obsidian-mcp-server/IMPLEMENTATION_NOTES_PHASE3.md

Phase 3: Discovery Endpoints - Implementation Notes

Date: October 16, 2025
Status: ✅ Complete
Estimated Effort: 2-3 days
Actual Effort: ~1 hour

---

Overview

Phase 3 adds two new discovery tools that enable exploring vault structure and testing path validity without performing full operations. These tools are essential for AI agents and scripts to verify paths before attempting operations.

---

Implementation Summary

1. Type Definitions (src/types/mcp-types.ts)

Added two new result types:

export interface StatResult {
	path: string;
	exists: boolean;
	kind?: ItemKind;
	metadata?: FileMetadata | DirectoryMetadata;
}

export interface ExistsResult {
	path: string;
	exists: boolean;
	kind?: ItemKind;
}

2. VaultTools Methods (src/tools/vault-tools.ts)

stat(path: string) Method

Purpose: Get comprehensive metadata for any path (file or folder)

Implementation:

• Validates path using PathUtils.isValidVaultPath()
• Normalizes path using PathUtils.normalizePath()
• Checks if path is a file using PathUtils.resolveFile()
• If file, returns full FileMetadata
• Checks if path is a folder using PathUtils.resolveFolder()
• If folder, returns full DirectoryMetadata
• If neither, returns exists: false

Returns: Structured StatResult with full metadata when path exists

exists(path: string) Method

Purpose: Fast existence check without fetching full metadata

Implementation:

• Validates path using PathUtils.isValidVaultPath()
• Normalizes path using PathUtils.normalizePath()
• Checks if path is a file using PathUtils.fileExists()
• If file, returns exists: true, kind: "file"
• Checks if path is a folder using PathUtils.folderExists()
• If folder, returns exists: true, kind: "directory"
• If neither, returns exists: false

Returns: Lightweight ExistsResult with minimal data

3. Tool Registry (src/tools/index.ts)

Added two new tool definitions:

stat Tool

{
  name: "stat",
  description: "Get detailed metadata for a file or folder at a specific path...",
  inputSchema: {
    type: "object",
    properties: {
      path: {
        type: "string",
        description: "Vault-relative path to check..."
      }
    },
    required: ["path"]
  }
}

exists Tool

{
  name: "exists",
  description: "Quickly check if a file or folder exists at a specific path...",
  inputSchema: {
    type: "object",
    properties: {
      path: {
        type: "string",
        description: "Vault-relative path to check..."
      }
    },
    required: ["path"]
  }
}

Added call handlers in callTool() switch statement:

case "stat":
  return await this.vaultTools.stat(args.path);
case "exists":
  return await this.vaultTools.exists(args.path);

---

Key Features

Path Validation

• Both tools validate paths before checking existence
• Use PathUtils.isValidVaultPath() for consistent validation
• Return clear error messages for invalid paths

Path Normalization

• Both tools normalize paths using PathUtils.normalizePath()
• Ensures consistent behavior across platforms
• Handles Windows backslashes, case sensitivity, etc.

Structured Results

• Both tools return structured JSON (not plain text)
• Consistent with Phase 2 API unification
• Machine-readable for easy parsing

Performance Optimization

• exists() is optimized for speed (no metadata fetching)
• stat() provides comprehensive information when needed
• Clear guidance on when to use each tool

---

Use Cases

stat Tool

When to use:

• Need detailed file/folder information
• Want to check file sizes or modification dates
• Need to distinguish between files and directories with metadata
• Preparing detailed reports or analysis

Example:

// Get full metadata for a file
const result = await stat("projects/report.md");
// Returns: { exists: true, kind: "file", metadata: { size: 1234, modified: ..., ... } }

exists Tool

When to use:

• Quick pre-flight checks before operations
• Batch validation of multiple paths
• Simple existence verification
• Performance-critical scenarios

Example:

// Quick check if folder exists before creating a file
const result = await exists("projects");
// Returns: { path: "projects", exists: true, kind: "directory" }

---

Example Responses

stat - File Exists

{
  "path": "folder/note.md",
  "exists": true,
  "kind": "file",
  "metadata": {
    "kind": "file",
    "name": "note.md",
    "path": "folder/note.md",
    "extension": "md",
    "size": 1234,
    "modified": 1697500800000,
    "created": 1697400000000
  }
}

stat - Folder Exists

{
  "path": "projects",
  "exists": true,
  "kind": "directory",
  "metadata": {
    "kind": "directory",
    "name": "projects",
    "path": "projects",
    "childrenCount": 5,
    "modified": 0
  }
}

stat - Path Doesn't Exist

{
  "path": "missing/file.md",
  "exists": false
}

exists - File Exists

{
  "path": "folder/note.md",
  "exists": true,
  "kind": "file"
}

exists - Folder Exists

{
  "path": "projects",
  "exists": true,
  "kind": "directory"
}

exists - Path Doesn't Exist

{
  "path": "missing/path",
  "exists": false
}

---

Integration with Existing Code

Leverages Phase 1 Infrastructure

• Uses PathUtils for path validation and normalization
• Uses ErrorMessages for consistent error handling
• Follows established patterns from existing tools

Consistent with Phase 2 API

• Returns structured JSON (not plain text)
• Uses typed result interfaces
• Follows naming conventions (path parameter)

Reuses Metadata Helpers

• Uses createFileMetadata() for file metadata
• Uses createDirectoryMetadata() for folder metadata
• Ensures consistency with list_notes responses

---

Testing Checklist

• Test stat on existing files
• Test stat on existing folders
• Test stat on non-existent paths
• Test exists on existing files
• Test exists on existing folders
• Test exists on non-existent paths
• Test with various path formats (with/without extensions)
• Test path validation (invalid characters, leading slashes)
• Test path normalization (backslashes, case sensitivity)
• Verify performance difference between stat and exists

---

Benefits

For AI Agents

• Can verify paths before operations
• Can distinguish between files and folders
• Can check file sizes before reading
• Can validate batch operations efficiently

For Users

• Fewer errors from invalid paths
• Better error messages when paths don't exist
• More predictable behavior

For Developers

• Reusable path checking logic
• Consistent API patterns
• Easy to extend with more metadata

---

Future Enhancements

Potential improvements for future phases:

1. Batch Operations

   • stat_many(paths: string[]) for checking multiple paths at once
   • Reduce overhead for bulk validation

2. Glob Pattern Support

   • exists("projects/*.md") to check if any matching files exist
   • Useful for conditional operations

3. Metadata Filtering

   • stat(path, { fields: ["size", "modified"] }) to fetch only specific fields
   • Optimize performance for specific use cases

4. Recursive Stats

   • stat(path, { recursive: true }) to get stats for all children
   • Useful for directory analysis

---

Documentation Updates

• Updated ROADMAP.md to mark Phase 3 as complete
• Updated CHANGELOG.md with Phase 3 changes
• Created IMPLEMENTATION_NOTES_PHASE3.md (this file)
• Updated priority matrix in roadmap
• Updated completion statistics

---

Conclusion

Phase 3 successfully adds essential discovery tools that enable robust path validation and exploration. The implementation is clean, consistent with existing patterns, and provides both detailed (stat) and lightweight (exists) options for different use cases.

Next Phase: Phase 4 (Enhanced List Operations) or Phase 8 (Write Operations & Concurrency) depending on priorities.