> ## Documentation Index
> Fetch the complete documentation index at: https://dripart-stale2000-router-model-pages.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Use LTX 2.5 Fast with Comfy Router

> Call ltx/ltx-2-5-fast through Comfy Router: endpoint, request shape and the response Router returns.

Use `ltx/ltx-2-5-fast` with the Comfy Router API. LTX provides the model; Router gives it the shared authentication and request route below.

## Quick start

Create a key at [platform.comfy.org/profile/api-keys](https://platform.comfy.org/profile/api-keys) and export it as `COMFY_API_KEY`. The Python and TypeScript snippets use the Comfy SDKs (`pip install comfy-sdk`, `npm install @comfyorg/sdk`); the cURL snippet is the same call over raw HTTP.

**Model ID:** `ltx/ltx-2-5-fast`

**Endpoint:** `POST https://api.comfy.org/v2/models/ltx/ltx-2-5-fast`

<CodeGroup>
  ```python Python theme={null}
  import uuid
  from comfy_sdk import Comfy

  # Reads COMFY_API_KEY from the environment. Save this key and reuse it if you
  # retry this request after the SDK returns an error.
  idempotency_key = str(uuid.uuid4())
  with Comfy() as client:
      result = client.models.run(
          "ltx/ltx-2-5-fast",
          {
              # Request fields are the provider's own — see Input below.
          },
          idempotency_key=idempotency_key,
      )

  print(result)
  ```

  ```typescript TypeScript theme={null}
  import { comfy } from "@comfyorg/sdk";

  // Reads COMFY_API_KEY from the environment. Save this key and reuse it if you
  // retry this request after the SDK returns an error.
  const idempotencyKey = crypto.randomUUID();
  const { data } = await comfy.models.run("ltx/ltx-2-5-fast", {
    // Request fields are the provider's own — see Input below.
  }, { idempotencyKey });

  console.log(data);
  ```

  ```bash cURL theme={null}
  # Request fields are the provider's own — see Input below.
  # Run this line once. Reuse ROUTER_REQUEST_KEY if you retry the curl command.
  ROUTER_REQUEST_KEY=$(uuidgen)
  curl https://api.comfy.org/v2/models/ltx/ltx-2-5-fast \
    -H "X-API-Key: $COMFY_API_KEY" \
    -H "Idempotency-Key: $ROUTER_REQUEST_KEY" \
    -H "Content-Type: application/json" \
    -d '{}'
  ```
</CodeGroup>

## Schema

### Input

<Note>
  Router has not published an authored input schema for this model yet: `GET /v2/models/ltx/ltx-2-5-fast/openapi.json` returns an open object with `x-comfy-input-schema-authored: false`. Router forwards the body to LTX unchanged, so LTX's own API documentation is authoritative for the request fields, and nothing is validated server side.
</Note>

### Output

<ResponseField name="completed_at" type="string">
  Job completion timestamp (ISO 8601)
</ResponseField>

<ResponseField name="created_at" type="string">
  Job creation timestamp (ISO 8601)
</ResponseField>

<ResponseField name="error" type="object">
  Present when status is failed
</ResponseField>

<ResponseField name="error.message" type="string" />

<ResponseField name="error.type" type="string" />

<ResponseField name="id" type="string">
  Unique job identifier
</ResponseField>

<ResponseField name="result" type="object">
  Present when status is completed; output URLs expire 24 hours after completion
</ResponseField>

<ResponseField name="result.video_url" type="string">
  URL of the generated video
</ResponseField>

<ResponseField name="status" type="string">
  Job status (pending, processing, completed, failed)
</ResponseField>

## Examples

### Output

```json theme={null}
{
  "completed_at": "2026-01-01T00:02:10Z",
  "created_at": "2026-01-01T00:00:00Z",
  "id": "3f7a1b28-5c0d-4e91-8a6f-1b2c3d4e5f60",
  "result": {
    "video_url": "https://example.invalid/ltx/generated.mp4"
  },
  "status": "completed"
}
```

## Before you ship

Save one `Idempotency-Key` for each call and reuse it for retries. Router can hold the connection for up to 10 minutes. The SDKs handle authentication; raw HTTP clients send the headers themselves.

Use `X-Comfy-Error-Type` to classify a failure. A `422` means Router rejected the input before calling the provider. Download generated assets promptly because [result URLs can expire](/development/comfy-router/reference#result-assets).

<CardGroup cols={3}>
  <Card title="Headers" icon="list" href="/development/comfy-router/headers">
    Authentication, idempotency, request IDs, error buckets, retry pacing, spend limits.
  </Card>

  <Card title="Using the Router API" icon="code" href="/development/comfy-router/models">
    Find models, inspect schemas, and retry safely.
  </Card>

  <Card title="Limitations" icon="triangle-exclamation" href="/development/comfy-router/limitations">
    What Router does not do today, and what to use instead.
  </Card>
</CardGroup>