/plan

name: plan
description: "Plan mode: write an actionable markdown plan to .hermes/plans/, no execution. Bite-sized tasks, exact paths, complete code."
version: 2.0.0
author: Hermes Agent (writing-craft adapted from obra/superpowers)
license: MIT
platforms: [linux, macos, windows]
metadata:
  hermes:
    tags: [planning, plan-mode, implementation, workflow, design, documentation]
    related_skills: [subagent-driven-development, test-driven-development, requesting-code-review]

Plan Mode

Use this skill when the user wants a plan instead of execution.

Core behavior

For this turn, you are planning only.

• Do not implement code.
• Do not edit project files except the plan markdown file.
• Do not run mutating terminal commands, commit, push, or perform external actions.
• You may inspect the repo or other context with read-only commands/tools when needed.
• Your deliverable is a markdown plan saved inside the active workspace under `.hermes/plans/`.

Output requirements

Write a markdown plan that is concrete and actionable.

Include, when relevant:

• Goal
• Current context / assumptions
• Proposed approach
• Step-by-step plan
• Files likely to change
• Tests / validation
• Risks, tradeoffs, and open questions

If the task is code-related, include exact file paths, likely test targets, and verification steps.

Save location

Save the plan with `write_file` under:

• `.hermes/plans/YYYY-MM-DD_HHMMSS-<slug>.md`

Treat that as relative to the active working directory / backend workspace. Hermes file tools are backend-aware, so using this relative path keeps the plan with the workspace on local, docker, ssh, modal, and daytona backends.

If the runtime provides a specific target path, use that exact path. If not, create a sensible timestamped filename yourself under `.hermes/plans/`.

Interaction style

• If the request is clear enough, write the plan directly.
• If no explicit instruction accompanies `/plan`, infer the task from the current conversation context.
• If it is genuinely underspecified, ask a brief clarifying question instead of guessing.
• After saving the plan, reply briefly with what you planned and the saved path.

---

Writing the Plan Well

The rest of this skill is the craft of authoring a *good* implementation plan — the content that goes inside the markdown file above.

Overview

Write comprehensive implementation plans assuming the implementer has zero context for the codebase and questionable taste. Document everything they need: which files to touch, complete code, testing commands, docs to check, how to verify. Give them bite-sized tasks. DRY. YAGNI. TDD. Frequent commits.

Assume the implementer is a skilled developer but knows almost nothing about the toolset or problem domain. Assume they don't know good test design very well.

**Core principle:** A good plan makes implementation obvious. If someone has to guess, the plan is incomplete.

When a Full Implementation Plan Helps

**Always use before:**

• Implementing multi-step features
• Breaking down complex requirements
• Delegating to subagents via subagent-driven-development

**Don't skip when:**

• Feature seems simple (assumptions cause bugs)
• You plan to implement it yourself (future you needs guidance)
• Working alone (documentation matters)

Bite-Sized Task Granularity

**Each task = 2-5 minutes of focused work.**

Every step is one action:

• "Write the failing test" — step
• "Run it to make sure it fails" — step
• "Implement the minimal code to make the test pass" — step
• "Run the tests and make sure they pass" — step
• "Commit" — step

**Too big:**

### Task 1: Build authentication system
[50 lines of code across 5 files]

**Right size:**

### Task 1: Create User model with email field
[10 lines, 1 file]

### Task 2: Add password hash field to User
[8 lines, 1 file]

### Task 3: Create password hashing utility
[15 lines, 1 file]

Plan Document Structure

Header (Required)

Every plan MUST start with:

# [Feature Name] Implementation Plan

> **For Hermes:** Use subagent-driven-development skill to implement this plan task-by-task.

**Goal:** [One sentence describing what this builds]

**Architecture:** [2-3 sentences about approach]

**Tech Stack:** [Key technologies/libraries]

---

Task Structure

Each task follows this format:

### Task N: [Descriptive Name]

**Objective:** What this task accomplishes (one sentence)

**Files:**
- Create: `exact/path/to/new_file.py`
- Modify: `exact/path/to/existing.py:45-67` (line numbers if known)
- Test: `tests/path/to/test_file.py`

**Step 1: Write failing test**

```python
def test_specific_behavior():
    result = function(input)
    assert result == expected

**Step 2: Run test to verify failure**

Run: `pytest tests/path/test.py::test_specific_behavior -v` Expected: FAIL — "function not defined"

**Step 3: Write minimal implementation**

def function(input):
    return expected

**Step 4: Run test to verify pass**

Run: `pytest tests/path/test.py::test_specific_behavior -v` Expected: PASS

**Step 5: Commit**

git add tests/path/test.py src/path/file.py
git commit -m "feat: add specific feature"

## Writing Process

### Step 1: Understand Requirements

Read and understand:
- Feature requirements
- Design documents or user description
- Acceptance criteria
- Constraints

### Step 2: Explore the Codebase

Use Hermes tools to understand the project:

```python
# Understand project structure
search_files("*.py", target="files", path="src/")

# Look at similar features
search_files("similar_pattern", path="src/", file_glob="*.py")

# Check existing tests
search_files("*.py", target="files", path="tests/")

# Read key files
read_file("src/app.py")

Step 3: Design Approach

Decide:

• Architecture pattern
• File organization
• Dependencies needed
• Testing strategy

Step 4: Write Tasks

Create tasks in order: 1. Setup/infrastr