[Kiro] Prelude CRC mismatch: expected ${preludeCRC}, got ${c

Error message

[Kiro] Prelude CRC mismatch: expected ${preludeCRC}, got ${computedPreludeCRC} — skipping corrupted frame

What it means

Error "[Kiro] Prelude CRC mismatch: expected ${preludeCRC}, got ${computedPreludeCRC} — skipping corrupted frame" thrown in diegosouzapw/OmniRoute.

Source

Thrown at open-sse/executors/kiro/eventstream.ts:111

  }
  return (crc ^ 0xffffffff) >>> 0;
}

/**
 * Parse AWS EventStream frame
 */
export function parseEventFrame(data: Uint8Array): EventFrame | null {
  try {
    const view = new DataView(data.buffer, data.byteOffset);
    const totalLength = view.getUint32(0, false);
    const headersLength = view.getUint32(4, false);

    // ── CRC32 validation ──
    // Prelude CRC covers bytes [0..7] (totalLength + headersLength)
    const preludeCRC = view.getUint32(8, false);
    const computedPreludeCRC = crc32(data.slice(0, 8));
    if (preludeCRC !== computedPreludeCRC) {
      console.warn(
        `[Kiro] Prelude CRC mismatch: expected ${preludeCRC}, got ${computedPreludeCRC} — skipping corrupted frame`
      );
      return null;
    }

    // Message CRC covers bytes [0..totalLength-5] (everything except the CRC itself).
    // Skipped by default (O(frame bytes) per frame) — the prelude CRC above already
    // validates framing and the stream is TLS-protected. Enable KIRO_VERIFY_FULL_CRC=true
    // to restore full validation for debugging corrupted-stream issues.
    if (KIRO_VERIFY_FULL_CRC) {
      const messageCRC = view.getUint32(data.length - 4, false);
      const computedMessageCRC = crc32(data.slice(0, data.length - 4));
      if (messageCRC !== computedMessageCRC) {
        console.warn(
          `[Kiro] Message CRC mismatch: expected ${messageCRC}, got ${computedMessageCRC} — skipping corrupted frame`
        );
        return null;
      }

View on GitHub (pinned to a179ffed5b)

When it happens

Trigger: Thrown at open-sse/executors/kiro/eventstream.ts:111 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of diegosouzapw/OmniRoute@a179ffed5b (2026-08-25). Data as JSON: /api/errors/d8db13bc937dc6d4. Report an issue: GitHub.