To connect to Postgres.app, you can leave all fields blank.
See also: Installing Postgres.app
To connect to a PostgreSQL server installed with the graphical installer from EnterpriseDB, click the “New Favorite” button and provide the following parameters:
To connect to a PostgreSQL server installed with MacPorts, use the following parameters:
Some protection products interfere with TCP connections. For example, a product named X3 Protect has been known to block connection attempts to local PostgreSQL servers. If you are having trouble connecting to a local PostgreSQL server, try disabling your firewall, or add an exception for port 5432.
This error message usually appears when there is a problem with the /etc/hosts file. Make sure there is an entry for localhost. As a workaround, you can also type “127.0.0.1” into the host field instead of “localhost”.
There are two ways to connect to a local PostgreSQL server:
Postico always uses TCP connections. Postico can't use socket connections because sandboxed apps are not allowed to access unix sockets outside their sandbox.
By default, PostgreSQL is always configured to listen for TCP connections on localhost, so that should not be a problem unless you explicitly disabled TCP connections.