Use Claude Sonnet 4.5 20250929 with Comfy Router

API Reference for anthropic/claude-sonnet-4-5-20250929, served by Comfy Router from Anthropic.

Quick start

Create a key at 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-sonnet-4-5-20250929 Endpoint: POST https://api.comfy.org/v2/models/anthropic/claude-sonnet-4-5-20250929

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-sonnet-4-5-20250929",
        {
            # Request fields are the provider's own — see Input below.
        },
    )

print(result)

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-sonnet-4-5-20250929", {
  // Request fields are the provider's own — see Input below.
});

console.log(data);

# Request fields are the provider's own — see Input below.
curl https://api.comfy.org/v2/models/anthropic/claude-sonnet-4-5-20250929 \
  -H "X-API-Key: $COMFY_API_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{}'

Schema

Input

Router has not published an authored input schema for this model yet: GET /v2/models/anthropic/claude-sonnet-4-5-20250929/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 is authoritative for the request fields, and nothing is validated server side.

Output

string

object

Token usage for an Anthropic Messages API call.

object

Per-TTL breakdown of cache-write input tokens for an Anthropic Messages API call.

integer

object[]

required

The reply’s content blocks, in order. Present on every completed message; empty when the turn produced nothing.

string

The block’s text. Present on text blocks and absent on every other kind.

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.

Examples

Output

{
  "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 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.

Headers

Authentication, idempotency, request IDs, error buckets, retry pacing, spend limits.

Quick Start

Typed error handling in Python and TypeScript, reading the 422, walking the catalog.

Limitations

What Router does not do today, and what to use instead.

Develop with Comfy

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Specifications

Use Claude Sonnet 4.5 20250929 with Comfy Router

Quick start

Schema

Input

Output

Examples

Output

Before you ship

Headers

Quick Start

Limitations

​Quick start

​Schema

​Input

​Output

​Examples

​Output

​Before you ship

Headers

Quick Start

Limitations

Quick start

Schema

Input

Output

Examples

Output

Before you ship