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 skills/nirholas/three.ws/solidity-playground-guidenpx skills add nirholas/three.ws --skill solidity-playground-guidegit clone --depth 1 https://github.com/nirholas/three.wsWrote 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/nirholas/three.ws/solidity-playground-guide)<a href="https://agentmods.dev/skills/nirholas/three.ws/solidity-playground-guide"><img src="https://agentmods.dev/badge/skills/nirholas/three.ws/solidity-playground-guide.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 | $0.00055 | $0.00958 |
| Opus 5 | $0.00028 | $0.00479 |
| Sonnet 5 | $0.00011 | $0.00192 |
| Haiku 4.5 | $0.00006 | $0.00096 |
Grade A, and why
solidity-playground-guide 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 — 142 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Lyra Web3 Playground — Solidity IDE Guide
A browser-based Solidity IDE for writing, compiling, deploying, and interacting with smart contracts. No local setup required — everything runs in the browser.
Features
| Feature | Description |
|---|---|
| Solidity Editor | Monaco editor with syntax highlighting |
| Compiler | In-browser Solc compilation |
| Deploy | Deploy to any EVM chain |
| Interact | Call contract functions from UI |
| Templates | Pre-built contract templates |
| ABI Viewer | Visual ABI explorer |
| Gas Estimator | Pre-deployment gas estimates |
| Verification | Auto-verify on block explorers |
Quick Start
- Open the playground in your browser
- Write or paste Solidity code
- Click "Compile"
- Connect wallet
- Click "Deploy"
- Interact with your contract
Supported Chains
| Chain | Testnet | Mainnet |
|---|---|---|
| Ethereum | Sepolia | ✅ |
| Arbitrum | Sepolia | ✅ |
| Base | Sepolia | ✅ |
| Polygon | Amoy | ✅ |
| BSC | Testnet | ✅ |
| Optimism | Sepolia | ✅ |
Contract Templates
ERC-20 Token
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
contract MyToken is ERC20 {
constructor(uint256 initialSupply) ERC20("My Token", "MTK") {
_mint(msg.sender, initialSupply * 10 ** decimals());
}
}
ERC-8004 Agent
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import "@erc8004/contracts/AgentNFT.sol";
contract MyAgentRegistry is AgentNFT {
function registerAgent(
string memory name,
string memory metadataURI
) external returns (uint256) {
return _mintAgent(msg.sender, name, metadataURI);
}
}
Sperax USDs Vault
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;
import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
contract USDsVault {
IERC20 public immutable usds;
constructor(address _usds) {
usds = IERC20(_usds);
}
function deposit(uint256 amount) external {
usds.transferFrom(msg.sender, address(this), amount);
}
function withdraw(uint256 amount) external {
usds.transfer(msg.sender, amount);
}
}
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 · 142 lines · 55 tokens per session scan A c5c930e5a15f
solidity-playground-guide is a skill published in the GitHub repository nirholas/three.ws (110 stars, last pushed today), licensed Apache-2.0. It adds 55 tokens to every session and 958 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 2026-09-03.
Other skills, from other repositories
blockchain-cross-chain
Cross-chain protocols, IBC, LayerZero, Wormhole, Axelar, CCIP, bridges, atomic composability, shared sequencer, cross-chain message passing. Covers trust models (light clients, external validators, ZK proofs), bridge security, token representation (canonical, wrapped, native), relayer economics, and cross-chain…
blockchain-security
Use this skill when asked about blockchain security, smart contract auditing, DeFi threat modeling, blockchain incident response, bug bounty programs, economic security, formal verification of smart contracts, and blockchain-specific security analysis. Languages: Solidity, Python, Rust, Haskell. Covers threat modeling…
blockchain-testing
Use this skill when asked about testing smart contracts, Foundry tests, Hardhat tests, fuzz testing, invariant testing, property-based testing, formal verification, audit preparation, integration testing for dApps, and blockchain testing patterns. Covers Foundry cheatcodes, Echidna fuzzing, Certora verification…
xpr-network-dev
XPR Network (formerly Proton) blockchain development - proton-tsc smart contracts, @proton CLI and web SDK, RPC and Hyperion queries, DeFi (MetalX, Alcor, LOAN), NFTs, the XPR Agents job board, node and Hyperion operations. Use for anything mentioning XPR, Proton, or @proton packages.
blockchain-management
Use this skill when asked about blockchain project management, DAO governance, multi-sig operations, treasury management, tokenomics design, and web3 project methodology. Languages: Solidity, TypeScript, Python. Covers DAO governance frameworks (Compound Governor, Aave, Snapshot, Tally), multi-sig wallet operations…
write-contracts
Generates secure Aptos Move V2 smart contracts with Object model, Digital Asset integration, security patterns, and storage type guidance. Includes comprehensive storage decision framework for optimal data structure selection. Triggers on: 'write contract', 'create NFT collection', 'build marketplace', 'implement…