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

An MCP server that bridges ChatGPT Web Pro to local tools, enabling file read/write, shell command execution, git operations, and search within a specified project directory.

MCP server that enables full-text search and link navigation over Markdown files as a knowledge graph.

Enables extraction of recipes from PDFs or JPG files and conversion into structured HTML, with interactive region selection and OCR via a web GUI.

This MCP server gives an AI coding host controlled, client-agnostic access to a local machine's developer capabilities: transactional file edits, shell and PTY execution, Git and project inspection, language-server operations, isolated browser automation, Windows UI automation, VS Code state, durable jobs, and checkpoints, all bounded by filesystem root allowlisting and resource admission controls. It speaks standard MCP over stdio, Streamable HTTP, and legacy HTTP+SSE, and can also run headless as a long-lived job runner without any hosted model vendor.

A local-first Graph-RAG system that combines ChromaDB with metadata-based graph relationships and Gemini 2.5 Flash for intelligent Q\&A over your Obsidian vault.

The local PDF workflow for Claude Desktop and MCP hosts: fill, sign, merge, split, extract, and analyze PDFs without sending files to a web app.

Enables AI agents to perform file operations through the GigAI Tools API, such as merging PDFs, converting and compressing images, extracting PDF text, and generating QR codes, with results saved locally and tools synced from the live API catalog.

Enables Codex or any local MCP client to read and edit Project Graph .prg files using the official runtime, with tools for inspecting, creating, editing, connecting, deleting, and laying out graph nodes.

MCP server that provides file operations and Moonshot API-powered tools (reasoning, code review, testing, research, web search, agent) for Kimi K2.5, requiring only a Moonshot API key.

A comprehensive MCP server with RESTful API that enables file operations, command execution, project management, and AI integration for remote development control with security features and real-time communication.

An MCP server that converts and processes document formats such as DOCX and PDF into Markdown, enabling AI assistants to work with document contents.

Enables AI assistants to convert and process various document formats through an MCP server interface.

Enables natural language interaction with Obsidian vaults through an MCP server, providing hybrid search, file management, and AI-powered analysis.

Enables AI agents to perform local video, audio, and file operations inside an isolated workspace, including cutting/concat videos, extracting audio, transcribing, and managing files, with typed responses and background job support.

MCP server for file operations with non-UTF-8/Unicode encoding: Cyrillic, CP1251, CP1252, ISO-8859, KOI8 auto-detection

Enables web ChatGPT to drive durable, sandboxed Claude Code sessions on a local Mac, with controlled read, modify, verify, and recover operations via six session control tools.

MCP server wrapping DeepSeek's agent harness tools into minimal/standard modes, enabling persistent shell, file editing, search, job management, and more via natural language.

A comprehensive tool server for reading, merging, and extracting content from PDF files via local paths or direct URLs. It enables metadata retrieval, regex searching, and page-specific text extraction with built-in caching and workspace-restricted security.

Enables AI assistants to perform controlled Linux system administration tasks like reading logs, managing services, cron jobs, WordPress, and executing sandboxed Python code, with strict security constraints.

MCP server for accurately reading and writing Excel .xlsx files while preserving structure, styles, and formulas. Provides tools for inspecting, editing, and aggregating spreadsheet data, with optional LibreOffice recalculation.