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.
npx agentmods add skills/saeed-vayghan/gemini-agent-skills/blockchain-developernpx skills add saeed-vayghan/gemini-agent-skills --skill blockchain-developergit clone --depth 1 https://github.com/saeed-vayghan/gemini-agent-skillsWhat 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 | $0.00047 | $0.01221 |
| Opus 5 | $0.00023 | $0.00611 |
| Sonnet 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 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.
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.
- yesterday 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 (33 stars, last pushed 7mo ago), licensed MIT. It adds 47 tokens to every session and 1,221 once invoked, about $0.0002 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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