Huggingface.js

Join the Hugging Face community

and get access to the augmented documentation experience

Collaborate on models, datasets and Spaces

Faster examples with accelerated inference

Switch between documentation themes

to get started

Interface: CommitEditFile

Edit an existing file by replacing byte ranges of its original content.

When originalContent is a XetBlob (as returned by downloadFile for xet-backed files), the unchanged parts of the file are neither downloaded nor re-chunked: the CAS server provides chunk-aligned edit windows and partial merkle data (GET /v2/file-chunk-hashes), so only the modified regions (plus their chunk-boundary neighborhood) are fetched, re-chunked and hashed.

For buckets (no sha256 involved), this means edits and appends require no download of the unchanged data at all.
For models/datasets/spaces, the unchanged data is still streamed once to compute the new file’s sha256 (required by the LFS protocol), instead of twice (sha256 + chunking).

With any other Blob as originalContent, the whole content is re-chunked locally and unchanged chunks are deduplicated against the remote (upload is skipped, but the content is read in full).