# Working with Source Files

TDO uses .csv files as data sources.  These files can be ingested (imported) directly into TDO, can be uploaded via API(<https://docs.apica.io/platform-docs/test-data-orchestrator-tdo/user-documentation/api-guide/data-movement-apis/ingest-upload-data-files>) or can be loaded into TDO via the Test Data Extractor (TDX) tool (<https://docs.apica.io/platform-docs/test-data-orchestrator-tdo/user-documentation/user-guide-for-tdx>).

Since the second and third methods are already covered in existing documents, this document will only cover the first method, manual ingestion.