Function sessionTitleSource

packages/runtime/src/session-title.ts:8–25

(input: { text: string; displayText?: string })

export const SESSION_TITLE_GENERATION_TIMEOUT_MS = 15_000;

export function sessionTitleSource(input: { text: string; displayText?: string }): string {
  const raw = input.displayText ?? input.text;
  const cleaned = (raw.match(/<user-message>([\s\S]*?)<\/user-message>/i)?.[1] ?? raw)
    .replace(/<system-reminder>[\s\S]*?<\/system-reminder>/gi, '')
    .trim();
  const bytes = new TextEncoder().encode(cleaned);
  if (bytes.length <= MAX_SOURCE_BYTES) return cleaned;
  let end = MAX_SOURCE_BYTES;
  const decoder = new TextDecoder('utf-8', { fatal: true });
  while (end > 0) {
    try {
      return decoder.decode(bytes.subarray(0, end));
    } catch {
      end -= 1;
    }
  }
  return '';
}

export function fallbackSessionTitle(sourceText: string): string | undefined {
  const firstLine = sourceText