MCP Server - Sei Docs

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
Windsurf
Claude Desktop
Claude CLI

Cursor Setup

Open Settings

Navigate to Cursor → Settings → Cursor Settings → MCP

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"
      }
    }
  }
}

Restart

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

Windsurf Setup

Open Settings

Navigate to Windsurf → Settings → Windsurf Settings → Cascade

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"
      }
    }
  }
}

Activate

Save and restart Windsurf. The server loads automatically.

Claude Desktop Setup

Install Claude

Download Claude Desktop from Anthropic.

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"
      }
    }
  }
}

Restart

Save and restart Claude Desktop to enable Sei tools.

Claude CLI Setup

Install CLI

npm install -g @anthropic-ai/claude-code

Add Server

claude mcp add sei-mcp-server npx @sei-js/mcp-server

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 0x742d35Cc6634C0532925a3b844Bc454e4438f44e”

→ 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:

Use a dedicated wallet - Create a new wallet specifically for MCP
Minimal funding - Only add funds needed for testing
Environment variables - Never hardcode private keys
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

​What is MCP?

​Capabilities

​Setup Guide

​Cursor Setup

​Windsurf Setup

​Claude Desktop Setup

​Claude CLI Setup

​Private Key Setup

​Features

​Blockchain Operations

​Coming Soon

​Available Tools

​Core Operations

​Token Management

​NFT Operations

​Blockchain Data

​AI Prompts

​my_wallet_address

​explore_block

​analyze_transaction

​analyze_address

​Usage Examples

​Resource URIs

​Configuration

​Environment Setup

​HTTP Server Mode

​Security Guidelines

​Troubleshooting

What is MCP?

Capabilities

Setup Guide

Cursor Setup

Windsurf Setup

Claude Desktop Setup

Claude CLI Setup

Private Key Setup

Features

Blockchain Operations

Coming Soon

Available Tools

Core Operations

Token Management

NFT Operations

Blockchain Data

AI Prompts

my_wallet_address

explore_block

analyze_transaction

analyze_address

Usage Examples

Resource URIs

Configuration

Environment Setup

HTTP Server Mode

Security Guidelines

Troubleshooting