premachb/obsidian-remote-mcp

Obsidian S3 MCP Server

A remote MCP (Model Context Protocol) server that gives Claude access to your Obsidian vault via S3. Access your notes from Claude on mobile, web, or desktop - anywhere.

Features

• Read notes - Read any note by path
• Write notes - Create or update notes
• List files - Browse your vault structure
• Search notes - Full-text search across your vault
• OAuth 2.0 - Secure authentication for Claude connectors
• Serverless - Runs on AWS Lambda, costs < $1/month for personal use

Architecture

┌─────────────────────────────────────────────────────────────┐
│                       S3 Bucket                              │
│                  (single source of truth)                    │
│                      *.md files                              │
└─────────────────────────────────────────────────────────────┘
        ▲                                       ▲
        │                                       │
        │ Direct read/write                     │ Sync (pull/push)
        │ via AWS SDK                           │ via Remotely Save
        │                                       │
┌───────┴───────┐                     ┌─────────┴─────────┐
│  MCP Server   │                     │     Obsidian      │
│   (Lambda)    │                     │   (on devices)    │
└───────────────┘                     └───────────────────┘
        ▲
        │
┌───────┴───────┐
│    Claude     │
│ Mobile / Web  │
└───────────────┘

Prerequisites

• Node.js 22+
• AWS CLI configured with credentials
• AWS CDK CLI (npm install -g aws-cdk)
• An AWS account

Quick Start

1. Clone and Install

git clone https://github.com/your-username/obsidian-s3-mcp.git
cd obsidian-s3-mcp
npm install

2. Configure AWS

If you haven't already, configure AWS CLI with your credentials:

aws configure --profile obsidian-mcp

Enter your AWS Access Key ID, Secret Access Key, and region (us-east-1 recommended).

3. Bootstrap CDK (First Time Only)

cd infra
AWS_PROFILE=obsidian-mcp npx cdk bootstrap
cd ..

4. Deploy

AWS_PROFILE=obsidian-mcp npm run deploy

This creates:

• S3 bucket for your vault (versioned, encrypted)
• Lambda function running the MCP server
• API Gateway with OAuth endpoints

Note the outputs, especially the McpUrl.

5. Upload Your Vault

Sync your existing Obsidian vault to S3:

aws s3 sync "/path/to/your/obsidian/vault" \
  s3://obsidian-vault-YOUR_ACCOUNT_ID-us-east-1/ \
  --profile obsidian-mcp

6. Connect Claude

1. Go to claude.ai → Settings → Connectors
2. Click "Add custom connector"
3. Enter:
   • Name: Obsidian Vault
   • URL: Your McpUrl from the deploy output (e.g., https://xxx.execute-api.us-east-1.amazonaws.com/mcp)
4. Leave OAuth Client ID and Secret empty (uses automatic registration)
5. Click "Add"

Claude will automatically authenticate via OAuth and connect to your vault.

Setting Up Obsidian Sync

To keep your local Obsidian vault in sync with S3, use the Remotely Save plugin:

Install Remotely Save

1. In Obsidian: Settings → Community Plugins → Browse
2. Search "Remotely Save" → Install → Enable

Configure S3 Connection

1. Settings → Remotely Save → Choose Service: S3 or S3-compatible

2. Configure:

   • Endpoint: Leave blank for AWS S3
   • Region: us-east-1 (or your region)
   • Access Key ID: Your AWS access key
   • Secret Access Key: Your AWS secret key
   • Bucket Name: obsidian-vault-YOUR_ACCOUNT_ID-us-east-1

3. Click "Check" to verify the connection

4. Enable auto-sync on open/close

Now your Obsidian vault syncs to S3, and Claude can access it via the MCP server.

Available Tools

Development

Run Locally

export S3_BUCKET_NAME="your-bucket-name"
export AWS_PROFILE="obsidian-mcp"
npm run dev

Server runs at http://localhost:8080.

Run Tests

npm test

Project Structure

obsidian-s3-mcp/
├── src/
│   ├── index.ts          # Express server entry point
│   ├── server.ts         # MCP server setup
│   ├── auth/
│   │   └── oauth.ts      # OAuth 2.0 implementation
│   ├── s3/
│   │   ├── client.ts     # S3 client singleton
│   │   └── operations.ts # S3 CRUD operations
│   ├── tools/
│   │   ├── read.ts       # read_note tool
│   │   ├── write.ts      # write_note tool
│   │   ├── list.ts       # list_files tool
│   │   └── search.ts     # search_notes tool
│   └── types/
│       └── index.ts      # TypeScript types
├── infra/
│   ├── stack.ts          # AWS CDK infrastructure
│   └── app.ts            # CDK app entry point
├── test/                 # Unit tests
├── package.json
└── tsconfig.json

Cost Estimate

For personal use (single user, ~1000 notes):

Security

• OAuth 2.0 with PKCE for authentication
• S3 encryption at rest (SSE-S3)
• HTTPS only for all endpoints
• No credentials in code - uses IAM roles

Troubleshooting

"Internal Server Error" on health check

Check Lambda logs:

aws logs tail "/aws/lambda/ObsidianMcpStack-McpHandler*" --since 10m --profile obsidian-mcp

OAuth flow not completing

1. Ensure all OAuth endpoints are deployed (check API Gateway in AWS Console)
2. Try removing and re-adding the connector in Claude

Notes not syncing

1. Verify Remotely Save plugin is configured correctly
2. Check S3 bucket permissions
3. Try manual sync in Obsidian (Command Palette → Remotely Save: Sync)

License

MIT