claude-exec

name	claude-exec
description	Use this skill to delegate tasks to Claude Code CLI as a sub-agent. Triggers on: 'ask claude', 'run it with claude', 'claude -p', or when the user explicitly wants to spawn a separate Claude Code session for a task.

Claude Code CLI Sub-Agent

A skill for invoking the Claude Code CLI as a sub-agent in non-interactive mode (-p / --print).

When to use

• You want to hand off an investigation or task to a separate Claude session and only receive the result.
• You want to run a side task in parallel without polluting the current conversation's context.
• You want structured output (JSON) so the result can be processed in a pipeline.

How to run

Run non-interactively with claude -p via the Bash tool.

Basic command (read / investigation use)

claude -p --no-session-persistence --permission-mode default \
  --disallowedTools Bash,Edit,Write -- "<task>"

For tasks that write files, explicitly allow only the tools you need via --allowedTools:

claude -p --no-session-persistence --permission-mode acceptEdits \
  --allowedTools Read,Edit,Write -- "<task>"

Common flags

Flag	Purpose
-p / --print	Run in non-interactive mode and exit
--output-format json	Return the result as JSON (stream-json is also available)
--model <name>	Select the model (opus / sonnet / haiku, etc.)
--permission-mode <mode>	default / acceptEdits / plan / bypassPermissions
--no-session-persistence	Do not persist the session to disk (requires -p)
--allowedTools <list>	Restrict to a comma-separated allowlist of tools (e.g. Read,Edit)
--disallowedTools <list>	Specify a comma-separated denylist of tools
--append-system-prompt <text>	Append to the system prompt
--add-dir <path>	Grant access to an additional directory
--max-budget-usd <amount>	Set a cost ceiling
--bare	Minimal mode (disables hooks, auto-memory, automatic CLAUDE.md loading, etc.)

Long prompts

Pipe the prompt via stdin (the prompt argument can then be omitted):

echo "<long prompt>" | claude -p --no-session-persistence \
  --permission-mode default --disallowedTools Bash,Edit,Write

Structured output

claude -p --output-format json --no-session-persistence \
  --permission-mode default --disallowedTools Bash,Edit,Write \
  -- "<task>" | jq -r '.result'

The JSON includes result / total_cost_usd / session_id / duration_ms / modelUsage, among others.

Notes

• --permission-mode bypassPermissions can be rejected by the auto-mode classifier (a safeguard against runaway sub-agents). For sub-agent use, prefer default + --disallowedTools or acceptEdits + --allowedTools first.
• Put -- before the prompt. Variadic flags such as --allowedTools / --disallowedTools also accept space-separated values, so without the separator they can swallow the following prompt argument as a flag value and produce an "Input must be provided..." error. A comma-separated list plus the -- separator is the safe form.
• Set a generous timeout (up to 10 minutes: timeout: 600000).
• The current conversation context is not carried over. Include any required information in the prompt.
• Summarize the result back to the user.