MCP Server

Enable AI assistants to interact with Sei networks through natural language using the Model Context Protocol

The Sei Model Context Protocol (MCP) Server enables AI assistants to interact with Sei networks through natural language. Built on the Model Context Protocol standard, it provides seamless blockchain integration for AI coding assistants.

The Sei MCP Server is open source. Contribute at github.com/sei-protocol/sei-js

What is MCP?

The Model Context Protocol is an open standard that connects AI systems with external tools and data sources. It enables:

• Real-time data access from external services
• Function execution and operations
• Context preservation across interactions
• Specialized capabilities beyond base training

The Sei MCP Server leverages this protocol to bring blockchain functionality directly to your AI assistant.

Capabilities

Category	Features
Account Management	Wallet addresses • Balance queries • Contract verification
Token Operations	SEI transfers • ERC20/721/1155 support • Token approvals
Blockchain Data	Block information • Transaction details • Network status
Smart Contracts	State queries • Function execution • Event logs
Networks	Mainnet • Testnet

Setup Guide

Cursor

Cursor Setup

1. Open Settings

   Navigate to Cursor → Settings → Cursor Settings → MCP

2. Configure Server

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

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

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

Windsurf

Windsurf Setup

1. Open Settings

   Navigate to 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"],
         "env": {
           "PRIVATE_KEY": "your_private_key_here"
         }
       }
     }
   }
   
3. Activate

   Save and restart Windsurf. The server loads automatically.

Claude Desktop

Claude Desktop Setup

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"],
         "env": {
           "PRIVATE_KEY": "your_private_key_here"
         }
       }
     }
   }
   
3. Restart

   Save and restart Claude Desktop to enable Sei tools.

Claude CLI

Claude CLI Setup

1. Install CLI

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

   claude mcp add sei-mcp-server npx @sei-js/mcp-server
   
3. Start Session

   claude
   

   The Sei MCP Server activates automatically in your session.

Private Key Setup

Security Notice: Generate a dedicated wallet for MCP operations. Never use your main wallet’s private key.

Export your private key from your wallet:

• Look for “Export Private Key” or “Show Private Key” in wallet settings
• Ensure the key starts with 0x
• Fund the wallet with small amounts for testing

Features

The Sei MCP Server enables your AI assistant to:

Blockchain Operations

• Query account balances and transaction history
• Execute token transfers
• Interact with smart contracts
• Monitor network status

Coming Soon

• Documentation search and explanation
• @sei-js library integration
• Boilerplate generation
• DeFi protocol interactions

Available Tools

Core Operations

Tool	Purpose	Example
get_address_from_private_key	Retrieve wallet address	”What’s my wallet address?”
get_balance	Check SEI balance	”Check balance of 0x123…”
transfer_sei	Send SEI tokens	”Send 1 SEI to 0x456…”
is_contract	Verify contract address	”Is 0x789… a contract?”

Token Management

Tool	Purpose	Example
get_token_info	Token metadata	”Get USDC token info”
get_token_balance	Token balance	”Check my USDC balance”
transfer_token	Token transfer	”Send 100 USDC to 0x123…”
approve_token_spending	Token approval	”Approve DEX for USDC”

NFT Operations

Tool	Purpose	Example
get_nft_info	NFT metadata	”Show NFT #123 details”
check_nft_ownership	Ownership verification	”Who owns NFT #456?”
transfer_nft	NFT transfer	”Send NFT #789 to 0xABC…”
get_nft_balance	Collection balance	”How many NFTs do I own?”

Blockchain Data

Tool	Purpose	Example
get_chain_info	Network information	”Show Sei mainnet info”
get_block_by_number	Block details by number	”Get block 12345”
get_latest_block	Latest block details	”Get latest block”
get_transaction	Transaction data	”Show tx 0xTXID…”
read_contract	Contract state	”Read DEX reserves”

AI Prompts

Pre-configured prompts for common tasks:

my_wallet_address

Get your wallet address

explore_block

Analyze block data

analyze_transaction

Transaction details

analyze_address

Address analysis

Usage Examples

Query Balance

”What’s my SEI balance?”

→ Returns wallet balance and address

Send Transaction

”Send 1 SEI to 0x742d35Cc6634C0532925a3b8D4C1C4e3153DC”

→ Executes transfer and returns transaction hash

Contract Analysis

”Is 0x3894085ef7ff0f0aedf52e2a2704928d1ec074f1 a contract?”

→ Identifies contract type and metadata

Resource URIs

Access blockchain data through standardized URIs:

# Network data
evm://sei/chain
evm://sei-testnet/chain

# Block information
evm://sei/block/latest
evm://sei/block/12345

# Transactions
evm://sei/tx/0xabc123...
evm://sei/tx/0xabc123.../receipt

# Token data
evm://sei/token/0x3894085ef7ff0f0aedf52e2a2704928d1ec074f1
evm://sei/token/0x389.../balanceOf/0x742d...

# NFT data
evm://sei/nft/0xNFT_ADDRESS/123
evm://sei/nft/0xNFT_ADDRESS/123/isOwnedBy/0x742d...

Configuration

Environment Setup

# .env file
PRIVATE_KEY=0x_your_private_key_here

# Optional (coming soon)
CUSTOM_RPC_URL=https://your-rpc.com
CUSTOM_CHAIN_ID=1329

HTTP Server Mode

For web applications:

# Start HTTP server
npx @sei-js/mcp-server --http

# Connect from web app
const eventSource = new EventSource('http://localhost:3001/sse');

Security Guidelines

Security Guidelines:

1. Use a dedicated wallet - Create a new wallet specifically for MCP
2. Minimal funding - Only add funds needed for testing
3. Environment variables - Never hardcode private keys
4. Monitor activity - Regularly check transaction history

For production:

• Implement transaction limits
• Use multi-signature wallets
• Add contract whitelisting
• Enable rate limiting

Troubleshooting

Connection issues: Verify Node.js 18+ is installed and restart your AI assistant.

Private key errors: Ensure key format starts with 0x and wallet has sufficient funds.

Cursor: The model returned an error. Try disabling the MCP servers, or switch models: Disable “Auto” in the model menu and select a specific model e.g. claude-4-sonnet