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

Provides tools for AI-powered graph analysis, including relationship extraction, adjacency matrix creation, and network centrality calculations. It enables users to perform complex structural analysis and generate interactive D3.js visualizations from structured data.

Provides an OpenAI-compatible gateway to the MiMo (Xiaomi) model series, with native MCP server tools for web search and visual analysis.

Enables deploying pre-built AI agent blueprints for RFx procurement and employee onboarding, with no signup or API key required.

Enables creating interactive data visualizations from natural language queries using DuckDB for local databases or Databricks for enterprise data warehouses. Supports multiple chart types, CSV imports, SQL queries, and automatic statistical analysis through Claude Desktop.

Scans code for exposed secrets, API keys, tokens, and credentials across 69 patterns covering cloud services, AI platforms, payment providers, authentication services, and databases.

Self-hosted personal knowledge graph for Claude that persists across sessions, devices, and tools. Built on Neo4j with local semantic embeddings; OAuth 2.1 lets Claude Code, Claude Desktop, and claude.ai web all hit the same graph.

Multi-agent swarm orchestrator for AI workflows. Exposes blackboard read/write, agent dispatch, permission gating (AuthGuardian), token budget enforcement (FederatedBudget), and audit log tools over MCP. Supports 14 AI framework adapters including LangChain, AutoGen, CrewAI, Codex, and A2A — mix any frameworks in one swarm with race-condition-safe shared state.(Traffic light for agents)

Local-first memory for Claude Code and any MCP client: hybrid vector + keyword search and a bi-temporal knowledge graph in one SQLite file. Local embeddings, no API key, $0/token.

Captures browser network traffic, analyzes API patterns, and exposes analysis tools through an MCP server for AI-assisted workflows.

Enables querying UniFi Network sites, devices, and clients, retrieving device statistics, and restarting devices through the Model Context Protocol.

MCP server for Cursor IDE offering tools for Human Design chart analysis, partner matching, n8n workflow management, and utility functions like UUID generation and calculation.

An improved implementation of persistent memory using a local knowledge graph with a customizable --memory-path. This lets Claude remember information about the user across chats.

Structural graph map of any codebase. Scans entities, relationships, and feature flows across 13 languages so LLMs navigate by structure instead of reading everything.

An MCP server for Microsoft Graph, exposing 60 tools across calendar, email, meetings, Teams chat, files, people, directory, tasks, and OneNote over stdio or Streamable HTTP.

Indexes a mono-repo into a knowledge graph and provides MCP tools to query code structure—packages, components, routes, HTTP calls—without file reads or grep round-trips.

A secure email gateway MCP server that protects AI agents from prompt injection attacks by scanning emails for malicious instructions before they reach the agent.

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.

Enables validating Sparkplug B topics, checking Unified Namespace conventions, and running an industrial AI-readiness diagnostic via MCP, with no API key or account required.

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