project-spine-rationale

project-spine-rationale is a skill for Claude Code, Codex from PetriLahdelma/project-spine. It costs 57 tokens per session (559 once invoked), scanned A, original, MIT.

A local review guide for checking a generated Project Spine rationale file before sharing it with a client.

In plain words
What is it for?
Inspecting and making client-facing project summaries safer after compiling the project's rationale.
Why use it?
It helps identify internal language, costs, constraints, warnings, and assumptions that may be unsuitable to share publicly.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Inspecting and making client-facing project summaries safer after compiling the project's rationale.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/petrilahdelma/project-spine/project-spine-rationale
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.

Any agent
npx skills add PetriLahdelma/project-spine --skill project-spine-rationale
Clone the repo
git clone --depth 1 https://github.com/PetriLahdelma/project-spine

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 project-spine-rationale

README.md
[![agentmods](https://agentmods.dev/badge/skills/petrilahdelma/project-spine/project-spine-rationale/github.svg)](https://agentmods.dev/skills/petrilahdelma/project-spine/project-spine-rationale)
Your own site
<a href="https://agentmods.dev/skills/petrilahdelma/project-spine/project-spine-rationale"><img src="https://agentmods.dev/badge/skills/petrilahdelma/project-spine/project-spine-rationale/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for project-spine-rationale

Your own site · 80×15
<a href="https://agentmods.dev/skills/petrilahdelma/project-spine/project-spine-rationale"><img src="https://agentmods.dev/badge/skills/petrilahdelma/project-spine/project-spine-rationale.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 57 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 559 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00057 $0.00559
Opus 5 $0.00028 $0.00280
Sonnet 5 $0.00011 $0.00112
Haiku 4.5 $0.00006 $0.00056

Measured 11d ago against content hash 73614b019c1f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

project-spine-rationale 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 11d 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/project-spine-rationale/SKILL.md · 54 lines

How it starts

The opening of the file, as written. The whole thing — 54 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Local rationale review

Goal: help the user review .project-spine/exports/rationale.md before they share it through their normal channel. The public OSS CLI generates the file locally; it does not publish hosted rationale URLs.

Prerequisites

  1. Project compiled — .project-spine/exports/rationale.md exists. If not, switch to project-spine-kickoff.
  2. Generated outputs are current — run spine drift check first if the user mentions stale instructions or changed inputs.

Step 1 — inspect the rationale

sed -n '1,220p' .project-spine/exports/rationale.md

Review the headings and content with the user. Do not paste the whole file into a public channel unless they explicitly ask.

Step 2 — check client-safety

Before the user shares the rationale, call out these sections:

  • Risks — may contain internal language that should be softened.
  • Constraints — may mention vendor costs, private process, or trade secrets.
  • Warnings — may reveal missing brief details or repo uncertainty.
  • Assumptions — should be phrased as assumptions, not promises.

If anything needs changing, edit the upstream brief.md or design inputs and rerun spine compile. Do not hand-edit rationale.md unless the user accepts that drift will be reported later.

Step 3 — prepare a shareable note

If the file is safe, summarize it into a short client note:

Here is the Project Spine rationale generated from the current brief and repo.
It captures goals, audience, constraints, assumptions, risks, stack summary,
and the first scaffold direction. The generated files are local and versionable;
future drift is checked with `spine drift check`.

Hosted publishing status

Do not tell users to run spine publish rationale, spine rationale list, or spine rationale revoke in the public OSS CLI. Those hosted commands exist in dormant source files but are intentionally not routed from spine --help.

What NOT to do

  • Do not publish or share rationale content that includes credentials, internal URLs, PII, or trade secrets.
  • Do not manually edit generated rationale files as the canonical fix. Edit inputs and recompile.
  • Do not claim there is a hosted branded URL flow in the public CLI.

Read the full file on GitHub · 54 lines

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. 11d ago First seen · 54 lines · 57 tokens per session scan A 73614b019c1f

Subscribe to this mod's changes

project-spine-rationale is a skill published in the GitHub repository PetriLahdelma/project-spine (2 stars, last pushed 1mo ago), licensed MIT. It adds 57 tokens to every session and 559 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 2026-08-31.