Options: uploads, volumes and rate limiting

All values sit under InvoiceApi. As an environment variable with a double underscore per level: InvoiceApi__MaxUploadBytes. Where the settings belong is set out under Configuration.

Uploads and volume limits

Option	Default	Effect
MaxUploadBytes	15728640 (15 MB)	the upper limit per file; above it, 413. Applies to the web server and to the multipart limit
SlowUploadWarnBytes	4194304 (4 MB)	from this size the form warns about a noticeable wait. Never blocks; 0 switches the notice off
MaxBatchItems	50	the hard ceiling on files per batch run, above the plan limits. What applies is the minimum of the two
MaxBulkRows	5000	the hard ceiling on table rows per bulk import
ResultTtlMinutes	30	the lifetime of a transiently held result — the result pages after an upload

Rate limiting

Option	Default	Effect
RateLimitPermitPerWindow	60	requests per window; above it, 429 immediately, without a queue
RateLimitWindowSeconds	60	the length of the window
AnonToolLimitEnabled	true	the hourly and daily cap for use without signing in
AnonToolLimitPerHour	20	tool calls per hour and client address
AnonToolLimitPerDay	50	tool calls per day and client address
FairUseHintThreshold	8	from this many calls in the current hour the fair-use notice appears; 0 switches it off

How partitioning works

Per client address — except for /api calls with a known API key, which are counted per key. Several systems behind one NAT address therefore do not share a window.

An unknown key value deliberately falls back to the address partition

Otherwise the limit could be circumvented entirely by using a random value per request.

Behind a reverse proxy without KnownProxies, all clients look alike

Rate limiting then partitions by the proxy’s address — all users share one window. See Running behind a reverse proxy.

The service checks these values at startup

The upload limit, result lifetime, rate-limit values and batch size must be positive. Given nonsense, the service aborts rather than quietly running on with unusable limits.

Values verified against the code on 22 October 2026.