Finance

Build a Currency Converter with AI

Build a clean, fast currency converter supporting 30+ world currencies. Features an instant swap button, country flag icons, and hardcoded exchange rates that your AI agent can update periodically with a simple follow-up prompt.

Build Prompt

Copy this prompt into Claude Code
Build a single-page currency converter as a static HTML/CSS/JS site. Page background #0f0f17 with a centered card (max-width 560px) using #12121a background, 1px solid #2a2a3a border, and 20px border-radius. Design mobile-first. At the top, display "Currency Converter" heading in white and a subtitle "Fast, offline-ready conversions" in #8888a0. Show a small "Rates updated: [date]" badge in #6a6a80 text below the subtitle. The converter layout has two currency rows stacked vertically with a swap button between them. Each row contains: a currency dropdown (searchable, with the currency code and full name, e.g., "USD - US Dollar") on the left (40% width) and an amount input on the right (60% width). Style dropdowns with #1a1a2a background, #2a2a3a border, white text, and a custom chevron icon. Style amount inputs with large 24px font, #1a1a2a background, right-aligned text. The top input is editable; the bottom shows the converted result (also editable for reverse conversion — both inputs should update each other in real-time). Between the two rows, place a circular swap button (48px diameter, #1a1a2a background, #3b82f6 icon) centered with horizontal lines extending to the edges. Clicking it swaps the from/to currencies with a smooth 180-degree rotation animation on the button icon. Include a conversion rate display between the rows showing "1 USD = X EUR" in #8888a0 text, updating dynamically when currencies change. Below the main converter, add a "Popular Conversions" quick-access grid — 6 buttons in a 3x2 grid showing common pairs: USD/EUR, USD/GBP, USD/JPY, EUR/GBP, USD/CAD, USD/AUD. Clicking a pair auto-selects those currencies. Style as small pill buttons with #1a1a2a background and #2a2a3a border. Below that, add a "Conversion Table" section that shows the selected base currency converted to the 10 most popular currencies in a compact table. Columns: Currency, Code, Rate, Converted Amount. Style with alternating row backgrounds (#12121a and #16161e). Hardcode exchange rates for at least 30 currencies as a JavaScript object at the top of the script (all rates relative to USD as base): USD, EUR, GBP, JPY, CAD, AUD, CHF, CNY, INR, MXN, BRL, KRW, SGD, HKD, NOK, SEK, DKK, NZD, ZAR, THB, PHP, IDR, MYR, TWD, PLN, TRY, RUB, AED, SAR, COP. Use realistic current exchange rates. Include a comment marking the rates object clearly so it is easy to find and update. Add a search/filter feature in the currency dropdowns that filters as the user types. The entire layout should be responsive and work beautifully on mobile. All conversions update in real-time with no button click needed. Read the guide at https://accessagent.ai/api/guide and follow it to deploy the site to AccessAgent.ai. My email is [your@email.com].

Update Prompt

Use this prompt to refresh exchange rates
Update the exchange rates in the currency converter. Find the JavaScript object containing the hardcoded exchange rates (all relative to USD as base currency) and update every rate to the latest values as of today. Also update the "Rates updated" date string shown in the UI to today's date. Do not change any other code, styling, or functionality — only update the rate values and the displayed date. After updating, redeploy the site following the guide at https://accessagent.ai/api/guide. My email is [your@email.com].

Make It Yours

Cryptocurrency Support

Add BTC, ETH, SOL, and other major cryptocurrencies to the currency list with their current USD exchange rates.

Historical Rate Chart

Show a 30-day rate history chart for the selected pair using hardcoded historical data that the agent can update weekly.

Travel Budget Mode

Enter a budget in your home currency and see how much you get in the destination currency with common expense breakdowns.

Rate Alerts

Let users set a target rate and store it in localStorage — show a banner when the hardcoded rate crosses their target after an update.

Fee Calculator

Add a toggle to include typical bank/ATM conversion fees (2-3%) to show the real amount received after fees.

Multi-Currency View

Show a single amount converted to 5 user-selected currencies at once for comparing rates across destinations.

SEO Tips

Monetization Ideas

Related Ideas

Ready to build your Currency Converter?

Copy the prompt above and paste it into Claude Code. Your converter will be live in minutes.

Get Started