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

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.

Provides automated data visualization and analysis tools that intelligently select from over 40 chart types based on data structure and patterns. It enables users to generate statistical insights, interactive dashboards, and professional reports in HTML, PNG, and Word formats.

MCP server that tracks and searches Microsoft Graph API schema changes, permissions, and roles, with historical data and an interactive schema visualizer.

A graph database MCP server that lets AI assistants build, analyze, and visualize relationship graphs with algorithms like PageRank and cycle detection.

Enables MCP-capable assistants to control an open ArcGIS Pro project locally over TCP 127.0.0.1, with 68 commands and 167 tools for layers, editing, symbology, layouts, geoprocessing, and arcpy execution.

Enables natural-language interaction with Ladybug Tools for building performance simulation, 3D modeling, and data visualization, allowing agents to perform complex environmental analysis tasks without CAD software.

MCP server for rendering Mermaid diagrams and generating source-code diagrams, with tools to render text/files and produce dependency/class diagrams.

Provides honest A/B test verdicts using interactive cards, with statistical calculations for conversion rates, sample sizes, and Bayesian probability-to-beat.

Connects to SQL databases to execute queries and return results as chart images (PNG) visible in MCP clients.

MCP server for managing a task graph with live visualization. Enables Claude Code to create, update, and link nodes (tasks, subtasks, ideas, etc.) while a browser viewer displays the graph in real time.

Enables validating IFC models against IDS requirements with coverage reporting, auditing LOD by project stage, and extracting quantity take-offs, including combined audit summaries and full BIM health checks. It exposes these capabilities as MCP tools for Claude Desktop, producing Excel, HTML, and BCF reports.

Enables users to create, validate, view, and export system stock-and-flow maps from a versioned JSON model through MCP-capable hosts over local stdio or hosted Streamable HTTP. Supports causal-loop and nested-level mapping while keeping submitted model content with the caller and requiring no LLM provider key.

Provides local, deterministic Four Pillars (Bazi) chart calculation via MCP tools, with JSON and PNG outputs, no API key or network required.

Enables Codex to control a Gephi 3D network view through natural language, including network generation, 3D layout, node focus and neighbor highlighting, layered views, and PNG/PDF export.

Enables users to inspect local Hyper files by listing files, schemas, and tables, previewing up to 100 rows, and generating sample sales Hyper data.

Generate annotated post-trade candlestick review-chart PNGs from broker or exchange fills. Includes capability checks, no-charge preflight validation, and chart rendering; no signals or order execution.

A free MCP server that renders bar, line, and area charts from structured data into clean, hand-designed SVG. No API key or payment needed, with colorblind-safe palettes and light/dark theme support.

AI-powered Fantasy Premier League assistant — scored captain picks, transfer suggestions, differentials, fixture outlook, price predictions, live points, and a full manager hub that auto-detects your squad, bank balance, and free transfers.

Enables creating scheduled Gantt charts with critical-path analysis from any MCP client using plain-language task descriptions, with no account or API key required.

Enables interactive math and statistics visualization, computation, and validation through graph plotting, 3D scenes, and presentations with verifiable results.