Currency Rates Skill

Currency conversion is a daily agent chore with a clean keyless answer: Frankfurter serves European Central Bank reference rates (current and historical) over bare HTTPS, and open.er-api.com covers the long tail of currencies Frankfurter doesn't track. This skill knows both, always quotes the rate and its date, and never confuses a reference rate with the rate any bank will actually give.

What This Skill Produces

• The conversion — the amount, converted, stated first
• The rate and its date — reference rates update on banking days; the date is part of the answer
• The command — exact curl, rerunnable and scriptable
• The caveat — reference rates ≠ what a card, bank, or exchange desk will charge; the spread is real

Required Inputs

Ask for these if not provided:

• From, to, and amount — ISO codes resolved from natural language ("dollars" → USD unless context says AUD/CAD/SGD — ask when genuinely ambiguous)
• When — today (default) or a historical date (Frankfurter serves history back to 1999)
• The purpose, if it matters — budgeting tolerance vs. invoice-precision changes how hard to caveat the spread

Framework: The Two Sources