---
url: https://docs.freetheai.org/guides/chub-ai.md
description: >-
  Use free AI models on chub.ai (Venus) with FreeTheAI. Where the OpenAI reverse
  proxy lives in Secrets, the base URL to use, and how to pick the model.
---

# Chub AI

Chub AI uses FreeTheAI as an OpenAI reverse proxy. You enter the base URL and key in Secrets, check the proxy, then choose the model in Configuration.

Category: [Roleplay apps](/guides/#roleplay-apps). Before you start, you need a FreeTheAI account, an API key, and today's [check-in](/getting-started/check-in).

## Settings

| Setting | Value |
| --- | --- |
| Secrets > OpenAI | `Reverse Proxy` |
| OpenAI Reverse Proxy | `https://api.freetheai.org/v1` |
| Reverse Proxy Key | Your FreeTheAI key (`ftai_...`, 53 characters) |
| Configuration > Prompt Structure > API | `OpenAI` |
| Model | `fta/zai/glm-5.3` |

## Steps

### Open Secrets

In any chat, open the menu (three lines, top right) and choose Secrets, then OpenAI.

### Turn on the reverse proxy

Choose Reverse Proxy instead of your own OpenAI key. Enter the base URL ending in /v1 (not /chat/completions) and your FreeTheAI key.

### Check the proxy

Press Check Proxy and wait for the green confirmation. Chub loads the model list from FreeTheAI at this step.

### Pick the model

Open the menu again, choose Configuration, then Prompt Structure. Set API to OpenAI and pick a model that starts with fta/. Save.

## Tips

* Refresh the page if the model list stays empty after a successful check.
* Chub's list may show models FreeTheAI does not serve. Only fta/ models work.

## Common questions

### Check Proxy fails on Chub. Why?

The URL must be the base URL [api.freetheai.org/v1](https://api.freetheai.org/v1). A full /chat/completions URL fails, because Chub adds the path itself.

### Can I use FreeTheAI on the Chub mobile site?

Yes. The same Secrets and Configuration menus are in the mobile chat view.

### Check Proxy works but no FreeTheAI models appear. What now?

Refresh the page, then look again under Configuration, Prompt Structure. Only models that start with fta/ work.

### Why do I get a 401 error?

The key is wrong or incomplete. Paste the whole ftai\_ key (53 characters), with no spaces.

### Why do I get a 403 error?

Free models need one check-in a day. Check in at [freetheai.org/checkin](https://freetheai.org/checkin), then try again.

### It loads for a long time, then shows an error or an empty reply. Why?

The model is busy. Try another model, and check [freetheai.org/status](https://freetheai.org/status).

### A model rejects my settings. How do I fix it?

Reset temperature and the other sampling settings to their defaults, then try again.

### Which models are good for roleplay on Chub?

`fta/zai/` and `fta/kimi/` models, for example `fta/zai/glm-5.3`. `fta/dog/` and `fta/lion/` models are for general chat and refuse roleplay.

## More help

* [Every API error and its fix](/errors)
* [Limits and the daily reset](/concepts/limits)
* [Chub AI website](https://chub.ai)

::: info How this guide was checked
Checked against Chub's API connection docs and current reverse proxy guides on 2026-09-29.
:::