Imported from bitbonsai/mcpvault (AGENTS.md). Install upstream with npx skills add bitbonsai/mcpvault. Copyright stays with the author.

Agent Instructions

Project Overview

MCPVault is a Model Context Protocol (MCP) server that provides a universal AI bridge for Obsidian vaults. It enables any MCP-compatible AI assistant (Claude, ChatGPT, Gemini, etc.) to safely read and write notes in Obsidian vaults while preserving YAML frontmatter and enforcing security boundaries.

Commands

# MCP server
npm run build          # Compile TypeScript to dist/
npm test               # Run test suite (Vitest)
npm run test:watch     # Tests in watch mode
npm start /path/vault  # Run server locally with tsx

# Single test
npm test -- path/to/test.test.ts
npm test -- -t "test name pattern"

# Publishing
npm run publish:dry     # Dry run
npm run publish:beta    # Explicit beta publish
# Production: follow RELEASING.md and create a GitHub Release

# Website
npm run website         # Start Astro dev server with Bun (http://localhost:4321)

# MCP Inspector
npx @modelcontextprotocol/inspector npm start /path/to/vault

Architecture

File Structure

server.ts              # MCP server entry point, tool registration, request handlers
src/
  filesystem.ts        # FileSystemService — all file operations with security
  frontmatter.ts       # FrontmatterHandler — YAML parsing via gray-matter
  pathfilter.ts        # PathFilter — security layer for path validation
  search.ts            # SearchService — full-text search with token-optimized output
  uri.ts               # Obsidian URI generation
  types.ts             # All TypeScript interfaces
  *.test.ts            # Co-located test files
website-shibumi/       # Bun + Hono + TSX website serving mcpvault.org (separate package)

Core Components

server.ts — Entry point. Registers 18 MCP tools, handles CLI args (--help, --version, --read-only, vault path), initializes services, routes tool calls. Read-only mode hides mutating tools and rejects direct mutation calls. Auto-trims whitespace from all path arguments. Exits on stdin EOF / SIGTERM / SIGINT (graceful server.close()), otherwise hosts orphan the process (#159).

FileSystemService (src/filesystem.ts) — Orchestrates file ops with security. Path resolution and traversal prevention. Implements: read, write, patch, delete, move, list, batch read, outline and line-range reads, frontmatter update, tag management, vault stats. Uses native fs/promises.

FrontmatterHandler (src/frontmatter.ts) — Parses/stringifies YAML frontmatter via gray-matter. Validates structure (blocks functions, symbols, invalid types). Preserves original content.

PathFilter (src/pathfilter.ts) — Blocks .obsidian/, .git/, node_modules/, system files, dot files. Note tools allow .md, .markdown, .txt; directory listings may include other file types by filename. Checks path components independently.

SearchService (src/search.ts) — Content and frontmatter search with multi-word matching and BM25 relevance reranking. Returns token-optimized results with minified field names: {p, t, ex, mc, ln, uri}. Max 20 results.

18 MCP Tools

Design Patterns

• Service layer: Each service has single responsibility, dependency-injected into server.ts, independently testable
• Security-first: All paths validated through PathFilter, resolvePath() prevents traversal, confirmation required for destructive ops
• Token optimization: Minified field names by default (fm not frontmatter), optional prettyPrint parameter, compact search format
• Error handling: Structured results with success boolean, failed batch ops return partial results (ok + err arrays)

Key Implementation Details

• Paths: Always relative to vault root. Leading slashes stripped. Whitespace trimmed automatically.
• Frontmatter: Always use FrontmatterHandler for read/write. originalContent field has raw file content. Empty frontmatter = no YAML block.
• Write modes: overwrite (default), append (content to end, merge frontmatter), prepend (content to beginning, merge frontmatter)
• Patch: Exact string match including whitespace/newlines. replaceAll: false (default) fails on multiple matches to prevent accidents.
• Version: Read from package.json at runtime. Used in MCP server init, --version flag, and website nav badge.

Website (Dual Content)

The website-shibumi/ directory is a separate Bun + Hono + TSX package serving mcpvault.org (deployed via shibumi-server, see website-shibumi/compose.yaml). It serves content in two formats that must be kept in sync:

When updating content, always update both.

Testing

Vitest with globals enabled, node environment. Test files co-located as *.test.ts.

When writing tests:

• Test both success and error cases
• Test path security (traversal, access denied)
• Test frontmatter parsing edge cases
• Use Promise.allSettled patterns for batch operations

Security

When modifying file operations:

• Always validate paths through PathFilter
• Always use resolvePath() to prevent traversal
• Never expose system directories or configuration
• Validate frontmatter before writing
• Require confirmation for destructive operations

Config Files

• tsconfig.json — Main TypeScript config (strict mode, ES2022 target, module/moduleResolution nodenext)
• tsconfig.build.json — Build config (excludes tests, outputs to dist/)
• vitest.config.ts — Test config (globals, node environment)

Gotchas

• dist/ is committed. Every src change needs npm run build + commit dist in the SAME change; src-only merges leave dist stale (happened twice: fde15eb engine swap, PR #151).
• TypeScript toolchain upgrades change dist output (TS7 altered .d.ts.map sourcemaps only) — rebuild + commit dist after any TS bump or the dirty tree blocks automation that requires clean main.
• Claude Code discovers skills only under .claude/skills/; repo keeps them in skills/. Committed symlink .claude/skills/triage -> ../../skills/triage bridges it — same pattern for any new skill.
• pathFilter.isAllowed + normalizePath must guard EVERY new tool's path input (PR #146 blocker: readNoteLines skipped them = read .obsidian/ files). Mirror readNote's guard block.
• Outline/heading parsing must be fence-aware: headings inside code fences do not count. Support backtick and tilde fences with up to three leading spaces, and require closing fences to use the same marker with at least the opening length.
• Read-only mode is defense-in-depth: mutating tools are both omitted from tools/list and rejected in tools/call. Every new mutating tool must be added to MUTATING_TOOLS in src/createServer.ts and covered by the read-only regression.
• Root server uses npm + package-lock.json; website uses Bun separately. Root bun.lock becomes stale/misleading; do not recreate.
• Before merging or publishing ANY website change, deploy a preview, capture screenshots of every affected page, and inspect them for visual regressions. Also smoke-test video playback, posters/static assets, badges/API endpoints, and direct route loads; green build/deployment checks alone are insufficient.
• MCP SDK v2 uses split @modelcontextprotocol/server, /client, /core, /node packages. @modelcontextprotocol/sdk@latest remains v1.x.
• Version bump updates website nav/Hero automatically only. Manually sync website-shibumi/src/components/UpdateCallout.tsx, website-shibumi/public/index.md, and CHANGELOG.md.
• Production npm publishing is triggered by a GitHub Release and runs with provenance. Follow RELEASING.md; do not manually run npm publish for normal production releases, and do not backfill a release for an npm version that already exists.
• website-shibumi Hono JSX: escapes string children even inside <script> — JSON-LD/inline scripts need raw(); HTML entities in JSX text double-escape, use literal Unicode chars.
• Bun TSX parser rejects dotted attribute names: Alpine modifiers need spread form {...{"x-on:click.outside": "close()"}}.
• Hono c.header() in middleware after next() rebuilds Response from .body — drops Bun.file().slice() Range bodies (video 206 becomes full file). Mutate c.res.headers.set() directly.
• hono serveStatic on Bun: incomplete Range support — video served by dedicated route on Bun.file().slice() (src/routes/video.ts), never serveStatic.
• website-shibumi container builds from REPO ROOT context (-f website-shibumi/Containerfile .): root package.json must be copied to /package.json or server exits 1 at import (version badge reads it).
• CSS: animation-fill-mode: forwards keeps finished animation attached forever and kills descendant backdrop-filter even with final transform: none; detach via .fade-in-done { animation: none } on animationend.