mcp-server-gpt-chat

An MCP (Model Context Protocol) server for the OpenAI ChatGPT API. Built in Rust, exposes chat completions, vision, embeddings, and model listing as MCP tools.

Communicates via stdio using JSON-RPC 2.0, like all MCP servers.

Tools

chat

Send a chat completion request. Supports multi-turn conversations via a JSON message history array, system prompts, structured output via JSON schema, temperature control, and model selection.

Parameters:

chat_with_vision

Analyse an image using ChatGPT's vision capabilities.

Parameters:

embedding

Generate text embeddings.

Parameters:

list_models

List all available OpenAI models. No parameters.

Prerequisites

• Rust (edition 2024)
• An OpenAI API key from platform.openai.com

Setup

Create the config file:

mkdir -p ~/.config/mcp-server-gpt-chat

Create `~/.config/mcp-server-gpt-chat/config.toml`:

api_key = "sk-..."

Build

cargo build --release

This produces `target/release/gpt-chat`.

For development:

cargo build              # debug build
cargo run                # run in dev mode
RUST_LOG=debug cargo run # run with debug logging

MCP Configuration

Add to your Claude Desktop config (`~/.config/Claude/claude_desktop_config.json`):

{
  "mcpServers": {
    "gpt-chat": {
      "command": "/path/to/gpt-chat"
    }
  }
}

Project Structure

src/
  main.rs    - entry point, config loading, stdio transport setup
  server.rs  - MCP tool definitions (chat, chat_with_vision, embedding, list_models)
  api.rs     - OpenAI HTTP client, request/response types, response formatters
  params.rs  - tool parameter types with serde and JSON Schema derives
  config.rs  - TOML config loading

License

MIT