Cyprus is not in the published Bonds-API country catalog (US, DE, KR, ZA, …). Call countries=CY only if you want the live error; start with US or ZA. Endpoint: GET /api/v1/latest?countries=&maturities= with query api_key.
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Request: latest US 10Y
curl "https://bonds-api.com/api/v1/latest?countries=US&maturities=10Y&api_key=YOUR_API_KEY"Sibling: official US curve (2026-04-14)
{
"success": true,
"data": {
"country": "US",
"date": "2026-04-14",
"curve": [
{"maturity": "3M", "yield": 4.30},
{"maturity": "6M", "yield": 4.22},
{"maturity": "30Y", "yield": 4.55}
]
}
}Keys are {CC}_{TENOR}. Do not invent a Windhoek-style yield for a missing ISO.