Function buildUsageHeaders

shared/registry/usage-headers.ts:238–254

(
    modelUsed: string,
    usage: Usage,
)

 * Returns headers with x-usage-* prefix for all non-zero usage types
 */
export function buildUsageHeaders(
    modelUsed: string,
    usage: Usage,
): Record<string, string> {
    const headers: Record<string, string> = {
        "x-model-used": modelUsed,
    };

    for (const [usageType, headerName] of Object.entries(USAGE_TYPE_HEADERS)) {
        const value = usage[usageType as UsageType];
        if (value && value > 0) {
            headers[headerName] = String(value);
        }
    }

    return headers;
}

/**
 * Parse usage headers back to Usage object