blockchain-development

Blockchain Development

Smart contracts, wallet UX, indexers, security review, and on-chain integration.

This skill is part of the uber-engineer plugin's discipline coverage. Pair with the discipline-router agent when a request crosses disciplines, and the build-validator agent before claiming any work is done.

When to use this skill

Trigger words: blockchain, Ethereum, Solidity, Foundry, Hardhat, Rust smart contracts, Solana, Anchor, wallet, ERC-20, ERC-721, NFT, DeFi, EVM, subgraph, indexer, RPC, MEV, wagmi, viem, ethers.js.

Use when the user wants any of:

• Author Solidity or Anchor contracts with explicit access control.
• Write deterministic test suites against forked mainnet state.
• Run static analysis (Slither, Mythril) before deploy.
• Design wallet flows that don't ask users to sign opaque blobs.
• Build event indexers for on-chain state into off-chain queries.
• Apply reentrancy, integer overflow, and signature-replay guards by default.

When NOT to use this skill

• general web3 frontend without contract code (use frontend-development)
• trading bots without on-chain integration

Workflow

1. Intake. Read the user intent. Identify which capability above applies. If the request crosses into another discipline (e.g. UI + DB), call the discipline-router agent before splitting work.
2. Inspect. Look at the actual repo state with Read/Grep/Glob before proposing changes. Do not assume what code exists from project name alone.
3. Source-check. For non-obvious technical claims, ground the answer in the official sources listed in references/official-sources.md. Use the Context7 MCP for live doc lookups instead of relying on training-data memory for fast-moving APIs.
4. Produce. Generate the appropriate artifact from the list below.
5. Verify. Run every verification layer below before claiming done. Build success is not done. 200 responses are not done. A real user seeing correct output is done.
6. Hand back. Report what shipped, what the visitor sees, what changed. No file paths, function names, or engineering jargon unprompted.

Artifacts this skill produces

• Contract spec: state, events, access roles, upgrade path.
• Foundry/Hardhat test suite with coverage report.
• Static analysis report with each finding triaged.
• Wallet UX flow: human-readable confirmations + simulation preview.
• Indexer schema mapped to contract events.
• Mainnet deploy checklist with multisig sign-off.

Anti-patterns this skill pushes back against

• Storing secrets / private keys in repo.
• Upgradeable proxies without storage layout discipline.
• Wallet prompts that ask users to sign raw hex.
• Tests passing on mocks while behavior differs on a fork.
• Treating audit as optional for non-trivial value transfer.

Verification required before claiming done

• Test coverage on contracts ≥ 95% lines + branches.
• Static analysis reports zero unresolved highs.
• Fork test matches mainnet state assumptions.
• Wallet flow simulation shown to a non-engineer who understands what they're signing.
• Multisig sign-off recorded before mainnet deploy.

Suggested commands

• /blockchain contract-review src/Vault.sol
• /blockchain fork-test --block=latest
• /blockchain wallet-flow approve-spend

References (load on demand)

• references/official-sources.md — authoritative documentation URLs.
• references/workflow-playbook.md — detailed step-by-step playbook.
• references/anti-patterns.md — anti-pattern catalog with fixes.
• references/quality-rubric.md — pass/fail rubric for review.
• references/examples.md — concrete examples, before/after diffs.

Scripts

• scripts/validate_skill.py — sanity-checks SKILL.md frontmatter and references.

Definition of done

A real user, operator, or downstream system experiences the correct outcome of this work. Build success and deploy success do not equal done. The discipline-specific states below must all hold:

• Test coverage on contracts ≥ 95% lines + branches.
• Static analysis reports zero unresolved highs.
• Fork test matches mainnet state assumptions.
• Wallet flow simulation shown to a non-engineer who understands what they're signing.
• Multisig sign-off recorded before mainnet deploy.

Verification actually happened — no claim of "verified" without evidence.