Curren$or 💱

A sleek currency converter you can self-host in seconds. Compare up to 5 currencies at once with live exchange rates, swap them around, search through 50 options. One HTML file, zero setup.

→ Try it live · → Use it inside Claude or ChatGPT

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Use it inside Claude or ChatGPT

Currensor also runs as a plugin (an MCP server) for Claude and ChatGPT. Ask for a conversion in plain words and a live Currensor card appears right in the chat. Change the amount on the card and every currency updates instantly.

Plugin address:

https://currensor-mcp.currensor-mcp.workers.dev/mcp

App	How to add it
Claude	Settings → Connectors → Add custom connector → paste the address → choose No sign-in
ChatGPT	Settings → Plugins → Developer mode on, then + → Create custom MCP server → paste the address → No Auth

Then ask: "Use Currensor to convert 250 CAD to INR, EUR and JPY."

• Live mid-market rates for 166 currencies, refreshed hourly, with a backup rate feed
• No sign-in, no API key, nothing about you stored. The server keeps only anonymous daily counts (which app, which currency pair) to see if people find it useful
• Free and open source: the server is in mcp/ and runs on Cloudflare Workers

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Features

• Live exchange rates — Fetched from open APIs with auto-refresh every 5 minutes
• 50 currencies — Grouped by region (Americas, Europe, Asia & Pacific, Middle East & Africa)
• Multi-currency view — See up to 5 conversions side by side
• Smart swap logic — Picking a currency already in use auto-swaps instead of duplicating
• Drag to reorder — Rearrange your target currencies by dragging the grip handle
• Dark & Light themes — Trading terminal dark mode or clean travel app light mode, saved to your preference
• Shareable conversion cards — Generate a branded PNG image of your conversion to share anywhere
• Export / Copy — One tap copies all conversions with currency symbols, ready to paste into WhatsApp, Slack, or email
• Bottom-sheet picker — Mobile-friendly currency selector with instant search
• Cross-platform flags — Twemoji flag images that render identically on every device
• Graceful fallback — Bundled rates kick in if APIs are unavailable
• Zero dependencies — One HTML file. No frameworks, no build step, no node_modules

How to Use

Option 1: Just open it

git clone https://github.com/Kay0sstheory/Currensor.git
cd Currensor
# Open index.html in your browser

Option 2: GitHub Pages (free hosting) Already live at kay0sstheory.github.io/Currensor

Supported Currencies

Americas: USD, CAD, MXN, BRL, ARS, CLP, COP, PEN Europe: EUR, GBP, CHF, SEK, NOK, DKK, PLN, CZK, HUF, RON, TRY, RUB, UAH, ISK Asia & Pacific: JPY, CNY, INR, KRW, SGD, HKD, TWD, THB, MYR, IDR, PHP, VND, PKR, BDT, LKR, AUD, NZD Middle East & Africa: AED, SAR, QAR, KWD, BHD, ILS, EGP, ZAR, NGN, KES, MAD

Tech Stack

• Pure HTML, CSS, JavaScript — no frameworks, no libraries
• Open Exchange Rates API (primary) + Currency API (backup)
• Twemoji CDN for cross-platform flag rendering
• DM Sans + Space Mono fonts via Google Fonts
• Canvas API for shareable card generation
• Dark/light themes via CSS variables with localStorage persistence
• Mobile-responsive down to 360px viewport

Version History

• v2.2 — Claude & ChatGPT plugin with an in-chat card; refreshed backup rates
• v2.1 — Swap logic fix, drag-to-reorder, cross-platform Twemoji flags, bigger rate text, dark/light theme toggle, shareable conversion cards, export/copy with currency symbols
• v2.0 — Live exchange rates, 50 currencies grouped by region, live status indicator, improved mobile UX
• v1.0 — Initial release with bundled rates and 20 currencies

Roadmap

• Interactive globe for selecting target currencies (v3)
• Historical rate sparkline charts
• Rate heatmap — weekly performance at a glance
• Volatility indicator per currency pair
• Purchasing power comparison
• Shareable URLs with encoded conversion state
• Favorites saved to localStorage

Why I Built This

I'm building tools with AI and learning in public. I can't write code from scratch (yet), but I can design, think through problems, and ship real products by collaborating with AI. Every project teaches me something new.

Follow along: @Kay0sstheory

License

MIT — do whatever you want with it.