Web site:

Available since acme4j 3.2.0

Connection URIs

  • acme://, acme:// - Production server, ECDSA certificate mode
  • acme:// - Production server, RSA certificate mode
  • acme://, acme:// - Testing server, ECDSA certificate mode
  • acme:// - Testing server, RSA certificate mode


  • This CA requires External Account Binding (EAB) for account creation. However, the CA's directory resource returns externalAccountRequired as false, which is incorrect. If you use one of the acme: URIs above, acme4j will patch the metadata transparently. If you directly connect to via https: URI though, Metadata.isExternalAccountRequired() could return a wrong value. (As of February 2024)


acme4j is not officially supported or endorsed by If you have acme4j related issues, please do not ask them for support, but open an issue here.