DeepChat
Connect DeepChat to Half Off Dev with one OpenAI-compatible provider and use Claude, GPT and Gemini models at 50% of the official price.
DeepChat is an open-source desktop chat app that can hold several model providers at once. Register Half Off Dev as an OpenAI-compatible provider and one key gives it Claude, GPT and Gemini, all billed at half the list price. Create an API key first.
Import in one click#
On API keys, go to Use in tools → DeepChat and press Open in DeepChat. DeepChat (which has to be installed) receives the provider with your key. The key is pre-filled right after you create it; for an existing key, paste it in full, because only its hash is stored.
Manual setup#
In DeepChat's provider settings, add one with:
| Field | Value |
|---|---|
| Provider type | OpenAI-compatible (or "New API") |
| API host | https://halfoff.dev |
| API key | your ho-... key |
Enter the host without /v1; DeepChat appends it. Next, add the model ids you want to chat with, such as gpt-6.1-sol, gemini-3.1-pro or claude-sonnet-5.5. Every id is on the model list.
Fixing errors#
| What you see | What to do |
|---|---|
401 Invalid or revoked API key | The key was mistyped, cut short or revoked. Paste it again or make a new one. |
404 Model '...' is not available | That id doesn't exist. Copy one from GET /v1/models or the model list. |
404 with /v1/v1/ in the path | The API host ends in /v1. Change it to https://halfoff.dev. |
404 Unknown endpoint | DeepChat is calling an API Half Off Dev doesn't serve, such as embeddings. Keep Half Off Dev for chat and set another provider for that feature. |
402 | The balance is empty or the key has hit its spend cap. See Billing. |
Any other status is explained in Errors.