context-canary

context-canary is a cursor rule for Cursor from mennyg19-cmyk/MasterGenAIInstructions. It costs 47 tokens per session (592 once invoked), scanned A, original, no licence file.

A per-turn check for detecting when an agent may have lost important conversation context. When it detects a problem, it records a checkpoint and restates the working context.

In plain words
What is it for?
Use it when checking context during long sessions or when the user says the agent lost context. It helps preserve a checkpoint and re-anchor the work.
Why use it?
Long or high-stakes sessions can drift without making the loss obvious. This provides a way to notice and recover from that drift.

Cursor rule for Cursor

Written for Cursor: installed under .cursor/.

Good fit Use it when checking context during long sessions or when the user says the agent lost context. It helps preserve a checkpoint and re-anchor the work.

Compare 6 cursor rules from other repositories ↓
Install with agentmods
npx agentmods add rules/mennyg19-cmyk/mastergenaiinstructions/context-canary
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.

Clone the repo
git clone --depth 1 https://github.com/mennyg19-cmyk/MasterGenAIInstructions

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-canary

README.md
[![agentmods](https://agentmods.dev/badge/rules/mennyg19-cmyk/mastergenaiinstructions/context-canary/github.svg)](https://agentmods.dev/rules/mennyg19-cmyk/mastergenaiinstructions/context-canary)
Your own site
<a href="https://agentmods.dev/rules/mennyg19-cmyk/mastergenaiinstructions/context-canary"><img src="https://agentmods.dev/badge/rules/mennyg19-cmyk/mastergenaiinstructions/context-canary/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.

agentmods 80×15 button for context-canary

Your own site · 80×15
<a href="https://agentmods.dev/rules/mennyg19-cmyk/mastergenaiinstructions/context-canary"><img src="https://agentmods.dev/badge/rules/mennyg19-cmyk/mastergenaiinstructions/context-canary.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 47 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 592 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown 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 $0.00047 $0.00592
Opus 5 $0.00023 $0.00296
Sonnet 5 $0.00009 $0.00118
Haiku 4.5 $0.00005 $0.00059

Measured 9d ago against content hash 8c5e8dbcaa4b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

context-canary 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 9d 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-canary.mdc · 51 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

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. 9d ago First seen · 51 lines · 47 tokens per session scan A 8c5e8dbcaa4b

Subscribe to this mod's changes

context-canary is a cursor rule published in the GitHub repository mennyg19-cmyk/MasterGenAIInstructions (2 stars, last pushed 2d ago), with no licence file. It adds 47 tokens to every session and 592 once invoked, about $0.0002 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.