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.
npx agentmods add instructions/muratcankoylan/agent-skills-for-context-engineering/claude-mdgit clone --depth 1 https://github.com/muratcankoylan/Agent-Skills-for-Context-EngineeringWhat 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 | $0.01849 | $0.01849 |
| Opus 5 | $0.00924 | $0.00924 |
| Sonnet 5 | $0.00370 | $0.00370 |
| Haiku 4.5 | $0.00185 | $0.00185 |
Grade A, and why
Agent-Skills-for-Context-Engineering CLAUDE.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 yesterday.
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 — 131 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
Project Overview
Agent Skills for Context Engineering is an open collection of Agent Skills teaching context engineering and harness engineering principles for production AI agent systems. Skills are platform-agnostic (Claude Code, Cursor, Codex/OpenAI Agent Skills, GitHub Copilot, any Open Plugins-conformant tool). v2.5.0 adds the long-horizon-prompting skill (pseudo-formal task briefs for long-running autonomous agents and parallel orchestrations) on top of the self-improvement-loops skill (v2.4.0) and the file-based researcher operating system with deterministic gates, cross-platform Agent Skills validation, and a continuous loop. Use the generated live inventory for current corpus counts.
Context engineering is the discipline of curating everything that enters a model's context window (system prompts, tool definitions, retrieved documents, message history, tool outputs) to maximize signal within limited attention budget.
Repository Structure
skills/- published skill directories, each containing aSKILL.mdwith YAML frontmatter (name,description) and optionalreferences/andscripts/subdirectoriesexamples/- complete demonstration projects; the generated inventory is the count authoritydocs/- Research materials and reference documentationresearcher/- File-based research-to-skill operating system: rubrics, mechanism registry, claim provenance, corpus index, run state machine, adversarial benchmarks, continuous loop, launchd service definitionstemplate/SKILL.md- Canonical skill template (use when creating new skills)SKILL.md(root) - Collection-level metadata and skill map.claude-plugin/marketplace.json- Claude Code marketplace manifest (single bundled plugin, v2.5.0).plugin/plugin.json- Open Plugins format manifest (v2.5.0)
Build & Test Commands
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.
- yesterday First seen · 131 lines · 1,849 tokens per session scan A cd04dcbdf69d
Agent-Skills-for-Context-Engineering CLAUDE.md is an instructions file published in the GitHub repository muratcankoylan/Agent-Skills-for-Context-Engineering (17,868 stars, last pushed 13d ago), licensed MIT. It adds 1,849 tokens to every session, about $0.0092 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 2026-08-30.
Other instructions, from other repositories
codex AGENTS.md
AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.
buildNext
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
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, applying the notice (cutover) and fallback chain (never fail the build).
spec-kit AGENTS.md
Instructions for github/spec-kit, covering agents.md, about spec kit and specify, quickstart — add a new integration in 5 steps, integration architecture and integrationmanifest — file tracking.
langchain 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.