Promptster for ChatGPT

io.github.promptster-dev/promptster

Test and compare prompts across any AI provider. Bring your own keys.

client:ChatGPT transport:streamable-http

Install Promptster in ChatGPT

Settings → Connectors → Advanced → Developer mode

https://www.promptster.dev/mcp

Custom connectors are a paid-plan feature and take a remote URL only. ChatGPT cannot run a packaged server locally. ChatGPT docs