theta¶

Rust CLI for managing agent configurations defined by theta-spec.

Installation¶

curl -sfL https://raw.githubusercontent.com/tamarillo/theta/main/scripts/install.sh | bash

Or build from source:

cargo install --path crates/theta

Quick start¶

theta init                                     # scaffold theta.toml
theta add rule python-types                    # add a rule
theta add tool fetch --command "uvx mcp-fetch" # mcp tool manual addition
theta add skill deploy org/skills@main         # GitHub shorthand
theta check                                    # validate everything
theta cast to claude-code                      # --> CLAUDE.md + .mcp.json + .claude/

What it does¶

theta reads theta.toml and resolves, locks, materializes, and casts agent configurations to any supported harness. Like a package manager but for agent harness resources.

Resolves dependencies (skills, tools, subagents) from local, git, or system store sources
Locks them deterministically into theta.lock
Materializes them into .theta/
Casts the manifest into any supported harness's native config format
Imports existing harness configs back into theta.toml

Create from harnesses¶

cd /path/to/your/project
theta cast from claude-code

Target	Cast	Import
Claude Code	Yes	Yes
Codex CLI	Yes	Yes
GitHub Copilot	Yes	Yes
Cursor (3+)	Yes	Yes

Commands¶

Group	Commands
Lifecycle	`init`, `check`, `lock`, `sync`, `cast to`, `cast from`, `tree`
Dependencies	`add rule/system/tool/skill/subagent`, `rm rule/system/tool/skill/subagent`
Inspection	`describe`, `list rules/tools/skills/subagents`
System store	`register skill/rule/agent`, `list store`, `rm store`, `init --from`

Documentation¶

Getting started — install, init, first cast
Guides — tools, skills, casting, system store, git sources
Concepts — sources, locking, caching
CLI reference — every verb, every flag
Settings — environment variables, directory overrides

It is more than recommended to read theta-spec first, given that this is the standard that theta implements.