Usage & cost

Admin → Usage & cost answers one question: what is this storage costing me, roughly, and where is it going.

filex does not meter your provider's bill. It reads the report the provider already writes, normalises it, and prices it with a table you can edit. Today that means Backblaze B2; the reader is an interface, so a second provider is a file, not a redesign.

⚠ Everything on that page is an estimate, even though the numbers come from the provider's own report. Free allowances are applied over the range you asked for rather than over the provider's billing month, taxes and minimums are not modelled, and providers round differently. It is for "where is my money going", not for reconciling an invoice.

How it works

Backblaze writes a usage report once a day into a bucket it owns, named b2-reports-<accountId>, under one folder per day. filex reads those files over the same S3 API it already speaks — no new dependency, no new credential type — and caches what it parsed, so opening the page does not fetch a month of CSVs every time.

b2-reports-<accountId>/
  2026-09-11/
    usage.account-<accountId>.csv     ← a standalone account

The account-level line and the per-bucket lines are rows of the same file; the account line is the one with an empty bucket_id. An account inside a Backblaze organization or group gets usage.<resource>.<location>.csv or usage.group-<groupId>.<location>.csv instead, and filex reads every usage.*.csv in the day's folder — skipping usage.audit-* and the *.reportingLocations.csv lookup table, which are not usage.

Setting it up

1. Make a read-only application key. In the Backblaze console, create an application key with read access. ⚠ Not the master key — B2's S3 endpoint rejects it with InvalidAccessKeyId: Malformed Access Key Id, which reads like a wrong secret and is not one. See STORAGE.md.

2. Attach the report bucket as a storage. Storages → Add, driver s3, endpoint https://s3.<region>.backblazeb2.com, bucket b2-reports-<accountId>, read-only. It holds no files of yours; it is a data source.

3. Point the page at it. On Usage & cost:

Field	What it is
Provider	`Backblaze B2`
Report storage	the storage you just made
Account ID	your B2 account id — the same one in the bucket's name. Optional: the day's folder is listed either way, and the id is only used to try `usage.account-<id>.csv` by name when it cannot be
Path prefix	only if the reports are not at the root of that bucket

The same values are rows in the settings table — usage.provider, usage.report_storage, usage.account_id, usage.prefix and usage.pricing — so they can also be written through PATCH /api/admin/settings. ⚠ There is no environment variable for any of them: unlike the antivirus family they are not seeded at first boot, so a compose file cannot configure this page. Set them here, or through the settings API.

The report appears the day after the account does. A brand-new B2 account has no b2-reports-… bucket at all until Backblaze writes its first daily report. Until then the page has nothing to read, and it says so rather than drawing an empty chart.

Pricing is configuration, not code

The usage.pricing setting holds the table the estimate is computed with, and the free allowances are their own fields rather than constants buried in a formula — so a price change is an edit, not a release.

The defaults are Backblaze's list prices as read on 2026-09-11:

Line	Default	Free allowance
Storage	$0.00695 / GB / month	first 10 GB
Download	$0.01 / GB	3× what you store
Class A/B/C transactions	free	—
Class D transactions	$0.004 / 10,000	2,500 / day

The page shows the allowance line separately from the billable line, because "your downloads were free this month" is usually the thing worth knowing.

Two rows that must never be added together

The provider reports an account-level row and a per-bucket row, and the same transactions appear in both. Summing them overstates by exactly the amount nobody notices, so filex keeps them apart: buckets are summed among themselves, and the account row is rendered as its own line with a note saying what it is.

The API

GET /api/admin/usage?days=30
GET /api/admin/usage?from=2026-08-01&to=2026-08-31

Supertenant-only. It answers 502 with a hint when the configuration points at something it cannot read — a missing storage, a bucket with no reports in it, a prefix that matches nothing — rather than an empty report, because an empty report reads as "you used nothing".

Usage & cost ​

How it works ​

Setting it up ​

Pricing is configuration, not code ​

Two rows that must never be added together ​

The API ​

See also ​