"Free Graph and Network Visualization Tools (No API Key Required)" 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.

Lets MCP clients discover x402 APIs, pay for calls from a local non-custodial wallet, and inspect balances and payment receipts.

An MCP server that enables fee-free USDC transfers on the Base blockchain network using Coinbase CDP MPC Wallet integration, with support for ENS and BaseName domain resolution.

Enforces pre-trade planning discipline by checking entry, stop, target, and risk/reward via a gate tool, and provides proof receipts, terminal links, and risk prompts for AI assistants.

Enables interaction with the Casper Network blockchain via MCP, providing tools for wallet creation, CSPR transfers, staking/delegation, and account queries.

Enables interaction with the Secret Network blockchain, including querying blockchain data, managing wallets, sending transactions, and executing smart contracts, all through natural language via the MCP protocol.

Model Context Protocol (MCP) server providing real-time institutional Spot Bitcoin (BTC) and Ethereum (ETH) daily net flow metrics for AI agents.

Eight crypto and DeFi data tools for AI agents: prices, gas, one ParaSwap route quote, GoPlus token security and top-holder samples, DefiLlama yields, Hyperliquid/dYdX funding, and observed wallet balances. Inspect prices free; pay 0.001–0.008 USDC per call on Base through x402. No API key or subscription.

MCP server for querying Lido liquid staking protocol data via The Graph's decentralized network, providing tools for staking stats, APR, withdrawals, node operators, and governance.

Provides a unified MCP interface over Uniswap V2, V3, and V4 across multiple chains via The Graph, enabling agents to query token prices, top pools, pairs, and recent swaps with clean JSON output.

Enables AI assistants to interact with RGB assets, Lightning Network operations, and Bitcoin transactions through RGB Lightning Node APIs. Supports asset management, invoice creation/payment, channel management, on-chain transactions, and asset swaps.

Enables agents to access live DeFi, social intelligence, risk, and API documentation tools with a caller-supplied API key.

Enables AI agents to access pay-per-call onchain and URL safety APIs over MCP, covering transaction explanations, token approval checks, address inspection, contract risk heuristics, URL safety, gas snapshots, ENS resolution, calldata decoding, and wallet portfolio data. Payments are handled per call in USDC on Base via x402, with no signup or API key required.

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

An unofficial, read-only MCP server for Sarwa Odyssey that provides portfolio, holdings, transactions, watchlists, and agent snapshots via deterministic JSON documents.

Enables MCP clients to read public web pages as clean markdown, verify whether a quote appears on a page, check the health of up to 25 links, and audit any origin's x402 and agent-readiness setup. Tools are pay-per-call in USDC on Base via x402 with free previews, requiring no signup or API key.

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.

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

MCP server for querying cryptocurrency portfolio data, transaction history, net worth, and historical snapshots across 20+ blockchains via the Octav API.

Trust layer for AI agents: 22 pay-per-call x402 tools for scam and fraud checks, payment pre-flight, wallet screening, policy approvals, contact extraction and company research. Free preview with no wallet; paid calls settle in USDC on Base.