OpenAI Image MCP
OpenAI Image MCP
Tiny remote MCP server for OpenAI image generation, designed to be easy to deploy on Render.
What this is
This project exposes a remote MCP endpoint at /mcp with one main tool:
generate_image: generate one or more images from a prompt using OpenAI.server_info: simple read-only check of the configured model and whether the API key is present.
It reads OPENAI_API_KEY from Render environment variables.
Important model note
This project defaults to:
OPENAI_IMAGE_MODEL=gpt-image-1
That is a likely safe default, not a guaranteed final recommendation. OpenAI image model names can change over time. If you already know the exact model you want, set OPENAI_IMAGE_MODEL on Render to that value instead.
Files
server.js- the remote MCP serverpackage.json- Node package configrender.yaml- optional Render blueprintProcfile- simple process declaration.gitignoreREADME.md
Tool interface
generate_image
Inputs:
prompt(required, string)size(optional):1024x1024,1536x1024,1024x1536,autoquality(optional):auto,low,medium,highbackground(optional):auto,opaque,transparentoutput_format(optional):png,webp,jpegmoderation(optional):auto,lown(optional, 1-4)user(optional string)
Output:
a text summary
one inline MCP image item per generated image when OpenAI returns base64 data
a short JSON text block per image with metadata like
revised_prompt
Deploy on Render
Option A: easiest manual deploy
Put this folder in a GitHub repo.
Log into Render.
Create a New Web Service.
Connect the GitHub repo.
Use these settings:
Runtime: Node
Build Command:
npm installStart Command:
npm start
Add environment variable:
OPENAI_API_KEY= your OpenAI API key
Optional environment variable:
OPENAI_IMAGE_MODEL=gpt-image-1
Deploy.
After deploy, note your service URL, for example:
https://your-app-name.onrender.com/mcp
Option B: Render Blueprint
If you prefer, commit render.yaml and create the service from that blueprint. You will still need to set OPENAI_API_KEY manually because secrets should not live in the repo.
Quick checks after deploy
Open these in a browser:
https://your-app-name.onrender.com/https://your-app-name.onrender.com/health
/health should return JSON and show hasOpenAIKey: true after you add the environment variable.
How Sand should add this remote MCP
After Render is live, Sand should add the remote MCP server URL:
MCP URL:
https://your-app-name.onrender.com/mcp
If Sand asks for a remote MCP endpoint, use the /mcp URL exactly.
Local run (optional)
npm install
OPENAI_API_KEY=your_key_here npm startThen the MCP endpoint is:
http://localhost:3000/mcp
Notes and limitations
This is intentionally tiny and simple.
It does not store files or prompts.
It returns inline image content from OpenAI base64 output.
Transparent backgrounds only work on some image models and formats.
Larger
nvalues can increase cost quickly.If OpenAI changes supported model names or parameter rules, update
OPENAI_IMAGE_MODELor the tool schema accordingly.