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

# Use Imagen 3.0 Fast Generate 001 with Comfy Router

> Call vertexai/imagen-3.0-fast-generate-001 through Comfy Router: endpoint, request shape and the response Router returns.

API Reference for `vertexai/imagen-3.0-fast-generate-001`, served by Comfy Router from Google.

## Quick start

Create a key in [your Comfy workspace](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:** `vertexai/imagen-3.0-fast-generate-001`

**Endpoint:** `POST https://api.comfy.org/v2/models/vertexai/imagen-3.0-fast-generate-001`

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

  # Reads COMFY_API_KEY from the environment.
  # The SDK automatically creates an idempotency key and reuses it for automatic retries.
  with Comfy() as client:
      result = client.models.run(
          "vertexai/imagen-3.0-fast-generate-001",
          {
              "instances": [
                  {
                      "prompt": "A single red maple leaf on a plain white background.",
                  },
              ],
              "parameters": {
                  "sampleCount": 1,
              },
          },
      )

  print(result)
  ```

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

  // Reads COMFY_API_KEY from the environment.
  // The SDK automatically creates an idempotency key and reuses it for automatic retries.
  const { data } = await comfy.models.run("vertexai/imagen-3.0-fast-generate-001", {
    instances: [
      {
        prompt: "A single red maple leaf on a plain white background.",
      },
    ],
    parameters: {
      sampleCount: 1,
    },
  });

  console.log(data);
  ```

  ```bash cURL theme={null}
  curl https://api.comfy.org/v2/models/vertexai/imagen-3.0-fast-generate-001 \
    -H "X-API-Key: $COMFY_API_KEY" \
    -H "Idempotency-Key: $(uuidgen)" \
    -H "Content-Type: application/json" \
    -d "{\"instances\": [{\"prompt\":\"A single red maple leaf on a plain white background.\"}], \"parameters\": {\"sampleCount\":1}}"
  ```
</CodeGroup>

## Schema

### Input

<ParamField body="instances" type="object[]" required />

<ParamField body="instances[].prompt" type="string" required>
  Text prompt for image generation
</ParamField>

<ParamField body="parameters" type="object" />

<ParamField body="parameters.addWatermark" type="boolean" />

<ParamField body="parameters.aspectRatio" type="string">
  Possible values: `1:1`, `9:16`, `16:9`, `3:4`, `4:3`
</ParamField>

<ParamField body="parameters.enhancePrompt" type="boolean" />

<ParamField body="parameters.includeRaiReason" type="boolean" />

<ParamField body="parameters.includeSafetyAttributes" type="boolean" />

<ParamField body="parameters.outputOptions" type="object" />

<ParamField body="parameters.outputOptions.compressionQuality" type="integer">
  Range: `0` to `100`
</ParamField>

<ParamField body="parameters.outputOptions.mimeType" type="string">
  Possible values: `image/png`, `image/jpeg`
</ParamField>

<ParamField body="parameters.personGeneration" type="string">
  Possible values: `dont_allow`, `allow_adult`, `allow_all`
</ParamField>

<ParamField body="parameters.safetySetting" type="string">
  Possible values: `block_most`, `block_some`, `block_few`, `block_fewest`
</ParamField>

<ParamField body="parameters.sampleCount" type="integer">
  Range: `1` to `4`
</ParamField>

<ParamField body="parameters.seed" type="integer">
  Format: `uint32`
</ParamField>

<ParamField body="parameters.storageUri" type="string" />

Generated from the schema Router serves at `GET /v2/models/vertexai/imagen-3.0-fast-generate-001/openapi.json`, the same document it validates a call against before the request reaches the provider.

### Output

<ResponseField name="predictions" type="object[]" />

<ResponseField name="predictions[].bytesBase64Encoded" type="string (byte)">
  Base64-encoded image content

  Format: `byte`
</ResponseField>

<ResponseField name="predictions[].mimeType" type="string">
  MIME type of the generated image
</ResponseField>

<ResponseField name="predictions[].prompt" type="string">
  Enhanced or rewritten prompt used to generate this image
</ResponseField>

## Examples

### Input

```json theme={null}
{
  "instances": [
    {
      "prompt": "A single red maple leaf on a plain white background."
    }
  ],
  "parameters": {
    "sampleCount": 1
  }
}
```

### Output

```json theme={null}
{
  "predictions": [
    {
      "bytesBase64Encoded": "PGJhc2U2ND4=",
      "mimeType": "image/png",
      "prompt": "A lighthouse at the edge of the harbour at dawn, warm low sun"
    }
  ]
}
```

## Before you ship

The SDKs create an `Idempotency-Key` and reuse it for automatic retries. For manual retries, reuse the original key. Router can hold the connection for up to 10 minutes.

When a request fails, Router sends an `X-Comfy-Error-Type` response header explaining why. 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/api">
    Model discovery, validation errors, retries, and billing.
  </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>