transfer-ai-mcp

transfer-ai-mcp is a small MCP server for relay or proxy AI endpoints. It reads configuration from environment variables and exposes tools for text generation and image generation.

Features

• Supports openai-style and gemini-style HTTP APIs
• Configurable url, key, and model through environment variables
• Saves generated images locally and returns file paths (no base64 in MCP response)
• Packaged as a standalone Node library for reuse on other machines

Changelog

v0.2.0

• Fix: generate_image no longer returns base64 image data in MCP response. This fixes a crash in MCP clients (e.g. Kiro) that occurred when processing large image payloads in subsequent turns. Images are saved to disk and only file paths are returned.
• Change: Default TRANSFER_AI_API_FORMAT changed from openai to gemini.
• Response now includes file size info for each saved image.

v0.1.0

• Initial release.

Install

npm install

For a global install:

npm install -g .

Then run:

transfer-ai-mcp

Environment variables

Required:

• TRANSFER_AI_API_KEY
• TRANSFER_AI_BASE_URL unless you use TRANSFER_AI_TEXT_URL and TRANSFER_AI_IMAGE_URL
• TRANSFER_AI_MODEL unless you set both TRANSFER_AI_TEXT_MODEL and TRANSFER_AI_IMAGE_MODEL

Optional:

• TRANSFER_AI_API_FORMAT
  • openai or gemini
  • default: gemini
• TRANSFER_AI_AUTH_MODE
  • bearer, query, x-goog-api-key, or none
  • default: bearer
• TRANSFER_AI_TEXT_MODEL
• TRANSFER_AI_IMAGE_MODEL
• TRANSFER_AI_TEXT_URL
• TRANSFER_AI_IMAGE_URL
• TRANSFER_AI_TEXT_PATH
• TRANSFER_AI_IMAGE_PATH
• TRANSFER_AI_OUTPUT_DIR

Default endpoint behavior

If TRANSFER_AI_API_FORMAT=openai:

• text requests default to /v1/chat/completions
• image requests default to /v1/chat/completions

If TRANSFER_AI_API_FORMAT=gemini:

• text requests default to /v1beta/models/{model}:generateContent
• image requests default to /v1beta/models/{model}:generateContent

Override any of these with TRANSFER_AI_TEXT_URL, TRANSFER_AI_IMAGE_URL, TRANSFER_AI_TEXT_PATH, or TRANSFER_AI_IMAGE_PATH.

Tools

• get_configuration_status
• generate_text
• generate_image
• get_last_image_info

generate_text arguments:

• prompt
• systemPrompt
• model
• temperature
• maxTokens
• extraBody

generate_image arguments:

• prompt
• systemPrompt
• model
• aspectRatio
• imageSize
• outputPath
• extraBody

Kiro / VS Code MCP example

{
  "mcpServers": {
    "transfer-ai": {
      "command": "node",
      "args": ["/path/to/transfer-ai-mcp/dist/index.js"],
      "env": {
        "TRANSFER_AI_API_FORMAT": "gemini",
        "TRANSFER_AI_AUTH_MODE": "bearer",
        "TRANSFER_AI_API_KEY": "your-api-key",
        "TRANSFER_AI_BASE_URL": "https://your-endpoint.example.com",
        "TRANSFER_AI_MODEL": "gemini-2.0-flash-preview-image-generation",
        "TRANSFER_AI_OUTPUT_DIR": "/path/to/output/images"
      },
      "disabled": false,
      "autoApprove": ["generate_image", "get_configuration_status"]
    }
  }
}

Codex MCP example

See examples/codex-config.toml.