How to reliably detect which Flow has failed?

[amirzp]

Hi

We’re looking for a recommended way to detect whether a specific Flow has failed, in a scalable and future-proof way.

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What we’ve checked so far

1. Metrics

Example:

worker_execution_failed{name="server",tag="default"} 7910

This is useful for alerting and knowing that failures occurred, but:

• It is aggregated
• It does not indicate which Flow or Job failed

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2. Jobs API

Example:

GET /api/w/{workspace}/jobs/list?script_path_start=...

This allows us to identify failed jobs and see flow/script paths and error messages.
However:

• It is pull-based, meaning we have to continuously query the API to detect failures

Ideally, we would prefer a push-based mechanism, where Windmill actively notifies us when a Flow or Job fails (e.g. via webhook or event), instead of us polling the Jobs API to find out what errored.

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3. Error handling inside Flows

Handling errors inside Flows (try/catch, error branches, notifications) is helpful for expected errors, but:

• It does not cover crashes or worker-level failures
• It requires per-flow implementation

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Questions

What approach would you recommend for detecting failed Flows in a way that:

• Works well with alerting
• Identifies the exact Flow
• Scales well for future Flows with minimal changes?

Thanks in advance 🙏