"MCP servers that work without API keys" matching MCP servers:

Controls a running KiCad 9+ instance via the official IPC API, enabling board edits, queries, and exports without reload.

An MCP server that turns the Game Boy Pan Docs into precise, citable lookups for registers, opcodes, memory, cartridges, and CPU behavior, enabling decompilation work.

Enables agents to query LAVA board farms, submit and manage test jobs, and open interactive board sessions via the LAVA REST API.

MCP server that connects WAGO PLCs to LLM agents via the WDx/WDA REST API, enabling AI assistants to read sensor values, change configuration, trigger firmware updates, or monitor entire PLC fleets without custom code.

MCP server that lets LLMs talk to serial devices: microcontrollers, routers, modems, embedded Linux, anything with a UART.

An MCP server for Nordic nRF Connect SDK development that enables users to list, read, and search documentation and sample code from the nrfconnect/sdk-nrf repository. It provides Claude with specialized tools to navigate SDK resources, source files, and configuration examples directly through the GitHub API.

An MCP server that turns Gowin EDA build reports into structured data.

An MCP server that enables AI assistants to control Siglent SDS oscilloscopes over a local network using SCPI commands. It allows users to measure signals, configure channel and acquisition settings, and capture waveforms or screenshots through natural language.

An MCP server that lets AI agents control an RS PRO RS-3005P/RS-6005P programmable DC power supply over USB/RS232, enabling voltage/current control, measurements, output switching, and memory operations.

MCP server for managing large fleets of BLE devices with connection pooling, scheduling, retries, and partial-failure handling. Enables AI agents to run fleet-level reads/writes without worrying about radio connection limits.

MCP server for controlling CNC machines via Universal GCode Sender. Lets Claude (or any MCP-compatible AI assistant) connect to a CNC machine, inspect G-code, and issue motion commands — all through the UGS Pendant REST API.

Enables AI assistants to compile, upload, and monitor Arduino boards via natural language, with electrical safety checks and dependency management.

AI-powered FPGA power estimation assistant that wraps Xilinx PDM API as MCP services for natural language power modeling and analysis.

A local-first, read-only MCP server for vehicle diagnostics that exposes structured OBD-II tools for reading PIDs, DTCs, and ECU snapshots without raw protocol access.

MCP server that lets AI assistants control Siglent SDG waveform generators over a local network using natural language, supporting signal generation, modulation, sweep, burst, and arbitrary waveforms.

A stateful Bluetooth Low Energy (BLE) MCP server that enables AI agents to scan, connect, read/write characteristics, and subscribe to notifications on BLE devices.

A read-only MCP server for AI agents to understand KiCad projects through progressive disclosure, providing compact summaries and drill-down tools for components, nets, traces, and ERC/DRC checks without blowing context budgets.

Enables AI assistants to analyze hardware simulation VCD waveforms and GTKWave save files, providing access to signal values, bus definitions, and groupings without loading entire files.

A local stdio MCP server wrapping arduino-cli to let agents detect boards, manage cores/libraries, compile and upload sketches, and communicate over serial, enabling hardware control without shell gymnastics.

A deterministic MCP server for BitBake and Yocto that allows users to search, scan, and parse recipe files. It enables the extraction of raw variable assignments from .bb and .bbappend files without performing variable evaluation.