Files API: upload and manage files, stored in the EU

POST /v1/files uploads a file as multipart/form-data with two fields: file and purpose. Use purpose batch for batch input, or user_data for files a tool such as code execution should read. The response is a file object with an id, bytes, filename, purpose and created_at. You refer to the file by its id everywhere else.

GET /v1/files lists your files, GET /v1/files/{file_id} returns one file object, GET /v1/files/{file_id}/content downloads the contents, and DELETE /v1/files/{file_id} removes it. Batch output and error files appear in the same list with purpose batch_output.

A batch input file is JSON Lines: one request per line, each with a custom_id you choose, a method of POST, the url such as /v1/chat/completions or /v1/embeddings, and a body that is exactly what you would send to that endpoint. All lines in one file should target the same endpoint.

Make custom_id meaningful, for example a ticket number or document id, because results can come back in any order and you match them using that value. Validate the file before upload: every line must be valid JSON, and a single malformed line can make the whole batch fail validation.

Files are stored in European data centres, are only accessible with keys from your organisation, and are never used to train models. Treat them like any other copy of your data: delete input files once the batch has completed and you have downloaded the results, and delete output files once they are processed.

A short clean-up step at the end of each job is enough, and it keeps the list readable as well as limiting how much sensitive data sits in storage. How long files are kept if you do not delete them depends on your contract, and we confirm it with you.

An upload without purpose, or with a value that is not supported, returns a 400 error. Files above the maximum size also return an error; split large inputs into several files and batches. The size limit depends on your plan, and we confirm it with you.

Requesting a file id that does not exist, or that belongs to another organisation, returns 404. Downloading the content of a file still being written, such as batch output before the batch has finished, is not possible; wait until the batch status is completed. Deleting a file that a running batch uses can make that batch fail, so delete inputs only afterwards.