Export & Fine-tuning

Langfuse is open-source and data tracked with Langfuse is open. You can export data via the public API or export it in the Langfuse UI.

You can use the exported data to train or fine-tune models on the production traces in Langfuse.

Public API

All data in Langfuse is available via the GET API. Refer to the API reference (opens in a new tab) for more information.

Example routes

• GET /api/public/traces
• GET /api/public/traces/:traceId
• GET /api/public/observations
• GET /api/public/observations/:observationId

Export via UI

The generations table in Langfuse allows you to export generations. All filters applied to the table will be applied to the export.

Available export formats:

• CSV
• JSON
• JSONL: This JSONL file can be imported directly into OpenAI and other services using the same format for fine-tuning. ⚠️ The export will include only generations that match the ChatML schema.

Trouble exporting?

If you're having trouble exporting data, please let us know and we'll help you out.