# DATASET: Dataset files

> The session archive as files: one gzipped JSON a finished day, minute series and per-strike ladders in all three books, a new day every evening. Every field's meaning, unit, book and first date is in the data dictionary.

Source: https://firmtape.com/docs/developers/dataset

The session archive as files: one gzipped JSON a finished day, minute series and per-strike ladders in all three books, a new day every evening. Every field's meaning, unit, book and first date is in the [data dictionary](https://firmtape.com/dataset/dictionary).

**This product serves:** [DATASET: The day files and the dictionary](https://firmtape.com/docs/dataset#archive-files), [DATASET: Dataset licence](https://firmtape.com/docs/dataset#dataset-licence), [DATASET: A new session every evening](https://firmtape.com/docs/dataset#evening-delivery), [DATASET: Three books in every file](https://firmtape.com/docs/dataset#three-books). **Plan:** [DATASET](https://firmtape.com/features/dataset). The DATASET licence, monthly or yearly. Reading single sessions on the site stays free.

**Delivery.** Fetch the day list (`GET /api/days`), then each day's file with the key in the header. A finished session is written the evening it closes and never rewritten, so a day you hold stays valid. The licence lifts the per-visitor breadth limit: mirror the archive in one pass, then take each new session the evening it lands.

**Schema.** The files are the payloads the terminal reads. Field suffixes name the book: `_volcp` and `_vol` the volume book, `_oi` the open-interest book, a neutral name the measured book. Magnitudes are never comparable across books. The dictionary is generated from the same source the LAB compiler reads.

**Keys.** Today the files open with the account's `lab` key (no LAB purchase needed). A key of the `dataset` scope is planned; see [Versioning](https://firmtape.com/docs/developers/versioning#planned).

**Terms.** Your own research only; showing the numbers to other people is [Licensing](https://firmtape.com/licensing). Licensed raw vendor data is never part of the files. The files you downloaded while the licence ran stay yours after it ends.

```sh
curl -s https://firmtape.com/api/days
curl -H "Authorization: Bearer $FIRMTAPE_LAB_KEY" \
  https://firmtape.com/snapshots/2026-10-09.json.gz -o 2026-10-09.json.gz
```

## Endpoints

| Request | What it gives | Plan | Key scope |
| --- | --- | --- | --- |
| `GET /snapshots/{file}` | [A day file](https://firmtape.com/docs/developers/dataset/files) | DATASET | dataset |

## More

- [The data dictionary](https://firmtape.com/docs/developers/dataset/dictionary): Every field of the day files and every LAB column, with its meaning, unit, book and the first session that carries it, grouped by book.

## Limits

| What | Limit | Notes |
| --- | --- | --- |
| DATASET files | No breadth limit for a licence holder | Mirror the archive in one pass, then take each new session the evening it closes. |