The API is built for one person’s Mac: it enforces these limits so a single request can’t exhaust memory or disk. A request over a limit gets 413, 422 or 429 with a detail that names it.
Files
Limit
Value
pdf_merge inputs
2 or more PDFs, no upper limit
pdf_run_batch inputs
1 to 50 PDFs
Steps in a pipeline or batch
1 to 10
Fields
Limit
Value
pages
Up to 200 characters, such as 1, 3-5
pdf_read_textmax_chars
100 to 200,000 (default 20,000)
pdf_extract_structuremax_chars
100 to 400,000 (default 60,000)
Passwords
Up to 127 characters
Watermark text
Up to 60 characters
Page label text
Up to 120 characters
Requests
Limit
Value
Request body
1 MB
Time to send a request
5 minutes to receive it; a tool then runs as long as it needs
Tool calls at once
4, of which 2 LibreOffice conversions; up to 64 more wait in order (then 429)
Jobs
Limit
Value
Jobs running at once
1, in the order received
Jobs waiting
100 (then 429)
Finished jobs kept
1 hour, at most 500, until the API stops
callback_url
Up to 2,048 characters
Webhooks
Limit
Value
Delivery attempts
5, after 1, 2, 4 and 8 seconds
Time to answer
10 seconds per attempt
Signature age accepted (by your receiver)
5 minutes
Security
Limit
Value
SUPERPDF_API_TOKEN
At least 32 characters
Concurrency
Tool calls are handled as they arrive and share this Mac’s processor, so several heavy calls at once each take longer. Jobs run one at a time, in the order received, so a batch never competes with itself. For many files, prefer one pdf_run_batch job over many parallel calls.
