Agent skill

Smart Contract Development

Solidity smart contract development on VeChainThor — Hardhat setup, ERC-20/721 patterns, upgradeable contracts, gas optimization, testing with Thor Solo, security auditing, and ABI codegen.

MITAuto-check passedBackend & APIs

Install Smart Contract Development

skills CLI

$ npx skills add vechain/x-app-template --skill smart-contract-development -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install vechain/x-app-template smart-contract-development --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/vechain/x-app-template.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/smart-contract-development .claude/skills/smart-contract-development && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "smart-contract-development" agent skill from https://github.com/vechain/x-app-template/tree/main/.agents/skills/smart-contract-development into .claude/skills/smart-contract-development/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "smart-contract-development", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/vechain/x-app-template/tree/main/.agents/skills/smart-contract-development

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add vechain/x-app-template --skill smart-contract-development -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install vechain/x-app-template smart-contract-development --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/vechain/x-app-template.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/smart-contract-development .agents/skills/smart-contract-development && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "smart-contract-development" agent skill from https://github.com/vechain/x-app-template/tree/main/.agents/skills/smart-contract-development into .agents/skills/smart-contract-development/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "smart-contract-development", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add vechain/x-app-template --skill smart-contract-development -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install vechain/x-app-template smart-contract-development --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/vechain/x-app-template.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/smart-contract-development .cursor/skills/smart-contract-development && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "smart-contract-development" agent skill from https://github.com/vechain/x-app-template/tree/main/.agents/skills/smart-contract-development into .cursor/skills/smart-contract-development/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "smart-contract-development", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/vechain/x-app-template.git --path .agents/skills/smart-contract-development

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add vechain/x-app-template --skill smart-contract-development -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install vechain/x-app-template smart-contract-development --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/vechain/x-app-template.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/smart-contract-development .gemini/skills/smart-contract-development && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "smart-contract-development" agent skill from https://github.com/vechain/x-app-template/tree/main/.agents/skills/smart-contract-development into .gemini/skills/smart-contract-development/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "smart-contract-development", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install vechain/x-app-template smart-contract-development

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add vechain/x-app-template --skill smart-contract-development -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/vechain/x-app-template.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/smart-contract-development .github/skills/smart-contract-development && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "smart-contract-development" agent skill from https://github.com/vechain/x-app-template/tree/main/.agents/skills/smart-contract-development into .github/skills/smart-contract-development/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "smart-contract-development", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add vechain/x-app-template --skill smart-contract-development -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install vechain/x-app-template smart-contract-development --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/vechain/x-app-template.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/smart-contract-development .opencode/skills/smart-contract-development && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "smart-contract-development" agent skill from https://github.com/vechain/x-app-template/tree/main/.agents/skills/smart-contract-development into .opencode/skills/smart-contract-development/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "smart-contract-development", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: smart-contract-development
GitHub stars: 450
Token cost: ~1.1k tokens
SKILL.md length: 479 words
Files: 6 (incl. references)
Skills in repo: 11
Repo updated: Jul 20, 2026
First seen: Oct 7, 2026
Licence: MIT

At a glance

Solidity smart contract development on VeChainThor — Hardhat setup, ERC-20/721 patterns, upgradeable contracts, gas optimization, testing with Thor Solo, security auditing, and ABI codegen.

Works in 5 steps: Check Node version → Detect project structure → Clarify before implementing → …
Tasks that involve Smart contracts
SKILL.md covers CRITICAL RULES, Scope, Default stack and Operating procedure, plus 1 more section
Calls nvm

What it does

Smart Contract Development is an agent skill from vechain/x-app-template. Solidity smart contract development on VeChainThor — Hardhat setup, ERC-20/721 patterns, upgradeable contracts, gas optimization, testing with Thor Solo, security auditing, and ABI codegen.

Its SKILL.md is about 1.1k tokens, which your agent loads only when the skill is triggered. The skill folder holds 6 other files, including reference files (for example `references/abi-codegen.md`, `references/security.md` and `references/smart-contracts-optimization.md`).

It sits in Backend & APIs, covering Smart contracts and Project scaffolding. It works with Solidity and Ethereum. The repository describes itself as: Vechain VeBetterDAO X-App template. The licence is MIT.

When your agent uses it

Tasks that involve Smart contracts
Tasks that involve Project scaffolding

Example prompts

“/smart-contract-development”

Requirements

Docker

Workflow steps

5 steps, taken from the step headings in SKILL.md.

Check Node version
Detect project structure
Clarify before implementing
Implement with VeChain-specific correctness
Verify and deliver

What it can do on your machine

Read from SKILL.md and the folder at commit 8692b6a. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
- nvm
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Smart Contract Development loads about 1.1k tokens when it runs, and up to ~18k if it reads all its reference files. Until then it costs about 54 tokens; SKILL.md has 479 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~54
When it runs · the whole SKILL.md, loaded when a task matches: ~1.1k
With references · SKILL.md plus every file in references/, read only if the agent opens them: ~18k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from vechain/x-app-template at commit 8692b6a, republished under its MIT licence (© vechain). 479 words, ~1,092 tokens.

Download SKILL.mdSave it as .claude/skills/smart-contract-development/SKILL.md (or your agent's skills folder). This skill also uses 5 other files; get the full folder from GitHub.

name: smart-contract-development
description: Solidity smart contract development on VeChainThor — Hardhat setup, ERC-20/721 patterns, upgradeable contracts, gas optimization, testing with Thor Solo, security auditing, and ABI codegen.
license: MIT
metadata.author: VeChain
metadata.version: 0.1.0

Smart Contract Development Skill

CRITICAL RULES

Read reference files FIRST. When the user's request involves any topic in the reference table below, read those files before doing anything else — before writing code, before making decisions. Briefly mention which files you are reading so the user can confirm the skill is active (e.g., "Reading smart contracts reference...").
Information priority for VeChain topics: (a) Reference files in this skill — always the primary source. (b) VeChain MCP tools — use @vechain/mcp-server for on-chain data, transaction building, and live network queries; use Kapa AI MCP for VeChain documentation lookups. (c) Web search — only as a last resort, and only for topics NOT covered in the reference files.
Prefer working directly in the main conversation for VeChain tasks. Plan mode and subagents do not inherit skill context and may fall back to web search instead of using reference files.
After compaction or context loss, re-read this SKILL.md to restore awareness of the reference table and operating procedure before continuing work.

Scope

Use this Skill for Solidity smart contract development on VeChainThor:

Solidity contracts with Hardhat + @vechain/sdk-hardhat-plugin
ERC-20, ERC-721, access control, upgradeable (UUPS) patterns
Gas optimization techniques
Testing with Hardhat + Thor Solo
Security reviews and audit checklists
ABI codegen and TypeChain setup

Default stack

Layer	Default	Alternative
Contracts	Solidity + Hardhat + `@vechain/sdk-hardhat-plugin`	--
EVM target	`paris` (mandatory)	--
Testing	Hardhat + Thor Solo (`--on-demand`)	--
Types	TypeChain (`@typechain/ethers-v6`)	`@vechain/vechain-contract-types` (pre-built)
Node	Node 20 LTS (managed via `nvm`)	--

Operating procedure

1. Check Node version

Before installing dependencies or running any command:

Check if .nvmrc exists in the project root. If yes, run nvm use to switch to the required version.
If .nvmrc does not exist, create one with 20 (Node 20 LTS) and run nvm use.

Show full SKILL.md (192 more words)Show less

2. Detect project structure

turbo.json present → follow Turborepo conventions (packages/contracts, packages/*)

3. Clarify before implementing

When the user's request is ambiguous or could be solved multiple ways, ask before building. Separate research from implementation.

4. Implement with VeChain-specific correctness

Network: always explicit (mainnet/testnet/solo)
EVM target: always paris
Gas: estimate first
Tokens: VET for value, VTHO for gas (dual-token model)

5. Verify and deliver

A task is not complete until all applicable gates pass:

Code compiles — no build errors
Tests pass — existing tests still pass; new logic has test coverage
Risk notes documented — any signing, fee, or token-transfer implications are called out

Reference files

Read the matching files BEFORE doing anything else. See Critical Rules above.

Topic	File	Read when user mentions...
Smart contracts	references/smart-contracts.md	Solidity, Hardhat, ERC-20, ERC-721, deploy, contract interaction, libraries, contract size, upgradeable, proxy, upgrade, reinitializer, version pattern, deploy helpers, NatSpec, Slither
Gas optimization	references/smart-contracts-optimization.md	gas, optimize, storage packing, assembly, unchecked
Testing	references/testing.md	test, Thor Solo, Docker, CI, fixtures
ABI / codegen	references/abi-codegen.md	TypeChain, ABI, typechain-types, code generation
Security	references/security.md	security, audit, vulnerability, reentrancy, access control, invariant, balance check, path symmetry, adversarial, edge cases, what could go wrong

Files

SKILL.md and 5 other files (references) in .agents/skills/smart-contract-development of vechain/x-app-template.

SKILL.md
references/abi-codegen.md
references/security.md
references/smart-contracts-optimization.md
references/smart-contracts.md
references/testing.md

Open the folder on GitHubat commit 8692b6a

Compare with similar skills

Smart Contract Development next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

Smart Contract Development compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
Smart Contract Development this skillvechain/x-app-template	450	—	~1.1k	Automated safety check: Pass	MIT	2 mo ago
Developing Smart ContractsLFDT-Lineth/lineth-monorepo	126	—	~1.4k	Automated safety check: Pass	AGPL-3.0	today
Ethskillsaustintgriffith/ethskills	294	—	~1.4k	Automated safety check: Pass	None	1 mo ago
Trustless Agentsinternet-court/internet-court-skill	6.4k	1 repos	~510	Automated safety check: Pass	MIT	1 mo ago
Smart Contract InteractionNethereum/Nethereum	2.3k	—	~1.9k	Automated safety check: Pass	MIT	2 days ago
Solidity Developmenthiromaily/go-crypto-wallet	128	—	~826	Automated safety check: Notes	MIT	5 mo ago

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Questions about Smart Contract Development

What does Smart Contract Development do?

Solidity smart contract development on VeChainThor — Hardhat setup, ERC-20/721 patterns, upgradeable contracts, gas optimization, testing with Thor Solo, security auditing, and ABI codegen. Smart Contract Development is an agent skill from vechain/x-app-template. Solidity smart contract development on VeChainThor — Hardhat setup, ERC-20/721 patterns, upgradeable contracts, gas optimization, testing with Thor Solo, security auditing, and ABI codegen.

When should I use Smart Contract Development?

Smart Contract Development fits situations like: tasks that involve Smart contracts; tasks that involve Project scaffolding.

How do I install Smart Contract Development in Claude Code?

Run `npx skills add vechain/x-app-template --skill smart-contract-development -a claude-code`. Or copy the skill folder (.agents/skills/smart-contract-development in vechain/x-app-template) into .claude/skills/smart-contract-development in your project. Claude Code loads it when a task matches its description.

How do I install Smart Contract Development in Codex?

Run `npx skills add vechain/x-app-template --skill smart-contract-development -a codex`. Or copy the skill folder (.agents/skills/smart-contract-development in vechain/x-app-template) into .agents/skills/smart-contract-development in your project. Codex loads it when a task matches its description.

Can I use Smart Contract Development in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add vechain/x-app-template --skill smart-contract-development -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/smart-contract-development, .gemini/skills/smart-contract-development, .github/skills/smart-contract-development and .opencode/skills/smart-contract-development in your project.

What does Smart Contract Development need to run?

Going by SKILL.md and its folder, Smart Contract Development needs the command-line tools its instructions call (nvm). Our summary lists: Docker.

Does Smart Contract Development access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is Smart Contract Development safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Smart Contract Development use?

Smart Contract Development is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Smart Contract Development use?

About 1.1k tokens (SKILL.md is roughly 4.4k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 17k tokens, read only when the agent opens those files.

What are the alternatives to Smart Contract Development?

Skills that share tags, products or a category with Smart Contract Development: Developing Smart Contracts (LFDT-Lineth/lineth-monorepo, 126 stars), Ethskills (austintgriffith/ethskills, 294 stars), Trustless Agents (internet-court/internet-court-skill, 6.4k stars) and Smart Contract Interaction (Nethereum/Nethereum, 2.3k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Smart Contract Development?

vechain (a GitHub organization) maintains it in vechain/x-app-template, which has 450 GitHub stars. The repository holds 11 skills in this directory. The repository was last updated on July 20, 2026.

Source: vechain/x-app-template on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install Smart Contract Development

Facts

At a glance

What it does

When your agent uses it

Example prompts

Requirements

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Smart Contract Development Skill

CRITICAL RULES

Scope

Default stack

Operating procedure

1. Check Node version

2. Detect project structure

3. Clarify before implementing

4. Implement with VeChain-specific correctness

5. Verify and deliver

Reference files

Files

Compare with similar skills

Similar skills

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Related

Questions about Smart Contract Development