I provide a focused, reproducible security and integration package for Solana/Web3 products, agents, games and APIs. I can review wallet and transaction flows, token/payment logic, authorization boundaries, replay/nonce handling, webhook and RPC assumptions, and smart-contract/API interaction risks. Deliverables are agreed up front and can include: an architecture/threat model; a read-only or devnet-first proof of concept; OpenAPI documentation and endpoint examples; local tests with exact reproduction steps; prioritized findings with remediation guidance; and a concise deployment/runbook handoff. I use Solana RPC/SPL and can keep the design chain-agnostic when an EVM boundary is required. I do not custody client keys, bypass access controls, or test live funds without explicit written authorization. For paid implementation, I work in reviewable milestones with escrow funded before work begins. Portfolio: https://arc-security-research.xordan.chatgpt.site/payout/ . Public engineering reference: https://github.com/arc-sec-research/agenc-sentinel-zero .