Delegating to Agents

When to Use

• Use when work should be handed to another AI agent with a complete prompt and progress checks.
• Use when you need to relay instructions to terminal or TUI agents without losing context.

Which agent to pick

• Coding (default) → Codex CLI. Strongest coding agent, especially for complex, long-running SWE tasks. It's on an unlimited-usage plan — effectively unlimited, don't ration it.
• Most other tasks → Pi Agent (pi in a cmux terminal). All Pi agents run opus-4.8-fast via OpenRouter at xhigh reasoning effort.
• Frontend / design → Pi. Opus 4.8 Fast beats Codex on UI, styling, design.
• Heavy multi-step work: you as orchestrator + Codex CLI executing in a right-hand cmux pane is a solid default setup.

Sending prompts to a TUI agent

1. ONE single line — never newlines in the message body. In a TUI, newline = Enter: a multi-line prompt submits at the first line and the rest arrives as fragmented mid-turn steering messages. Use ". " or "; " instead of line breaks, then one explicit enter. For long instructions, write them to a file and send: read /tmp/task.md and follow it.
2. Wrap the prompt in plain double quotes — NEVER escaped. cmux send --surface surface:N "your prompt". The recurring bug is emitting \" — in bash that's literal-broken and dies with unexpected EOF. Inside the prompt, avoid apostrophes and literal double quotes (write "dont", "wont", "lets"); rephrase instead of escaping. If a send failed, the cause was the escaped \", not the quote type.
3. Exact command names: cmux send --surface surface:N then cmux send-key --surface surface:N enter. There is NO send-surface or send-key-surface.