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

Human-in-the-loop approval: a person approves the exact AI action with a passkey, and any service can check the signed approval offline.

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.

Local-first MCP server that lets AI agents design Cisco-style networks and generate L1/L2/L3 topology diagrams, device tables, and AI-ready context files.

Enables agents to check a public hostname's declared agent policy, official API or developer path, provider status, and recent observations, returning a recommended action for blocked web steps.

Amazon MCP server and Amazon product data API for AI agents. Lets Claude, Cursor, ChatGPT and other MCP clients search Amazon, get real-time prices, reviews, product details, sellers, deals and best seller ranks, or look up any ASIN. One API key, 100 free requests a month.

MCP server that exposes tools to route natural language queries to typed IDs, describe catalog entries, and list repository verification commands for the m-dev-tools organization.

Get access to real-time SEO data, including: keyword insights, backlink data, traffic estimates and more. Allow AI tools and Large Language Models (LLMs) to tap into the real-time SEO Review Tools API with natural language commands.

Enables MCP-compatible clients to list verified free HTTP, SOCKS4, and SOCKS5 proxies, pick top-ranked ones, and summarize the current proxy snapshot through three read-only tools, without forwarding traffic or accepting arbitrary URLs.

Open end-to-end encrypted messaging protocol and MCP server (a4a-mcp) that gives AI agents a cryptographic address (apub1...) to exchange messages, tasks, and signed agreements directly across NAT without port forwarding.

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

Offers 29 free tools for text processing, AI-powered generation, SEO optimization, utilities, cron tasks, file processing, and ideas management, all without requiring an API key.

Enables AI agents to search, describe, and call paid data services from the Pocket Network agentic marketplace, paying per request in USDC via x402.

MCP gateway for GREEN-API WhatsApp that lets AI agents send messages, manage instances, and receive notifications via WhatsApp using the Model Context Protocol.

Enables AI agents to discover, pay for, and retrieve receipts for external APIs via USDC micropayments through the SynapseNetwork Gateway, supporting stdio and Remote MCP.

Gives Claude direct access to the Africa API for comprehensive data on all 54 African nations, including economic indicators, markets, trade, government, elections, and policies.

Remote, read-only MCP connector to check any company's witnessed trust record on the Trooth Network, across identity, security, privacy, and AI practices. Also does a neutral read of a domain's public security surface and verifies signed Trust Ledger Tokens. No key, no account.

A remote MCP server that lets AI agents generate PDFs from Markdown or HTML, extract text from images and PDFs, validate and screen email addresses, convert or host images, and create QR codes and barcodes. It also exposes account, subscription, and API-discovery tools, with every call running against the same REST quotas tied to the caller's own API key.

Provides deterministic tools for transforming, formatting, and inspecting structured data for AI agents.

Provides a collection of MCP servers for computational chemistry tasks including molecular generation and retrosynthesis. Also offers property prediction and molecule pricing capabilities.