Use FLUX 2 Pro with Comfy Router - ComfyUI

Use bfl/flux-2-pro with the Comfy Router API. Black Forest Labs 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: bfl/flux-2-pro Endpoint: POST https://api.comfy.org/v2/models/bfl/flux-2-pro

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(
        "bfl/flux-2-pro",
        {
            # 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("bfl/flux-2-pro", {
  // 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/bfl/flux-2-pro \
  -H "X-API-Key: $COMFY_API_KEY" \
  -H "Idempotency-Key: $ROUTER_REQUEST_KEY" \
  -H "Content-Type: application/json" \
  -d '{}'

Schema

Input

integer

default:"1024"

Height of the image.Range: 256 to 2048

string

Base64 encoded image for image-to-image generation.

string

Base64 encoded image for image-to-image generation.

string

Base64 encoded image for image-to-image generation.

string

Base64 encoded image for image-to-image generation.

string

Base64 encoded image for image-to-image generation.

string

Base64 encoded image for image-to-image generation.

string

Base64 encoded image for image-to-image generation.

string

Base64 encoded image for image-to-image generation.

string

Base64 encoded image for image-to-image generation.

string

default:"\"jpeg\""

Output format for the generated image.Possible values: jpeg, png

string

required

Text description of the image to generate.

boolean

default:"true"

Automatically modify prompt for generation.

integer

default:"2"

Moderation tolerance level (Flux 2 Max only).Range: 0 to 5

integer

Seed for reproducibility.

integer

default:"1024"

Width of the image.Range: 256 to 2048

Generated from the schema Router serves at GET /v2/models/bfl/flux-2-pro/openapi.json, the same document it validates a call against before the request reaches the provider.

Output

number

Provider-reported cost in credits, populated once the task is Ready.Format: float

string

required

BFL task identifier.

number

Optional generation progress reported by BFL.Range: 0 to 1Format: float

object

required

The finished generation. Not nullable here: this component’s required entry is a promise that a 200 carries the result, and a nullable result would reduce it to a key-presence check.

number

Provider-reported cost of the generation. This is BFL’s number, not the Comfy charge.Format: double

number

Provider-reported generation duration in seconds.Format: double

number

Provider-reported completion time of the generation, in seconds since the Unix epoch. double for the same reason as start_time.Format: double

string

The prompt the generation actually ran, after any prompt upsampling.

string (uri)

Signed URL for the generated asset. Router re-hosts the asset onto Comfy storage and rewrites this field, so it is normally a Comfy-hosted URL valid for up to 24 hours - signed for 24 hours when minted, and replayed from a 23-hour memo, so a later poll can hand back one with as little as an hour left; a leaf whose re-host could not be performed keeps BFL’s own short-lived delivery URL instead - roughly two hours for video, roughly ten minutes for images. Either way the link expires, so download the asset rather than storing the URL.Format: uri

integer

The seed the generation used, whether supplied or chosen by the provider. Declared int64 because BFL returns seeds above 2^31 (e.g. 2784347701), which an unformatted integer generates as a 32-bit field in many SDK generators.Format: int64

number

Provider-reported start time of the generation, in seconds since the Unix epoch. double, not float: float32 spacing near a present-day epoch value is ~128 seconds, which collapses a whole generation’s span to a single decoded value.Format: double

string

required

Task status: Pending, Reasoning, Generating, Ready, Request Moderated, Content Moderated, Error, or Task not found.

Examples

Input

{
  "prompt": "A single red maple leaf on a plain white background."
}

Output

{
  "cost": null,
  "id": "b2e0c1a4-0f2f-4a55-9f2e-2f9a1c0d4e77",
  "progress": null,
  "result": {
    "cost": null,
    "duration": 3.4,
    "end_time": 1767225603.4,
    "prompt": "A watercolor painting of a lighthouse at dawn, soft light on the water",
    "sample": "https://example.invalid/bfl/flux-pro-1.1/sample.png",
    "seed": 2784347701,
    "start_time": 1767225600
  },
  "status": "Ready"
}

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.