snosi: Command for GitHub Copilot

.github/prompts/native-ab-change.md

native-ab-change is a command for GitHub Copilot from frostyard/snosi. It costs 0 tokens per session (497 once invoked), scanned A, original, MIT.

A guided change procedure for modifying a product's built-in A/B update path while preserving the repository's documented layout and release rules. A/B updates let software switch between two system versions or partitions.

In plain words
What is it for?
Use it when changing native A/B update behaviour, checking configuration output before and after a refactor, and verifying that published products still pass their release guard.
Why use it?
It reduces the risk of mixing unrelated configuration, using stale build data, or publishing a development-only product by mistake.

Command for GitHub Copilot

Written for GitHub Copilot: a Copilot chat mode or prompt. Also seen: mentions CLAUDE.md.

This is frostyard/snosi's own configuration. It tells GitHub Copilot how to work on snosi itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything snosi configures →

Reuse

Borrowing it

Nothing to install: this file belongs to frostyard/snosi. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/frostyard/snosi/main/.github/prompts/native-ab-change.md
Clone the repo
git clone --depth 1 https://github.com/frostyard/snosi

Made for: GitHub Copilot.

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 native-ab-change

README.md
[![agentmods](https://agentmods.dev/badge/commands/frostyard/snosi/native-ab-change.svg)](https://agentmods.dev/commands/frostyard/snosi/native-ab-change)
Your own site
<a href="https://agentmods.dev/commands/frostyard/snosi/native-ab-change"><img src="https://agentmods.dev/badge/commands/frostyard/snosi/native-ab-change.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 497 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 $0.00000 $0.00497
Opus 5 $0.00000 $0.00249
Sonnet 5 $0.00000 $0.00099
Haiku 4.5 $0.00000 $0.00050

Measured today against content hash 54186fdb90ca, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

native-ab-change 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 today.

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.

.github/prompts/native-ab-change.md · 42 lines

What it actually says

Prompt: change the native A/B path

Goal: <the native A/B behavior to add or fix>

Read first: docs/native-ab-contracts.md (the frozen source of truth for naming, paths, and policy), docs/native-ab-capacities.md, docs/native-ab-publication.md, and the "Native A/B" sections of CLAUDE.md.

Rules that are easy to break here:

  • Product-neutral disk/boot mechanics live in shared/outformat/ab-root/. Per-product repart definitions, sysupdate transfers, and channel settings live in shared/native-ab/channels/<product>/. Never move one into the other.
  • mkosi accumulates list settings (Packages=, FinalizeScripts=, …) in Include= encounter order across the whole resolved config. The arbiter for any composition refactor is a byte-level diff of mkosi --profile <p> summary before and after, normalizing Seed:, Prepare Scripts: tmpdirs, and Image Version:. Delete .mkosi-private/history/latest.json first, or the cached profile silently overrides --profile.
  • floe-ab-raw is a permanent, never-published dev fixture. The published products are floe-ab, snow-ab, and snowfield-ab, and they must keep passing check-native-publication-guard.sh.
  • Enablement belongs in presets or static /usr wants links, never in shipped /etc symlinks or runtime systemctl enable/disable.
  • The PCR signing key must be RSA-2048; the MOK key stays RSA-4096.

Validate, cheapest first:

test/native-ab-static-test.sh
test/native-ab-contracts-test.sh
check-native-publication-guard.sh

then, only if the change warrants it and the machine has root plus KVM, the matching QEMU harness (test/native-ab-update-test.sh, test/native-ab-components-test.sh, test/native-ab-secure-boot-test.sh, test/native-installer-e2e-test.sh).

Finish by recording contract or capacity changes in docs/native-ab-contracts.md / docs/native-ab-capacities.md and summarizing them in CLAUDE.md.

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. today Changed 54186fdb90ca
  2. yesterday First seen · 42 lines · 0 tokens per session scan A 64da2172b0cc

Subscribe to this mod's changes

native-ab-change is a command published in the GitHub repository frostyard/snosi (24 stars, last pushed today), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 497 tokens. 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 2026-09-06.