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.
git clone --depth 1 https://github.com/tacoda/keystoneWrote 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.
[](https://agentmods.dev/rules/tacoda/keystone/keystone-charter)<a href="https://agentmods.dev/rules/tacoda/keystone/keystone-charter"><img src="https://agentmods.dev/badge/rules/tacoda/keystone/keystone-charter.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00185 | $0.00185 |
| Opus 5 | $0.00093 | $0.00093 |
| Sonnet 5 | $0.00037 | $0.00037 |
| Haiku 4.5 | $0.00018 | $0.00018 |
Grade A, and why
keystone-charter 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 3d 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- keystone — 91% identical, 1 lines differ
What it actually says
Charter
You must read CHARTER.md now, before doing anything in this repo. It carries the iron laws and the ambient rules that govern the charter; they apply whether or not this file restates them. Do not proceed without loading it.
On this host — Cursor
- No subagents — run agent-defined reviews inline yourself; the
agents/bodies are still the instructions. - No slash commands — invoke a command/playbook by opening its body and following the steps.
- Skills — auto-activate by their
triggers:. - No automatic hooks — run the checks a hook would fire (lint, type-check, test, build) yourself before claiming done.
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.
- 3d ago First seen · 17 lines · 185 tokens per session scan A 84f6d79734aa
keystone-charter is a cursor rule published in the GitHub repository tacoda/keystone (44 stars, last pushed 2mo ago), licensed MIT. It adds 185 tokens to every session, about $0.0009 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 2026-09-03.
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