"Free Graph and Network Visualization Tools (No API Key Required)" matching MCP servers:

Enables AI agents to call 16 small, deterministic, read-only tools over a free, no-auth remote streamable HTTP MCP endpoint, covering business idea scoring, price headroom, hotel OTA commissions, open-source SaaS swaps, ads policy notice risk, App Store 4.2 prechecks, and Japan trip planning. Each tool is also exposed as a plain JSON API with OpenAPI docs.

Enables generation of 11 chart types — including A-share K-line, decision tree, combo and waterfall — from JSON data, with automatic CJK font detection and light/dark themes.

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

Enables access to Usage and Billing APIs for managing accounts, products, meters, plans, and usage reporting. Supports operations like creating products/plans, reporting usage, and retrieving billing information.

Free Polish VAT invoice generation MCP server with PDF output and preview. No API key required.

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 deterministic calculations for AI API and subscription costs, meeting time zones, recurring schedules, and cron next-run previews, returning normalized inputs, units, assumptions, dated sources, and links to results.

MCP server for querying the SEC Ownership Graph, providing curated read-only tools to analyze activist campaigns, control chains, and board interlocks from SEC filings. Answers cite accession numbers and abstain when data is insufficient.

MCP server that exposes the OBBBA No Tax on Tips federal deduction logic as callable tools, enabling users to check eligibility and estimate tip deductions.

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 that exposes unified AI-friendly tools over Messari's standardized lending subgraphs on The Graph. One natural-language query → fan out across 40+ lending protocols on multiple chains → get back structured, comparable data.

MCP server for querying AAVE V2/V3 lending protocol and governance data via The Graph subgraphs. Exposes 14 tools and 5 guided prompts that any AI agent (Claude, Cursor, Copilot, etc.) can use to query lending markets, user positions, health factors, liquidations, flash loans, rate history, and AAVE governance — across 7 chains (Ethereum, Base, Arbitrum, Polygon, Optimism, Avalanche, Fantom) via

Provides real-time access to Pyth Network's decentralized oracle price feeds across 1,930+ assets and 107+ blockchains, enabling AI agents to fetch current prices, historical data, and TWAP calculations for crypto, equity, FX, metal, and rates markets.

An MCP server that enables querying Polymarket prediction market data through The Graph subgraphs. It provides tools for accessing market stats, trader P\&L, user positions, and orderbook activity using AI agents.

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.

Provides access to the Reuters Business and Financial News API to retrieve articles, trending news, and market data. It enables searching and filtering financial content by date, author, category, and keywords.

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

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

Enables AI agents to query multi-cloud costs, inventory, waste, and commitments across AWS, GCP, Cloudflare, and OVH through read-only MCP tools.