print-ctx-size

print-ctx-size is a cursor rule for Cursor from tuananh/hyper-mcp. It costs 40 tokens per session, scanned A, original, from a forked repository, Apache-2.0.

A response-formatting rule for an agent that uses an MCP server, a standard way to connect tools to AI agents. It requires each reply to show the approximate context size and the files currently in view.

In plain words
What is it for?
Use it when checking an agent's context budget or auditing which files are included in its current work.
Why use it?
It makes the agent's context use visible, helping you see how much information is available and which files it can access.

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/tuananh/hyper-mcp/print-ctx-size
Clone the repo
git clone --depth 1 https://github.com/tuananh/hyper-mcp

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 print-ctx-size

README.md
[![agentmods](https://agentmods.dev/badge/rules/tuananh/hyper-mcp/print-ctx-size.svg)](https://agentmods.dev/rules/tuananh/hyper-mcp/print-ctx-size)
Your own site
<a href="https://agentmods.dev/rules/tuananh/hyper-mcp/print-ctx-size"><img src="https://agentmods.dev/badge/rules/tuananh/hyper-mcp/print-ctx-size.svg" alt="Measured on agentmods" height="20"></a>
Per session 40 This file is loaded in full into every session.
When invoked 40 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin fork From a forked repository.
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 $0.00040 $0.00040
Opus 5 $0.00020 $0.00020
Sonnet 5 $0.00008 $0.00008
Haiku 4.5 $0.00004 $0.00004

Measured 5d ago against content hash 9946efb48816, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

print-ctx-size 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 5d 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/print-ctx-size.mdc · 10 lines

What it actually says

Your rule content

  • End every request with "Total context size: ~nk tokens" and list the files you have in view.
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. 5d ago First seen · 10 lines · 40 tokens per session scan A 9946efb48816

Subscribe to this mod's changes

print-ctx-size is a cursor rule published in the GitHub repository tuananh/hyper-mcp (2 stars, last pushed 7mo ago), licensed Apache-2.0. It adds 40 tokens to every session, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It comes from a forked repository.