2 creditsSign PDF API — PAdES signatures with your own certificate
Seal a PDF with your own PKCS#12 certificate — PAdES B-B, or B-T with an RFC 3161 timestamp.
Sign PDF applies a PAdES digital signature using a PKCS#12 certificate you upload once and keep under your own account, encrypted at rest. The default profile is PAdES B-B; configure an RFC 3161 timestamp authority and the signature becomes B-T, carrying a trusted time that survives your certificate's own expiry. The signature can be invisible or placed as a visible field on any page. **The passphrase is required on every call and is never stored** — ASHDOCS cannot use your certificate without you supplying it. The response includes the signer's own validation summary: whether the signature is intact, whether it covers the entire file, and whether the certificate chain is trusted. That last flag is reported, not asserted — a certificate is trusted only if its chain validates against the verifying system's roots, and a self-signed certificate will correctly report as untrusted.
How does the Sign PDF API work?
One HTTP request from any language. Every ASHDOCS endpoint uses the same X-API-Key header.
curl -X POST 'https://api.ashdocs.com/api/v2/tools/pdf-sign' \
-H 'X-API-Key: ash_live_...' \
-F 'file=@document.pdf' \
-F 'options={"cert_id":"scert_...","passphrase":"…","reason":"Approved"}'Common use cases
- →Sealing generated invoices so downstream systems can verify them
- →Applying a company signature to contracts at the end of a workflow
- →Making a document tamper-evident before archiving
Frequently asked questions
How much does the Sign PDF API tool cost?+
2 credits per successful call. Sandbox keys (prefix ash_test_) run the tool end-to-end without ever consuming credits — use them in CI or for tuning.
What is the endpoint URL for this tool?+
The endpoint is documented in the curl example on this page. All ASHDOCS endpoints share the base URL https://www.ashdocs.com and require an X-API-Key header.
Can I run this tool inside Make, Zapier, or n8n?+
Yes — through each platform's built-in HTTP mechanism (Make's HTTP module, Webhooks by Zapier, n8n's HTTP Request node). Nothing to install: point it at this exact endpoint with your X-API-Key header. See /integrations/make, /integrations/zapier or /integrations/n8n for step-by-step setup.
Does this tool support batch or scheduled runs?+
Yes. POST /api/v1/batch runs any tool over up to 50 files with a single credit ledger entry, and pipeline schedules let you trigger the same tool on a cron. Both are documented in /docs.