crossrule AGENTS.md

Shared repository instructions written in the AGENTS.md format, which is understood by several AI coding tools. The example includes a rule requiring API input parameters to be validated.

In plain words
What is it for?
Use it to define agent instructions for this repository, including API-validation requirements and other project rules.
Why use it?
It gives compatible coding assistants a common place to read project-specific rules and reduces differences between tools.

Instructions file for CodexOpenCode

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 instructions/ssakone/crossrule/agents-md
Clone the repo
git clone --depth 1 https://github.com/ssakone/crossrule

Made for: Codex, OpenCode.

Per session 48 This file is loaded in full into every session.
When invoked 48 The same file — it is already loaded in full.
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 $0.00048 $0.00048
Opus 5 $0.00024 $0.00024
Sonnet 5 $0.00010 $0.00010
Haiku 4.5 $0.00005 $0.00005

Measured 2d ago against content hash 08b294f331d1, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

crossrule 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 2d 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 · 8 lines

What it actually says

Project Agent Rules

AGENTS.md shared format - works with Codex CLI, OpenCode, VSCode Agents, AGENTS.md Compatible. Docs: https://agents.md

---- api-validation ----

Always validate API input parameters

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. 2d ago First seen · 8 lines · 48 tokens per session scan A 08b294f331d1

Subscribe to this mod's changes

crossrule AGENTS.md is an instructions file published in the GitHub repository ssakone/crossrule (4 stars, last pushed 11mo ago), licensed MIT. It adds 48 tokens to every session, about $0.0002 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.

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