first-tree-write

first-tree-write is a skill for Claude Code, Codex from first-tree-ai/first-tree-legacy. It costs 73 tokens per session (946 once invoked), scanned A, original, Apache-2.0.

A source-based tool for updating a Context Tree, a durable project knowledge map, from material such as code changes, design documents, meeting notes, or raw text.

In plain words
What is it for?
Use it to draft a small set of linked and reviewed tree changes from one concrete source, such as a pull request or meeting note.
Why use it?
It helps preserve decisions, constraints, ownership changes, and relationships that should remain available after the original source is no longer being discussed.

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/first-tree-ai/first-tree-legacy/first-tree-write
Any agent
npx skills add first-tree-ai/first-tree-legacy --skill first-tree-write
Clone the repo
git clone --depth 1 https://github.com/first-tree-ai/first-tree-legacy

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 first-tree-write

README.md
[![agentmods](https://agentmods.dev/badge/skills/first-tree-ai/first-tree-legacy/first-tree-write.svg)](https://agentmods.dev/skills/first-tree-ai/first-tree-legacy/first-tree-write)
Your own site
<a href="https://agentmods.dev/skills/first-tree-ai/first-tree-legacy/first-tree-write"><img src="https://agentmods.dev/badge/skills/first-tree-ai/first-tree-legacy/first-tree-write.svg" alt="Measured on agentmods" height="20"></a>
Per session 73 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 946 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 $0.00073 $0.00946
Opus 5 $0.00036 $0.00473
Sonnet 5 $0.00015 $0.00189
Haiku 4.5 $0.00007 $0.00095

Measured 5d ago against content hash a0a25d914431, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

first-tree-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 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.

skills/first-tree-write/SKILL.md · 86 lines

How it starts

The opening of the file, as written. The whole thing — 86 lines — stays where its author put it; the contents beside it link to each section on GitHub.

First Tree Write

Read these first:

  • ../first-tree/SKILL.md
  • ../first-tree/references/anti-patterns.md
  • ../first-tree/references/maintenance.md

What This Skill Does

Take one specific source — a PR, a doc, a note — and produce zero, one, or a small set of tree changes that capture what's durable and decision- relevant. The output is a tree-repo PR linked to the source.

When To Use This Skill

Use this skill Use a different skill
User pastes a PR link and says "reflect this in the tree" User asks "is the tree up to date?" → first-tree-sync
User pastes a meeting note about a decision Repo is unbound → first-tree-onboarding first
User pastes raw text and asks for the tree implication A GitHub notification needs only a label / comment → first-tree-github-scan
GitHub Scan agent classifies a notification as route=write Audit drift since a release → first-tree-sync

The Default Stance

Default to not writing. The tree compresses expensive context; a node nobody reads is worse than a missing node. If the source does not clearly establish a decision, constraint, ownership change, or cross-domain relationship, write nothing and tell the user why.

How To Run

Phase Reference
Decide what is tree-worthy references/what-belongs.md
Draft the update references/workflow.md
Shape the tree node references/node-shape.md
Decide between write and sync references/boundary.md

Read the full file on GitHub · 86 lines

Files

What ships with it

6 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. 5d ago First seen · 86 lines · 73 tokens per session scan A a0a25d914431

Subscribe to this mod's changes

first-tree-write is a skill published in the GitHub repository first-tree-ai/first-tree-legacy (47 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 73 tokens to every session and 946 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.