solidity-playground-guide

solidity-playground-guide is a skill for Claude Code, Codex from nirholas/three.ws. It costs 55 tokens per session (958 once invoked), scanned A, original, Apache-2.0.

A browser-based workspace for writing, compiling, deploying, and using Solidity smart contracts. It supports contract editing, compilation, wallet connections, multiple EVM blockchains, templates, ABI inspection, gas estimates, and explorer verification.

In plain words
What is it for?
Writing or pasting Solidity, compiling contracts, deploying them to supported testnets or mainnets, estimating gas, viewing ABIs, and calling contract functions.
Why use it?
It lets developers experiment with and test contracts from a browser without setting up a local development environment.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/nirholas/three.ws/solidity-playground-guide
Any agent
npx skills add nirholas/three.ws --skill solidity-playground-guide
Clone the repo
git clone --depth 1 https://github.com/nirholas/three.ws

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for solidity-playground-guide

README.md
[![agentmods](https://agentmods.dev/badge/skills/nirholas/three.ws/solidity-playground-guide.svg)](https://agentmods.dev/skills/nirholas/three.ws/solidity-playground-guide)
Your own site
<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>
Per session 55 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 958 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce 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

Measured yesterday against content hash c5c930e5a15f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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.

data/skills/development/solidity-playground-guide/SKILL.md · 142 lines

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

  1. Open the playground in your browser
  2. Write or paste Solidity code
  3. Click "Compile"
  4. Connect wallet
  5. Click "Deploy"
  6. 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);
    }
}

Read the full file on GitHub · 142 lines

Changes

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.

  1. yesterday First seen · 142 lines · 55 tokens per session scan A c5c930e5a15f

Subscribe to this mod's changes

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.

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