"Tools and methods for plotting graphs without an API key" matching MCP servers:

Free DEX aggregator API that returns executable swap calldata across 46 EVM chains. No API key required. Single GET request returns ready-to-sign transactions for any token pair.

Bitcoin data for AI agents. Pay-per-query via x402 micropayments. No API keys. No subscriptions. No tokens.

Enables autonomous Web3 security monitoring by watching honeytoken decoy private keys in the mempool to detect intrusions and trigger tripwire alerts. It also supports smart contract auditing, callgraph verification, and DeFi vulnerability triage through MCP.

MCP server providing real-time crypto prices (Chainlink + Binance), Polymarket prediction market data, deep web research, and JS-rendered web scraping. All services available via x402 Solana micropayments.

55+ pay-per-call tools for AI agents over MCP: live telemetry, blockchain/on-chain checks, environmental, transit, finance, and network utilities. No API key or signup — agents pay per request with x402 USDC micropayments (Base and Solana).

Enables monitoring honeytoken decoy private keys for mempool activity, detecting and alerting on potential intrusions.

Provides access to measured x402 ecosystem data, allowing users to query which merchants actually accept payment (verified by real on-chain settlements) and explore market concentration and health statistics.

Enables natural language interaction with the Avalanche blockchain through AI assistants, allowing users to execute Avalanche CLI commands and AvalancheJS API operations without technical knowledge.

MCP server for pay-per-call DeFi and crypto data via x402 micropayments on Base. 8 endpoints: token prices, TVL, funding rates, token security, gas tracker, whale monitoring, wallet profiling, and yield scanning.

Non-custodial crypto swaps for AI agents: Solana (Jupiter) + 7 EVM chains (KyberSwap), 1288+ assets, cross-chain routing, priority-fee oracle, Hyperliquid perps. Returns unsigned transactions — your wallet signs, no API key, no KYC. Hosted at https://swaptitan.net/mcp

Wallet-funded MCP client for six paid Utilia tools: Solana priority fees, transaction diagnosis and simulation, token-risk checks, PDF-to-Markdown, and audio normalization over x402. MIT-licensed and installable from npm.

Enables interaction with lightning addresses and common lightning tools via your LLM, providing Lightning Network functionality through natural language.

23 tools for AI agents working with Nostr Open source. No API key. No account. NIP-46 remote signing Publish notes, reply, react, repost Encrypted DMs (NIP-04 + NIP-44) Fetch events, profiles, social graph

A comprehensive toolkit for Ethereum blockchain analysis within Claude AI, enabling contract auditing, wallet analysis, profitability tracking, and on-chain data retrieval.

Enables MCP clients to use paid tools for secret scanning, agent-config auditing, and OG image rendering, with payments handled over the x402 protocol on Base.

MCP server for cross-chain bridging, enabling AI agents to find routes, estimate costs, check risks, execute transfers, and track status across blockchains.

43 x402-enabled API tools — DeFi, wallet security, AI/ML, developer tools, SEO. Pay-per-call USDC on Base via x402 protocol.

MCP server for managing TON blockchain sites, deployments, DNS, and storage via the Resistance Tools platform.

An MCP server that enables LLMs to query DAOs, proposals, and voting data from Tally's blockchain governance API across multiple networks.

Enables AI assistants to query blockchain chain data, including chain details, RPC endpoints, and chain relationships, through a Model Context Protocol server.