Borrowing it
Nothing to install: this file belongs to onesimplecode/agent-engineering-standards. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/onesimplecode/agent-engineering-standards/main/AGENTS.mdgit clone --depth 1 https://github.com/onesimplecode/agent-engineering-standardsWrote 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.
[](https://agentmods.dev/instructions/onesimplecode/agent-engineering-standards/agents-md)<a href="https://agentmods.dev/instructions/onesimplecode/agent-engineering-standards/agents-md"><img src="https://agentmods.dev/badge/instructions/onesimplecode/agent-engineering-standards/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.
<a href="https://agentmods.dev/instructions/onesimplecode/agent-engineering-standards/agents-md"><img src="https://agentmods.dev/badge/instructions/onesimplecode/agent-engineering-standards/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.07802 | $0.07802 |
| Opus 5.5 | $0.03121 | $0.03121 |
| Sonnet 5.5 | $0.01560 | $0.01560 |
| Haiku 4.5 | $0.00780 | $0.00780 |
Grade A, and why
agent-engineering-standards 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 657 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS.md — Public Agent Conventions
These conventions are the portable, tool-neutral layer of the AI Engineering Standards. They can be read by Claude Code, Cursor, Codex, Gemini CLI, or any agent that accepts repository instructions.
The goal is not to make agents more verbose. The goal is to make agent-assisted software work bounded, reviewable, and auditable.
Core Rules
Requirements Syntax
Write requirements in EARS style when they become acceptance criteria:
When
<trigger>, the system shall<observable behavior>.
Avoid vague words like "should" once a requirement is active.
Data Routing (TR-SEC-003)
Data that can identify a person, expose a secret, or reveal private business context must be handled by a local/private workflow unless an ADR documents an explicit exception.
Cloud-backed agents may work on public docs, public code, synthetic examples, and low-risk drafting. They must not receive secrets or private datasets.
Loop Contracts (TR-AGT-003)
Every multi-step agent node declares four fields before implementation:
- Input schema — expected state or data.
- Output schema — produced state or data.
- Exit condition — observable evidence that the node is done.
- Resource budget — max iterations, token budget, or wall-clock timeout.
Missing any field means the design is incomplete.
The exit condition must be verified by deterministic evidence when the agent changes persistent state, writes files, sends messages, or calls tools with side effects (TR-TEST-006).
See examples/engine-interface/ for a concrete reference implementation: a
SearXNG-inspired multi-source polling pattern where source_name (identity),
default_timeout (budget), a never-raising fetch() (exit condition), and a
normalized list[Result] (output schema) map directly onto the four fields above.
MCP Tool Annotations (TR-AGT-003, field 5)
When a node is exposed as an MCP tool, declare four hint flags describing its blast radius. These are advisory hints to MCP clients (Claude Code, Cursor, opencode) — the MCP protocol does not enforce them, so declare them accurately regardless.
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.
- 1mo ago Changed · +18 lines · +210 tokens per session 092feca804d0
- 1mo ago First seen · 639 lines · 7,592 tokens per session scan A f3c416b4833a
agent-engineering-standards AGENTS.md is an instructions file published in the GitHub repository onesimplecode/agent-engineering-standards (3 stars, last pushed 1mo ago), licensed MIT. It adds 7,802 tokens to every session, about $0.0312 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.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
vscode model-prompts.instructions.md
Model-specific prompt authoring and registry guidelines.