> ## Documentation Index
> Fetch the complete documentation index at: https://docs.alterhq.com/llms.txt
> Use this file to discover all available pages before exploring further.

# API Gateway Won't List Models

> Fix empty model lists when connecting external apps to Alter's API

<Note>
  **Using the API Gateway?** This lets you use Alter's models in other apps like SillyTavern, NovelCrafter, or your own code.
</Note>

## What's happening?

You're trying to connect another app to Alter's API, but:

* The app connects but shows no available models
* You have to manually type model names
* Model requests fail unless you specify the exact name

## Why this happens

Many AI apps expect OpenAI's simple model format (like `gpt-5`), but Alter supports multiple providers. So we use a special format to identify which provider each model comes from.

## The solution

<Card title="Model Format: Provider#Model-name" icon="hashtag">
  Instead of just `gpt-5`, use: `OpenAI#gpt-5`

  The format is always: **Provider name** + **#** + **Model name**
</Card>

## Setup steps

<Steps>
  <Step title="Get your API credentials">
    1. Open Alter → Settings (`Cmd + ,`)
    2. Go to the **Router** tab
    3. Click **Add New Key** to generate an API key
    4. Copy the key (starts with `sk-...`)
    5. Note the endpoint: `https://alterhq.com/api`
  </Step>

  <Step title="Configure your external app">
    In the app you're connecting:

    * **Base URL:** `https://alterhq.com/api` (or try `https://alterhq.com/api/v1`)
    * **API Key:** Your generated key from step 1
  </Step>

  <Step title="Manually set the model">
    Since automatic listing might not work, manually enter a model:

    | Provider | Model Name  | Full ID                        |
    | -------- | ----------- | ------------------------------ |
    | OpenAI   | GPT-5       | `OpenAI#gpt-5`                 |
    | OpenAI   | GPT-5 Nano  | `OpenAI#gpt-5-nano`            |
    | Claude   | Sonnet 4    | `Claude#claude-sonnet-4-6`     |
    | Gemini   | 2.5 Pro     | `Gemini#gemini-2.5-pro`        |
    | Mistral  | Large       | `Mistral#mistral-large-latest` |
    | Alter    | Best Router | `Alter#best`                   |
  </Step>
</Steps>

## Test the connection

Try this simple test:

1. Send a chat completion request with model `OpenAI#gpt-5-nano`
2. **Success:** You should get a response back through Alter

If it works with one model, it will work with all of them – just change the model ID!

<Tip>
  **Pro tip:** The Alter API works exactly like OpenAI's API. If your app supports "OpenAI-compatible" endpoints, it will work with Alter.
</Tip>

## Still having issues?

* Make sure you're using a valid Alter API key (not your provider's key)
* Try both endpoints: `/api` and `/api/v1`
* Some apps cache the model list – try restarting the app after setup

## Related help

* [API Gateway full guide](/api-router/api-gateway)
* [List of all available models](/how-to/choose-generative-model)