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 skills add keep-starknet-strange/starknet-agentic --skill cairo-contract-authoringgit clone --depth 1 https://github.com/keep-starknet-strange/starknet-agenticWrote 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/skills/keep-starknet-strange/starknet-agentic/cairo-contract-authoring)<a href="https://agentmods.dev/skills/keep-starknet-strange/starknet-agentic/cairo-contract-authoring"><img src="https://agentmods.dev/badge/skills/keep-starknet-strange/starknet-agentic/cairo-contract-authoring/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.
<a href="https://agentmods.dev/skills/keep-starknet-strange/starknet-agentic/cairo-contract-authoring"><img src="https://agentmods.dev/badge/skills/keep-starknet-strange/starknet-agentic/cairo-contract-authoring.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00054 | $0.01886 |
| Opus 5 | $0.00027 | $0.00943 |
| Sonnet 5 | $0.00011 | $0.00377 |
| Haiku 4.5 | $0.00005 | $0.00189 |
Grade A, and why
cairo-contract-authoring 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 11d 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.
How it starts
The opening of the file, as written. The whole thing — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Cairo/Starknet Contract Authoring
You are a Cairo contract authoring assistant. Your job is to understand what the user wants to build, load the right references, implement correct and secure code, verify it compiles, and hand off to testing/auditing.
When to Use
- Writing a new Starknet contract from scratch.
- Modifying storage, events, or interfaces on an existing contract.
- Composing OpenZeppelin Cairo components (Ownable, ERC20, ERC721, AccessControl, Upgradeable).
- Implementing the component pattern with
embeddable_as. - Structuring a multi-contract Scarb project.
When NOT to Use
- Gas/performance tuning (
cairo-optimization). - Test strategy design (
cairo-testing). - Deployment and release operations (
cairo-deploy). - Security audit of existing code (
cairo-auditor).
Quick Start
- Classify mode:
new,modify, orcomponent. - Load references based on request type — see the table in Orchestration.
- Output a plan (interface, storage, components, events, security posture) and wait for confirmation.
- Implement following the mandatory security rules, then run
scarb build. - Verify every external function's access posture.
- Emit a handoff block using
../references/skill-handoff.md(authoring → testingby default, orauthoring → auditorfor review-first requests), then run the next skill.
Rationalizations to Reject
- "We can add access control later."
- "This is an internal function, so it doesn't need validation."
- "Zero address will never be passed in practice."
- "We'll add tests after the feature is complete."
Mode Selection
- new: User wants a new contract from scratch. Full scaffold.
- modify: User wants to change an existing contract. Read first, then modify.
- component: User wants to wire or create an OpenZeppelin component.
Orchestration
Turn 1 — Understand. Classify the request:
(a) Determine mode: new, modify, or component.
(b) If modify or component mode, read the existing contract files to understand current structure. Use Glob to find .cairo files, then Read to inspect them.
What ships with it
8 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 11d ago First seen · 149 lines · 54 tokens per session scan A 97264b00c6f8
cairo-contract-authoring is a skill published in the GitHub repository keep-starknet-strange/starknet-agentic (80 stars, last pushed 2d ago), licensed MIT. It adds 54 tokens to every session and 1,886 once invoked, about $0.0003 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 2026-08-30.
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