The Sei MCP Server supports three transport modes for different integration scenarios. In most cases, stdio is the best choice, but understanding these modes is important if you need a remote MCP server or if your AI tool doesn’t support MCP. Each transport offers unique advantages depending on your use case and client requirements.

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Transport Overview

stdio

Default Mode Direct process communication via standard input/output streams.

streamable-http

HTTP API RESTful HTTP server with streaming capabilities for web integrations.

http-sse (deprecated)

Server-Sent Events HTTP with server-sent events (deprecated, use streamable-http instead).

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Choosing the Right Transport

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Configuration

Claude Desktop
{
  "mcpServers": {
    "sei": {
      "command": "npx",
      "args": ["-y", "@sei-js/mcp-server"]
    }
  }
}
Environment Variables
# stdio is the default, no configuration needed
SERVER_TRANSPORT=stdio  # Optional, this is default
npx @sei-js/mcp-server