I've been using Obsidian for years as my primary thinking environment. At some point I got tired of switching between my notes and AI tools, copy-pasting context back and forth. So I built something that works the way I actually think.
Memex Chat is an Obsidian plugin that lets you chat with your vault using Claude AI with proper context retrieval, not just keyword search.
What it does:
Semantic vault search — a TF-IDF index over all your notes, no external API needed for retrieval
Local embeddings — optional on-device semantic search using BGE Micro v2, fully offline after one model download (~22 MB)
Auto context — relevant notes are automatically found and attached to your query before it even reaches Claude
@ mentions — reference specific notes directly in your message with autocomplete
Context preview — see and edit which notes are included before sending
Related notes sidebar — always-on panel showing the most similar notes to whatever you have open, ranked by semantic similarity, frontmatter links, and shared tags
Thread history — chats saved as Markdown in your vault, so nothing disappears
Source links — every answer shows which notes were used as context
Prompt buttons — configurable header buttons that extend Claude's system prompt (e.g. draft check, monthly review)
Installation is manual for now — download main.js, manifest.json, and styles.css from the latest release, drop them into .obsidian/plugins/memex-chat/, enable in Community Plugins, and add your Anthropic API key.
svemagie