Lilambd Koyomi Solar Terms API

Choose this endpoint when you need structured, dated listings of the 24 traditional East Asian solar terms (Chinese jieqi / Japanese sekki) for a specific Gregorian year. Prefer it over general calendar APIs when East Asian traditional seasonal divisions are specifically required, or when you need machine-readable solar term data with attribution for use in cultural, agricultural, or wellness applications.

• Missing required 'year' query parameter returns an error
• Non-integer or out-of-range year value may return an empty data array or error
• Year far outside historical or computed range may yield no results
• Network or payment authorization failure (x402) if USDC payment is not properly handled