Quickstart

Configure Sei MCP Server with Cursor, Windsurf, Claude Desktop, or CLI

Cursor IDE

1. Open Settings

   Navigate to Cursor → Settings → Cursor Settings → MCP

   Cursor → Settings → Cursor Settings → MCP
   
2. Configure Server

   Click “Add new Global MCP server” and add this configuration to mcp.json:

   {
     "mcpServers": {
       "sei": {
         "command": "npx",
         "args": ["-y", "@sei-js/mcp-server"]
       }
     }
   }
   
3. Restart

   Restart Cursor to activate the MCP server. You’ll see a notification when it’s ready.

Windsurf

1. Open Settings

   Navigate to Windsurf → Settings → Windsurf Settings → Cascade

   Windsurf → Settings → Windsurf Settings → Cascade
   
2. Add Configuration

   Add the Sei MCP Server to your configuration:

   {
     "mcpServers": {
       "sei": {
         "command": "npx",
         "args": ["-y", "@sei-js/mcp-server"]
       }
     }
   }
   
3. Activate

   Save and restart Windsurf. The server loads automatically.

Claude Desktop

1. Install Claude

   Download Claude Desktop from Anthropic.

2. Edit Configuration

   Open Settings → Developer → Edit Config and add:

   {
     "mcpServers": {
       "sei": {
         "command": "npx",
         "args": ["-y", "@sei-js/mcp-server"]
       }
     }
   }
   
3. Restart

   Save and restart Claude Desktop to enable Sei tools.

Remote MCP Servers: Claude Desktop also supports connectors for remote HTTP servers. If you want to use a remote Sei MCP server instead of running it locally, set up the server using the Remote Servers (http) tab above, then add a connector configuration instead of the local server setup.

Claude CLI

1. Install CLI

   npm install -g @anthropic-ai/claude-code
   
2. Add Server

   # Read-only mode (default)
   claude mcp add sei-mcp-server npx @sei-js/mcp-server
   
   # Wallet-enabled mode
   claude mcp add sei-mcp-server-wallet npx @sei-js/mcp-server --env WALLET_MODE=private-key PRIVATE_KEY=0x123...
   
3. Start Session

   claude
   

   The Sei MCP Server activates automatically in your session.

Remote Servers (http)

The Sei MCP Server can be run as a standalone HTTP server via the streamable-http transport.

1. Start HTTP Server

   Launch the MCP server with streamable-http transport:

   # Basic API setup (port: 8080, path: /mcp)
   SERVER_TRANSPORT=streamable-http npx @sei-js/mcp-server
   

   Or with custom configuration:

   # Custom port and path
   SERVER_TRANSPORT=streamable-http \
   SERVER_PORT=3001 \
   SERVER_PATH=/api/sei \
   SERVER_HOST=0.0.0.0 \
   npx @sei-js/mcp-server
   
2. Verify Server

   The server will output:

   EVM MCP Server initialized for networks: sei, sei-devnet, sei-testnet
   MCP Server ready (streamable-http transport on localhost:8080/mcp)
   
3. Test with curl

   Test the API endpoint with curl:

   # List available tools
   curl -X POST http://localhost:8080/mcp \
     -H "Content-Type: application/json" \
     -H "Accept: application/json, text/event-stream" \
     -d '{
       "jsonrpc": "2.0",
       "id": 1,
       "method": "tools/list"
     }'
   
   # Get latest block info
   curl -X POST http://localhost:8080/mcp \
     -H "Content-Type: application/json" \
     -H "Accept: application/json, text/event-stream" \
     -d '{
       "jsonrpc": "2.0",
       "id": 2,
       "method": "tools/call",
       "params": {
         "name": "get_latest_block",
         "arguments": {
           "network": "sei"
         }
       }
     }'
   

Verification

After setup, verify the server is working by asking your AI assistant:

1. Test Connection

   Ask: “What Sei tools are available?”

   You should see a list of available blockchain tools.

2. Test Read Operations

   Ask: “What’s the latest block on Sei?”

   This tests basic blockchain connectivity.

3. Test Wallet (Optional)

   If you configured wallet access (see environment variables for setup):

   Ask: “What’s my wallet address?”

   This confirms wallet tools are enabled.

Next Steps

Environment Variables

Configure wallet access and custom RPC endpoints

Available Tools

Explore 50+ blockchain tools and capabilities

Troubleshooting

Solutions to common setup and configuration issues

Context & Prompts

Learn how to effectively interact with the server