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

# Use Claude Fable 5 with Comfy Router

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

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

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

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

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

  # Reads COMFY_API_KEY from the environment. Each call sends a fresh
  # Idempotency-Key and waits up to 10 minutes for the finished result.
  with Comfy() as client:
      result = client.models.run(
          "anthropic/claude-fable-5",
          {
              # Request fields are the provider's own — see Input below.
          },
      )

  print(result)
  ```

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

  // Reads COMFY_API_KEY from the environment. Each call sends a fresh
  // Idempotency-Key and waits up to 10 minutes for the finished result.
  const { data } = await comfy.models.run("anthropic/claude-fable-5", {
    // Request fields are the provider's own — see Input below.
  });

  console.log(data);
  ```

  ```bash cURL theme={null}
  # Request fields are the provider's own — see Input below.
  curl https://api.comfy.org/v2/models/anthropic/claude-fable-5 \
    -H "X-API-Key: $COMFY_API_KEY" \
    -H "Idempotency-Key: $(uuidgen)" \
    -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/anthropic/claude-fable-5/openapi.json` returns an open object with `x-comfy-input-schema-authored: false`. Router forwards the body to Anthropic unchanged, so [Anthropic's own API reference](https://docs.claude.com/en/api/messages) is authoritative for the request fields, and nothing is validated server side.
</Note>

### 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

### Output

```json theme={null}
{
  "content": [
    {
      "text": "ok",
      "type": "text"
    }
  ],
  "id": "msg_01ExampleInvalidPlaceholder",
  "model": "claude-haiku-4-5-20251001",
  "role": "assistant",
  "stop_reason": "end_turn",
  "stop_sequence": null,
  "type": "message",
  "usage": {
    "input_tokens": 16,
    "output_tokens": 3
  }
}
```

## Before you ship

The snippets above are the shortest working call. Three things are the same for every model and are documented once on the [Comfy Router headers](/development/comfy-router/headers) page: send an `Idempotency-Key` on every paid call and reuse it when you retry, expect the connection to be held up to Router's 10 minute deadline, and keep `X-Comfy-Request-Id` from every response. The SDKs do all three for you; the cURL tab does none of them. On failure, `X-Comfy-Error-Type` names the bucket, and a `422` means the body failed the model's schema and was never billed.

<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="Quick Start" icon="rocket" href="/development/comfy-router/quickstart">
    Typed error handling in Python and TypeScript, reading the 422, walking the catalog.
  </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>