schemaguard: Instructions file for Codex

AGENTS.md

schemaguard AGENTS.md is an instructions file for Codex, OpenCode from sethclawd-prog/schemaguard. It costs 498 tokens per session, scanned B, original, MIT.

Instructions for connecting SchemGuard, a tool that checks and compares OpenAPI specifications. OpenAPI specifications describe the endpoints and data formats of a web API.

In plain words
What is it for?
Use it to compare two API specifications, lint one for quality issues, or run a pass-or-fail safety check in continuous integration.
Why use it?
It helps detect missing details, security concerns, and API changes that could break existing users before deployment.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md. Also seen: reads .claude/ paths; mentions Claude Code; mentions Codex.

This is sethclawd-prog/schemaguard's own configuration. It tells Codex and OpenCode how to work on schemaguard 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 schemaguard configures →

Reuse

Borrowing it

Nothing to install: this file belongs to sethclawd-prog/schemaguard. 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/sethclawd-prog/schemaguard/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/sethclawd-prog/schemaguard

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.

agentmods badge for schemaguard AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/sethclawd-prog/schemaguard/agents-md.svg)](https://agentmods.dev/instructions/sethclawd-prog/schemaguard/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/sethclawd-prog/schemaguard/agents-md"><img src="https://agentmods.dev/badge/instructions/sethclawd-prog/schemaguard/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 498 This file is loaded in full into every session.
When invoked 498 The same file — it is already loaded in full.
Security scan B 1 finding. 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 $0.00498 $0.00498
Opus 5 $0.00249 $0.00249
Sonnet 5 $0.00100 $0.00100
Haiku 4.5 $0.00050 $0.00050

Measured 7d ago against content hash 699af906a09f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade B, and why

schemaguard AGENTS.md scanned grade B with 1 finding 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 7d 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.

Reads agent configuration directoriesmediumAgent snooping

.claude/, .codex/, .gemini/ hold keys, settings and other credentials a mod has no legitimate need for.

**Claude Code** (`~/.claude/settings.json`):
AGENTS.md · 76 lines

What it actually says

SchemGuard — Agent Integration Guide

For Claude Code / Codex / OpenClaw / Any MCP-Compatible Agent

MCP Server Setup

Add SchemGuard as a tool server in your agent config:

Claude Code (~/.claude/settings.json):

{
  "mcpServers": {
    "schemaguard": {
      "command": "node",
      "args": ["/path/to/node_modules/@sethclawd/schemaguard/mcp-server.js"]
    }
  }
}

Or project-level (.claude/settings.json in repo root):

{
  "mcpServers": {
    "schemaguard": {
      "command": "npx",
      "args": ["@sethclawd/schemaguard", "--mcp"]
    }
  }
}

Available Tools

Once connected, agents get three tools:

Tool When to Use
schemaguard_diff Comparing two OpenAPI specs — shows breaking vs safe changes
schemaguard_lint Validating spec quality — missing fields, security, etc.
schemaguard_check CI-style pass/fail — "is this safe to deploy?"

Direct CLI Usage (No MCP)

Agents can also shell out directly:

# Diff two specs
npx @sethclawd/schemaguard diff old.yaml new.yaml

# CI check
npx @sethclawd/schemaguard ci --spec ./openapi.yaml --baseline ./baseline.yaml

# Lint
npx @sethclawd/schemaguard lint ./openapi.yaml

# JSON output (machine-readable)
npx @sethclawd/schemaguard diff old.yaml new.yaml --format json

When Should Agents Use This?

  • Before committing changes to an OpenAPI spec
  • When reviewing PRs that modify API routes
  • After generating/updating OpenAPI specs from code
  • Before deploying API changes to production
  • When validating that a migration maintains backward compatibility

Exit Codes

Code Meaning
0 No breaking changes (safe)
1 Breaking changes detected (blocked)
2 Error (invalid spec, file not found)
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. 7d ago First seen · 76 lines · 498 tokens per session scan B 699af906a09f

Subscribe to this mod's changes

schemaguard AGENTS.md is an instructions file published in the GitHub repository sethclawd-prog/schemaguard (0 stars, last pushed 6mo ago), licensed MIT. It adds 498 tokens to every session, about $0.0025 per session on Opus 5. A static security scan graded it B with 1 finding (reads agent configuration directories). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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