"A tool or technique to improve prompt writing" 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.

Universal pay-per-call tool API for AI agents. Web search, price feeds, hive memory, LLM routing, code sandbox. Free tier (10 calls/day, no signup). x402 payments on Base + Solana.

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.

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.

x402 MCP web parser: URLs to Markdown for agents. USDC on Base, Polygon, Arbitrum, Ethereum.

Find the cheapest EVM chain across up to 9 networks with savings %. Pay-per-call via x402 on Base.

Deterministic market-state engine for trading agents — zero LLM in the signal path. 8 tools: structural market state & phase, action gate (GO/WATCH/HOLD) as a transition posture, entry/target/invalidation coordinates, bar-by-bar state timeline, composed view cards, and pre-trade intent validation. Every output traces to a bar-stamped ledger with a public daily self-scoring track record (misses included). Crypto + TradFi synthetics (gold, oil, S&P 500, Tesla, NVIDIA, KOSPI 200).

Audited crypto intel for agents: A-F trade checks, scored signals, liq maps, regime, trade journal.

MCP server connecting AI agents to non-custodial staking data across 130+ networks.

x402-paid tools: text to 3D-printable STL, web search, and search+read. USDC on Base.

x402-gated agentic vending stack for AI agents — dynamic-priced payload vending, Ghost Layer decision-notarization resale, and a real multi-seller marketplace for x402-payable APIs. Base/USDC + XRPL/RLUSD settlement.

Free, open, read-only MCP server for live crypto market intelligence: analyst briefs, funding rates, open interest, liquidations, and a market-regime signal. No API key required.

Audited crypto market intelligence for agents. Pre-trade check (check_trade: grade any trade idea A–F against positioning crowding, event risk, liquidation distance, proven edges), signals with published win rates, liquidation maps, market regime state. Every verdict logged and publicly scored at n0brains.com/proof. 28 tools, free tier available.

Print & mail PDF/HTML/Markdown/text/DOCX/images to US addresses; pay per call in x402 USDC on Base.