"Capture The Flag (CTF) cybersecurity competitions and challenges" matching MCP servers:

Feature flag service for A2A networks with DID-keyed targeting, percentage rollouts, and USDC settlement on Base L2.

x402 capability chassis: 170+ AI-callable, pay-per-call data tools (US/global equities, crypto/DeFi, prediction markets, gov/legal, research, infra) settled in USDC on Base mainnet via the Coinbase CDP facilitator. No API keys or accounts — the x402 payment is the auth. Remote MCP at https://the-stall.intuitek.ai/mcp.

MCP server that lets an AI analyst place real bets on Binance prediction markets, using Kelly criterion sizing, and tracks its performance through a transparent record of betting slips and outcomes.

Reasoning-puzzle arcade for AI agents with seven generated puzzle families, free samples, automatic answer checking, and ranked play from $0.02 USDC on Base via x402. Connect through MCP or HTTP. Browse and try samples without a wallet; run paid tools locally with an explicit spending limit.

This MCP wraps Bitrefill public API to allow agents to search for products and shop using cryptocurrencies like Bitcoin, Ethereum, Solana, and many more.

TCG oracle as an MCP server: 22 focused tools. Search 455K+ trading cards, live market snapshots, AI grading and grade-or-not decisions, conformal-calibrated price forecasts with a public accuracy scorecard, card-collateral loan terms, fantasy and sports souls leagues. Every root proven on-chain. Same tools as the hosted endpoint at mcp.the-undesirables.com, over stdio; no keys.

Provides real-time cryptocurrency prices, market cap, and 24h change using CoinGecko, with free access and no API key required.

On-chain crypto indicators (EMA, RSI, VWAP, Bollinger) via Chainlink oracles.

📈 提供股票、加密货币的数据查询和分析功能MCP服务器

Provides 31 AI-powered crypto trading tools for Claude, Cursor, and any MCP client, enabling strategy creation, backtesting, bot deployment, copy trading, and portfolio management across multiple exchanges.

AgentBureau provides the legal and physical infrastructure for AI agents to operate within the German jurisdiction. We bridge the gap between digital intelligence and real-world action by providing "Embodiment-as-a-Service." Through our API, agents can perform legally binding actions—like sending faxes, mailing physical letters, issuing invoices, forming entire companies (GmbH/UG), ...

Provably fair crypto casino API for AI agents. Place bets on 8 games (coin flip, dice, roulette, blackjack, crash, plinko), run tournaments, issue 1v1 challenges, and earn 10% referral commissions. No KYC, pure API.

Real-time access to Frankencoin (ZCHF) protocol data including supply, prices, peg health, savings, minting positions, liquidation challenges, governance, insurance products, and historical analytics across all supported chains.

Enables AI agents to detect and verify the language of texts, run bundle checks, and top up prepaid credits by paying per call in USDC on Solana, with no account, API key, or subscription needed. Payment is handled transparently via x402 challenges, prepaid credit tokens, or a funded payer wallet with sponsored gas.

Enables MCP hosts to invoke pay-per-call wallet, risk, web, repo, and x402 catalog utilities while automatically handling 402 challenges, EIP-3009 USDC payments on Base, and spend guards with a local agent wallet.

Enables AI agents to perform free KushBitx token previews, advisory SpendGuard policy evaluations, and discovery of unsigned x402 payment challenges through three MCP tools, with no signing or payment execution.

Exposes three read-only MCP tools for previewing Base token market data, evaluating USDC spend against SpendGuard policies before funds move, and discovering x402 payment challenges without signing or paying.

Enables keyless interaction with KushBitx token-risk APIs: free token previews, advisory SpendGuard policy evaluations, and discovery of unsigned x402 payment challenges, without requiring LLM keys, wallets, or payments.

Production-grade Model Context Protocol (MCP) server delivering paywalled Web3 micro-services powered by autonomous x402 payment challenges on Base Mainnet.

Checks live x402 routes across Base, Solana, and Algorand before agents spend. $0.003 USDC settles only for a valid live eligible route; normal typed misses are not settled. Free preview and validate tools. Seller payment is separate; the agent keeps its wallet. Optional signed route-binding receipts support buyer-side checks.

Rug pull risk scores and on-chain forensics for memecoins on Solana, Ethereum, Base and Robinhood Chain - launch-bundle detection, funding-origin tracing, deployer history, insider networks and whale flow. 15 read-only tools.

Provides live and historical market data for Bitcoin and any Binance pair via two read-only tools: current price snapshot and historical OHLC candles.

Rescues USDC, USDT and USDG from wallets with no gas. Agents check a wallet for stuck or frozen stablecoins, quote a send or a swap into the gas coin, collect the wallet signature and track the transfer. Base, Arbitrum, Ethereum, Polygon, Avalanche, BNB Chain, HyperEVM, Robinhood Chain, Solana and Tron.

Enables agents to search and inspect live service offerings, generate x402 payment snippets, and understand blockchain-only balance policies.

MCP Server for the Luno Cryptocurrency API

Live Proof-of-Work mining data for AI agents: difficulty, hashrate, solo-mining odds, cost of production and hardware profitability across 126+ networks and 770+ ASIC/GPU/CPU models. Sourced and timestamped, read-only.

MCP server for RugGuard, enabling AI agents to perform pre-trade rug checks on tokens, with paid tools for token scanning and pre-trade verification, and a free metrics resource.

Hourly news sentiment and typed market events (hack, regulation, listing, delisting, legal) for 30 crypto pairs, with source links on every signal. Four tools cover the latest score per symbol, history, classified events and the symbol list, and a free API key works out of the box

Enables MCP-capable agents to retrieve a tamper-evident decomposition of x402 network growth on Base and to place $399 human-reviewed endpoint or wallet audits paid over the x402 rail, without moving funds itself.

Provides live financial data for any LLM agent, including stock quotes, crypto prices, SEC filings, XBRL financials, FX rates, and macro indicators, through ten MCP tools.