"Services or tools available for free without requiring an API key" matching MCP servers:

Universal hands-free voice input for MCP-compatible AI assistants using Whisper speech-to-text.

A zero-cost, China-accessible MCP server providing four free AI capabilities: text chat, image generation, speech-to-text, and text-to-speech, ready to use after cloning.

MCP server that wraps MiniMax platform APIs (speech, video, image, music, and file management) as tools over stdio, enabling natural language interaction with MiniMax's AI services.

An MCP server enabling video processing via natural language: transcription with Whisper, segment cutting with FFmpeg, and file management.

Enables MCP clients to leverage the Intel Arrow Lake NPU for local speech transcription, screenshot OCR, private semantic search, and hardware diagnostics, all processed locally.

MCP server providing tools to fetch YouTube video transcripts with metadata, supporting direct YouTube transcripts and audio transcription via multiple backends (whisper, AssemblyAI, OpenAI, Gemini).

An MCP server providing tools for speech-to-text, translation, language detection, question answering, and text-to-speech using Sarvam AI models, enabling multilingual voice agents.

Official MCP server for Theta EdgeCloud's On-Demand Model APIs, providing access to 20+ AI models including image generation, audio transcription, and LLMs, directly from MCP-compatible clients.

MCP server for audio transcription using OpenRouter models, supporting verbatim, cleaned, and custom transcription modes.

A low-latency text-to-speech MCP server that uses local Kokoro GGUF inference via TTS.cpp, providing say, get_voices, and get_status tools for AI agents to synthesize speech and manage playback queues.

Converts text or transcripts into MP3 audio using Microsoft Edge's free neural voices. Provides text-to-speech and voice listing tools with no API key required.

Provides various AI capabilities through DeepInfra's OpenAI-compatible API including image generation, text processing, embeddings, speech recognition, object detection, and classification tasks. Enables users to access multiple AI models for diverse tasks like generating images from prompts, transcribing audio, analyzing text sentiment, and performing computer vision operations.

Enables users to convert text into high-quality audio by accessing the OpenAI Text-to-Speech API. It supports customizable model selection and voice options for synthesized speech generation via the MCP protocol.

MCP server for fetching YouTube video transcripts without an API key.

Let your AI agent call your phone and talk to you — MCP servers for live, interruptible voice calls + tiered alerts, using free self-hosted pieces (pjsua2 + whisper.cpp + Linphone). No paid telephony, no extra API key.

MCP server for SpeechWeave transcription, enabling AI assistants to transcribe local files and URLs via wait-first or async tools.

Transcribe audio/video URLs and detect silence for cutting, with pay-per-call billing in USDC via x402, no account or API key required.

Provides on-device Chinese speech recognition with traditional Chinese (Taiwan) output via MCP server, HTTP API, and CLI, ensuring privacy by processing audio locally without uploading to cloud services.

Text to speech for MCP clients. Reads numbers, dates and order IDs correctly. 23 languages, six voices, every render watermarked. Free key with 100,000 characters, no card.

Enables local text-to-speech synthesis for Claude and Cursor using Supertonic 3, with support for multiple voices, expressions, and languages. No API key or cloud required.