Connect Open WebUI to PromptUnit
Add PromptUnit as a connection in Open WebUI's admin settings. Your models then appear in the model selector like any other connection.
Get your PromptUnit key
Sign up free at PromptUnit (no credit card) and connect the AI provider key you already use, for example your OpenAI or OpenRouter key. Your requests keep running on that key.
Then open API Keys in your dashboard and copy your PromptUnit key. Connecting more than one app? Under Routing, + New routing gives each app its own key and settings.
Add the connection
In Open WebUI, open the Admin Panel, then Settings, then Connections. Next to OpenAI API, click + to add a connection and fill in:
URL
the address for the provider whose key you connected (below)Key
your PromptUnit key from Step 1Your OpenAI key
https://www.promptunit.ai/api/proxy/openaiYour OpenRouter (models from many providers) key
https://www.promptunit.ai/api/proxy/openrouterYour Google Gemini key
https://www.promptunit.ai/api/proxy/googleYour Groq key
https://www.promptunit.ai/api/proxy/groqYour DeepSeek key
https://www.promptunit.ai/api/proxy/deepseekClick Verify Connection, then Save.
Pick a model and chat
Open a new chat and choose a model in the model selector. The list shows the models your own provider account can use.
Watch the costs
Each message shows up on your PromptUnit dashboard with what it cost. PromptUnit checks every request and uses a cheaper model only when it would answer just as well; otherwise it uses the model you chose. Your first $5 of savings is free, no card needed.
If something doesn't look right
If the connection check fails, make sure the URL ends at the provider name (for example /openai, with or without /v1) and that the same provider's key is connected in PromptUnit. Open WebUI shows PromptUnit's error message, which says what is missing.
Quick reference
The address you'll paste in, if you need it again:
https://www.promptunit.ai/api/proxy/openai