ActionID is a single sign on provider, used to login to many applications in the progressive ecosystem. Accounts are freely available to anyone who wants to create them, and many tools (such as openVPB) allow users to begin volunteering immediately upon account creation. For more restricted access (such as to VoteBuilder or NGP), system administrators are still in control of whether users with ActionIDs can log in and have fine grained controls over feature availability and data access. Third party applications have the same options - either trust all accounts or apply additional security.
ActionID is an OpenID Connect identity provider. Most programming languages have widely available libraries for OpenID Connect authorization.
ActionID is available now at http://accounts.ngpvan.com, and relevant integration info is available at https://accounts.ngpvan.com/oidc/.well-known/openid-configuration. Please note that this integration will not work without our whitelisting of your relying party endpoint URLs.
For more information on the technical details of ActionID, check out the OpenID Connect spec.