# List language models (/docs/api/voice-agents/providers/listModels)

> For the complete documentation index, see [llms.txt](https://docs.tandemcx.ai/llms.txt). Any page on this site can be fetched as Markdown by appending `.md` to its URL.

`GET /v1/agent-media/providers/llm/models`

List language models

The models this organization may select, which is the curated catalog narrowed to what's actually available: models Tandem hosts appear always, and a vendor's models appear only once the organization has connected its own integration for that vendor. Capability flags travel with each entry so a client needs no second call — `audioIn` means the model consumes audio directly (no speech-to-text slot), `audioOut` means it produces speech itself (no voice slot).

## Request

**Base URL:** `https://api.tandemcx.ai`

**Authentication:** `Authorization: Bearer <token>` — A Tandem bearer token. Requests are scoped to the organization the token belongs to; no organization header is required.

No parameters or request body.

## Responses

### 200 — The selectable models.

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `models` | array of object | No | — |
| `models[].id` | string | No | The value to store as `slots.llm.model`. |
| `models[].label` | string | No | — |
| `models[].company` | string | No | — |
| `models[].audioIn` | boolean | No | The model consumes audio directly; omit the `stt` slot. |
| `models[].audioOut` | boolean | No | The model produces speech itself; omit the `tts` slot. |
| `models[].reasoning` | boolean | No | The model supports extended thinking. |
| `models[].voiceProvider` | string | No | Present when `audioOut`; the voice provider the model is bound to. |

### 400 — The request was malformed. `error` names the reason, such as `invalid_agentId`, `invalid_version`, `invalid_slot`, or `invalid_prompt`.

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `error` | string | No | A stable machine-readable code. |
| `message` | string | No | A human-readable explanation, safe to show to an end user. Present on errors an operator can act on; browser clients display this field in preference to a generic fallback. |
| `limit` | integer | No | Present on some errors (e.g. `prompt_too_long`) that reject a value against a fixed bound: the bound itself. |
| `length` | integer | No | Present on some errors (e.g. `prompt_too_long`) that reject a value against a fixed bound: the measured size of the rejected value. |
| `reason` | string | No | Present on some errors (e.g. `invalid_avatar_image`) that have more than one cause: which one applied. |

### 401 — Missing, malformed, or expired bearer token.

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `error` | string | No | A stable machine-readable code. |
| `message` | string | No | A human-readable explanation, safe to show to an end user. Present on errors an operator can act on; browser clients display this field in preference to a generic fallback. |
| `limit` | integer | No | Present on some errors (e.g. `prompt_too_long`) that reject a value against a fixed bound: the bound itself. |
| `length` | integer | No | Present on some errors (e.g. `prompt_too_long`) that reject a value against a fixed bound: the measured size of the rejected value. |
| `reason` | string | No | Present on some errors (e.g. `invalid_avatar_image`) that have more than one cause: which one applied. |

### 502 — An upstream catalog lookup failed.

| Field | Type | Required | Description |
| --- | --- | --- | --- |
| `error` | string | No | A stable machine-readable code. |
| `message` | string | No | A human-readable explanation, safe to show to an end user. Present on errors an operator can act on; browser clients display this field in preference to a generic fallback. |
| `limit` | integer | No | Present on some errors (e.g. `prompt_too_long`) that reject a value against a fixed bound: the bound itself. |
| `length` | integer | No | Present on some errors (e.g. `prompt_too_long`) that reject a value against a fixed bound: the measured size of the rejected value. |
| `reason` | string | No | Present on some errors (e.g. `invalid_avatar_image`) that have more than one cause: which one applied. |