{"how_to_use":"POST the PDF as the raw request body (Content-Type: application/pdf) or as JSON {\"pdf_base64\": \"...\"}","max_size_bytes":20971520,"example":"curl --data-binary @signed.pdf -H 'Content-Type: application/pdf' https://pdf-signature-checker-formatho.filesformatho.workers.dev/api","returns":"per-signature /ByteRange coverage, signature metadata (SubFilter, signing time, reason, signer), unsigned/trailing bytes, incremental-update count, and a structural verdict","limitation":"structural coverage check — does not cryptographically verify the certificate chain or digest","decoded_by":"Formatho edge API — zero tracking","full_tool":"https://formatho.com/tools/pdf-signature-checker"}