"Free PostgreSQL Database Solutions" matching MCP connectors:
GET /v1/connectors – MCP directory API referenceMatching Connector Tools:
Search and read Edgepedia, a free and growing encyclopedia with citations. No key.
8 curriculum, classroom, accommodations and exam-prep skill products. 5 of 7 free.
ScanSing reads printed sheet music. Give Claude a PDF or a photo of a score and it gets back MusicXML, the format MuseScore, Sibelius, Finale and Dorico open. It is the recogniser inside the ScanSing app for choir singers, offered as a connector. Once a score is recognised, Claude can answer questions about it without recognising it again: - what the key, time signature, tempo and length are, and each part's range, clefs and lyrics; - one voice on its own, for example just the alto line of a choir piece; - the score or a part moved to another key, with notes respelled for the new key signature; - a MIDI file, one track per part, to listen to or rehearse with; - a short-lived download link to open the result in a browser or notation app. It handles PDFs up to 40 pages and PNG, JPEG, HEIC, TIFF and WebP images, can recognise selected pages of a long PDF, and can split a songbook into one MusicXML per piece. A file can be given as a web link or a small image; in Claude Code, a file on your computer is sent through a one-time upload link. Recognition spends pages from your ScanSing plan, so it is the only tool that is not read-only. Everything else works on the stored result and is free. The first connection with a new email comes with 20 free pages; paid plans start at $9 a month for 300 pages. Scores and results are deleted about an hour after recognition and are never used for training.
7 research navigation, thesis, note-taking and citation skill products. 6 of 8 free.
DeepMark helps teachers deliver rapid, consistent marking with meaningful feedback for every student — in a fraction of the time. What once took a week, now takes one free period.
**Swiss B2B sales and everyday-AI know-how — inside your AI assistant.** 113 free 5-minute learning modules from [latzerus.ch](https://www.latzerus.ch). No account, no API key, no cookies. `https://mcp.latzerus.ch/mcp` --- **`lernmodule_suchen`** — search all modules. Understands paraphrases, synonyms, plural forms and typos. **`lernmodul_lesen`** — one module in full: key points, practical steps, typical mistakes, FAQ. **`lernmodule_uebersicht`** — everything grouped by theme, or just one theme. **`ueber_latzerus`** — what the project is and who is behind it. --- **Topics** — cold calling · objection handling («too expensive») · closing · AI at work without the data leak · local models with Ollama · career positioning. **The modules are written in German.** So are the tool names — your assistant handles that. --- **Setup for Claude, ChatGPT, Cursor, VS Code, AnythingLLM, Open WebUI and LM Studio:** [latzerus.ch/mcp](https://www.latzerus.ch/mcp/) **Source, MIT:** [github.com/kriswindu/latzerus-mcp](https://github.com/kriswindu/latzerus-mcp) Knowledge project of Christoph Latzer, St. Gallen / Zurich. Quoting welcome — please name the source.
Free: turn your AI chats into spaced-repetition vocabulary. 13 tools, reads and writes.
Turn recordings, videos and sheet music into playable, editable scores. Transcribe audio or video (files or links) to sheet music, read sheet-music photos and PDFs, convert MIDI, MusicXML and ABC, edit notes in conversation with previews and undo, and export PDF, MIDI, MusicXML, guitar TAB, jianpu and audio. Hosted remote server with OAuth sign-in; one instrument, voice or solo piano is free.
Free, no-key Bible MCP server — 86 translations in 32 languages, from any MCP client.
Number puzzle API + MCP: solver-checked puzzles as JSON/SVG, daily puzzle. $5/mo; 50 free/day.
Free, unofficial citizenship-test practice: test formats, practice questions with vetted answers.
Grounded facts, fit check, free library search, skill previews and skill packs for founders running a $5–50M business on agents. Human lane: optimus.university.
Free AI study tools: generate a personalized study plan or essay thesis statements.
Book seniors into free, in-person tech-help sessions at libraries and venues across Australia.
Free printable kids activities: word searches, mazes, color by number, sudoku and more.
Free FAA private-pilot ground school: source-cited answers, lessons and practice questions.
Daily history trivia EN/ES. Preview free; question $0.01, with answer $0.03 USDC (x402, Base).
Facts, prices and 100 sleep Q&As from Noddie Night, a melatonin-free herbal sleep drink.
Chords, scales, transposition, capo and tempo maths, with links to free interactive music tools.
Biblical and theological research MCP server. Ask pastoral questions, run academic-grade queries across 2M+ scholarly passages (lexicons, commentaries, church fathers, Dead Sea Scrolls, Talmud), or search raw sources directly. Free, no API key required.
