FLUX 3 ComfyUI

ComfyUI custom nodes for the FLUX 3 API, delivered through Muapi.

The pack follows the focused Muapi workflow pattern used by MiniMax H3 ComfyUI: add one API Key node, connect it to a generation node, then save or preview the returned media.

Muapi currently lists the five FLUX 3 routes as coming soon/early access. The nodes are wired to the exact API contract so the same workflows can be used as soon as the corresponding route is enabled for your key.

📺 FLUX 3 API: Image & Video Generation from One Multimodal Model →

Included nodes

Node	What it does
FLUX 3 API Key	Stores one Muapi API key for the workflow.
FLUX 3 Text-to-Image	Generates a 1k, 2k, or 4k image from a prompt.
FLUX 3 Dev	Uses the faster, lower-cost FLUX 3 Dev image route.
FLUX 3 Image-to-Image	Edits an image using up to four references and an instruction prompt.
FLUX 3 Text-to-Video	Generates a 4–10 second video at 480p–1080p, with optional native audio.
FLUX 3 Image-to-Video	Animates one start frame into a video, with optional native audio.
FLUX 3 Save Image	Downloads a generated image into ComfyUI/output and returns an IMAGE.
FLUX 3 Save Video	Downloads a generated video into ComfyUI/output and returns decoded frames.

Installation

Copy this directory into ComfyUI/custom_nodes/flux-3-comfyui, then install the dependencies in the same Python environment ComfyUI uses:

pip install -r ComfyUI/custom_nodes/flux-3-comfyui/requirements.txt

Restart ComfyUI. The example workflows can be loaded with File → Load.

Included examples:

• FLUX3_T2I_Example.json
• FLUX3_I2I_Example.json
• FLUX3_T2V_Example.json
• FLUX3_I2V_Example.json

API key

Use the 🔑 FLUX 3 API Key node and connect its output to a generation node. Alternatively, leave the node field empty and configure one of these:

export MUAPI_API_KEY="your_muapi_key"

or:

muapi auth configure --api-key YOUR_KEY

The nodes also read ~/.muapi/config.json when it contains an api_key field. Keys are only used for requests and are not written into generated workflow files unless you explicitly save them in a node field.

Quick workflows

Text-to-image

1. Add 🔑 FLUX 3 API Key.
2. Add 🖼️ FLUX 3 Text-to-Image or ⚡ FLUX 3 Dev.
3. Choose an aspect ratio and 1k, 2k, or 4k resolution.
4. Connect image to 🖼️ FLUX 3 Save Image or ComfyUI's Preview Image node.

Image-to-image

Connect up to four Load Image → IMAGE outputs to the image_1 … image_4 inputs on 🖌️ FLUX 3 Image-to-Image. Each slot also has an image_url_N field for a hosted URL or a local file path. Connected IMAGE inputs take precedence over their URL fields.

Use an instruction-style prompt, for example:

Replace the background with a warm, softly lit studio while keeping the subject's identity, pose, and clothing unchanged.

Text-to-video

Connect 🔑 FLUX 3 API Key → 🎬 FLUX 3 Text-to-Video, choose an aspect ratio, 480p, 720p, or 1080p, a duration from 4–10 seconds, and whether to generate synchronized native audio. Connect video_url to 🎬 FLUX 3 Save Video and first_frame to Preview Image.

Image-to-video

Connect Load Image → IMAGE to 🎬 FLUX 3 Image-to-Video, or provide a hosted URL/local path in image_url. The node uploads the image when needed and sends it as the single-item images_list required by the API.

API contract

Workflow	Endpoint	Required media fields
Text-to-image	POST /api/v1/flux-3-text-to-image	prompt
Image-to-image	POST /api/v1/flux-3-image-to-image	prompt, images_list (up to 4)
FLUX 3 Dev	POST /api/v1/flux-3-dev	prompt
Text-to-video	POST /api/v1/flux-3-text-to-video	prompt
Image-to-video	POST /api/v1/flux-3-image-to-video	prompt, images_list (one image)
Poll task	GET /api/v1/predictions/{request_id}/result	—
Upload local image	POST /api/v1/upload_file	multipart file

Image routes send aspect_ratio and resolution. Video routes send aspect_ratio, resolution, duration, and generate_audio. All requests use the x-api-key header and generation is asynchronous.

For local testing against a compatible Muapi deployment, set FLUX_3_API_BASE_URL. Polling can be tuned with FLUX_3_POLL_INTERVAL and FLUX_3_MAX_WAIT.

Requirements

Python 3.8+, requests, Pillow, numpy, and opencv-python. ComfyUI supplies the installed PyTorch runtime used by IMAGE tensors. For video playback inside ComfyUI, install ComfyUI-VideoHelperSuite.

Related projects

• MiniMax H3 ComfyUI — the focused reference pack for this repository's node layout.
• Flux-3-Dev-API — Python wrapper for the FLUX 3 family through Muapi.
• Muapi API docs — FLUX 3 capabilities and availability.
• Muapi ComfyUI integration — the full multi-model node pack.

License

MIT