iso-write

iso-write is a skill for Claude Code, Codex from IsaiaScope/ai. It costs 172 tokens per session (2,879 once invoked), scanned A, original, MIT.

A tool that implements a written coding plan using TDD, or test-driven development: writing tests around expected behaviour while building the change. It leaves the edits uncommitted for review.

In plain words
What is it for?
Use it to build features or fixes from a Markdown plan. It supports working in place, on a named or derived branch, or in a separate Git worktree, and runs the implementation without creating commits.
Why use it?
It turns an agreed plan into working code while preserving the user's chance to inspect the complete diff before committing. It can also place the work on a suitable branch or isolated worktree.

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/isaiascope/ai/iso-write
Any agent
npx skills add IsaiaScope/ai --skill iso-write
Clone the repo
git clone --depth 1 https://github.com/IsaiaScope/ai

Made for: Claude Code, Codex.

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 iso-write

README.md
[![agentmods](https://agentmods.dev/badge/skills/isaiascope/ai/iso-write.svg)](https://agentmods.dev/skills/isaiascope/ai/iso-write)
Your own site
<a href="https://agentmods.dev/skills/isaiascope/ai/iso-write"><img src="https://agentmods.dev/badge/skills/isaiascope/ai/iso-write.svg" alt="Measured on agentmods" height="20"></a>
Per session 172 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,879 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 $0.00172 $0.02879
Opus 5 $0.00086 $0.01439
Sonnet 5 $0.00034 $0.00576
Haiku 4.5 $0.00017 $0.00288

Measured 4d ago against content hash 6e94d3908205, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

iso-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 4d ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/write.sh, scripts/write.test.sh), 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.

skills/iso-write/SKILL.md · 207 lines

How it starts

The opening of the file, as written. The whole thing — 207 lines — stays where its author put it; the contents beside it link to each section on GitHub.

iso-write

Execute a Claude/Codex-authored plan using TDD in the workspace mode the user picks. Never commit. Leave every change in the working tree so the user reviews the full diff at the end of the writing session and commits manually.

Input

Invoked as /iso-write <plan_path> [workspace-flag]<plan_path> is the path to the plan markdown file (e.g. docs/superpowers/plans/2026-05-26-feat-thing.md).

An optional workspace flag selects where the implementation happens. The flags are mutually exclusive:

Flag Workspace
(none) Reuse, resume, or cut — on a base branch (dev, develop, test, prod, main, master) or detached HEAD, derive <type>/<slug> from the plan filename: check it out if it exists, create it if not. Already on a feature branch: stay on it, create nothing.
--no-branch In place — stay on the current branch, no checkout.
--branch=<name> Named branch — checkout <name>, creating it if missing.
--worktree Worktree — isolated worktree on a fresh <type>/<slug> branch via the using-git-worktrees skill.

If <plan_path> is missing or the file does not exist, halt: iso-write: plan not found: <plan_path>.

If more than one workspace flag is given, halt: iso-write: pick one workspace mode.

Pre-flight

# scripts/write.sh resolve refuses on all three: no git, no repo, no plan.
eval "$(scripts/write.sh resolve "$plan_path" $workspace_flag)"
# $mode and $branch are now set

A dirty working tree (staged or unstaged) is not refused. How Step 2 handles it depends on the mode: the default and --branch=<name> modes stash the changes and carry them onto the target branch; --no-branch leaves them in place; --worktree leaves them in the main checkout (the worktree starts clean).

Tracking

Each transition below runs through one guarded call. It is a no-op when the script is absent or the working directory is not a repo — tracking must never be able to fail a write run:

Read the full file on GitHub · 207 lines

Files

What ships with it

3 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. 4d ago First seen · 207 lines · 172 tokens per session scan A 6e94d3908205

Subscribe to this mod's changes

iso-write is a skill published in the GitHub repository IsaiaScope/ai (2 stars, last pushed 7d ago), licensed MIT. It adds 172 tokens to every session and 2,879 once invoked, about $0.0009 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.

Related

Other skills, from other repositories

writing-skills

Use when creating new skills, editing existing skills, or verifying skills work before deployment.

oyi77/1ai-skills · 20 tokens

test-driven-development

Drives development with tests. Use when implementing any logic, fixing any bug, or changing any behavior. Use when you need to prove that code works, when a bug report arrives, or when you're about to modify existing functionality.

addyosmani/agent-skills · 50 tokens

skillshare-implement-feature

Implement a feature from a spec file or description using TDD workflow. Use this skill whenever the user asks to: add a new CLI command, implement a feature from a spec, build new functionality, add a flag, create a new internal package, or write Go code for skillshare. This skill enforces test-first development…

runkids/skillshare · 114 tokens

agent-architecture-planner

Use when designing an autonomous agent, planning agent architecture, building a scheduled automation, or creating a Claude Code agent workflow. Triggers: 'design an agent', 'build an automation', 'agent architecture', 'automate this workflow', 'create a scheduled agent', 'shell script agent'.

majiayu000/claude-skill-registry · 64 tokens

81-pipecat

Create your Pipecat skill from official documentation, then learn to improve it throughout the chapter.

majiayu000/claude-skill-registry · 18 tokens

2026-legal-research-agent

Expert legal research agent for finding and scraping expungement data state by state. Knows authoritative sources, URL patterns, Firecrawl configuration, and 2026 legal landscape. Activate on "find expungement data", "scrape state laws", "legal research", "court URLs", "statute sources", "Clean Slate laws", "automatic…

majiayu000/claude-skill-registry · 103 tokens