Every document,
sealed with certainty.
Send a document, get back who signed it, when, with what certificate — in one API call. Supports PDF, KRX, ASiC-E, XAdES, JAdES and all eIDAS formats.
No credit card required · 100 free validations/month
Three steps to document trust
No infrastructure to manage. No certificates to configure. Just an API call.
- 01 Send
Upload your document
POST your file to our API. PDF, KRX, ASiC, XAdES, JAdES — any eIDAS format accepted. Max 50MB. No storage — your document is never saved.
- 02 Validate
We validate everything
Cryptographic signature integrity, certificate chain, OCSP revocation, qualified timestamps, eIDAS trust list — all in one pass.
- 03 Trust
Get an audit-ready report
Structured JSON with signer identity, signature level (QES/AdES), validity period, timestamps and certificate chain. Store it. Query it. Export it.
Built for the documents Europe actually signs
Native support for the formats, signature levels and privacy rules that matter in regulated EU and CEE workflows.
Hungarian e-government, first-class
Sealium is the only platform with native KRX container support — the Hungarian government document format used by banks, insurers and public administration. DÁP qualified signatures, Hungary's citizen e-signature, verify out of the box — as do documents authenticated through AVDH, Hungary's central e-administration service, which are standard PAdES/ASiC underneath.
1 API call → 3 documents validated
Know if a signature is legally binding
Every validation returns the eIDAS signature level: QES, AdES or unknown. A QES carries the same legal weight as a handwritten signature across all 27 EU member states — we tell you immediately if you have one.
eIDAS signature level, returned every time
Your documents never leave your hands
We process documents in-memory and discard them immediately after validation. Only the JSON report is stored — never the original file. GDPR-friendly by architecture, not by policy.
In-memory processing. The file is never stored.
Validate 50 documents in one job
Upload a batch, get webhook callbacks when complete. Perfect for document management systems, legal workflows and compliance pipelines. Per-document results, partial success handling included.
Upload once, get callbacks when each report is ready
1 API call → 3 documents validated
EU DSS is a library. Sealium is the engine around it.
We’re built on the same EU DSS library your team would reach for — it’s excellent, and open source. The catch is the long road between a DocumentValidator call and an answer you’d put in front of an auditor. The engine is that road, already paved.
Roll your own on EU DSS
Everything below is yours to build, test and keep running.
- Pick the right validator for every format — and know the format before you start.
- Stand up a trusted-list job: schedule the LOTL refresh, manage the cache, wire the OJ keystore.
- Patch the JVM truststore with each national CA (HU, ES, IE, PL…) just to fetch the trust lists.
- Write KRX container unpacking from scratch — DSS has never heard of the format.
- Decode raw Indication / SubIndication codes and 20+ qualification enums into something a human reads.
- Track every DSS release and the TLv6 deadline (mandatory 28 Apr 2026) yourself.
Built in, on day one
The same crypto core — wrapped in everything production needs.
- One endpoint, any format. Magic-byte detection across PDF, PAdES, XAdES, CAdES, JAdES, ASiC-E/S and KRX.
- 31 EU trusted lists kept fresh — with the national-CA truststore already merged in for you.
- Native KRX: every ID-N payload extracted, validated and rolled up with partial-success handling.
- A stable JSON report — signer, eIDAS level (QES / AdES), cert chain, timestamps, revocation. Not a JAXB tree.
- Plain-language verdicts: “certificate expired, but a trusted timestamp proves it was signed before expiry.”
- Certificate-expiry warnings 90 days out, in-memory only, structured errors — never a stack trace.
Integrate in minutes
One endpoint. One header. Any format.
curl -X POST https://api.sealium.eu/v1/validate \ -H "Authorization: Bearer slm_live_..." \ -F "file=@contract.pdf"The example is trimmed for clarity — every call returns the full report: per-signature detail, certificate chain, timestamps, revocation status and LOTL summary.
See the full response schemaSimple, transparent pricing
Start free. Scale as you grow. Paddle handles all EU VAT compliance.
Free
billed monthly
For developers exploring the API
Start for free- 100 API calls / month
- 1 concurrent request
- All formats (PDF, KRX, ASiC, XAdES, JAdES)
- Validation history
- Community support
Pro
billed monthly
For developers integrating in production
Get started with Pro- Everything in Free, plus:
- 5,000 API calls / month
- 3 concurrent requests
- Search by signer & organization
- Certificate expiry alerts
- Email support
- $0.015 / extra call
Business
billed monthly
For software companies and teams
Get started with Business- Everything in Pro, plus:
- 25,000 API calls / month
- 10 concurrent requests
- Advanced filters & CSV export
- Batch processing (50 docs/job)
- Webhooks
- 99.5% SLA · Priority support
- $0.010 / extra call
Enterprise
Tailored to your volume
For banks, insurers and public administration
Contact sales- Everything in Business, plus:
- Unlimited API calls
- On-premise deployment option
- FTP / S3 batch pipeline
- Request logs & compliance
- Custom SLA & dedicated support
- Azure AD, Okta & any OIDC provider
All plans include overage billing. Prices exclude VAT — Paddle handles EU tax compliance automatically.
Running at enterprise scale?
Sealium On-Premise brings the full validation engine to your infrastructure. Docker-based, works with your existing identity provider, FTP and S3 batch pipelines included. Your documents never leave your network.
- Full data sovereignty
- Azure AD, Okta & any OIDC provider
- FTP / S3 / API batch processing
- Dedicated support & SLA
- Hungarian KRX & DÁP QES support
No external connections · documents never leave your network