Can I cancel a running experiment?

There is no cancel or stop action for experiments in the Langfuse UI or API.

• Experiments run with the SDK (run_experiment / experiment.run) execute in your own process. Stop the process to stop the experiment. Items that already finished stay in Langfuse.
• Experiments started from the UI run in the Langfuse worker until every dataset item is processed. They cannot be stopped once started.

To limit the impact of a mistake, try a prompt or model on a small dataset first. To remove the results of an experiment afterwards, see Delete experiment data.

See Experiments via SDK and Experiments via UI.

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