Documents are the last thing
still stuck in the past
Every day, trillions of dollars worth of business data travels as PDFs — unstructured, unreadable by machines, re-keyed by hand. We're building the infrastructure to end that.
Our mission
Make every business document machine-verifiable by default
SDF — Smart Document Format — bundles a human-readable PDF and structured JSON into a single, digitally-signed, self-validating file. One format. Zero OCR. Zero re-keying.
We're building for the long term: an open standard, a reference implementation, a CLI, language SDKs, ERP connectors, and a SaaS platform — the full stack of infrastructure that enterprise and government document workflows need.
Principles
How we build
Open by default
The SDF specification is public domain. The reference implementation is open source. Vendor lock-in is a format smell — we designed against it.
Security is structural
Raw keys never touch the database. Private keys are AES-256-GCM encrypted at rest. Timing-safe comparisons everywhere. These aren't features — they're table stakes.
Offline-first design
An SDF file is fully self-describing. Schema is bundled inside the archive. No network call required to validate — not today, not in 20 years.
General purpose
Invoice, purchase order, government form, health report — same format, same tools. Vertical-specific assumptions are a tax on adoption.
Backward compatible
Any PDF viewer opens any SDF file. No special software required on the receiving end. Adoption is additive, never disruptive.
Documented rigorously
The format spec is 17 sections and 1,200+ lines. Every MUST, SHOULD, and MAY is deliberate. You should be able to build a compatible implementation from the spec alone.
Team
Built by practitioners
Yunus YILDIZ
Full Stack Developer
Always learning. Always building.
Transforming ideas into digital experiences.
Passionate about solving real-world challenges through technology.
Founder & CEO, Etapsky
Designed and built SDF from the ground up — spec, reference implementation, CLI, SDKs, ERP connectors, VS Code extension, OS integrations, and SaaS platform.
Etapsky is currently a one-person company. Building in public. Get in touch if you'd like to contribute or partner.
Open source
Core infrastructure belongs to the community
The SDF specification, reference implementation, CLI, and SDKs are open source under BUSL-1.1 — converting to Apache-2.0 on 2030-03-17. Forever free for individuals and non-production use.
@etapsky/sdf-kit Core TypeScript SDK — producer, reader, validator, signer
@etapsky/sdf-cli CLI — inspect, validate, sign, keygen, wrap, convert
@etapsky/sdf-schema-registry Schema management, diff, and migration engine
@etapsky/sdf-server-core Fastify server — REST API, queue, storage, ERP connectors
etapsky-sdf Python SDK — producer, reader, validator, signer
License: BUSL-1.1 — free for individual and non-production use, converts to Apache-2.0 on 2030-03-17.
Start building with SDF
Five minutes to your first machine-readable document. No account required for the open-source tools.