plan-split

plan-split is a skill for Claude Code, Codex from paulbaranowski/wild-horses. It costs 71 tokens per session (2,894 once invoked), scanned A, original, MIT.

A planning skill that breaks one software plan into smaller implementation tasks and connects them in dependency order. A plan is marked as blocked when it cannot start until another task is finished.

In plain words
What is it for?
It is for splitting specifications, designs, or execution plans into independently dispatchable tasks saved in a repository's plans directory.
Why use it?
It makes a large piece of work easier to assign and execute in separate slices while preserving which tasks must come first.

Skill for Claude CodeCodex

Installs and runs on its own, but its text points at files inside its plugin — anything it tells you to read at a ${CLAUDE_PLUGIN_ROOT} path is only there once the plugin is installed. Installing the plugin gets both.

Part of the plan-keeper plugin — 9 skills shipped together

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/paulbaranowski/wild-horses/plan-split
Any agent
npx skills add paulbaranowski/wild-horses --skill plan-split
Clone the repo
git clone --depth 1 https://github.com/paulbaranowski/wild-horses

Made for: Claude Code, Codex.

Or install plan-keeper, the plugin that ships this one along with the rest of its 9 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for plan-split

README.md
[![agentmods](https://agentmods.dev/badge/skills/paulbaranowski/wild-horses/plan-split.svg)](https://agentmods.dev/skills/paulbaranowski/wild-horses/plan-split)
Your own site
<a href="https://agentmods.dev/skills/paulbaranowski/wild-horses/plan-split"><img src="https://agentmods.dev/badge/skills/paulbaranowski/wild-horses/plan-split.svg" alt="Measured on agentmods" height="20"></a>
Per session 71 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,894 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 $0.00071 $0.02894
Opus 5 $0.00036 $0.01447
Sonnet 5 $0.00014 $0.00579
Haiku 4.5 $0.00007 $0.00289

Measured 5d ago against content hash 4ac173cf9e82, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

plan-split 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 5d ago.

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.

plugins/plan-keeper/skills/plan-split/SKILL.md · 178 lines

How it starts

The opening of the file, as written. The whole thing — 178 lines — stays where its author put it; the contents beside it link to each section on GitHub.

plan-split

Decompose one plan into N child implementation-task plans under ~/plans/<repo>/, each a thin vertical slice (tracer bullet), wired together with plan-keeper's native Blocked-by: dependencies and staged at todo. Queue the staged slices through plan-crew (which stamps each one's Agent: tag — the dispatch gate file-meta set doesn't write) and groundcrew runs the wave in dependency order — the ready ones immediately, the blocked ones the moment their prerequisites finish.

This is the to-issues decomposition pattern retargeted from an external issue tracker to the plans tree. It composes the existing CLI (save, file-meta get, file-meta set) — there is no new subcommand.

Where this sits

plan-keeper's unit of work is a task, and every task is a plan file. A planning task spawns more plans; an implementation task produces code (see ../../README.md "The model"). plan-split is the bridge: it takes one source plan (a spec / design / exec-plan) and spawns its child implementation tasks, each ready for groundcrew. It does not file anything to Linear/Jira — that stays the occasional plan-linear / plan-jira export.

Quick reference

  • Source plan: the single plan being decomposed. A saved file in ~/plans/<repo>/ (named by path, topic, or "the plan I just saved") or the current conversation's plan. See Choosing the source.
  • Slice (child plan): one tracer-bullet plan written as ~/plans/<repo>/<date>-<project>-NN-<slice>--exec-plan.md, Kind: exec-plan, Status: todo.
  • Ordinal: each slice topic carries a zero-padded ordinal (01, 02, …) so the wave sorts in order in plan-list.
  • Dependencies: the native Blocked-by: frontmatter field (comma-separated prerequisite ticket IDs). groundcrew holds a todo slice until every prerequisite is done, then auto-dispatches. See ../../groundcrew/README.md "Dependencies between plans".
  • Provenance: each slice records a Source: frontmatter key pointing at the source plan — provenance, not a dependency (keep it distinct from Blocked-by:).
  • Source plan disposition: when it was a saved file, it is marked done after slicing (its deliverable — the child plans — has been produced).
  • <repo>: auto-derived or override — see ../../repo-derivation.md.
  • Approval gate: the breakdown is presented and iterated with the user; nothing is written until the user approves.

Read the full file on GitHub · 178 lines

Files

What ships with it

1 file 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. 5d ago First seen · 178 lines · 71 tokens per session scan A 4ac173cf9e82

Subscribe to this mod's changes

plan-split is a skill published in the GitHub repository paulbaranowski/wild-horses (11 stars, last pushed 17d ago), licensed MIT. It adds 71 tokens to every session and 2,894 once invoked, about $0.0004 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.

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