Check mode

kura --check --level 2b in.pdf

Check mode runs the entire detection pipeline against a document, writes nothing, and reports what would have to change for the input to conform. It is the same engine and the same passes as a conversion, with the output discarded.

{"file":"in.pdf","ok":true,"level":"2b","engine":"BentoPDF Kura Engine 1.1.0",
 "mode":"check","compliant":false,"findings":2,"issues":[
  {"code":"OUTPUT_INTENT_ADDED","detail":"added sRGB PDF/A output intent","fixed":true},
  {"code":"FONT_SUBSTITUTED","detail":"embedded LiberationSans as substitute for /Helvetica","fixed":true}]}

compliant is true when the document already conforms. findings counts the repairs a conversion would make, and issues lists them. Exit status is 0 when compliant, 1 when there are findings, and 2 when the file cannot be read at all, so it drops into a shell pipeline like any other preflight tool.

What counts as a finding

A finding is a repair the converter would apply, minus the three normalizations it performs on every document regardless: XMP_REBUILT, CONTENT_FILTERED and OUTPUT_INTENT_PRESENT. Those three are not evidence of a defect, so a document that needs nothing else reports findings: 0 and compliant: true.

Findings marked (visual risk) are repairs that need --allow-visual-risk on a real conversion.

What it cannot see

Check mode sees exactly what the converter can repair. That has a consequence worth stating plainly:

• It never reports a false finding. Measured against veraPDF over 568 PDF/A-1b files it agrees on every one, and over 970 PDF/A-2b files it agrees on 954.
• It is blind to any defect the converter itself does not know how to fix. Every one of the 16 disagreements above is a file veraPDF rejects that Kura does not know how to repair.

If a pass could not finish, because a content stream or metadata packet could not be read, the report carries a SCAN_INCOMPLETE finding rather than staying silent. Treat it as "unknown", not "clean".

So: use check mode as a preflight, to decide whether a document needs conversion and to see what conversion would do. Use an independent validator for certification.

Check-only flavours

x4p, x5g, x5n, x5pg, x6n, x6p and vt2 are PDF/X and PDF/VT flavours that reference an external press profile rather than embedding one. Kura validates against them but does not produce them, so they are only accepted with --check.

Idempotence

Converting a document and then checking the result always reports compliant: true with zero findings. This is asserted in the project's test lanes for every level.

In the other surfaces

The npm package exposes it as check(); the C API as verify_only on kura_options; the browser build as { check: true } in the options object.