"How to Query a Knowledge Graph Using an Ontology" matching MCP connectors:

Is a wallet frozen by Tether/Circle? Free freeze checks + full history, screening & KYT. 9 chains.

Teardrop is the native economic layer for AI agents, providing a robust suite of tools for multi-chain portfolio tracking, DeFi yield analysis, and gas estimation. It enables autonomous agents to securely find Web3 data and manage micro-payments on-chain with zero human intervention.

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

Trade crypto perpetual futures and spot on Rubin, a self-custody decentralized exchange, from AI agents — place and manage orders and read order books, candles, positions, and balances.

Live AI agent contest platform on Solana mainnet. Compete in skill tournaments (ART, STORY, JOKE) for real USDC payouts via on-chain Anchor smart contract. Confidential-rubric LLM judging on four dimensions: originality, theme_alignment, execution, surprise. Engine never holds private keys — entries use a two-call co-sign handshake.

Search and license 5,000+ fully cleared music tracks via MCP. AI agents can find music by genre, mood, BPM, and instrumentation, then license instantly with USDC on Base. No human in the loop. Also includes free music industry knowledge tools: platform loudness standards, royalty calculators, and genre conventions.

Free, keyless MCP server with 50 read-only blockchain tools for Bitcoin, Ethereum, and Mezo. No installation, no API key required -- just add the URL to your MCP client and start querying balances, transactions, blocks, ENS names, ERC-20 tokens, smart contracts, and more. Runs on Cloudflare's global edge network via Streamable HTTP. All tools are strictly read-only and stateless.

Free, keyless MCP server with 50 read-only blockchain tools for Bitcoin, Ethereum, and Mezo. No installation, no API key required -- just add the URL to your MCP client and start querying balances, transactions, blocks, ENS names, ERC-20 tokens, smart contracts, and more. Runs on Cloudflare's global edge network via Streamable HTTP. All tools are strictly read-only and stateless.

Per-transaction crypto trade validator for AI agents. Returns deterministic PROCEED / CAUTION / BLOCK verdicts using WaveGuard anomaly detection, history checks, and rug-pull risk analysis.

A paid, growing marketplace of real AI agents -- Ed25519-proven, verifiable in your own process.

TRON blockchain MCP server powered by the GoTRON SDK — query accounts, balances, TRC20 tokens, blocks, transactions, and smart contracts; build and sign transactions for transfers, staking, voting, and contract calls. Supports mainnet, Nile, and Shasta testnets with Go-based tooling for energy estimation and transaction building. Available via stdio or hosted Streamable HTTP

PayRam is a self-hosted crypto payment gateway. You deploy it on your own server — no signup, no KYC, no third-party custody. Accept USDT, USDC, Bitcoin, and ETH across Ethereum, Base, Polygon, and Tron.

The MCP-native bridge to ERC-8004 (on-chain agent identity/reputation/validation): resolve registrat

Celestia knowledge base: CIPs, docs, forum, videos, GitHub, plus live on-chain state

Onchain safety, wallet & account intelligence, lending, and AI reads on Base — 100+ tools paid per call over x402. Send a prepaid credit token via the x-credit-token header for unlimited calls, or get 1 free call/day per tool. No wallet or API key required.

Agent-to-agent escrow on Robinhood Chain. Post quests with ETH/USDG bounties and settle on-chain.

x402 V2 payment-to-access on Solana USDC with receipts, entitlements, atomic metering and webhooks.

Pay-per-query x402 business intelligence on Base, settled in USDC via the native 402 payment flow.

Pay-per-call live telemetry, environmental metrics, transit state vectors, blockchain reads, network/security lookups and real-time utilities for AI agents using x402 and MCP.

Provide AI agents and automation tools with contextual access to blockchain data including balance…