# MicroRAG > MicroRAG is a free, open-source (MIT) private AI knowledge vault that runs from an SD card. It answers questions from the user's own documents with citations, fully offline. Developed by William Mapp. Site: https://microrag.dev/ Source: https://github.com/Mach-Advisory/MicroRAG ## What it does - Answers plain-English questions from the user's own PDFs, Word files, notes and text, and cites the passages used. - Runs entirely on the computer the card is plugged into. Documents, search index and AI models stay on the card. No account, no cloud, no telemetry. - Needs internet once, to download the runtime and models (about 5 GB). After that it works offline. ## Features - Proof view: each citation is checked against its source, with a strong, partial or weak support badge and PDF page numbers. - Zero-Network Proof: a live view of the connections the app opens. - Contradiction Finder: finds passages in the vault that disagree. - Vault Map: a visual map of how documents relate. - Phone mode and Camera Ask: use the vault from a phone on the same Wi-Fi with a 6-digit PIN (plain HTTP on the local network). - Air-gap mode: refuses to run while any network is up. - Encrypted vault, on-device OCR (Apple Vision on a Mac), instant briefing. ## Facts and limits - Built and tested on a Mac. Windows and Linux launchers are included but untested. - Uses small local models (Qwen3 4B or 1.7B, nomic embeddings), which are weaker than the largest cloud models on open-ended tasks. Answers can be wrong; check the citations. - Roughly 5 GB for the app and models. 8 GB RAM works with the small model; 16 GB or more is comfortable with the larger one. - License: MIT. ## Why an SD card, not a USB stick Speed. The app reads a ~2.3 GB model at every start and searches its index on every question. Measured once on the author's Mac, the same card loaded the 4B model in 31 s via the built-in SD slot and 1 min 48 s via a USB card reader. SD cards print performance classes (A2 for random reads, V30 for sustained writes) that typical USB sticks do not publish. A USB stick was not tested head to head; a fast USB 3 SSD can match or beat a mediocre card. ## Compared with cloud AI chat Cloud AI chat needs files uploaded to a server and usually an account. MicroRAG runs locally and needs neither. The trade-off is model size.