Certo is an open‑source infrastructure for issuing, managing, verifying, and exchanging digital credentials. It implements Open Badges 3.0 and W3C Verifiable Credentials, the open standards that make credentials portable, machine‑verifiable, and vendor‑independent.

Designed to be self‑hosted, standards‑compliant, API‑first, exportable, and extensible, Certo lets organizations run the platform inside their own infrastructure, air‑gapped network, or sovereign cloud without vendor lock‑in.

Use cases span educational institutions, training organizations, event organizers, companies, open‑source communities, and professional associations. The demo at https://certo.schroedinger-hat.org/ showcases how Schroedinger Hat conferences and workshops issue badges and certificates.

Key features include badge template creation, bulk issuance via CSV, cryptographic verification, revocation support, evidence attachments, endorsements, LinkedIn sharing, and a plugin interface for extensibility. All data is exportable in open formats, keeping ownership with the issuer.