SillyTavern Free API: Connect FreeTheAI (Custom OpenAI)
SillyTavern talks to FreeTheAI through its Chat Completion API with the Custom (OpenAI-compatible) source. It lists every model your key can use.
Before you start
- Create a free account and an API key. Create an account
- Check in once a day to unlock the free models. Daily check-in
- Pick a model ID from the models page. Browse models
Settings
- API
Chat Completion- Chat Completion Source
Custom (OpenAI-compatible)- Custom Endpoint (Base URL)
https://api.freetheai.org/v1- Custom API Key
your FreeTheAI key (ftai_..., 53 characters)- Model ID
fta/zai/glm-5.3- Prompt Post-Processing
Semi-strict (alternating roles)
Steps
Open API Connections
Click the plug icon in the top bar.
Choose the source
Set API to Chat Completion and Chat Completion Source to Custom (OpenAI-compatible).
Enter the endpoint and key
Paste the base URL into Custom Endpoint (Base URL). SillyTavern adds /chat/completions itself, so do not add it. Paste your key into Custom API Key.
Pick a model and connect
Type a model ID into Enter a Model ID, or pick one from Available Models after connecting. Press Connect.
Set Prompt Post-Processing
On the same screen, set Prompt Post-Processing to Semi-strict. With None, some models answer "Bad Request" because the chat can reach them without a message from you.
How this guide was checked: Checked against SillyTavern's source (release branch, API connection panel) on 2026-09-29.
Tips
- Your key is hidden after you press Connect. Keep a copy somewhere safe.
- If replies stop early, raise Max Response Length in the sampler panel.
- Save the connection as a Connection Profile to switch models quickly.
Troubleshooting
SillyTavern connects but no models appear. What now?
Type the model ID by hand in Enter a Model ID, for example fta/zai/glm-5.3. Also check that you checked in today at freetheai.org/checkin.
Should the base URL end in /v1?
Yes. Use https://api.freetheai.org/v1. SillyTavern appends /chat/completions.
SillyTavern says "API returned an error: Bad Request". How do I fix it?
Set Prompt Post-Processing to Semi-strict in API Connections and try again. Some models need at least one message from you in every request, and that setting makes sure there is one.
Common errors
- 401: the key is wrong or incomplete. Paste the whole key.
- 403: check in for today, or confirm your email.
- 404: the model ID or URL is wrong.
- 429: daily limit reached, or too many requests at once.