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

# Use Claude Fable 5.1 with Comfy Router

> Call anthropic/claude-fable-5-1 through Comfy Router: endpoint, request shape and the response Router returns.

API Reference for `anthropic/claude-fable-5-1`, served by Comfy Router from Anthropic.

## 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:** `anthropic/claude-fable-5-1`

**Endpoint:** `POST https://api.comfy.org/v2/models/anthropic/claude-fable-5-1`

<Tabs>
  <Tab title="Wait for the result">
    <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(
              "anthropic/claude-fable-5-1",
              {
                  "max_tokens": 16,
                  "messages": [
                      {
                          "content": "Reply with the single word: ok",
                          "role": "user",
                      },
                  ],
              },
          )

      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("anthropic/claude-fable-5-1", {
        max_tokens: 16,
        messages: [
          {
            content: "Reply with the single word: ok",
            role: "user",
          },
        ],
      });

      console.log(data);
      ```

      ```bash cURL theme={null}
      curl https://api.comfy.org/v2/models/anthropic/claude-fable-5-1 \
        -H "X-API-Key: $COMFY_API_KEY" \
        -H "Idempotency-Key: $(uuidgen)" \
        -H "Content-Type: application/json" \
        -d "{\"max_tokens\": 16, \"messages\": [{\"content\":\"Reply with the single word: ok\",\"role\":\"user\"}]}"
      ```
    </CodeGroup>
  </Tab>

  <Tab title="Queue and collect later">
    <Note>
      Queued delivery is rolling out per workspace. Until yours is enabled, the submit route answers `403` with `X-Comfy-Error-Type: not_enabled`. Nothing about the request is wrong, and the same body works through the synchronous route in the meantime.
    </Note>

    The same body, sent to `POST https://api.comfy.org/v2/models/anthropic/claude-fable-5-1/requests`. Router answers `201` with a `request_id` as soon as the run is admitted, and the result is collected once it is ready, from this process or another one. [Queued delivery](/development/comfy-router/queue) walks through status, cancellation and collection.

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

      # Reads COMFY_API_KEY from the environment.
      # Each submit() call mints its own Idempotency-Key and reuses it for automatic retries.
      with Comfy() as client:
          handle = client.models.submit(
              "anthropic/claude-fable-5-1",
              {
                  "max_tokens": 16,
                  "messages": [
                      {
                          "content": "Reply with the single word: ok",
                          "role": "user",
                      },
                  ],
              },
          )
          print("request_id:", handle.request_id)  # with the model ID, all another process needs

          # Poll until the request completes, waiting the Retry-After the server names.
          for update in handle.iter_events():
              print(update.status, update.queue_position)

          # The provider's own payload, the same value models.run() returns.
          # A request that failed or was cancelled raises the typed Router error here.
          result = handle.get()

      print(result)
      ```

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

      // Reads COMFY_API_KEY from the environment.
      // Each submit() call mints its own Idempotency-Key and reuses it for automatic retries.
      const handle = await comfy.models.submit("anthropic/claude-fable-5-1", {
        max_tokens: 16,
        messages: [
          {
            content: "Reply with the single word: ok",
            role: "user",
          },
        ],
      });
      console.log("requestId:", handle.requestId); // with the model ID, all another process needs

      // Poll until the request completes, waiting the Retry-After the server names.
      for await (const update of handle.events()) {
        console.log(update.status, update.queuePosition);
      }

      // The same result models.run() returns. A request that failed or was cancelled rejects here.
      const result = await handle.get();

      console.log(result.data);
      ```

      ```bash cURL theme={null}
      # 1. Submit. Router answers 201 with request_id, status_url, response_url and cancel_url.
      curl https://api.comfy.org/v2/models/anthropic/claude-fable-5-1/requests \
        -H "X-API-Key: $COMFY_API_KEY" \
        -H "Idempotency-Key: $(uuidgen)" \
        -H "Content-Type: application/json" \
        -d "{\"max_tokens\": 16, \"messages\": [{\"content\":\"Reply with the single word: ok\",\"role\":\"user\"}]}"

      # 2. Poll until status is COMPLETED, waiting the Retry-After seconds each response names.
      REQUEST_ID="<request_id from the 201 body>"
      curl -i https://api.comfy.org/v2/models/anthropic/claude-fable-5-1/requests/$REQUEST_ID/status \
        -H "X-API-Key: $COMFY_API_KEY"

      # 3. Collect. 200 with the model's native output, 202 with the status body while it is still running.
      curl https://api.comfy.org/v2/models/anthropic/claude-fable-5-1/requests/$REQUEST_ID \
        -H "X-API-Key: $COMFY_API_KEY"
      ```
    </CodeGroup>
  </Tab>
</Tabs>

## Schema

### Input

<ParamField body="max_tokens" type="integer" required>
  Maximum number of tokens to generate before stopping.
</ParamField>

<ParamField body="messages" type="object[]" required>
  Conversation turns. See Anthropic Messages API docs for the full content-block taxonomy.
</ParamField>

<ParamField body="messages[].content" type="object" required>
  Either a string shorthand or an array of content blocks (text, image, document, tool\_use, tool\_result, ...).
</ParamField>

<ParamField body="messages[].role" type="string" required>
  Possible values: `user`, `assistant`
</ParamField>

<ParamField body="model" type="string">
  Anthropic model identifier (e.g. `claude-sonnet-4-5`, `claude-opus-4-7`).
</ParamField>

<ParamField body="stream" type="boolean">
  When true, the response is a `text/event-stream` of Anthropic message events instead of a single JSON body.
</ParamField>

<ParamField body="system" type="object">
  Top-level system prompt. Either a string or an array of content blocks; both reach Anthropic unchanged.
</ParamField>

Generated from the schema Router serves at `GET /v2/models/anthropic/claude-fable-5-1/openapi.json`, the same document it validates a call against before the request reaches the provider.

### Output

<ResponseField name="id" type="string" />

<ResponseField name="model" type="string" />

<ResponseField name="role" type="string" />

<ResponseField name="stop_reason" type="string" />

<ResponseField name="stop_sequence" type="string" />

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

<ResponseField name="usage" type="object">
  Token usage for an Anthropic Messages API call.
</ResponseField>

<ResponseField name="usage.cache_creation" type="object">
  Per-TTL breakdown of cache-write input tokens for an Anthropic Messages API call.
</ResponseField>

<ResponseField name="usage.cache_creation.ephemeral_1h_input_tokens" type="integer" />

<ResponseField name="usage.cache_creation.ephemeral_5m_input_tokens" type="integer" />

<ResponseField name="usage.cache_creation_input_tokens" type="integer" />

<ResponseField name="usage.cache_read_input_tokens" type="integer" />

<ResponseField name="usage.input_tokens" type="integer" />

<ResponseField name="usage.output_tokens" type="integer" />

<ResponseField name="content" type="object[]" required>
  The reply's content blocks, in order. Present on every completed message; empty when the turn produced nothing.
</ResponseField>

<ResponseField name="content[].text" type="string">
  The block's text. Present on `text` blocks and absent on every other kind.
</ResponseField>

<ResponseField name="content[].type" type="string">
  The block kind. `text` is the one that carries `text`; `thinking`, `redacted_thinking`, `tool_use`, `server_tool_use` and the tool-result blocks are the others Anthropic sends today, and the list is open.
</ResponseField>

## Examples

### Input

```json theme={null}
{
  "max_tokens": 16,
  "messages": [
    {
      "content": "Reply with the single word: ok",
      "role": "user"
    }
  ]
}
```

### Output

```json theme={null}
{
  "content": [
    {
      "text": "ok",
      "type": "text"
    }
  ],
  "id": "msg_01ExampleInvalidPlaceholder",
  "model": "claude-fable-5-1",
  "role": "assistant",
  "stop_reason": "end_turn",
  "stop_sequence": null,
  "type": "message",
  "usage": {
    "input_tokens": 16,
    "output_tokens": 3
  }
}
```

## 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>