Use Gen 4 Image with Comfy Router

Use runway/gen4_image with the Comfy Router API. Runway 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 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: runway/gen4_image Endpoint: POST https://api.comfy.org/v2/models/runway/gen4_image

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(
        "runway/gen4_image",
        {
            # Request fields are the provider's own — see Input below.
        },
        idempotency_key=idempotency_key,
    )

print(result)

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("runway/gen4_image", {
  // Request fields are the provider's own — see Input below.
}, { idempotencyKey });

console.log(data);

# 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/runway/gen4_image \
  -H "X-API-Key: $COMFY_API_KEY" \
  -H "Idempotency-Key: $ROUTER_REQUEST_KEY" \
  -H "Content-Type: application/json" \
  -d '{}'

Schema

Input

Router has not published an authored input schema for this model yet: GET /v2/models/runway/gen4_image/openapi.json returns an open object with x-comfy-input-schema-authored: false. Router forwards the body to Runway unchanged, so Runway’s own API reference is authoritative for the request fields, and nothing is validated server side.

Output

string (date-time)

required

Task creation timestampFormat: date-time

string

required

Task ID

string[]

The finished generation’s asset URLs — for runway/gen4_image each element is an IMAGE URL. Present once the task terminates successfully; this list IS the result.

number

Float value between 0 and 1 representing the progress of the task. Only available if status is RUNNING.Range: 0 to 1Format: float

string

required

Possible statuses for a Runway task.Possible values: SUCCEEDED, RUNNING, FAILED, PENDING, CANCELLED, THROTTLED

Examples

Output

{
  "createdAt": "2027-01-01T00:00:00Z",
  "id": "5f7c1b28-9a03-4e61-8d2f-1b2c3d4e5f60",
  "output": [
    "https://example.invalid/runway/gen4_image/generated.png"
  ],
  "status": "SUCCEEDED"
}

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.

Headers

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

Using the Router API

Find models, inspect schemas, and retry safely.

Limitations

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

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Specifications

Use Gen 4 Image with Comfy Router

Quick start

Schema

Input

Output

Examples

Output

Before you ship

Headers

Using the Router API

Limitations

​Quick start

​Schema

​Input

​Output

​Examples

​Output

​Before you ship

Headers

Using the Router API

Limitations

Quick start

Schema

Input

Output

Examples

Output

Before you ship