Configuration

mold looks for config.toml inside the base mold directory (~/.mold/ by default, or override with MOLD_HOME).

Config File

default_model = "flux2-klein:q8"
models_dir = "~/.mold/models"
server_port = 7680
default_width = 1024
default_height = 1024

# Global default negative prompt (CFG models only)
# default_negative_prompt = "low quality, worst quality, blurry, watermark"

[models."flux-dev:bf16"]
default_steps = 25
default_guidance = 3.5
# lora = "/path/to/adapter.safetensors"
# lora_scale = 0.8

[models."sd15:fp16"]
default_steps = 25
default_guidance = 7.5
negative_prompt = "worst quality, low quality, bad anatomy"

[expand]
enabled = false
backend = "local"
model = "qwen3-expand:q8"
temperature = 0.7

# Per-family expansion tuning
# [expand.families.sd15]
# word_limit = 50
# style_notes = "Short keyword phrases for CLIP-L."

# [expand.families.flux]
# word_limit = 200
# style_notes = "Rich natural language descriptions."

Environment Variables

Environment variables take precedence over config file values.

Core

Variable	Default	Description
MOLD_HOME	~/.mold	Base directory for config and cache
MOLD_DEFAULT_MODEL	flux2-klein	Default model name
MOLD_HOST	http://localhost:7680	Remote server URL
MOLD_MODELS_DIR	$MOLD_HOME/models	Model storage directory
MOLD_PORT	7680	Server port
MOLD_LOG	warn / info	Log level

Generation

Variable	Default	Description
MOLD_EAGER	—	1 to keep all components loaded
MOLD_OFFLOAD	—	1 to force CPU↔GPU block streaming
MOLD_EMBED_METADATA	1	0 to disable PNG metadata
MOLD_PREVIEW	—	1 to display images inline in terminal
MOLD_T5_VARIANT	auto	T5 encoder: auto/fp16/q8/q6/q5/q4/q3
MOLD_QWEN3_VARIANT	auto	Qwen3 encoder: auto/bf16/q8/q6/iq4/q3
MOLD_SCHEDULER	—	SD1.5/SDXL: ddim/euler-ancestral/uni-pc

Prompt Expansion

Variable	Default	Description
MOLD_EXPAND	—	1 to enable expansion
MOLD_EXPAND_BACKEND	local	local or OpenAI-compatible URL
MOLD_EXPAND_MODEL	qwen3-expand:q8	LLM model for expansion
MOLD_EXPAND_TEMPERATURE	0.7	Sampling temperature
MOLD_EXPAND_THINKING	—	1 to enable thinking mode
MOLD_EXPAND_SYSTEM_PROMPT	—	Custom system prompt template
MOLD_EXPAND_BATCH_PROMPT	—	Custom batch prompt template

Server

Variable	Default	Description
MOLD_OUTPUT_DIR	~/.mold/output	Image output directory (set empty to disable)
MOLD_CORS_ORIGIN	—	Restrict CORS to specific origin

Auth

Variable	Default	Description
HF_TOKEN	—	HuggingFace token for gated models

Advanced

Device and Path Overrides

Variable	Default	Description
MOLD_DEVICE	—	Force device placement, currently cpu for debugging
MOLD_TRANSFORMER_PATH	—	Override transformer weights path
MOLD_VAE_PATH	—	Override VAE weights path
MOLD_T5_PATH	—	Override T5 encoder path
MOLD_CLIP_PATH	—	Override CLIP-L encoder path
MOLD_CLIP2_PATH	—	Override CLIP-G encoder path for SDXL
MOLD_T5_TOKENIZER_PATH	—	Override T5 tokenizer path
MOLD_CLIP_TOKENIZER_PATH	—	Override CLIP-L tokenizer path
MOLD_CLIP2_TOKENIZER_PATH	—	Override CLIP-G tokenizer path for SDXL
MOLD_TEXT_TOKENIZER_PATH	—	Override generic text tokenizer path for Qwen/Z-Image
MOLD_DECODER_PATH	—	Override Wuerstchen decoder weights path

These are mainly useful for custom local model layouts, manual debugging, or testing alternative weight files without editing config.toml.

Debug and Family-Specific Knobs

Variable	Default	Description
MOLD_SD3_DEBUG	—	Enable verbose SD3.5 pipeline logging
MOLD_QWEN_DEBUG	—	Enable verbose Qwen-Image pipeline logging
MOLD_WUERSTCHEN_DEBUG	—	Enable verbose Wuerstchen pipeline logging
MOLD_WUERSTCHEN_DECODER_GUIDANCE	0.0	Override decoder-stage CFG guidance for Wuerstchen

These are intended for troubleshooting and development rather than normal use.