Specifying your Configuration Preferences

You can provide your configuration preferences in multiple locations; the MCP server and Natural Language Agent give preference to options specified in the following order (highest to lowest):

1. Command line flags (highest priority)
2. Environment variables
3. Configuration file
4. Hard-coded defaults (lowest priority)

The server can read configuration preferences from a YAML file, making it easier to manage settings without environment variables. When configuring your MCP server and Natural Language Agent, keep your use and environment in mind:

• Development: Use environment variables or configuration files for easy iteration.
• Production: Use configuration files with command-line overrides for sensitive values.
• Claude Desktop: Use environment variables in the MCP configuration for simplicity.
• Secrets Management: Never commit API keys or passwords to version control.
• Connection Strings: Should use SSL/TLS in production (sslmode=require or sslmode=verify-full).

Specifying Properties in a Configuration File

By default, the configuration file is named pgedge-postgres-mcp.yaml, and resides in the same directory as the binary. On the command line, you can use the -config flag to specify a different location.

A complete example configuration file with detailed comments is available here.

The following table lists the configuration options you can use to specify property values:

Configuration Priority Examples

The following examples demonstrate how the MCP server's configuration priority works.

Example 1: Command Line Override

# Config file has: address: ":8080"
# Environment has: PGEDGE_HTTP_ENABLED="true"

./bin/pgedge-postgres-mcp \
  -http \
  -addr ":3000"

# Result:
# - HTTP enabled: true (from command line, highest priority)
# - Address: :3000 (from command line, highest priority)

Example 2: Environment Override

# Config file has: http.address: ":8080"
export PGEDGE_HTTP_ADDRESS=":9090"

./bin/pgedge-postgres-mcp

# Result:
# - Address: :9090 (environment overrides config file)

Example 3: Config File with Defaults

# No command line flags, no environment variables
# Config file has partial settings

./bin/pgedge-postgres-mcp -config myconfig.yaml

# Result:
# - Values from config file where present
# - Hard-coded defaults for missing values

Command Line Flags

Any configuration option specified in the configuration file can be overridden with a command line flag. Use the following command line options:

General Options:

• -config - Path to configuration file (default: same directory as binary)

HTTP/HTTPS Options:

• -http - Enable HTTP transport mode
• -addr - HTTP server address (default ":8080")
• -tls - Enable TLS/HTTPS (requires -http)
• -cert - Path to TLS certificate file
• -key - Path to TLS key file
• -chain - Path to TLS certificate chain file

Authentication Options:

• -no-auth - Disable API token authentication
• -token-file - Path to token file (default: {binary_dir}/pgedge-postgres-mcp-tokens.yaml)
• -add-token - Add a new API token
• -remove-token - Remove token by ID or hash prefix
• -list-tokens - List all API tokens
• -token-note - Annotation for new token (with -add-token)
• -token-expiry - Token expiry duration: "30d", "1y", "2w", "12h", "never" (with -add-token)
• -token-database - Bind token to specific database name (with -add-token, empty = first configured database)

See Authentication Guide for details on API token management.

Examples - Running the MCP Server

Starting the server in stdio mode with properties specified in a configuration file in the default location:

# Configure database connection via environment variables, config file, or flags
./bin/pgedge-postgres-mcp

The following example starts the MCP server in HTTP mode using properties specified on the command line and in a configuration file:

# Configure database connection via environment variables, config file, or flags
./bin/pgedge-postgres-mcp \
  -http \
  -addr ":9090"