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 rules/rajitsaha/100xprism/update-claude-mdgit clone --depth 1 https://github.com/rajitsaha/100xprismWrote 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/rajitsaha/100xprism/update-claude-md)<a href="https://agentmods.dev/rules/rajitsaha/100xprism/update-claude-md"><img src="https://agentmods.dev/badge/rules/rajitsaha/100xprism/update-claude-md.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 | $0.00022 | $0.00371 |
| Opus 5 | $0.00011 | $0.00186 |
| Sonnet 5 | $0.00004 | $0.00074 |
| Haiku 4.5 | $0.00002 | $0.00037 |
Grade A, and why
update-claude-md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Suggested model tier: fast / low-cost (mechanical task)
Update-Claude — CLAUDE.md Rule Writer
After any correction, update CLAUDE.md with a rule to prevent the same mistake recurring.
How to use
/update-claude— after a correction, write a rule to CLAUDE.md
Phase 1 — Identify the pattern
What went wrong? What should have been done instead? Be specific — one clear pattern, not a vague note.
Phase 2 — Write a rule
Formulate as a clear, actionable rule:
- [Rule]: [What to do / not to do]. Why: [brief context].
Short rules stick. Long paragraphs get ignored.
Phase 3 — Update CLAUDE.md
PROJECT_ROOT=$(git rev-parse --show-toplevel)
INSTRUCTION_FILE=$(for f in CLAUDE.md AGENTS.md .cursorrules; do [ -f "$PROJECT_ROOT/$f" ] && echo "$PROJECT_ROOT/$f" && break; done)
Append the rule under a ## Rules or ## Corrections section in the project's instruction file. If no instruction file exists, create CLAUDE.md in the project root.
Phase 4 — Confirm
Tell the user: "Updated [file] with: [rule summary]"
If the rule isn't reducing mistakes after 2–3 sessions: rewrite it — be more specific or more prominent.
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.
- 2d ago First seen · 52 lines · 22 tokens per session scan A 15dfa0a425d6
update-claude-md is a cursor rule published in the GitHub repository rajitsaha/100xprism (10 stars, last pushed 6d ago), licensed MIT. It adds 22 tokens to every session and 371 once invoked, about $0.0001 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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