Function calculateContextPercentages

src/utils/context.ts:118–144

(
  currentUsage: {
    input_tokens: number
    cache_creation_input_tokens: number
    cache_read_input_tokens: number
  } | null,
  contextWindowSize: number,
)

 * Returns used and remaining percentages, or null values if no usage data.
 */
export function calculateContextPercentages(
  currentUsage: {
    input_tokens: number
    cache_creation_input_tokens: number
    cache_read_input_tokens: number
  } | null,
  contextWindowSize: number,
): { used: number | null; remaining: number | null } {
  if (!currentUsage) {
    return { used: null, remaining: null }
  }

  const totalInputTokens =
    currentUsage.input_tokens +
    currentUsage.cache_creation_input_tokens +
    currentUsage.cache_read_input_tokens

  const usedPercentage = Math.round(
    (totalInputTokens / contextWindowSize) * 100,
  )
  const clampedUsed = Math.min(100, Math.max(0, usedPercentage))

  return {
    used: clampedUsed,
    remaining: 100 - clampedUsed,
  }
}

/**
 * Returns the model's default and upper limit for max output tokens.