context-os

context-os is a cursor rule for Cursor from kok-o/koko-contextos-agents. It costs 6 tokens per session (1,093 once invoked), scanned A, original, MIT.

ContextOS is a set of project rules for assembling only the background an AI coding agent needs for a task. It classifies the project, affected areas, and type of work before loading guidance.

In plain words
What is it for?
It helps analyze a task, identify project layers such as frontend or database, choose a scope such as bug fix or refactor, and load required skills.
Why use it?
It reduces irrelevant context and helps the agent focus on the parts of the project that matter for the current request.

Cursor rule for Cursor

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 rules/kok-o/koko-contextos-agents/context-os
Clone the repo
git clone --depth 1 https://github.com/kok-o/koko-contextos-agents

Made for: Cursor.

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 context-os

README.md
[![agentmods](https://agentmods.dev/badge/rules/kok-o/koko-contextos-agents/context-os.svg)](https://agentmods.dev/rules/kok-o/koko-contextos-agents/context-os)
Your own site
<a href="https://agentmods.dev/rules/kok-o/koko-contextos-agents/context-os"><img src="https://agentmods.dev/badge/rules/kok-o/koko-contextos-agents/context-os.svg" alt="Measured on agentmods" height="20"></a>
Per session 6 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,093 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00006 $0.01093
Opus 5 $0.00003 $0.00547
Sonnet 5 $0.00001 $0.00219
Haiku 4.5 $0.00001 $0.00109

Measured 4d ago against content hash d3ed21bc9516, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

context-os 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 4d 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.

.cursor/rules/context-os.mdc · 170 lines

How it starts

The opening of the file, as written. The whole thing — 170 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skill: context-os

context-os

Overview

A brief summary of what the skill does and its core philosophy.

When to Use

Context for when this skill is applicable.

Rules & Patterns

You are the Context Compiler. Your job is NOT to know everything. Your job is to assemble the minimum context needed for the current task.

Pipeline

When a user gives you a task, follow this pipeline:

Stage 1: Intent Analysis

Analyze the user's prompt and determine:

intent:
  project_type: [webapp, api, mobile, cli, library, saas, crm, ecommerce]
  industry: [healthcare, fintech, education, social, general]
  layers:
    frontend: true/false
    backend: true/false
    database: true/false
    auth: true/false
    ai: true/false
    payments: true/false
    realtime: true/false
  scope: [new_project, feature, bugfix, refactor, architecture]

Stage 2: Dependency Resolution

For each required layer, load the skill graph:

  1. Read skill.yaml from each relevant skill directory
  2. Resolve requires — load mandatory dependencies
  3. Check conflicts — ensure no incompatible skills are loaded
  4. Apply optional — suggest but don't force
  5. Respect project profile (if set) — apply rules from profiles/

Dependency resolution example:

Need: nextjs
  → requires: react, typescript
    → react requires: typescript (already loaded)
  → optional: tailwind, prisma, next-auth
  
Loaded: [nextjs, react, typescript]
Suggested: [tailwind, prisma, next-auth]

Stage 3: Context Compilation

Assemble context from three levels:

Level 1 — Vision (always available):

  • docs/PRD.md — what are we building
  • docs/ROADMAP.md — where are we going
  • docs/PROJECT_GRAPH.md — project structure

Level 2 — Architecture (load when needed):

  • docs/ARCHITECTURE.md — system design
  • docs/DATABASE.md — data model
  • docs/API.md — API contracts
  • docs/decisions/ — prior decisions

Level 3 — Development (load per task):

  • Relevant skill .md files
  • docs/UI.md — for frontend tasks
  • docs/TASKS.md — current sprint

Read the full file on GitHub · 170 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. 4d ago First seen · 170 lines · 6 tokens per session scan A d3ed21bc9516

Subscribe to this mod's changes

context-os is a cursor rule published in the GitHub repository kok-o/koko-contextos-agents (2 stars, last pushed 4d ago), licensed MIT. It adds 6 tokens to every session and 1,093 once invoked, about $0.0000 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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