plan

A command that turns a software specification into a written implementation plan before code is changed.

In plain words
What is it for?
Breaking a coding task into small steps, documenting expected changes and checks, and saving the plan for review.
Why use it?
It makes the work, files, commands, and checks reviewable in advance, which is useful when you want approval before implementation.

Command

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 commands/vrennat/developersdevelopers/plan
Clone the repo
git clone --depth 1 https://github.com/vrennat/developersDevelopers
Per session 34 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 395 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 $0.00034 $0.00395
Opus 5 $0.00017 $0.00198
Sonnet 5 $0.00007 $0.00079
Haiku 4.5 $0.00003 $0.00040

Measured yesterday against content hash f68f44c8807e, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

plan 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 yesterday.

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.

commands/plan.md · 37 lines

What it actually says

/plan

Generate an explicit implementation plan from a spec. Output: docs/plans/YYYY-MM-DD-<slug>.md.

Use this when you want a written plan you can review before any code is touched. For most work, /impl handles planning inline and saves you a round-trip.

Procedure

  1. Read the input spec or freeform description.
  2. Map the file structure: which files are created vs modified, and what each is responsible for.
  3. Decompose into atomic tasks. Each task = one file or one logical unit (2-5 minutes of work). Each task ends with a commit.
  4. For each task, write:
    • Files (create / modify with line ranges)
    • Steps as a checkbox list (- [ ])
    • Complete code blocks for any code change (no placeholders, no "implement similar to task N")
    • The exact commands to run with expected output
  5. Self-review: spec coverage (every requirement has a task), placeholder scan, type/name consistency across tasks.
  6. Write the plan to docs/plans/YYYY-MM-DD-<slug>.md.
  7. Commit: docs: implementation plan for <slug>.
  8. Report path. Do NOT auto-execute.

Rules

  • No placeholders. No "TBD" / "TODO" / "implement later" / "add appropriate error handling".
  • No "see Task N" cross-references. Repeat the code if needed.
  • Each task is self-contained and committable independently.

When NOT to use

  • The work is simple-to-medium and clear: just /impl directly, no plan needed.
  • The user said "just build it": skip the plan.
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. yesterday First seen · 37 lines · 34 tokens per session scan A f68f44c8807e

Subscribe to this mod's changes

plan is a command published in the GitHub repository vrennat/developersDevelopers (2 stars, last pushed 1mo ago), licensed MIT. It adds 34 tokens to every session and 395 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 2026-08-31.