Authentication - User Management

User accounts provide interactive authentication with session-based access. Users authenticate with username and password to receive a 24-hour session token.

• Use an API Token for direct machine-to-machine access. Tokens are long-lived and easily managed by administrators.
• Use a User Account for interactive applications; an account is session-based, and users can manage own password access.

By default, user details are stored in a file named pgedge-postgres-mcp-users.yaml in the same directory as the MCP server binary. The file has bcrypt-hashed passwords (cost factor 12), and requires that permissions are set to 0600 (owner read/write only). Each session token generated as a result of user authentication is 32 bytes, and is valid for 24-hour validity.

When configuring user authentication, you should keep the following best practices in mind:

Password Security

• Enforce minimum complexity requirements for passwords.
• Ensure passwords are not logged or displayed.
• Always use HTTPS for secure password transmission in production.
• Regularly prompt your users to update passwords.

Session Management

• Store session tokens securely (not in localStorage for web apps)
• Users should re-authenticate before a token expires.
• Implement proper logout processing, with client-side token deletion.
• Consider implementing per-user session limits for the concurrent session count.

Account Security

• Configure max_failed_attempts_before_lockout to automatically disable accounts after repeated failed login attempts.
• Log successful and failed authentication events.
• Disable accounts after a period of inactivity.
• Use annotations to track user roles and permissions.

When integrating authentication with your applications, check the session token's expiration date and time before use; if the token is valid, connect with the token:

# Good: Check token expiration before use
from datetime import datetime, timezone

def is_token_expired(expiry_str):
    expiry = datetime.fromisoformat(expiry_str.replace('Z', '+00:00'))
    return datetime.now(timezone.utc) >= expiry

if not client.session_token or is_token_expired(client.token_expiry):
    client.authenticate(username, password)

# Now use the token
result = client.call_tool("query_database", {...})

User Account Management Syntax

You can add a user at the command line in interactive mode with the following command:

# Add user with prompts
./bin/pgedge-postgres-mcp -add-user

The server will prompt you for:

• a unique username for the account
• a password (hidden, with confirmation)
• optionally, a description (e.g., "Alice Smith - Developer")

You can also add username/password pairs non-interactively with the following syntax:

# Add user with all details specified
./bin/pgedge-postgres-mcp -add-user \
  -username alice \
  -password "SecurePassword123!" \
  -user-note "Alice Smith - Developer"

To generate a list of users, use the command:

./bin/pgedge-postgres-mcp -list-users

Output:

Users:
==========================================================================================
Username             Created                   Last Login           Status      Annotation
------------------------------------------------------------------------------------------
alice                2024-10-30 10:15          2024-11-14 09:30     Enabled     Developer
bob                  2024-10-15 14:20          Never                Enabled     Admin
charlie              2024-09-01 08:00          2024-10-10 16:45     DISABLED    Former emp
==========================================================================================

To update a user account, use the following syntax variations:

# Update password
./bin/pgedge-postgres-mcp -update-user -username alice

# Update with new password from command line (less secure)
./bin/pgedge-postgres-mcp -update-user \
  -username alice \
  -password "NewPassword456!"

# Update annotation only
./bin/pgedge-postgres-mcp -update-user \
  -username alice \
  -user-note "Alice Smith - Senior Developer"

To disable or enable a user account, use the following commands:

# Disable a user account (prevents login)
./bin/pgedge-postgres-mcp -disable-user -username charlie

# Re-enable a user account
./bin/pgedge-postgres-mcp -enable-user -username charlie

To delete a user account:

# Delete user (with confirmation prompt)
./bin/pgedge-postgres-mcp -delete-user -username charlie

To specify the location of a custom user file:

# Specify custom user file path
./bin/pgedge-postgres-mcp -user-file /etc/pgedge/pgedge-postgres-mcp-users.yaml -list-users