Market Pulse

A zero-config, browser-only dashboard showing eight financial instruments organized into four categories:

Prices for the four dollar-priced instruments (Bitcoin, gold, copper, Brent) can be shown in USD, CAD or INR — see Currency. A collapsed Today's read row under the header carries a short daily note, written by Claude from the day's figures, that puts the numbers in context — see Today's read.

No backend, no API keys, no auth. Deploys as static files to Netlify, Vercel, GitHub Pages, or Cloudflare Pages.

npm install
npm run dev      # http://localhost:5173
npm run build    # static bundle in dist/
npm run preview  # serve dist/
npm test         # unit tests for the CI scripts (Node's built-in runner)

Bitcoin is fetched directly from Coinbase's public spot endpoint (CORS-enabled) and refreshes every 8 seconds. The 24-hour reference price and sparkline for BTC come from CoinGecko, refreshed every 5 minutes.

Copper, Brent crude, Treasury yields (10Y/30Y), gold, USD/JPY, and the US Dollar Index come from Yahoo Finance's unofficial chart endpoint. Yahoo does not send Access-Control-Allow-Origin, so the request is proxied. The data is 15-minute delayed, so each symbol is polled every 5 minutes and the seven fetches are staggered ~400ms apart to stay under the free proxies' per-IP burst limits.

The header carries a USD · CAD · INR picker. It converts exactly the four instruments that are dollar amounts — Bitcoin, gold, copper and Brent — including their absolute change and the unit in their sublabel ($/oz → C$/oz). The other four tiles never convert: the 10Y and 30Y yields are percentages, the Dollar Index is a unitless index, and USD/JPY is itself a USD pair. Percent changes are identical in every currency, by definition.

The rate comes from Yahoo (CAD=X / INR=X) on the same 5-minute poll and through the same proxy rotation as the tiles, and only the selected currency's rate is fetched — USD is the base, so the default view issues no extra request. Conversion happens at render time: quotes are fetched and cached in USD, so switching currency never disturbs a poll loop or a stored last-good value.

Because that FX quote is itself 15-minute delayed, the footer names the rate actually applied (FX USD/CAD 1.3764 · UPD 14:32:08) — Bitcoin's spot price is live, but its converted value is only as fresh as the rate. If the rate hasn't arrived yet, or can't be fetched at all, the tiles show honest USD with a $ prefix and the footer says so rather than displaying a number the app can't back up. The choice persists in localStorage under mp-currency.

Under the header sits a one-line TODAY'S READ — <headline> ▾ row. Click it and you get two to four short paragraphs explaining what moved and how today compares with the past week, month and year, a strip of week / month / year-to-date moves for the eight tiles, and an AI-generated … not investment advice footer. It's collapsed by default so the dashboard still fits one screen; the choice persists in localStorage under mp-commentary-open. Notes are written per trading session, so on a weekend, a holiday, or a weekday before that day's note has landed, the row is labelled LAST READ · SEP 4 rather than calling Friday's read today's.

The note is a static file (public/data/commentary.json) written once a day by the CI job described under Daily snapshot log and commentary — the browser fetches it from the site's own origin. No key, no LLM call, nothing dynamic on the client. If the file isn't there (a fresh clone, a fork that hasn't enabled the job) the row simply doesn't appear. If it's more than four days old — Friday's note is current through a Monday holiday — the row says no commentary since <date> rather than passing off an old note as current.

A self-hosted copy — npm run dev, or a dist/ you serve yourself — only carries the note it was last pulled or built with, so whenever that local note isn't today's the dashboard also checks the copy the job commits to this repo's main (raw.githubusercontent.com sends CORS headers, so no proxy is involved) and shows whichever is newer, re-checking hourly. A missing local file still means no row: a fork that has never run the job won't display this repo's note. If you fork and run your own job, point COMMENTARY_REMOTE_URL in src/lib/commentary.ts at your repo, or set it to "" to stay strictly on your own origin.

Yahoo sends no CORS headers, so its requests must be proxied. The primary proxy is a self-hosted Cloudflare Worker (source and one-command deploy in worker/): it forwards only Yahoo's v8 chart endpoint, adds CORS headers, and caches responses at the edge for 2 minutes so all visitors share one Yahoo fetch per symbol. The free Workers tier (100k requests/day) is far more than this dashboard can use.

The deployed worker is origin-locked: it answers requests from satusd.com and from localhost (so npm run dev of any clone gets the fast path), and 403s everything else. A deployed fork therefore falls through to the public proxies until you deploy your own worker (below) — edit ALLOWED_ORIGINS in worker/index.js to your own domain.

The free public proxies remain in the rotation as fallback, so a fresh clone works without deploying anything — but don't count on them alone: corsproxy.io's free tier now serves only localhost/dev origins (it 403s in production as of mid-2026), api.allorigins.win/raw is valid but often slow (10–20s) or 5xx, and api.codetabs.com gets throttled by Yahoo's edge. Resilience comes from layering:

• Rotation — each request tries the proxies in order (worker first), validating the JSON inside the loop so a proxy that answers 200 with junk (an HTML interstitial, "Edge: Too Many Requests") falls through to the next instead of poisoning the tile.
• Per-attempt timeout — each proxy attempt is capped at 8s (AbortController) so one stalled proxy can't hold up the tick.
• Retry — if a full rotation fails, the fetcher pauses ~700ms and runs the rotation once more, which clears most transient single-tick failures.

Deploying your own worker (recommended for forks): cd worker && npx wrangler deploy (needs a free Cloudflare account), then replace the first entry of the PROXIES array in src/lib/fetchers.ts with your worker's URL plus /?url=. The rotation lives in fetchYahooOnce; the retry wrapper is fetchYahoo.

The worker also accepts non-browser requests (no Origin) that carry an X-MP-Token header matching its MP_PROXY_TOKEN secret — used only by the daily snapshot job below. npx wrangler secret put MP_PROXY_TOKEN enables it; leaving the secret unset turns the path off.

Independently of the live dashboard, a GitHub Action (.github/workflows/daily-commentary.yml) runs scripts/snapshot.mjs on weekdays after the US close and appends one JSON line per exchange session — every instrument's settled close (the daily bar, not the last trade), previous close and timestamp, plus BTC spot and its 24h reference — to public/data/snapshots.jsonl, then commits it and triggers the satusd.com deploy. The line is dated by the session it describes, not by the clock: GitHub delays scheduled runs on public repos by hours, not minutes, and a run that lands after the futures reopen or past midnight would otherwise record a live print under the wrong day (#8). Re-running for the same session replaces that line rather than duplicating it; a weekend or holiday run just re-records Friday's. The dashboard's own fetching (and the 30-day sparkline) is untouched; this log is the raw material for the daily commentary of issue #6.

Run it by hand with node scripts/snapshot.mjs (add --history-out file.json to also dump a year of daily closes per symbol, BTC included). node scripts/stats.mjs --history file.json then turns that dump plus the log into a stats pack — per-instrument 1d/1w/1m/3m/YTD moves, 52-week range position, realized-volatility regime, and cross-asset reads (30Y–10Y curve, BTC in gold ounces, copper/gold, the dollar's own move). Those are the only facts the commentary is allowed to cite; scripts/trends.mjs is the pure, tested module behind it (SPEC §3.7).

The last step, scripts/commentary.mjs, hands that stats pack to Claude Fable 5.1 and writes a short house-view note — a thesis headline and two or three paragraphs on what the configuration of yields, curve, dollar, commodities and gold/BTC says about the US economy, argued from the interplay between them — to public/data/commentary.json (latest) and public/data/commentary.jsonl (every day). The prompt keeps it honest: every figure comes from the pack with its horizon named, general macro logic is allowed but no outside news or events, interpretation of the present but no forecasts or advice, and an explicit "markets were closed" framing on non-trading days. The answer is schema-constrained JSON; server-side refusal fallbacks are on and the model that actually answered is recorded in the file. A session that already has a note is skipped without calling the API — weekend and holiday runs resolve to Friday's session — so notes are written for trading days only; tick regenerate on a manual run (or pass --force) to rewrite one. It needs an ANTHROPIC_API_KEY repo secret (the Anthropic SDK is a devDependency used only here — it never enters the browser bundle); without the secret the step prints a notice and the snapshot still commits, so forks lose nothing by leaving it unset. Roughly $2–3/month at Fable 5.1 rates. node scripts/commentary.mjs --stats stats.json --dry-run shows the exact prompt without calling the API. (SPEC §3.8.) It tries Yahoo directly, then the worker with MP_PROXY_TOKEN if that env var is set (GitHub's runner IPs are often blocked by Yahoo, so forks that want reliable snapshots should deploy their own worker and add the token as a repo secret of the same name), then the public proxies. A day where some sources fail is still recorded, with the failed keys listed under errors.

(See SPEC.md §9 for other contingencies — Yahoo crumb/cookie requirements, CoinGecko rate limits, etc.)

Each tile manages its own loading and error state. A failure in one fetch never affects another tile. When a Yahoo tile that has already loaded hits a transient failure, it keeps showing its last good price — the UPD timestamp reveals how stale it is — rather than blanking to "fetch failed". Only a tile that has never loaded shows the error state. Disconnecting the network keeps the last values frozen (timestamps stop advancing); reconnecting refreshes them on the next successful tick.

The last good quote for each Yahoo tile is also persisted to localStorage, so on a cold page load the tiles immediately show the previous session's prices (honestly stale, per their UPD timestamps) while the first fetch is in flight — and a visitor only ever sees "fetch failed" if every proxy fails on a browser that has never successfully loaded that tile.

• Centered, max-width 980px; sections always stack, so desktop shows at most two tiles per row
• 4 categorized sections (Scarce Assets, Energy & Metals, US Treasuries, Currencies), 2 tiles each, compact enough that the whole dashboard fits one desktop viewport height without scrolling
• Header (clock + date + currency picker + theme toggle), source/disclaimer footer
• Responsive: each section is a two-column grid that collapses to a single stacked column at ≤640px (page/tile padding tightens, the title scales fluidly with clamp, readable down to ~320px). Sections stack vertically at every width, so desktop never shows more than two tiles per row. The breakpoint lives in src/styles.css (.tile-grid, .app-shell, .app-frame, .tile).
• Aesthetic target: refined Bloomberg terminal, not crypto-bro dashboard

Light by default, dark via the moon/sun toggle in the header. The palette is shared with satusd.com — the tokens live as CSS custom properties in src/styles.css (:root light, :root[data-theme="dark"] dark). The choice persists in localStorage under the theme key, the same one satusd.com uses, so when the dashboard is served at satusd.com/market-pulse the preference carries across both pages. An inline script in index.html applies the saved theme before first paint to avoid a flash. OS prefers-color-scheme is deliberately ignored, matching satusd.com.

By default, npm run build produces a root-relative bundle that drops onto any static host (Netlify, Vercel, GitHub Pages, Cloudflare Pages) and works at the domain root.

If you need to serve the dashboard from a sub-path instead — e.g. example.com/market-pulse/ — use:

npm run build:satusd

That builds with Vite's --base=/market-pulse/ so asset URLs resolve under the sub-path. Copy the resulting dist/ into your host's market-pulse/ directory.

This repo also ships a .github/workflows/deploy-satusd.yml Action that builds and pushes the output to saubyk/satusd.com. It is specific to the satusd.com deploy and is irrelevant to other forks — feel free to delete it if you're using market-pulse elsewhere.

Not investment advice. Prices are delayed by at least 15 minutes for commodities and Treasury yields. Bitcoin spot is sourced from Coinbase. Data sources may rate-limit or fail without notice.