PGPASSWORD

PGPASSWORD is an environment variable used by PostgreSQL client libraries (libpq) to supply a password for authentication without prompting the user. When a client connects to a server and password-based authentication is required, and no password is provided interactively, libpq can read the value of PGPASSWORD and use it as the password.

Usage is straightforward in scripts and automation. On Unix-like systems, you can export PGPASSWORD='secret'; then run a libpq-based client such as psql (for example, psql -h host -U user db). On Windows, you can set PGPASSWORD=secret before invoking the client. Note that PGPASSWORD is read by libpq-based applications and does not apply to programs that implement their own authentication logic.

Security considerations are important. PGPASSWORD exposes the credential in the process environment, which can be visible to other users on the same host via process listings or environment dumps, and may be captured in logs or core dumps. For improved security in automated contexts, prefer password files (pgpass) or other authentication methods. The pgpass mechanism can store host/user/password combinations in a file whose location can be customized with the PGPASSFILE environment variable or defaults to a standard path, reducing the need to expose passwords in environments. When possible, use stronger authentication methods such as GSSAPI, Kerberos, or SSL certificate-based approaches.

See also: pgpass (the password file), PGPASSFILE for locating the password file, and libpq documentation on authentication methods.