---
url: https://docs.freetheai.org/guides/sillytavern.md
description: >-
  Connect SillyTavern to free models with FreeTheAI. Chat Completion, Custom
  (OpenAI-compatible) source, base URL, key, and model ID, step by step.
---

# SillyTavern

SillyTavern talks to FreeTheAI through its Chat Completion API with the Custom (OpenAI-compatible) source. It lists every model your key can use.

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 |
| --- | --- |
| 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.

## 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.

## Common questions

### 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](https://freetheai.org/checkin).

### Should the base URL end in /v1?

Yes. Use [api.freetheai.org/v1](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.

## More help

* [Every API error and its fix](/errors)
* [Limits and the daily reset](/concepts/limits)
* [SillyTavern website](https://sillytavern.app) and [source code](https://github.com/SillyTavern/SillyTavern)

::: info How this guide was checked
Checked against SillyTavern's source (release branch, API connection panel) on 2026-09-29.
:::