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

# List Models (Public)

> List Bland's TTS models in an OpenAI-compatible catalog. No API key required, so tooling can discover models before authenticating.

## Overview

Returns Bland's TTS model catalog in the OpenAI `list` format. No authentication is required.

Use it when your tooling expects an OpenAI-style `GET /models` endpoint, or when you need to discover models before a user has entered an API key. Each entry carries the same capabilities manifest as [List TTS Models](/api-v2/get/tts-models): supported encodings, sample rates, containers, and voice controls.

If you are already authenticated and only need the manifests, [List TTS Models](/api-v2/get/tts-models) returns them without the OpenAI wrapper. Its behavior is unchanged.

Responses are cacheable for up to 5 minutes (`Cache-Control: public, max-age=300`).

***

## Response

<ResponseField name="object" type="string">
  Always `list`.
</ResponseField>

<ResponseField name="data" type="array">
  Array of model entries.

  <Expandable title="Model fields">
    <ResponseField name="id" type="string">
      Model identifier, for example `btts-3`. Same value as the `x-model` header on [Synthesize Speech](/api-v2/post/tts).
    </ResponseField>

    <ResponseField name="object" type="string">
      Always `model`.
    </ResponseField>

    <ResponseField name="created" type="number">
      Always `0`. Present for OpenAI compatibility.
    </ResponseField>

    <ResponseField name="owned_by" type="string">
      Always `bland`.
    </ResponseField>

    <ResponseField name="name" type="string">
      Human-readable name. Currently matches `id`.
    </ResponseField>

    <ResponseField name="modality" type="string">
      Always `text-to-speech`.
    </ResponseField>

    <ResponseField name="capabilities" type="object">
      The model's capabilities manifest.

      <Expandable title="Capability fields">
        <ResponseField name="encodings" type="string[]">
          Supported audio codecs. Pass one as `audio.encoding`.
        </ResponseField>

        <ResponseField name="sample_rates" type="number[]">
          Supported PCM sample rates in Hz. `mulaw` is fixed at 8000 regardless of this list.
        </ResponseField>

        <ResponseField name="containers" type="string[]">
          Supported byte framings (`raw`, `wav`).
        </ResponseField>

        <ResponseField name="controls" type="object">
          Supported voice controls and their allowed ranges. Each entry is an object with `min` and `max`.
        </ResponseField>
      </Expandable>
    </ResponseField>
  </Expandable>
</ResponseField>

<ResponseExample>
  ```json Response theme={null}
  {
    "object": "list",
    "data": [
      {
        "id": "btts-3",
        "object": "model",
        "created": 0,
        "owned_by": "bland",
        "name": "btts-3",
        "modality": "text-to-speech",
        "capabilities": {
          "encodings": ["pcm_s16le", "mulaw"],
          "sample_rates": [8000, 16000, 24000, 44100, 48000],
          "containers": ["raw", "wav"],
          "controls": {
            "expressiveness": { "min": 0, "max": 1 },
            "stability": { "min": 0, "max": 1 }
          }
        }
      },
      {
        "id": "btts-2",
        "object": "model",
        "created": 0,
        "owned_by": "bland",
        "name": "btts-2",
        "modality": "text-to-speech",
        "capabilities": {
          "encodings": ["pcm_s16le", "mulaw"],
          "sample_rates": [8000, 16000, 24000, 44100, 48000],
          "containers": ["raw", "wav"],
          "controls": {
            "expressiveness": { "min": 0, "max": 1 },
            "stability": { "min": 0, "max": 1 }
          }
        }
      }
    ]
  }
  ```

  ```json Error theme={null}
  {
    "error": {
      "message": "Failed to list models.",
      "type": "api_error",
      "param": null,
      "code": "internal_error"
    }
  }
  ```
</ResponseExample>

### Error codes

| Code             | HTTP | Meaning                                       |
| ---------------- | ---- | --------------------------------------------- |
| `internal_error` | 500  | Catalog generation failed. Retry the request. |

***

Docs for agents: [llms.txt](/llms.txt)