Harnesses and Scope

`tuff harness`

A harness is the coding agent product Tuff installs for, such as Claude Code or Codex. Its id, such as claude, is what -a selects.

Configure the default harness

# Project default
tuff harness set-default open-agents

# Global default
tuff harness set-default claude --global

Commands that accept -a/--harness use this value when the flag is omitted. An explicit -a always overrides the default, and repeated flags apply an operation to several harnesses.

List available and registered harnesses

tuff harness list

# Show the global default
tuff harness list --global

The REGISTERED column shows which harnesses are available for Tuff operations in the selected config. The DEFAULT column shows which registered harness is used when -a/--harness is omitted.

Register a harness

tuff harness add open-agents
tuff harness add claude
tuff harness add codex
tuff harness add cursor
tuff harness add opencode

Registering a harness also creates its project directory (.agents/ or .claude/) if it does not already exist.

claude-code remains an alias for claude. codex, cursor, and opencode are dedicated adapter IDs. opencode takes policies and MCP servers, and tuff init does not register it.

Remove a harness

tuff harness remove open-agents

Unregisters the harness from the project configuration. It does not delete capabilities, emitted files, baselines, MCP registrations, or lockfile entries. Use tuff delete <id> or tuff untrack <id> for the configured default agent. Pass -a <agent> when selecting a different agent.

Scope

Tuff supports two scopes:

Scope	Location	Use
`project`	`tuff.lock` in repo root	Shared with team via version control
`global`	Tuff user state directory	Available across all projects

Resolution order: project always wins. If the same primitive exists at both scopes, the project copy shadows the global one. tuff status flags shadowed primitives. See Scopes & Overrides for more.