server/src/lib/error-redaction.ts

const MAX_PROVIDER_ERROR_LENGTH = 240;

const REDACTIONS: Array<[RegExp, string]> = [
  [/\bBearer\s+[A-Za-z0-9._~+/-]+=*/gi, 'Bearer [redacted]'],
  // Quote-tolerant so JSON bodies like {"api_key": "..."} are caught too.
  [/(["']?)\b(api[_-]?key|access[_-]?token|token|secret|authorization)\b\1(\s*[:=]\s*)(["']?)[^"',\s}\]]+/gi, '$1$2$1$3$4[redacted]'],
  [/\bsk-[A-Za-z0-9_-]{8,}\b/g, '[redacted-key]'],
  [/\bgsk_[A-Za-z0-9_-]{8,}\b/g, '[redacted-key]'],
  [/\bfreellmapi-[A-Za-z0-9_-]{8,}\b/g, '[redacted-key]'],
  [/\bAIza[0-9A-Za-z_-]{20,}\b/g, '[redacted-key]'],
  [/\b[A-Za-z0-9_-]{20,}\.[A-Za-z0-9_-]{20,}\.[A-Za-z0-9_-]{20,}\b/g, '[redacted-token]'],
  // Bare high-entropy tokens with no known prefix: any unbroken alphanumeric
  // run of 32+ chars is overwhelmingly a credential, never prose.
  [/\b[A-Za-z0-9]{32,}\b/g, '[redacted-token]'],
  [/\bhttps?:\/\/[^\s"'<>)]*/gi, '[redacted-url]'],
];

export function sanitizeProviderErrorMessage(message: unknown): string {
  let sanitized = typeof message === 'string' ? message : String(message ?? '');
  sanitized = sanitized.trim();

  if (!sanitized) return 'Provider error';

  for (const [pattern, replacement] of REDACTIONS) {
    sanitized = sanitized.replace(pattern, replacement);
  }

  sanitized = sanitized.replace(/\s+/g, ' ').trim();
  if (sanitized.length > MAX_PROVIDER_ERROR_LENGTH) {
    sanitized = `${sanitized.slice(0, MAX_PROVIDER_ERROR_LENGTH - 3).trimEnd()}...`;
  }

  return sanitized;
}

// Cap for the per-hop `request_attempts.error_summary` column: one short line
// per failover attempt, tighter than the parent row's error text.
const MAX_ATTEMPT_ERROR_SUMMARY_LENGTH = 200;

/**
 * The short per-attempt error summary the failover ladder stores per hop:
 * the same secret/URL redactions as sanitizeProviderErrorMessage, re-capped
 * at 200 chars so the drill-down stays one line per attempt.
 */
export function summarizeAttemptError(message: unknown): string {
  let summary = sanitizeProviderErrorMessage(message);
  if (summary.length > MAX_ATTEMPT_ERROR_SUMMARY_LENGTH) {
    summary = `${summary.slice(0, MAX_ATTEMPT_ERROR_SUMMARY_LENGTH - 3).trimEnd()}...`;
  }
  return summary;
}