SillyTavern supports any OpenAI-compatible provider. Point it at Composite's OpenAI-compatible base URL to run community presets, lorebooks and plugins on your own provider key, or on Synth, LuciditySH's creative model, free on Composite, with no key at all, in your existing chats. Using ChubAI instead? See the dedicated ChubAI proxy guide.
SillyTavern does not run its own models. Under Chat Completion Source you point it at an OpenAI-compatible API, and every message you send is forwarded there and the reply is shown in your chat. That forwarding service is what people mean by a "proxy" or "reverse proxy" for SillyTavern. It sits between the frontend you use to write and the model actually generating replies. Composite is one such proxy: it authenticates your API key, applies the presets, lorebooks and plugins attached to it, sends the request to your own provider or to the model you picked, and returns a standard OpenAI-formatted response. One Composite key reaches every model on the platform, so there is no separate setup to repeat when you switch models mid-story. The same key and base URL also work in ChubAI, Agnai, and RisuAI, if you use more than one frontend.
Copy these directly into the API settings panel in SillyTavern.
Use these fields in the API settings panel. Choose OpenAI as the connection type.
OpenAIhttps://composite.lucidity.sh/v1YOUR_API_KEYminimax/minimax-m3Chat Completion and Chat Completion Source to OpenAI.https://composite.lucidity.sh/v1 into the Custom Endpoint (Base URL) field.API: Chat Completion
Chat Completion Source: OpenAI
Custom Endpoint: https://composite.lucidity.sh/v1
API Key: YOUR_API_KEY
Model: minimax/minimax-m3Using ChubAI, Agnai, or RisuAI instead? Each has its own dedicated setup guide: ChubAI, Agnai, RisuAI.
You do not need a credit card to get a working SillyTavern connection. Create a Composite account and make a key on the Keys page. Bind it to your own OpenRouter, DeepSeek, Anthropic, OpenAI, Gemini or Mistral key on the API Keys page to use that provider's models at no charge from Composite (the BYOK quickstart shows how), or leave it unbound and use Synth, lucidityai/synth-2.5-flash, which is free on every account. Paste the key into the API Key field alongside the base URL above. Community presets and lorebooks you apply on Composite follow the key into SillyTavern.
SillyTavern's TTS extension can read replies aloud through Composite. Open Extensions, then TTS, set the provider to OpenAI Compatible, and fill in the fields below. List the voices you want in Available Voices, then use the voice map to give each character one.
Provider: OpenAI Compatible
Provider Endpoint: https://composite.lucidity.sh/v1/audio/speech
API Key: YOUR_API_KEY
Model: mistralai/voxtral-mini-tts-2603
Available Voices: gb_jane_neutral,gb_oliver_neutral,en_paul_neutral/v1/audio/models lists every speech model with its voices and per-character price. On a key with credits, speech is charged per character of input at the listed price times the listed multiplier; a plan draws the listed price from its pool. Models priced per second or per token of audio are not offered. A key bound to your own provider speaks on that provider, unbilled by Composite, if it serves OpenAI-style speech (OpenRouter and OpenAI do). Anthropic has no speech API.
The most common problems when using Composite as a SillyTavern proxy, and how to fix them.
Confirm Chat Completion Source is set to OpenAI, the Custom Endpoint (Base URL) is exactly https://composite.lucidity.sh/v1 with nothing appended after it, and the API key was pasted with no leading or trailing spaces. If the model dropdown stays empty after Connect, the endpoint is the most likely cause: SillyTavern needs the base URL here, not the full chat-completions path. Use Test Message to confirm the connection before trusting a longer chat to it.
A 429 response on Synth means today's Synth requests are used up: 80 a day, or 300 a day in your first week after joining with a referral code. They reset once a day at the time shown on your account page, and credits or a plan make Synth unlimited. A key bound to your own provider has no Composite daily limit, so a 429 there is your provider's own rate limit.
Composite API keys start with cmp- and are sent as a bearer token, so the API Key field should hold only the key itself. SillyTavern adds the Bearer header for you. An invalid-key error usually means the key was revoked, mistyped, or deleted; generate a fresh one on the API Keys page. Each key can also be scoped to specific models, so a key that works for one model can still fail on another it is not allowed to use.
| Use case | Suggestion |
|---|---|
| General roleplay, default choice | minimax/minimax-m3 |
| No provider key yet | lucidityai/synth-2.5-flash (Synth), free on every account |
| Long-running character or campaign | A higher context-length model from the Models page, paired with a memory-layer setting on the key |
| Highest reply quality, budget flexible | Compare current premium models on the Models page |
The catalog changes as models are added, so treat the Models page as the source of truth rather than a fixed list.
Every model has a fixed context window. Once a conversation exceeds it, Composite trims older messages to keep the request within limits, so long-running characters can start losing early details unless the key is set to one of Composite's memory-layer modes, which summarize and retrieve older history instead of dropping it outright. If replies start ignoring established facts in a long chat, check the key's memory-layer setting before assuming the model itself is at fault.
Still stuck after working through the above? The full docs cover account setup, API keys, and model access in more detail, and the feedback page reaches Composite directly if something looks broken rather than misconfigured.