skills-win/langgraph-plan-review/SKILL.md

---
name: langgraph-plan-review
description: Use the LangGraph plan-review workflow from the current Claude Code session. Trigger when the user asks to create Taskxx plans, run the Claude/Codex review loop, generate or revise Notes/Taskxx.md, or use the LangGraph workflow described by Task00.md. This skill uses the current Claude Code environment for Claude steps and only invokes the Python LangGraph app for Codex review and discuss file numbering.
---

# LangGraph Plan Review Workflow

Use this skill to run the LangGraph plan-review workflow. All scripts are bundled under the skill's own `scripts\` directory (`C:\Users\bowei\.claude\skills\langgraph-plan-review\scripts\`) — no dependency on `E:\LangGraph_Design\lab00`.

## Pre-flight: Environment Setup

Before running the workflow for the first time (or when unsure the environment is ready), verify that the required packages are installed in the `langgraph` conda env:

```powershell
# Install langgraph dev server, SDK, and HTTP client
conda run -n langgraph pip install "langgraph-cli[inmem]" langgraph-sdk httpx

# Verify the SDK is importable
conda run -n langgraph python -c "from langgraph_sdk import get_sync_client; print('SDK OK')"

# Verify the langgraph dev command is available
conda run -n langgraph langgraph --version
```

| Package | Purpose |
|---|---|
| `langgraph-cli[inmem]` | Provides the `langgraph dev` server command |
| `langgraph-sdk` | Python client used by `run_workflow.py` to submit runs |
| `httpx` | HTTP health-check in `run_workflow.py` |

**Codex auth** (if not already set up): `C:\Users\bowei\.codex\auth.json` must contain a valid ChatGPT OAuth token. Run `codex auth login` if the file is missing.

## Invariants

- Use the current Claude Code session for all Claude Code work. Do not launch another `claude` process.
- Assume the current Claude Code session already has `--dangerously-skip-permissions`.
- Run Python through the recorded conda environment. `run_langgraph.ps1` resolves conda from `-CondaExe`, `CONDA_EXE`, `conda` on PATH, or the user-profile miniconda fallback:
  ```powershell
  <resolved conda.exe> run -n langgraph python
  ```
- Codex CLI is installed in the `langgraph` conda env as `codex.cmd` at `C:\Users\bowei\.conda\envs\langgraph\codex.cmd`. It must be invoked via `cmd /c` because `.cmd` files are not directly executable by Python subprocess on Windows.
- Codex auth uses ChatGPT OAuth tokens stored in `C:\Users\bowei\.codex\auth.json`. No API key is needed.
- `run_langgraph.ps1` sets `CODEX_HOME` from `-CodexHome`, existing `CODEX_HOME`, or `<UserProfile>\.codex`.
- **Always use `review_task.py` as the Codex review shim.** Pass it via `--codex-review-command` as a JSON array with no spaces. This shim handles all Windows-specific codex invocation requirements: `cmd /c`, stdin prompt passing, `--skip-git-repo-check`, session resume, and explicit `cwd`.
- Keep all workflow files under `<Claude launch work_dir>\Notes` unless the user explicitly overrides `-NotesDir`.
- `TaskId` is the numeric suffix, such as `01`; write the plan to `Notes\Task01.md`.
- `discussxx-yy.md` numbering is managed by the LangGraph app for Codex review files. If Claude rejects a review comment, create the next numbered discuss file manually before rerunning review.
- The workflow uses LangGraph `interrupt()` and persists state via the langgraph dev server.
- Each `run_langgraph.ps1` invocation advances the graph to the next interrupt or completion. Use `-Resume` to continue the same thread after completing the requested Claude Code action.

## Dev Server Lifecycle

The `langgraph dev` server must be running for the entire duration of a workflow session.
Use `manage_dev_server.ps1` to start it before the first `run_langgraph.ps1` call and stop it after the workflow completes.

```powershell
# Start (idempotent — safe to call even if already running)
C:\Users\bowei\.claude\skills\langgraph-plan-review\scripts\manage_dev_server.ps1 start

# Stop (call once when workflow returns {"status":"done"})
C:\Users\bowei\.claude\skills\langgraph-plan-review\scripts\manage_dev_server.ps1 stop

# Status check
C:\Users\bowei\.claude\skills\langgraph-plan-review\scripts\manage_dev_server.ps1 status
```

- `start` waits up to 45 s for `http://127.0.0.1:2024/ok` to respond, then prints the Studio URL.
- `stop` kills the process by PID file and removes it; falls back to killing by port 2024 if the PID is stale.
- If the server is already running, `start` is a no-op.
- Server stdout/stderr logs are written to `%TEMP%\langgraph_dev_server.stdout.log` and `%TEMP%\langgraph_dev_server.stderr.log` for debugging.
- **Studio URL**: `https://smith.langchain.com/studio/?baseUrl=http://127.0.0.1:2024` — open in browser to track workflow execution in real time.

## Workflow

1. Determine `TaskId` from the user. If missing, ask for it.
2. Start the dev server (idempotent):
   ```powershell
   C:\Users\bowei\.claude\skills\langgraph-plan-review\scripts\manage_dev_server.ps1 start
   ```
   Wait for the "[dev-server] Ready" line in the output. Then **immediately tell the user** in your text response:
   - that the dev server is running, and
   - the Studio URL: `https://smith.langchain.com/studio/?baseUrl=http://127.0.0.1:2024`

   Example message to user:
   > LangGraph dev server 已就绪。可在浏览器中打开 Studio 实时监控工作流：
   > https://smith.langchain.com/studio/?baseUrl=http://127.0.0.1:2024
3. Start or resume the LangGraph app:
   ```powershell
   # Use double backslashes (\\) in the JSON string so Windows paths are valid JSON.
   # $task_path / $latest_discuss_path / etc. are Python Template placeholders — keep them literal.
   $codexCmd = '["C:\\Users\\bowei\\.conda\\envs\\langgraph\\python.exe","C:\\Users\\bowei\\.claude\\skills\\langgraph-plan-review\\scripts\\review_task.py","$task_path","$latest_discuss_path","$codex_session_id","$work_dir"]'
   C:\Users\bowei\.claude\skills\langgraph-plan-review\scripts\run_langgraph.ps1 `
     -TaskId <TaskId> `
     -Prompt "<original user request>" `
     -CodexReviewCommand $codexCmd `
     -Timeout 300
   ```
4. Inspect the returned JSON. If `status` is `waiting`, perform `action_required` in the current Claude Code session:
   - `write_plan`: write `Task<TaskId>.md` with project background, task objective, and concrete implementation plan, then resume with `-Resume 'true'`.
   - `decide`: read the discuss file and resume with `-Resume '{"accepts":true}'` or `-Resume '{"accepts":false,"reason":"..."}'`.
   - `revise`: revise `Task<TaskId>.md`, then resume with `-Resume 'true'`.
   - `write_rejection`: write the specified `output_path`, then resume with `-Resume 'true'`.

   **Why `review_task.py`**: Using the shim keeps all codex-specific logic in Python, and the JSON array stays simple.

   `run_langgraph.ps1` base64-encodes the JSON command and resume payload before passing them through `conda run`, so normal PowerShell single-quoted JSON can be used. **Windows paths inside the JSON string must use `\\` (double backslash) to produce valid JSON**, e.g. `C:\\Users\\bowei\\...`. `run_langgraph.ps1` automatically sets `PYTHONIOENCODING=utf-8` so prompts containing Unicode (Chinese, etc.) pass through correctly.
5. Inspect the command output after each resume.
   - Check `"status"` to determine next action: `"waiting"` means perform the next `action_required`; `"done"` means the workflow is complete.
   - If a new `latest_discuss_path` is present in the output, read that discuss file for context.
6. Stop when the workflow returns `{"status":"done", ...}`:
   ```powershell
   C:\Users\bowei\.claude\skills\langgraph-plan-review\scripts\manage_dev_server.ps1 stop
   ```

## Rejection File Rule

When the `action_required` is `write_rejection`, the interrupt payload already contains the exact file path:

```json
{"action": "write_rejection", "output_path": "Notes/discuss04-01.md", "reason_hint": "..."}
```

Write the rejection content directly to `action_required.output_path`:

```markdown
# discuss<TaskId>-<yy>

## Claude Code Rejection

<reason>
```

## Notes

- The LangGraph app automatically scans existing discuss files and writes the next Codex review file without overwriting old discussions.
- The app no longer accepts Claude command arguments; Claude actions happen in this current session.
- If `codex` is unavailable, report that the review step cannot run rather than simulating it.
- `review_task.py` passes the review prompt through stdin with `-` to avoid Windows command-line quoting issues with multiline prompts.
- `review_task.py` passes `--skip-git-repo-check` so the workflow can run from Claude launch directories that are not git repositories.
- `review_task.py` reads Codex final output via `--output-last-message` so intermediate JSONL progress messages are not treated as review findings.
- `review_task.py` persists the Codex session id through LangGraph state and uses `codex exec resume` on later review passes.
- `review_task.py` runs Codex with the original Claude Code launch working directory as cwd.
- Codex review output is normalized to JSON for `agents.py`: `{"has_serious_issue":true/false,"comment":"...","codex_session_id":"..."}`.
- If the dev server restarts, `run_workflow.py` detects that the stored thread no longer exists and creates a new thread automatically.
- `run_workflow.py` passes the codex command and timeout as `config["configurable"]` per run — no server restart needed when switching projects.