mcp-injector: Instructions file for Codex

AGENTS.md

mcp-injector AGENTS.md is an instructions file for Codex, OpenCode from noblepayne/mcp-injector. It costs 7,776 tokens per session, scanned A, original, MIT.

A set of instructions for the mcp-injector codebase, including a research-first way to plan changes before writing code.

In plain words
What is it for?
Use it when exploring the codebase, researching implementation options, asking clarifying questions, and writing a specification before a major feature.
Why use it?
It helps avoid rebuilding tools that already exist and reduces unnecessary complexity or poorly understood changes.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md. Also seen: mentions AGENTS.md; built for openclaw.

This is noblepayne/mcp-injector's own configuration. It tells Codex and OpenCode how to work on mcp-injector 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 mcp-injector configures →

Reuse

Borrowing it

Nothing to install: this file belongs to noblepayne/mcp-injector. 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/noblepayne/mcp-injector/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/noblepayne/mcp-injector

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 mcp-injector AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/noblepayne/mcp-injector/agents-md.svg)](https://agentmods.dev/instructions/noblepayne/mcp-injector/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/noblepayne/mcp-injector/agents-md"><img src="https://agentmods.dev/badge/instructions/noblepayne/mcp-injector/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 7,776 This file is loaded in full into every session.
When invoked 7,776 The same file — it is already loaded in full.
Security scan A 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 $0.07776 $0.07776
Opus 5 $0.03888 $0.03888
Sonnet 5 $0.01555 $0.01555
Haiku 4.5 $0.00778 $0.00778

Measured 7d ago against content hash decd2218ae0f, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

mcp-injector AGENTS.md scanned grade A 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

[babashka.curl :as curl]
AGENTS.md · 1,039 lines

How it starts

The opening of the file, as written. The whole thing — 1,039 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md - mcp-injector

"Simple is the opposite of complex. Easy is the opposite of hard." — Rich Hickey

Philosophy: Grumpy Pragmatism

We write situated programs that are reliable, robust, and data-driven. We reject OOP nonsense in favor of simple, composable systems. This codebase follows the philosophy of grumpy senior developers who've been burned by complexity:


Research-First Workflow (Shotgun Pattern)

"AI coding tools make you fast at building. They don't make you fast at knowing what to build."

Before implementing major features, ALWAYS follow this workflow:

1. Ask: "Does this already exist?"

  • Don't assume you need to build from scratch
  • Search for existing solutions (libraries, proxies, frameworks)
  • The answer is often "yes, it's called X"

2. Research Phase

Before writing ANY code for a new feature:

  1. Read the existing codebase to understand current patterns
  2. Search for existing solutions in the ecosystem
  3. Check if similar functionality exists elsewhere
  4. Ask clarifying questions if requirements are unclear

3. Specify Phase

Write a spec before coding that includes:

  • What already exists in the codebase
  • What needs to be built
  • Acceptance criteria
  • Edge cases to handle

4. Break Big Changes into Staged PRs

  • Don't ship monster PRs
  • Break features into reviewable chunks
  • Each stage should be independently testable

Example Research Workflow

User: We need usage tracking for LLM calls

Agent (should ask first): 
- Does this already exist? Let me search...
- Found: LiteLLM Proxy has built-in usage tracking
- Alternative: Build custom (3-4 weeks) vs integrate LiteLLM (5 days)
- Recommendation: Use LiteLLM

Peer Review Process

We value external review from senior colleagues. Before merging significant changes, we prepare a comprehensive review bundle to get a "stern but fair" stamp of approval.

Read the full file on GitHub · 1,039 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.

  1. 7d ago First seen · 1,039 lines · 7,776 tokens per session scan A decd2218ae0f

Subscribe to this mod's changes

mcp-injector AGENTS.md is an instructions file published in the GitHub repository noblepayne/mcp-injector (5 stars, last pushed 4d ago), licensed MIT. It adds 7,776 tokens to every session, about $0.0389 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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