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UMCP provides a command-line interface for running, validating, and testing your MCP aggregation configuration.

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Quick Start

# Start umcp with default stdio transport
umcp serve

# Start umcp with HTTP transport
umcp serve --transport http --port 8787

# Validate your configuration
umcp validate

# Preview tool discovery without starting the server
umcp dry-run

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Available Commands

serve

Start the UMCP aggregation server

validate

Validate your configuration file

dry-run

Preview tool discovery without starting

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Global Flags

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--config
string
default:"~/.config/umcp/umcp.jsonc"
Path to the UMCP configuration file. Supports only .jsonc format.
umcp serve --config /path/to/custom.jsonc
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--help
boolean
Display help information and exit.
umcp --help
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-h
boolean
Short form of --help.

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Help Text

Running umcp --help displays: 
umcp - Unified MCP Aggregator

Usage:
  umcp serve [--transport stdio|http] [--host 127.0.0.1] [--port 8787] [--path /mcp] [--config /path/to/umcp.jsonc]
  umcp validate [--config /path/to/umcp.jsonc]
  umcp dry-run [--config /path/to/umcp.jsonc]

Compatibility flags:
  umcp --validate [--config /path/to/umcp.jsonc]
  umcp --dry-run [--config /path/to/umcp.jsonc]

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Compatibility Flags

For backward compatibility, UMCP supports legacy flag syntax: 
# Legacy syntax (still supported)
umcp --validate
umcp --dry-run

# Modern syntax (recommended)
umcp validate
umcp dry-run
Both forms are functionally identical.

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Default Behavior

When no command is specified, UMCP defaults to serve: 
# These are equivalent
umcp
umcp serve

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Error Handling

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Unknown Command

If you provide an invalid command: 
umcp invalid-command

Error: Unknown command 'invalid-command'. Use --help for usage.

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Invalid Flag Values

UMCP validates flag values and provides clear error messages: 
umcp serve --transport invalid

Error: Invalid --transport value 'invalid'. Expected 'stdio' or 'http'.

umcp serve --port abc

Error: Invalid value for --port: abc

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Flag Parsing

UMCP supports multiple flag formats: 
# Space-separated
umcp serve --transport http

# Equals sign
umcp serve --transport=http

# Boolean flags (presence = true)
umcp --validate

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Next Steps

Serve Command

Learn about all serve command options

Configuration

Configure your MCP providers

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