Delegate codebase exploration or scripted actions to a non-interactive Codex exec run (codex exec / codex e). Use when you want a subagent to read lots of code or take actions without human interaction, and you can accept CLI output and optional file changes as the result.
Content & Writing
130 Stars
18 Forks
Updated Jan 17, 2026, 03:33 PM
Why Use This
This skill provides specialized capabilities for jxnl's codebase.
Use Cases
Developing new features in the jxnl repository
Refactoring existing code to follow jxnl standards
Understanding and working with jxnl's codebase structure
---
name: subagent
description: Delegate codebase exploration or scripted actions to a non-interactive Codex exec run (codex exec / codex e). Use when you want a subagent to read lots of code or take actions without human interaction, and you can accept CLI output and optional file changes as the result.
---
# Subagent
## When to use
- Delegate large codebase reading, searching, or multi-step actions to a non-interactive exec run.
- Offload scripted or CI-style tasks that should finish without questions.
## Inputs / outputs
- Inputs: a prompt string; optional flags such as `--cd`, `--model`, `--json`, or `--full-auto`.
- Outputs: CLI output from the exec run; possible file edits in the target repo.
## Prompt template
Use a structured prompt to keep exec runs focused:
```
Goal:
Scope/paths:
Constraints:
Deliverables:
Context:
```
## Steps
1. Decide the task and repo root; include constraints and expected deliverables in the prompt.
2. Choose a model using `resources/references/codex-exec.md` heuristics.
3. Prefer resuming when the follow-up builds on the same context (e.g., providers after a repo overview, reviewing verbose test output, or continuing a multi-step investigation). Use `codex exec resume <SESSION_ID> "<prompt>"`.
4. Start a new run when the task changes repos, needs a clean context, or should branch into a separate thread (e.g., exploring three unrelated areas in parallel).
5. Run `codex exec` directly with flags; attach images with `-i/--image` when needed. Use `--skip-git-repo-check` when running outside a Git repo.
6. Wait for completion; review output and any file changes.
7. If the task references a plan directory, update `learnings.md` in that plan directory with key findings and decisions.
## Result checklist
- Did it identify the right files and entry points?
- Are key decisions and rationale explicit?
- Are edits (if any) listed clearly?
- Are tests or verification steps noted?
## Session tracking
- Always copy the exec `session id` into the main thread for resuming.
## Safety
- Avoid `--yolo` unless inside an isolated runner.
- Prefer `--full-auto` or explicit sandbox settings when you need workspace changes.
- Keep prompts specific about allowed paths and operations.
## Resources
- `resources/references/codex-exec.md` includes flags, model selection, and code-reading guidance.
