Neuro Vault MCP

🧠💾 Make your personal vault usable by agents. Low-token retrieval, explicit provenance, and safe writes for your Obsidian notes — in Claude Code, Cursor, Windsurf, and any MCP client.

https://github.com/user-attachments/assets/25c1bafb-7b90-43ac-aa50-50e85705fb5b

Your second brain stops being a folder you open between contexts and becomes a first-class participant in every project. Agents can recall the right notes, inspect the evidence, and write back through vault-aware operations — without grepping the whole folder or flooding the context window.

"What did I write about that idea last month?" — and now your assistant can actually answer.

✨ Why Neuro Vault?

• 🧠 Semantic search that already knows your vault — reuses Smart Connections embeddings. No re-indexing, no API keys, no extra infrastructure.
• 🎯 Quick or deep, your call — fast direct lookups for "find that note", or exploratory mode with related-note expansion when the question is fuzzy.
• 🧾 Context with provenance, not mystery memory — results come back with paths, matched queries, block-level snippets, and backlink counts so the assistant can show where an answer came from.
• 🧭 A real navigation toolkit for your agent — instead of grepping files and opening notes one by one, your assistant walks the vault like a database: filter by tags and properties, batch-read metadata, traverse the wikilink graph, discover the structure, jump to semantic neighbours.
• 🔎 Ask structured questions in plain language — "active projects tagged #ai", "todo tasks with a deadline this week", "meeting notes from Work/ newest first" — one call, ranked answer, no chains of reads.
• ✍️ Full write surface for your notes — create, in-place replace, or rewrite the whole body; manage frontmatter, tags, and daily notes. Frontmatter and creation route through the Obsidian CLI so Smart Connections, sync, and other plugins stay in the loop; in-place edits write directly to disk and the watcher catches up.
• ⚡ Zero infrastructure — local stdio MCP server, in-memory index, no database, no background processes, no watchers.
• 🔌 Drop-in for any MCP client — Claude Code, Cursor, Windsurf — configuration is a single JSON block.

🧰 Two superpowers, one server

Most "vault MCP" servers give you one or the other. Neuro Vault gives you both, and lets your assistant pick the right one per question:

| | 🔭 Semantic recall | 🛠 Vault operations | | ---------------- | ------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------ | | What it does | Finds notes by meaning, not keywords. Surfaces neighbours and duplicates. | Reads, writes, edits notes (in-place replace and full-body rewrite); manages frontmatter, tags, daily notes. | | Best for | "What did I think about X?", fuzzy recall, exploratory research. | Structured queries, capturing decisions, updating tasks, batch reads. | | Powered by | Smart Connections embeddings (already in your vault). | The official Obsidian CLI — Smart Connections, sync, plugins all stay in sync. |

The two work together: semantic search finds the right region of the vault, vault operations let the assistant actually do something with what it found.

✨ What it looks like in practice

Before: "Could you check my notes about that LangGraph experiment?" → Assistant lists Notes/, opens 12 files, greps for "LangGraph", gives up halfway, you paste the relevant note manually.

After: "Could you check my notes about that LangGraph experiment?" → One semantic search, top-3 ranked notes back, follow-up question already grounded in your own writing.

A few more questions Neuro Vault makes one-shot:

"What are my active projects tagged #ai with a deadline this quarter?" "Show meeting notes from Work/ from the last two weeks, newest first." "Find notes similar to this one I'm reading." "Append today's decision to the daily note." "What's on my agenda today — and what did I capture in other notes since this morning?" "What did past-me write about retrieval policy before I started building it?"

One question, one answer. Your assistant stops being a file browser and starts being an actual second brain.

→ See docs/guide/vault-operations.md for the full query language and examples.

🔍 Hybrid search: scope semantic with structural filters

search_notes accepts an optional filter to narrow the candidate set before semantic ranking — combining the precision of query_notes with the recall of vector search. Useful when domain-relevant notes are crowded out by larger narrative clusters.

{ "query": "trading lessons", "filter": { "tags": ["trading"] } }

filter accepts path_prefix (string or array), exclude_path_prefix (string or array — drops matched subtrees), tags (ANY-of), and a frontmatter sift filter. Composition is include → exclude → tags → frontmatter → threshold → semantic. See the Semantic Search guide for full details.

🏗 How it works

flowchart LR
    You([You]) --> AI[AI assistant]
    AI <-->|MCP| NV[Neuro Vault]
    NV <--> Vault[(Obsidian vault)]

You ask, the assistant calls Neuro Vault, Neuro Vault reads your vault — semantic search uses embeddings already in .smart-env/, vault operations go through the obsidian CLI. No database, no background processes.

For module wiring and internal data flow, see docs/architecture/module-structure.md.

⚡ Quickstart

npm install -g neuro-vault-mcp

Single vault

Add to your MCP client config (here: Claude Code's ~/.claude/settings.json):

{
  "mcpServers": {
    "neuro-vault": {
      "command": "neuro-vault-mcp",
      "args": ["--vault", "/absolute/path/to/your/vault"]
    }
  }
}

Vault directory names must match ^[a-zA-Z0-9_-]{1,64}$ — ASCII letters, digits, _, or -; 1–64 chars. Spaces and Unicode are rejected. The MCP-side alias is the directory basename, so if Obsidian shows the vault as "My Vault", the directory itself must be My_Vault or similar.

🗂 Multi-vault — two vaults, one server

Pass --vault once per vault:

neuro-vault-mcp \
  --vault /Users/me/Vaults/Sandbox \
  --vault /Users/me/Vaults/TeamWiki

Two vaults registered, with names Sandbox and TeamWiki. In your MCP config:

{
  "mcpServers": {
    "neuro-vault": {
      "command": "neuro-vault-mcp",
      "args": ["--vault", "/Users/me/Vaults/Sandbox", "--vault", "/Users/me/Vaults/TeamWiki"]
    }
  }
}

Two vaults cannot share the same directory basename — the basename doubles as the alias and must be unique. If you have a basename collision, rename one of the directories.

With multiple vaults registered:

• Every tool accepts an optional vault: "<name>" parameter to target a specific vault.
• search_notes, query_notes, get_vault_overview, and list_tags fan out across all registered vaults when vault is omitted. The response shape switches to results_by_vault: [...] (one entry per vault) plus skipped_vaults: [...] for any vault the tool could not reach and failed_vaults: [...] for per-vault runtime errors ({ vault, error: { code, message, details? } }). A single failed vault does not abort the whole call.
• All other tools (writes, reads of specific paths, single-vault diagnostics) require an explicit vault in multi-vault mode. Omitting it returns VAULT_REQUIRED.
• Semantic fan-out silently skips vaults whose Smart Connections .smart-env/multi/ index is unavailable. Targeting such a vault explicitly with vault: "<name>" returns SEMANTIC_INDEX_NOT_FOUND.

Then ask your assistant:

"What did I write about building AI agents?"

On first run the embedding model downloads automatically (~40 MB). Subsequent starts are fast.

For other clients (Cursor / Windsurf / npx), see docs/guide/installation.md.

📚 Documentation

Every tool accepts an optional vault parameter. In multi-vault mode, search_notes, query_notes, and get_vault_overview fan out across all registered vaults when vault is omitted.

User guide lives in docs/guide/:

• Installation
• Semantic Search — search_notes, get_similar_notes, find_duplicates
• Vault Operations — note CRUD, daily notes, properties, tags, structured queries (query_notes), vault snapshot (get_vault_overview)
• Routing Between Tools
• Configuration — CLI args, troubleshooting, limitations, development

Architecture / internals: docs/architecture/.

Vault-specific conventions for external agents

When the server starts, it looks for <vault>/.neuro-vault/for-external-agents.md. If the file exists, its content is appended to the MCP instructions that clients receive at initialize, under a ## Vault-specific conventions section. Use this file to teach external agents vault-specific rules that cannot be derived from the snapshot — for example, closed sets of frontmatter type values, or folders that are off-limits for writes. The file is optional; without it the server still ships sane defaults plus a pointer to get_vault_overview.

📄 License

ISC — see LICENSE.

Changelog: Releases