What is groundhog-day AGENTS.md?

A working guide for AI agents contributing to Groundhog Day, a standalone Bash program that watches local Copilot skills and syncs changes to GitHub.

Use it when modifying the Groundhog Day script, installer, launch-agent files, or related documentation. It also identifies the checks to run after changes.

It explains the project structure, file ownership, design decisions, and checks needed to change the code without breaking its watcher, sync, or scheduled health-check behavior.

How DUBSOpenHub/groundhog-day configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to DUBSOpenHub/groundhog-day. 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/DUBSOpenHub/groundhog-day/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/DUBSOpenHub/groundhog-day

Made for: Codex, OpenCode.

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/dubsopenhub/groundhog-day/agents-md/github.svg)](https://agentmods.dev/instructions/dubsopenhub/groundhog-day/agents-md)

Your own site

<a href="https://agentmods.dev/instructions/dubsopenhub/groundhog-day/agents-md"><img src="https://agentmods.dev/badge/instructions/dubsopenhub/groundhog-day/agents-md/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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/dubsopenhub/groundhog-day/agents-md"><img src="https://agentmods.dev/badge/instructions/dubsopenhub/groundhog-day/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 900 This file is loaded in full into every session.

When invoked 900 The same file — it is already loaded in full.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00900	$0.00900
Opus 5.5	$0.00360	$0.00360
Sonnet 5.5	$0.00180	$0.00180
Haiku 4.5	$0.00090	$0.00090

Measured 2mo ago against content hash ce63c8cfd364, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

groundhog-day AGENTS.md 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 2mo 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.

AGENTS.md · 81 lines

How it starts

The opening of the file, as written. The whole thing — 81 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md: Working Guide for AI Agents

This file tells any AI agent how to work effectively on the Groundhog Day codebase.

Architecture

Groundhog Day is a standalone bash daemon that watches ~/.copilot/skills/ and auto-syncs changes to a GitHub repository. It is NOT a Copilot CLI skill — it's infrastructure that protects skills.

~/bin/groundhog                          ← main script (bash)
├── watch mode (fswatch → rsync → git)   ← real-time file watcher
├── sync (rsync + git add/commit/push)   ← core sync logic
├── checkup (13-point diagnostic)        ← daily health check at 6 AM
└── status (quick health check)          ← manual status

~/Library/LaunchAgents/
├── com.dubsopenhub.groundhog.plist           ← keeps watcher alive
└── com.dubsopenhub.groundhog.checkup.plist   ← nightly checkup at 6 AM

File Ownership Map

File	Purpose	Change Rules
`groundhog`	Main script	All logic lives here. Test with `groundhog checkup` after changes.
`install.sh`	One-line installer	Must stay idempotent. Re-running should not break existing installs.
`com.dubsopenhub.groundhog.plist`	LaunchAgent (watcher)	KeepAlive=true. Update home dir paths if changing user support.
`com.dubsopenhub.groundhog.checkup.plist`	LaunchAgent (nightly)	Runs at 6 AM. No KeepAlive — runs once and exits.
`README.md`	Documentation	Keep GIFs, keep the tone. Don't remove the Bill Murray energy.

Key Design Decisions

1. No external dependencies beyond standard tools

Groundhog Day uses only: bash, fswatch, rsync, git, python3 (stdlib only). No pip packages. No node modules. This is intentional — it must survive on a fresh machine with just Homebrew basics.

2. Single file architecture

Everything lives in one bash script. No splitting into modules. This keeps installation trivial (cp one file) and debugging simple (cat one file).

3. Lock file for concurrency

/tmp/groundhog.lock is a directory-based lock (atomic on all filesystems). mkdir succeeds or fails atomically. Always release with trap ... RETURN.

Read the full file on GitHub · 81 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.

2mo ago First seen · 81 lines · 900 tokens per session scan A ce63c8cfd364

Subscribe to this mod's changes

groundhog-day AGENTS.md is an instructions file published in the GitHub repository DUBSOpenHub/groundhog-day (5 stars, last pushed 4mo ago), licensed MIT. It adds 900 tokens to every session, about $0.0036 per session on Opus 5.5. 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.

automation backup copilot-cli github-copilot skills

groundhog-day AGENTS.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
groundhog-day AGENTS.mdDUBSOpenHub/groundhog-day	Instructions file	5	4mo ago	MIT	A	900	Codex, OpenCode
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	9,719	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	yesterday	MIT	A	4,680	Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	5,516	GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	yesterday	MIT	A	3,093	GitHub Copilot
deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness	Instructions file	274k	2d ago	MIT	A	4,313	Codex, OpenCode

groundhog-day: Instructions file for Codex