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/usrrname/cursorrules/create-update-agentgit clone --depth 1 https://github.com/usrrname/cursorrulesWhat 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 | $0.00000 | $0.00909 |
| Opus 5 | $0.00000 | $0.00454 |
| Sonnet 5 | $0.00000 | $0.00182 |
| Haiku 4.5 | $0.00000 | $0.00091 |
Grade A, and why
create-update-agent 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 yesterday.
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.
How it starts
The opening of the file, as written. The whole thing — 103 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Critical Rules
- All agents will be referred to as a team in prompts and the one with the best abilities for the task will volunteer to perform it.
- Understand existing agents in .cursor/modes.json
- Follows the format specified in .cursor/templates/mode-format.md
- Adds or updates agent information in .cursor/modes.json
- If updating an agent, clarify which aspects of an agent require updating or modification
- Custom agents can NEVER delete files or folders in .cursor/
- Custom agents can NEVER delete other agents.
- Agents should create user stories, documents and other markdown project artifacts in the ./ai/** folder. If it doesn't already exist, it should be created.
- If an agent was invoked by name, the system should infer that subsequent requests are directed at the same agent.
- If there is an agent with capabilities better suited for a task, ask the user if they would like to delegate the requested activty to a different agent before executing the user's request.
Examples
AI: I'll help you create a new Cursor agent called SageDaddy based on Senshi from Dungeon Meshi. Let me first check the current modes.json and format requirements.
[AI reads .cursor/modes.json and docs/mode-format.md]
Here's what I propose for this new agent:
Name: SageDaddy Description: Software Architect - SageDaddy Model: claude-3.7-sonnet Persona: Adorably grumpy, quietly confident, logical, resourceful, calm and empathetic.
Would you like me to proceed with adding this agent? I'll need to update both the modes.json file and the custom-agents.md documentation.
User: Yes, please add him with access to all cursor tools and Tavily for research.
[AI updates both .cursor/modes.json and .cursor/templates/custom-agents.md with the new agent]
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.
- yesterday First seen · 103 lines · 0 tokens per session scan A ae061f6b7e47
create-update-agent is a cursor rule published in the GitHub repository usrrname/cursorrules (10 stars, last pushed 4mo ago), licensed ISC. It costs nothing until one of its globs matches a file; then it loads 909 tokens. 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.
Other cursor rules, from other repositories
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