Thought Agent Obsidian
2026An AI agent that reads, links, and edits your Obsidian vault like a second brain with hands.
An Obsidian community plugin built around a 14-tool ReAct agent loop that treats a vault as a living knowledge graph: it searches semantically, traverses graph links, proposes edits, and generates visual diagrams, all without touching a single file until the user approves.
Nothing left of the dashed line writes to the vault without a reviewable diff.
Hybrid retrieval
Every query runs through a multi-stage search before the agent sees any context: local semantic search via all-MiniLM-L6-v2 (running in-browser through Transformers.js, so a vault’s contents never have to leave the machine for this step), BM25 keyword scoring, a fusion pass that blends the two (0.7 semantic / 0.3 BM25), graph re-ranking that boosts linked neighbors of top results, and MMR filtering so the final context pack stays diverse instead of collapsing into near-duplicate chunks.
Safe write workflow
Every proposed note creation, edit, and diagram goes through a diff view first: the agent proposes, the user approves or rejects each change individually, and only approved changes ever reach the vault. Multi-file restructuring (reorganize) goes through the same per-step approval rather than one blanket confirmation.
Excalidraw integration
A layout engine sits behind five diagram tools (create_diagram, update_diagram, search_diagrams, read_diagram, annotate_diagram) supporting mindmaps, flowcharts, timelines, and entity graphs, generated from natural language and written into the vault as ordinary .excalidraw files with deterministic placement and anchor-aware arrows.
Provider support
The agent is provider-agnostic by design: Anthropic (Claude Sonnet, Opus, or Haiku) for cloud reasoning quality, or any OpenAI-compatible local server (LM Studio, Ollama, llama.cpp) for a fully offline, private vault where prompts never leave the machine.
Tool inventory
14 tools across two categories. Ten vault tools are always available (search_notes, get_note, get_neighbors, get_backlinks, query_graph, create_note, edit_note, link_notes, reorganize, set_session_constraint); five diagram tools activate when the Excalidraw plugin is installed. query_graph opens a visual, filterable subgraph view directly in Obsidian:
Ships as a listed Obsidian Community Plugin (search “Thought Agent” in-app), with BRAT and manual-install paths for pre-release builds.