step-ca is an online certificate authority (CA) for running your own private PKI, aimed at DevOps environments. The server issues X.509 (TLS) certificates and SSH certificates and acts as an ACME server, so common ACME clients can request certificates automatically. Supported provisioners include OIDC single sign-on, cloud instance identity and JWK tokens. Keys can be protected with HSMs, cloud KMS or YubiKey PIV, and it integrates with Kubernetes cert-manager. It is server software that you run yourself, together with the step command-line client.
step-ca is maintained by Smallstep Labs, Inc., a company based in San Francisco, in the United States, and is released under the Apache 2.0 licence. Because you operate the CA yourself, certificates, keys and issuance logs stay under your control. Smallstep also offers a commercial platform and a hosted authority for features step-ca does not include; its documentation does not state a hosting region for that hosted service.