plan-write

A skill for turning agreed software requirements into a detailed implementation plan saved as a Markdown file under the plan/ folder. Markdown is a plain-text document format commonly used for project notes and documentation.

In plain words
What is it for?
Use it when you have a rough design or requirements and need a written plan covering the work, without starting implementation.
Why use it?
It gives developers a self-contained roadmap to review before writing code.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/besimple-oss/broccoli/plan-write
Any agent
npx skills add besimple-oss/broccoli --skill plan-write
Clone the repo
git clone --depth 1 https://github.com/besimple-oss/broccoli

Made for: Claude Code, Codex.

Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 738 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00036 $0.00738
Opus 5 $0.00018 $0.00369
Sonnet 5 $0.00007 $0.00148
Haiku 4.5 $0.00004 $0.00074

Measured 3d ago against content hash ea19eb0630ee, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

plan-write scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 3d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/run_plan_write.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

prompt-templates/skills/plan-write/SKILL.md · 74 lines

How it starts

The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Write Plan Doc

Preconditions

  • Confirm you are in the intended repo: git rev-parse --show-toplevel
  • Do not start implementation in this skill; only write/update the plan document.
  • Plan critique is a separate step (use plan-critique-loop); plan-write does not run critique internally.

Expected runtime

Typically runs 15–45 minutes. Callers should allow the full --timeout (default 3600s) before interrupting.

If you use --progress-log, do not tail -f it into the main context unless you must debug; prefer checking progress via log line counts (for example: wc -l <progress-log>) and/or the heartbeat counters.

Workflow — Option A (external script, preferred)

Run the plan-write as a standalone CLI invocation:

resolve_skill_dir() {
  local name="$1"
  local repo_root=""
  repo_root="$(git rev-parse --show-toplevel 2>/dev/null || pwd)"

  local candidates=(
    "$repo_root/.agents/skills/$name"
    "$repo_root/.claude/skills/$name"
    "$HOME/.agents/skills/$name"
    "$HOME/.codex/skills/$name"
    "$HOME/.claude/skills/$name"
  )

  for d in "${candidates[@]}"; do
    if [[ -d "$d" ]]; then
      echo "$d"
      return 0
    fi
  done

  echo "Error: skill '$name' not found in repo-scoped or user-scoped skill dirs." >&2
  return 1
}

PLAN_WRITE_SKILL_DIR="$(resolve_skill_dir plan-write)"
python3 "$PLAN_WRITE_SKILL_DIR/scripts/run_plan_write.py" sketch/<generated-name>.md

Flags:

  • --cli codex|claude — override auto-detected CLI
  • --model MODEL — pass a specific model to the CLI
  • --reasoning-effort LEVEL — pass explicit reasoning effort (vhigh aliases to xhigh)
  • --timeout N — CLI invocation timeout in seconds (default: 3600)
  • --progress-log PATH — optional path to append streamed subagent output
  • --heartbeat-seconds N — heartbeat cadence in seconds (0 disables)

Default behavior:

  • When using Codex and no overrides are provided, the script uses --model gpt-5.2 with high reasoning effort.
  • When using Codex, the script always runs with --sandbox danger-full-access, -a never, and --search so it can do bounded official-doc research when “latest” matters.

Read the full file on GitHub · 74 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 3d ago First seen · 74 lines · 36 tokens per session scan A ea19eb0630ee

Subscribe to this mod's changes

plan-write is a skill published in the GitHub repository besimple-oss/broccoli (285 stars, last pushed 4mo ago), licensed MIT. It adds 36 tokens to every session and 738 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.