Generating Images

The web Create composer shows an advisory peak-VRAM estimate for the selected machine before you submit. Video models expose their supported camera-motion controls under Advanced, and a durable sequence remains attached after a page reload so its server-side progress does not disappear from the workspace. Setting Output to Sequence filters the model picker to compatible installed video checkpoints and selects one when possible, remembering your one-shot model for the way back. If none are installed, Browse video models opens Models → Discover with the Video and Models filters already applied. Two-stage LTX-2 dev checkpoints render single clips; multi-stage sequences require a distilled or one-stage checkpoint.

On phone-sized web views, Create keeps every interactive target at least 44px high and editable fields at a zoom-safe 16px.

While a print renders, the web canvas develops it live: for families that stream latent previews (FLUX.1, Flux.2, Z-Image) the forming image appears under the film-grain wash, its blur tightening step by step while the grain thins away, on a bed matching the print's aspect ratio. The progress ring and stage line cover the bed only until the first preview arrives. Once a run completes, the Seed section offers lock last (seed) to pin that print's seed for the next generate.

Basic Usage

# Default model (flux2-klein:q8 — fast 4-step, Apache 2.0, fully ungated)
mold run "a red apple on a wooden table"

# Explicit model selection
mold run flux-dev:q4 "a photorealistic landscape at golden hour"

# Custom output path
mold run "cyberpunk cityscape" -o cityscape.png

# Reproducible output (same seed = same image)
mold run "a cat" --seed 42

# Custom dimensions (multiples of 16)
# See each model's recommended dimensions to avoid warnings
mold run "a banner" --width 1024 --height 512

# Batch generation (multiple images with incrementing seeds)
mold run "abstract art" --batch 4 --seed 100

# JPEG output
mold run "a sunset" --format jpeg -o sunset.jpg

Here's what that looks like — FLUX Schnell Q8, seed 42:

Need a quick answer on family capabilities or expected speed? See Feature Support and Performance.

Recommended Dimensions

Each model family has a set of recommended dimensions that produce the best results. Using non-recommended dimensions will trigger a warning (generation still proceeds). All dimensions must be multiples of 16.

# Square (works with all families)
mold run "a cat" --width 1024 --height 1024

# Landscape (FLUX, Flux.2 Klein)
mold run flux2-klein "a panorama" --width 1024 --height 576

# Portrait (SDXL, SD 3.5, Qwen-Image)
mold run sdxl-turbo "a portrait" --width 832 --height 1216

See each model family page for the full list of recommended dimensions and aspect ratios.

Image Editing

qwen-image-edit-2511:* is a distinct edit family, not standard img2img. It uses one or more ordered --image inputs, supports negative prompts, and derives default output dimensions from the first input image when you omit --width and --height.

# Single-image edit
mold run qwen-image-edit-2511:q4 \
  --image ./chair.png \
  "turn this fabric chair into dark red leather"

# Multi-image edit
mold run qwen-image-edit-2511:q4 \
  --image ./chair.png \
  --image ./swatch.png \
  "make Picture 1 match the leather color and finish from Picture 2"

Use regular img2img families when you need --strength-based denoising. Use qwen-image-edit when you want instruction-following edits against one or more reference images.

In Mold Studio's web Create workspace, open Advanced → Edit images to attach the ordered target and reference images. Ordinary source-image families instead show denoise strength plus all five fit policies; SD1.5 also suggests installed ControlNet checkpoints while allowing a custom checkpoint name.

On a phone, Create follows one vertical workflow: prompt and style, model and core controls, Generate, the developing/result canvas, then recent prints. Advanced options remain in the mobile sheet so the primary flow stays compact.

For a multi-prompt video, set Output — the control beside Model in the Create settings column — from One shot to Sequence. Multi-clip video is a setting, not a separate page: the composer becomes a clip rail. Mold starts with two clips, requires a description for each, and joins them with seam pills that name each transition in words — Smooth, Cut, or Fade 8f, with LTX-Video's zero-overlap joins reading Join. Clicking a seam pill opens the seam editor with its three teaching rows and the fade-length stepper. New clips take their frame count from the selected model's own advertised default rather than a fixed constant, and the summary shows the stitched duration before you generate. Switching Output back to One shot keeps clip 1 as the prompt and parks the rest — nothing is erased. Sequence tools contains TOML import/export and other script-oriented controls. On a multi-machine web setup, the durable job and its live progress stay on the machine selected by Run on.

Sequences queue in the same activity strip as ordinary prints, with watch, cancel, and resume. Once one settles it leaves the strip: the video lands in the Create canvas with Edit sequence and Show in library, its print is in the Library, and its job record is in Library ▸ History ▸ Sequences — which is also where the host-scoped Clear inactive and Clean up disk actions live.

A finished sequence can be edited in place. Its clips reload onto the rail and each pill shows whether that clip is cached (✓) or will re-render (↻) as you edit; Update sequence re-renders only from the earliest changed clip. Changing a transition type or a fade length re-renders nothing at all — those are applied when the video is stitched. From a sequence print in the Library, Edit sequence is the primary action and re-enters the original job on the machine that produced it so rendered clips stay cached. Duplicate as new starts a fresh sequence from the recorded clips, telling you how many it restored and naming anything a print does not record.

On every surface, a ↺ Reset in the Create settings header restores the generation settings to the selected model's defaults — shape, resolution, detail, prompt strength, seed, and the Advanced groups — while keeping your prompt, model choice, and batch. On the web it is undoable from the toast it raises.

Video Generation

mold supports text-to-video generation with the LTX Video model family. Video output defaults to APNG, with GIF, WebP, and MP4 also supported.

# Generate a 25-frame video clip with the fast distilled path
mold run ltx-video-0.9.6-distilled:bf16 "A cat walking across a sunlit windowsill"

# Custom frame count (must be 8n+1: 9, 17, 25, 33, 49, 97, ...)
mold run ltx-video-0.9.8-2b-distilled:bf16 "Ocean waves at sunset" --frames 33

# Custom FPS (current LTX defaults use 30 FPS)
mold run ltx-video-0.9.6:bf16 "A timelapse of clouds" --frames 49 --fps 30

# Pipe to a video player
mold run ltx-video-0.9.6-distilled:bf16 "A robot dancing" | mpv -

# Direct MP4 output
mold run ltx-video-0.9.6-distilled:bf16 "A waterfall" --format mp4 -o waterfall.mp4

ltx-video-0.9.6-distilled:bf16 is the recommended default today. The 0.9.8 family is also supported end to end: mold pulls the required spatial upscaler asset, runs the full multiscale refinement path, and keeps the current compatible VAE on the published LTX-Video-0.9.5 source until the newer VAE layout is ported.

Frame count constraint

LTX Video requires frame counts of the form 8n+1 (9, 17, 25, 33, 49, 97, etc.) due to the VAE's 8x temporal compression. mold will reject invalid counts with a helpful error message.

VRAM usage

LTX Video uses sequential load-use-drop to manage VRAM: T5 encoder loads first, then drops before the transformer loads, then the transformer drops before VAE decode. Peak VRAM depends heavily on the selected LTX checkpoint.

Video dimensions must be multiples of 32 (not 16 like images). Current LTX defaults use 1216×704 at 30 FPS.

Joint Audio-Video Generation

LTX-2 / LTX-2.3 is exposed as a separate ltx2 family. Unlike ltx-video, its default container is MP4 and it can keep a synchronized audio track when the request stays in MP4.

# Text-to-audio+video
mold run ltx-2-19b-distilled:fp8 \
  "a toy train rolling through a snowy diorama, gentle mechanical hum" \
  --frames 97 \
  --format mp4

# Audio-to-video
mold run ltx-2-19b-distilled:fp8 \
  "abstract paper sculpture reacting to a cello performance" \
  --audio-file ./cello.wav

# Keyframe interpolation
mold run ltx-2-19b-distilled:fp8 \
  "a drone shot over a canyon river" \
  --pipeline keyframe \
  --frames 97 \
  --keyframe 0:./start.png \
  --keyframe 96:./end.png

LTX-2 also adds:

• --audio / --no-audio
• --audio-file
• --video
• repeatable --keyframe <frame:path>
• --pipeline one-stage|two-stage|two-stage-hq|distilled|ic-lora|keyframe|a2vid|retake
• --retake <start:end>
• repeatable --lora
• --camera-control <preset-or-path>
• --spatial-upscale <x1.5|x2>
• --temporal-upscale x2

Catalog checkpoints may contain the LTX-2 transformer without vae.* weights. mold pull cv:<id> detects that layout and fetches the matching LTX-2 or LTX-2.3 video VAE automatically. Diffusion-only LTX-2.3 exports also fetch the separate Gemma hidden-state projection. The resolved assets are pinned in each chain stage, so multi-prompt chains do not fall back to the transformer file. ConvRot W4A4 exports use automatic full block streaming because their packed on-disk byte size understates the BF16 weights reconstructed by the runtime. If the Gemma prompt encoder exhausts VRAM, Mold retries only Gemma on CPU while keeping the transformer and video VAE on CUDA. Multi-prompt chains support both one-stage and distilled LTX-2 checkpoints; multi-pass and specialized conditioning pipelines remain explicit non-chain modes. Mold checks this before creating a durable job and keeps server, stage, cancel, resume, and retake errors visible on the job card.

Some community checkpoints contain only the video transformer (plus Mold's separate video VAE) and do not include the audio VAE or vocoder. Mold detects this from the installed safetensors and disables Generate audio in web, desktop, and iPhone while leaving text/image-to-video available. CLI users can pass --no-audio; an explicit unsupported audio request is rejected before prompt encoding or denoising.

The native CUDA matrix is validated across 19B/22B text+audio-video, image-to-video, audio-to-video, keyframe, retake, public IC-LoRA, spatial upscale, and temporal upscale workflows.

Backend policy

LTX-2 now runs natively in Rust inside mold-inference. CUDA is the supported backend for real local generation, CPU is correctness-only, and Metal is unsupported for this family.

Negative Prompts

Guide what the model should avoid. Works with CFG-based models (SD1.5, SDXL, SD3, Wuerstchen, Qwen-Image, Qwen-Image-Edit); ignored by FLUX, Z-Image, and Flux.2 Klein.

mold run sd15:fp16 "a portrait" -n "blurry, watermark, ugly, bad anatomy"
mold run sdxl:fp16 "a landscape" --negative-prompt "low quality, jpeg artifacts"

# Suppress config default
mold run sd15:fp16 "a cat" --no-negative

Precedence: CLI --negative-prompt > per-model config > global config > empty.

Scheduler Selection

Choose the noise scheduler for SD1.5/SDXL models:

mold run sd15:fp16 "a cat" --scheduler uni-pc         # Fast convergence
mold run sd15:fp16 "a cat" --scheduler euler-ancestral # Stochastic

LoRA Adapters

Apply fine-tuned style adapters across the supported families — FLUX, Flux.2, LTX-2, SD1.5, SD3, SDXL, Qwen-Image (+ Qwen-Image-Edit), Z-Image:

# Basic LoRA (FLUX example)
mold run flux-dev:bf16 "a portrait" --lora style.safetensors

# Adjust strength (0.0 = no effect, 1.0 = full, up to 2.0)
mold run flux-dev:bf16 "anime style" --lora style.safetensors --lora-scale 0.7

# Works with quantized models too
mold run flux-dev:q4 "a portrait" --lora style.safetensors --lora-scale 0.8

# Same flag syntax across families
mold run sdxl:fp16    "a sunset" --lora sdxl-style.safetensors
mold run z-image:bf16 "anime"    --lora cv:2904324

LoRA requirements

Requires .safetensors format. Z-Image / FLUX accept diffusers (PEFT canonical), Kohya/sd-scripts, OneTrainer, and PEFT default-adapter naming. BF16 FLUX on 24 GB cards can adaptive-offload, keeping fitting blocks on GPU and streaming only overflow blocks; LTX-2 can use the conservative full-streaming offload path. Wuerstchen and legacy LTX-Video are not yet wired — attaching a LoRA there returns a 400 with the supported-family list.

Inline Preview

Display generated images in the terminal:

mold run "a cat" --preview

Requires the preview feature at build time. Auto-detects Kitty graphics, iTerm2, Sixel, or Unicode half-block fallback.

Set MOLD_PREVIEW=1 to enable permanently.

PNG Metadata

Generated PNGs embed prompt, model, seed, size, steps, and a mold:parameters JSON chunk by default. Disable with:

mold run "a cat" --no-metadata
# or globally
MOLD_EMBED_METADATA=0 mold run "a cat"

Piping

mold is pipe-friendly in both directions. When stdout is not a terminal, raw image bytes go to stdout and status goes to stderr.

# Pipe output to an image viewer
mold run "neon cityscape" | viu -

# Pipe prompt from stdin
echo "a cat riding a motorcycle" | mold run flux2-klein

# Full pipeline
echo "cyberpunk samurai" | mold run flux-dev:q4 | viu -

# Force stdout in interactive mode
mold run "a cat" --output -

Inference Modes

1. Remote (default) — connects to mold serve via HTTP
2. Local fallback — if server unreachable, auto-falls back to local GPU
3. Local forced (--local) — skip server, run on local GPU directly

Models auto-pull if not downloaded.

Browser UI

mold serve ships with a Vue 3 SPA baked into the binary. Visit http://<host>:7680/ to open the Create composer. The canonical routes are /create, /library, /models, /machines, and /settings; retired paths such as /generate and /catalog render Page Not Found:

• The model selector shows human-readable catalog names while preserving cv: / hf: identifiers internally for requests.
• Enter submits, Shift+Enter inserts a newline, empty Enter is a no-op.
• Per-GPU running-job cards stream SSE progress (stage, denoise step N/M, VAE decode) and tag the finished image with the GPU ordinal that produced it.
• Fire multiple prompts in quick succession; the server queues them and the UI surfaces HTTP 503 / Retry-After cleanly when --queue-size is reached.
• img2img works via upload or the From Gallery picker; video-family models are grouped with a 🎬 badge and frames are clamped to 8n+1 automatically.
• Library's print viewer keeps media bound to its owning host, restores the saved model family on Reuse settings (a print a sequence produced reloads its clips onto the Create clip rail instead, with Edit sequence offered when its durable job still exists on the machine that made it), and shows the recorded steps, guidance, scheduler, LoRAs, prompts, file details, and copyable prompt/seed. Upscale... returns the print to Create with the installed default upscaler selected.
• Prompt expansion modal offers live preview + variation picker (requires qwen3-expand installed on the server).
• Prompt, model, size, steps, guidance, and batch persist in localStorage.
• Modal and sheet workflows contain keyboard focus, lock background scrolling, close on Escape, and restore focus to the control that opened them. The Templates popover also dismisses on Escape or an outside click.