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.
npx agentmods add skills/first-tree-ai/first-tree/first-tree-writenpx skills add first-tree-ai/first-tree --skill first-tree-writegit clone --depth 1 https://github.com/first-tree-ai/first-treeWhat 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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00062 | $0.00918 |
| Opus 5 | $0.00031 | $0.00459 |
| Sonnet 5 | $0.00012 | $0.00184 |
| Haiku 4.5 | $0.00006 | $0.00092 |
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 3d 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.
How it starts
The opening of the file, as written. The whole thing — 96 lines — stays where its author put it; the contents beside it link to each section on GitHub.
First Tree Write — Local Context
Purpose and authority
Reflect a concrete source artifact into the current Agent's private Local
Context. This payload is the managed Local variant of first-tree-write; its
public name and routing description intentionally match the Remote payload.
Local Context is not Team-approved truth and has no Git, forge, PR/MR, Reviewer, Audit, Seed, Cloud Tree IO, or Web workflow. Any current Chat, human decision, design document, PR/MR, Issue, meeting note, or other inspectable material can be a source. Never manufacture organization facts from model memory. The generated Context Tree Policy remains the content-model baseline.
Source gate and Double Test
Write only when the source establishes or changes a durable decision, constraint, ownership fact, or cross-domain relationship. It must both matter to future choices and remain true if the triggering implementation is rewritten. Implementation detail, refactors, request shapes, fixtures, build configuration, and one-off fixes stay in their source system.
If nothing passes, write nothing and explain why.
Workflow
-
Identify the exact source, smallest existing target, parent, relevant normal
soft_links, and ownership-adjacent member content. New top-level domains,ownerschanges, anddecisionLocksCodechanges still require explicit human-owner authority. -
Run:
<firstTreeInvocation> --json tree local resolve --ensure --intent writeUse only the returned
data.path. The guard accepts no caller path and rechecks runtime identity, fixed containment, limits, latch, and Server binding.repairOnly: truemeans the live Tree is invalid: repair existing mechanically provable content before any expansion. If correct business content cannot be determined from the files and source, stop and ask a human; do not delete or invent facts just to pass validation. -
Read the source and surrounding live Tree. Then edit the live root directly with native file tools. Do not create a lock, snapshot, candidate, fingerprint, worktree, journal, rollback state, approval diff, commit, or PR/MR. Local V0 accepts last-write-wins and moving reads.
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.
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.
- 3d ago First seen · 96 lines · 62 tokens per session scan A b85179178d3a
first-tree-write is a skill published in the GitHub repository first-tree-ai/first-tree (139 stars, last pushed 5d ago), licensed Apache-2.0. It adds 62 tokens to every session and 918 once invoked, about $0.0003 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.
Other skills, from other repositories
github-scan
Operate the first-tree github scan CLI — the GitHub notification daemon and inbox runtime. Use whenever you need to run, start, stop, inspect, poll, or debug github-scan; view or respond to GitHub-triggered work from the terminal; or wire up the github-scan statusline hook.
first-tree-sync
Audit and repair drift between merged code and the Context Tree in both directions — tree→code (does code still support tree facts?) and code→tree (does the tree register everything code now contains?). Use when the tree may be stale, wrong, outdated, or missing coverage for recent code changes; after a large merge…
first-tree-github-scan
Agent skill for handling a single GitHub notification spawned by the First Tree github-scan daemon. Use when an agent needs to decide how to tag, comment on, escalate, or hand off a PR, issue, review request, mention, or CI event, and when it needs to choose between handling on GitHub or routing to first-tree-sync /…
first-tree-write
Write Context Tree updates from explicit source material — code PRs, design docs, meeting notes, raw text. Use when the user gives you a concrete source and wants the right durable tree change drafted, linked, and reviewed. This skill is source-driven and targeted; use first-tree-sync instead for broad drift audits…
first-tree
Canonical whitepaper and routing skill for First Tree. Explains what belongs in a Context Tree, how source or workspace roots, tree repos, and bindings relate, and how the current first-tree tree and first-tree github scan surfaces fit together. Use when you need shared First Tree concepts, need to choose between…
first-tree-onboarding
One-shot onboarding command for First Tree. Drives a repo or workspace from "no first-tree" all the way to "tree bound, real content drafted, daemon running, agent templates confirmed" — end to end, in one skill invocation. Trigger this skill when the user invokes /first-tree-onboarding, says "onboard this repo to…