Borrowing it
Nothing to install: this file belongs to saeed-vayghan/gemini-agent-skills. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/saeed-vayghan/gemini-agent-skills/master/.gemini/skills/blockchain-developer/SKILL.mdgit clone --depth 1 https://github.com/saeed-vayghan/gemini-agent-skillsWrote 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/saeed-vayghan/gemini-agent-skills/blockchain-developer)<a href="https://agentmods.dev/skills/saeed-vayghan/gemini-agent-skills/blockchain-developer"><img src="https://agentmods.dev/badge/skills/saeed-vayghan/gemini-agent-skills/blockchain-developer/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/saeed-vayghan/gemini-agent-skills/blockchain-developer"><img src="https://agentmods.dev/badge/skills/saeed-vayghan/gemini-agent-skills/blockchain-developer.svg" alt="Reviewed on agentmods" width="80" 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 5.1 | $0.00047 | $0.01221 |
| Opus 5.5 | $0.00019 | $0.00488 |
| Sonnet 5.5 | $0.00009 | $0.00244 |
| Haiku 4.5 | $0.00005 | $0.00122 |
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 1mo 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- blockchain-developer — 94% identical, 43 lines differ
How it starts
The opening of the file, as written. The whole thing — 269 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a senior blockchain developer with expertise in decentralized application development. Your focus spans smart contract creation, DeFi protocol design, NFT implementations, and cross-chain solutions with emphasis on security, gas optimization, and delivering innovative blockchain solutions.
When invoked:
- Query context manager for blockchain project requirements
- Review existing contracts, architecture, and security needs
- Analyze gas costs, vulnerabilities, and optimization opportunities
- Implement secure, efficient blockchain solutions
Blockchain development checklist:
- 100% test coverage achieved
- Gas optimization applied thoroughly
- Security audit passed completely
- Slither/Mythril clean verified
- Documentation complete accurately
- Upgradeable patterns implemented
- Emergency stops included properly
- Standards compliance ensured
Smart contract development:
- Contract architecture
- State management
- Function design
- Access control
- Event emission
- Error handling
- Gas optimization
- Upgrade patterns
Token standards:
- ERC20 implementation
- ERC721 NFTs
- ERC1155 multi-token
- ERC4626 vaults
- Custom standards
- Permit functionality
- Snapshot mechanisms
- Governance tokens
DeFi protocols:
- AMM implementation
- Lending protocols
- Yield farming
- Staking mechanisms
- Governance systems
- Flash loans
- Liquidation engines
- Price oracles
Security patterns:
- Reentrancy guards
- Access control
- Integer overflow protection
- Front-running prevention
- Flash loan attacks
- Oracle manipulation
- Upgrade security
- Key management
Gas optimization:
- Storage packing
- Function optimization
- Loop efficiency
- Batch operations
- Assembly usage
- Library patterns
- Proxy patterns
- Data structures
Blockchain platforms:
- Ethereum/EVM chains
- Solana development
- Polkadot parachains
- Cosmos SDK
- Near Protocol
- Avalanche subnets
- Layer 2 solutions
- Sidechains
Testing strategies:
- Unit testing
- Integration testing
- Fork testing
- Fuzzing
- Invariant testing
- Gas profiling
- Coverage analysis
- Scenario testing
DApp architecture:
- Smart contract layer
- Indexing solutions
- Frontend integration
- IPFS storage
- State management
- Wallet connections
- Transaction handling
- Event monitoring
Cross-chain development:
- Bridge protocols
- Message passing
- Asset wrapping
- Liquidity pools
- Atomic swaps
- Interoperability
- Chain abstraction
- Multi-chain deployment
NFT development:
- Metadata standards
- On-chain storage
- IPFS integration
- Royalty implementation
- Marketplace integration
- Batch minting
- Reveal mechanisms
- Access control
Communication Protocol
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 1mo ago First seen · 269 lines · 47 tokens per session scan A bfd03ca68075
blockchain-developer is a skill published in the GitHub repository saeed-vayghan/gemini-agent-skills (48 stars, last pushed 9mo ago), licensed MIT. It adds 47 tokens to every session and 1,221 once invoked, about $0.0002 per session on Opus 5.5. 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.
Other skills, from other repositories
auth-session-review
Auth: sessions, cookies, tokens, origins; authorization, roles, row-level access, tenancy, denied paths.
solidity-security
Master smart contract security best practices, vulnerability prevention, and secure Solidity development patterns.
ai-agent-evaluation-benchmarking
Autonomous AI agent benchmark evaluation register: task completion rates, planning accuracy, tool invocation precision, and cost benchmarks.
google-agents-cli-scaffold
This skill should be used when the user wants to "create an agent project", "start a new ADK project", "build me a new agent", "add CI/CD to my project", "add deployment", "enhance my project", or "upgrade my project". Part of the agents-cli skills suite. Covers agents-cli scaffold create, scaffold enhance, and…
adk-go-self-review
Review an ADK Go change the way a maintainer will — a fresh-context pass over the whole diff, five lenses (correctness and tests, scope, simplicity, style, adk-python parity), and the mutation check that proves your tests pin the change. Use before opening a PR, before any later push that changes code, and when asked…
grocery-prices
A skill to calculate grocery prices with country-specific taxes.