its suite passes, then commit on its branch (scoped git add of named files only). The UI implementer mocks the hook in unit tests, so it does not need the API worktree's files to go green; TypeScript integration is checked after merge.

Step 4 — Merge + full suite (integration green)

git worktree add .claude/worktrees/<slug>-merge -b ind/<slug> HEAD
cd .claude/worktrees/<slug>-merge
git merge --no-ff ind/<slug>-ingestion ind/<slug>-api ind/<slug>-ui   # or sequentially

Resolve any conflicts (should be none if ownership held), add the spec file, then run the FULL gates exactly as CI does, from the merge worktree root:

python -m pytest scripts/tests scripts/api/tests scripts/trade_blotter -q
python -m pytest cloud/tests -q
bun install --frozen-lockfile && (cd web && bun install --frozen-lockfile)
bunx vitest run --config vitest.config.ts
(cd web && npm run typecheck)

Fix integration failures here yourself (type mismatches across worktree seams, missed lockstep pins, coverage ratchet). Do not loosen a pin test to get green.

Step 5 — Live browser verification (honest freshness)

1. Run the real ingestion once against Turso (laptop writes direct-to-cloud) so the tab has production data: python scripts/fetch_<name>.py --json | head. Verify the rows in Turso (not the JSON file).
2. Start the dev server from the merge worktree (cd web && npx next dev -p 3100 or let Playwright's webServer do it with PLAYWRIGHT_PORT). Never kill 3000/8321/8765.
3. Run the Playwright spec, plus a screenshot pass: page.goto("/regime/<slug>") against the live API (no route mocks) → page.screenshot({ path: "docs/indicators/<slug>-tab.png", fullPage: false }).
4. Assert on the live page: the chart <svg> has stroked paths (real data, not the empty state); the header clock/SOURCE UPDATED cell shows the actual ingest/source timestamps; the freshness rail ([data-testid="<name>-freshness-rail"]) shows As of <data_date> and a ticking Next sample countdown whose target equals the next OnCalendar slot of cloud/services/radon-<name>.timer (compute it from the unit file, do not eyeball it); and no copy claims a cadence the backend does not meet — grep the new UI strings for Refresh|Updated|hourly|daily|5m and check each against the real timer OnCalendar. Screenshot both themes if the change touches theme tokens.

Step 6 — Ship and verify production

1. Bring the verified branch onto main: from the main worktree, git merge ind/<slug> (or cherry-pick the squashed commits). Stage nothing extra — operator WIP stays untouched; git status before committing. Commit style: feat(regime): <NAME> indicator - ingestion, API, chart tab (+ the Claude Code trailer). Do not commit while a deploy is in flight.
2. Push once. gh run watch (or poll gh run list --workflow=ci.yml --limit 1) to green — the deploy job runs in the same workflow.
3. Verify production: migration applied (schema_migrations has the new version), Turso has the snapshot + history rows, prod API returns the payload (expect the auth perimeter as anon), and load https://app.radon.run/regime/<slug> in a real browser session for a final screenshot.
4. Confirm the deploy installed and enabled the timer (systemctl list-timers radon-<name>.timer; the deploy log prints install-units: installed=2 when the manifest carried both hashes), then trigger one run (systemctl start radon-<name>.service as root) and check the service_health row.
5. Clean up: git worktree remove the four worktrees, delete the ind/* branches, update tasks/todo.md review section.

Deliverables to show the user: red test output (Step 2), per-worktree green (Step 3), full-suite green (Step 4), the tab screenshot with real data (Step 5), CI run URL + production evidence (Step 6).