corrupted-event-log

This error occurs when the Workflow runtime encounters an event in the event log that no registered consumer can process. This means the event log is in an invalid state — typically due to duplicate or orphaned events.

This is a workflow-level fatal error. It cannot be caught or handled inside your workflow code. A corrupted event log immediately fails the entire run without executing any more user code. The run must be retried from outside the workflow.

Error Message

Unconsumed event in event log: eventType=<type>, correlationId=<id>, eventId=<id>. This indicates a corrupted or invalid event log.

Why This Happens

Workflows persist their progress as an ordered event log. During replay, the runtime processes each event in sequence — every event must be consumed by a matching callback (e.g., a step or sleep waiting for its result). When an event has no matching consumer, the runtime cannot advance past it, which would block all subsequent events and hang the workflow indefinitely.

Instead of silently hanging, the runtime raises a WorkflowRuntimeError to fail the workflow fast and surface the problem.

Common scenarios that produce this error:

1. Duplicate completion events — Two wait_completed events for a single wait_created, or two step_completed events for the same step. The first is consumed normally, but the second has no consumer.
2. Orphaned events — A step_completed or wait_completed event whose correlationId doesn't match any step or sleep in the workflow code.
3. Events after terminal state — An event that arrives after its corresponding step or wait has already reached a terminal state (e.g., step_retrying after step_completed).

What To Do

This error indicates a bug in the Workflow SDK or Workflow server — not in your workflow code. Your workflow code does not need to change. Follow these steps to resolve the issue:

1. Upgrade to the latest workflow package

The bug that caused the corrupted event log may have already been identified and fixed in a newer version. Update to the latest version:

npm install workflow@latest

2. Retry the failed run

Since this is a fatal error, the run is automatically marked as failed. You can re-run it using the Re-run button in the Workflow Dashboard.

3. Report the issue

If the error persists after upgrading, please open an issue on GitHub so we can investigate and fix the underlying bug. Include the following details to help us diagnose the problem:

• The version of the workflow package you are using
• The run ID(s) of the affected workflow run(s)
• The error message (including eventType, correlationId, and eventId)
• Any details about the event log or the workflow that triggered the error

This Error Cannot Be Caught

Unlike other workflow errors, a corrupted event log error is not catchable inside your workflow function. Because the event log itself is invalid, the runtime cannot safely continue executing any user code. The entire run fails immediately and is marked as failed.

To handle this programmatically from outside the workflow, you can check the run status:

import { getRun } from "workflow/api";

const run = getRun("wrun_abc123");
const status = await run.status;
if (status === "failed") {
  console.error("Run failed");
}