"QA review sentinel test marker" matching MCP connectors:

Pay-per-call safety checks for AI agents: screen a crypto address or URL before you transact.

Signed agent discovery, security attestations, paid work, and verified settlement reputation.

Barker's real-time stablecoin yield index + AI advisor + non-custodial deposit/redeem (x402 paid).

KYA: fail-closed CLEAR/REVIEW/BLOCK counterparty screen (OFAC + on-chain), signed receipt.

Native cross-chain swaps: Bitcoin, Ethereum, Solana, Polkadot, Tron, Arbitrum. Quote, swap, track.

Crypto prices, gas, DeFi TVL, and live Polymarket odds. x402 pay-per-call, $0.001, no API key.

Hyperliquid perp market data for LLMs: OHLCV, funding, open interest, positioning & forecasts.

Bitcoin-anchored sealed-forecast record: search, grades, calibration, luck test. Read-only, no key.

Live prediction markets: Polymarket + Kalshi prices, odds, order books. Pay-per-call USDC, no key.

Pay-per-call MCP server. Vetted human experts review AI-generated content (text, images, video, audio, social posts), audit reasoning chains, run prepublish safety checks, and gate high-stakes actions for human approval. 7 paid tools at $1.00 each plus 4 free tools (list_offerings, list_expert_profiles, get_result, verify_certificate). Payment via x402, USDC on Base mainnet. Approved outputs receive an on-chain Taste content certificate downstream agents verify before consuming.

Expert review for AI agents. On-chain proof of human review.

A comprehensive market data MCP server maintained by Bitget, aggregating 20 tools across crypto, DeFi, derivatives, TradFi, macro, and on-chain data

Crypto prices, market overview, DeFi TVL, whale flows & anomaly scans for trading agents.

x402 skill catalog on lvlltd.com — search, quote, pay with Base USDC, unlock sealed packs.

US tax classification for on-chain transactions: category, treatment, confidence, review flags.

AI agents publish bounties for real-world tasks. Gasless USDC payments via x402.

Enterprise supply chain AI, warehouse optimization, logistics intelligence, real-time crypto/forex/stock data, shipping rates. 61+ MCP tools. Credit-based pricing at $0.001/credit with x402 USDC payments on Base/Polygon.

DeFi MCP fleet: oracle, security audit, treasury yield, QA attestation, and compute tools on Base.

Tenderly MCP server for blockchain dev — simulate, debug, and test on 100+ networks.

AI LLM with Gemini, MiniMax, Replicate, OpenRouter. Vision, search, code review. USDC on Base.