docs/fields.md

Fields

This page describes every file under manifests/ and catalog/. The manifests are the source of truth. The tables under catalog/ are a derived view: they are generated from manifests/ each time a source is updated. Where the two differ, the manifests are right.

Layout

• manifests/<source>/<batch>/collection.json: the header of one batch.
• manifests/<source>/<batch>/part-NNNNN.jsonl.gz: the pointers of the batch, as gzip-compressed JSON Lines with one line per file, numbered from part-00000.
• catalog/<source>.parquet: all pointers of one source as one flat table, read by the viewer on the dataset page.

A source whose batches are periods, such as the Common Crawl crawls or the Stack Exchange dumps, names each batch after its period, such as 2026-39 or 2024-06-30, even when it has only one. Any other source with a single batch calls it all, and one with several batches names each after the volume the source gives it, such as 2024-06-30-revised; batch names are lower case with hyphens.

Pointer fields

Every line of a part file is one pointer with these fields:

• schema_version: version of the pointer format (artifact-pointer-v0).
• pointer_id: unique id of the pointer, <source>:<collection>:<relative path>.
• source: the source the pointer belongs to; also the name of the source's folders under manifests/ and catalog/.
• collection: a group within the source. For sources whose batches are periods (such as the Stack Exchange dumps) it is the batch; otherwise it is a group the source defines, such as a project, a mailing list, a site or a term, and notes in collection.json usually says which.
• uri: where to download the file. s3:// addresses usually have a public https address in alt_uris; hf://datasets/<repo>@<revision>/<path> stands for https://huggingface.co/datasets/<repo>/resolve/<revision>/<path>.
• size_bytes: size of the file in bytes, or null when the source does not publish it.
• hashes: hashes of the file (md5, sha1, sha256, sha512, crc32, etag, git_blob_sha1), lower-case hex; empty when the source publishes none.
• hash_source: where the hashes come from: source_published (published by the source), http_head (HTTP response headers), name_convention (part of the file name), computed (computed from the content when the catalog was built), computed_on_fetch (not available; compute them after download).
• ext: lower-case file extension, without the dot; empty when the file has none.

Optional fields:

• alt_uris: other addresses that serve the same bytes.
• range: {offset, length}; the file is that byte range of uri, for example one record inside a WARC file. size_bytes then equals length.
• hash_scope: what the hashes cover: file (the whole download; the default), http_payload or api_body (see retrieval.md).
• media_type: MIME type given by the source.
• content: the content kinds of this file, when they differ from those of its batch (content in collection.json).
• license_override: the license of this file when it differs from its batch: spdx (SPDX id or expression), training_ok, redistribution_ok, and notes (the license as the source states it); see licenses.md.
• access: whether downloading needs a login or a form (needs_auth), with a note where useful.
• source_meta: a flat object of facts from the source; source_meta_keys in collection.json explains its keys.
• origin: for web captures, the original URL (url) and capture time (captured_at).
• capture_count: for web captures, how many captures share this payload.
• parent_pointer_id, member_path: for a file inside an archive that has its own pointer.

Batch header fields (collection.json)

Each batch folder has one collection.json with these fields:

• schema_version: version of the pointer format.
• source: the source name, as in the pointers and the folder names.
• content: the content kinds of the batch, such as emails or spreadsheets.
• collector: the name of the collector that generated the pointers.
• title, description: what the source is and what one pointer stands for.
• files, bytes: the number of pointers in the batch and the sum of their size_bytes (sizes that are not published count as 0).
• by_ext: files and bytes per extension; (none) stands for files without an extension.
• by_collection: files and bytes per value of the pointer field collection, when the collector counts them (empty otherwise).
• hash_sources: the number of pointers per hash_source.
• license: the license of the batch: name, url, statement (quoted from the source where possible), attribution, per_file (where licenses are given per file), and the tiers training_ok and redistribution_ok; see licenses.md.
• fetch: how to retrieve and verify the files of this source: method, verify and failures; see retrieval.md.
• shards: the part files of the batch, in order: name, rows (pointers in the part), and the bytes and sha256 of the .gz file as stored in this repository.
• notes: facts about the source and how its pointers were made, often including what the collection field stands for.
• source_meta_keys: what each key of source_meta in the pointers means.
• text_version: version of the descriptive text.

Some sources add keys of their own, such as collection (details of an upstream batch) or by_site (files and bytes per site); notes explains them.

Catalog columns

Each row of catalog/<source>.parquet is one pointer, in the order of the batches and part files. The license columns are already resolved: the value from license_override when the pointer has one, otherwise the value of its batch.

• source, collection: as in the pointers.
• batch: the batch the pointer belongs to, the folder name under manifests/<source>/; filter on it to see one batch.
• content: the kind of content of the file; several kinds are separated by a comma.
• ext: lower-case file extension.
• size: the size in KB, MB, GB or TB; size_bytes: the size in bytes, or empty when the source does not publish it.
• training_ok, redistribution_ok: the license tiers of this file; license: its license.
• uri: where to download the file; alt_uris: other addresses that serve the same bytes.
• pointer_id: unique id of the pointer, <source>:<collection>:<relative path>.
• sha256, md5, sha1: hashes published for the file, when available; other hashes are in the pointers; hash_source: where they come from.
• media_type: MIME type given by the source.
• needs_auth: whether downloading needs a login or a form (empty when not known).
• has_range: whether the file is a byte range of uri (see range in the pointers).
• source_meta: facts from the source, as JSON text; source_meta_keys in collection.json explains its keys.