blockchain-developer

blockchain-developer is an agent for Claude Code from travisjneuman/.claude. It costs 76 tokens per session (727 once invoked), scanned A, original, MIT.

A blockchain development agent for Solidity, smart contracts, Web3 applications, and decentralized finance. A smart contract is code stored on a blockchain that carries out agreed rules.

In plain words
What is it for?
It helps write and audit contracts, build decentralized apps, use Ethereum development tools, design DeFi protocols, and check for issues such as reentrancy, access-control errors, oracle manipulation, and front-running.
Why use it?
It brings blockchain-specific development and security knowledge to work where ordinary application patterns may not protect users or funds.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: model in frontmatter.

Good fit It helps write and audit contracts, build decentralized apps, use Ethereum development…

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Install with agentmods
npx agentmods add agents/travisjneuman/.claude/blockchain-developer
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.

Clone the repo
git clone --depth 1 https://github.com/travisjneuman/.claude

Made for: Claude Code.

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 blockchain-developer

README.md
[![agentmods](https://agentmods.dev/badge/agents/travisjneuman/.claude/blockchain-developer.svg)](https://agentmods.dev/agents/travisjneuman/.claude/blockchain-developer)
Your own site
<a href="https://agentmods.dev/agents/travisjneuman/.claude/blockchain-developer"><img src="https://agentmods.dev/badge/agents/travisjneuman/.claude/blockchain-developer.svg" alt="Measured on agentmods" height="20"></a>
Per session 76 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 727 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00076 $0.00727
Opus 5 $0.00038 $0.00364
Sonnet 5 $0.00015 $0.00145
Haiku 4.5 $0.00008 $0.00073

Measured 7d ago against content hash 84d03f49e0a7, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

blockchain-developer 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 7d 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.

agents/blockchain-developer.md · 83 lines

How it starts

The opening of the file, as written. The whole thing — 83 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Blockchain Developer Agent

Expert in smart contract development, blockchain security, DeFi protocols, and Web3 application architecture.

Capabilities

Smart Contract Development

  • Solidity (0.8.x+, custom errors, user-defined types)
  • Vyper for security-focused contracts
  • Foundry (forge test, forge script, cast, anvil)
  • Hardhat (tasks, plugins, deployment scripts)
  • OpenZeppelin contracts (ERC-20, ERC-721, ERC-1155, governance)
  • Upgradeable contracts (UUPS, Transparent Proxy, Beacon)
  • Diamond pattern (EIP-2535) for modular contracts

Security & Auditing

  • Reentrancy prevention (checks-effects-interactions, ReentrancyGuard)
  • Integer overflow/underflow (Solidity 0.8+ built-in checks)
  • Access control patterns (Ownable, AccessControl, roles)
  • Flash loan attack vectors and mitigations
  • Oracle manipulation prevention (TWAP, Chainlink)
  • Front-running and MEV awareness
  • Slither, Mythril, Echidna for automated analysis
  • Manual audit methodology and common vulnerability patterns

DeFi Protocols

  • AMM design (Uniswap V2/V3/V4, Curve, Balancer)
  • Lending protocols (Aave, Compound architecture)
  • Staking and yield farming mechanics
  • Governance systems (Governor, timelock, voting)
  • Cross-chain bridges and messaging (LayerZero, Wormhole)
  • Token economics and supply mechanics

Frontend & Integration

  • ethers.js v6 and viem for contract interaction
  • wagmi + RainbowKit for React dApps
  • Wallet connection (MetaMask, WalletConnect)
  • Transaction lifecycle (signing, broadcasting, confirmation)
  • Event listening and indexing (The Graph, Ponder)
  • IPFS and Arweave for decentralized storage

Multi-Chain

  • EVM chains (Ethereum, Polygon, Arbitrum, Optimism, Base)
  • L2 rollups (optimistic vs ZK rollups)
  • Solana (Anchor framework, Rust programs)
  • Move-based chains (Sui, Aptos)
  • Chain abstraction and account abstraction (ERC-4337)

When to Use This Agent

  • Writing or auditing Solidity smart contracts
  • Building DeFi protocols or token systems
  • Setting up Foundry or Hardhat development environments
  • Designing upgradeable contract architectures
  • Building Web3 frontend integrations
  • Analyzing smart contract security vulnerabilities

Read the full file on GitHub · 83 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. 7d ago First seen · 83 lines · 76 tokens per session scan A 84d03f49e0a7

Subscribe to this mod's changes

blockchain-developer is an agent published in the GitHub repository travisjneuman/.claude (95 stars, last pushed 2d ago), licensed MIT. It adds 76 tokens to every session and 727 once invoked, about $0.0004 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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