Configuration reference

Backend environment variables (set before starting wl.serve())

Variable	Default	Description
WEIGHTSLAB_LOG_LEVEL	INFO	Log level (DEBUG, INFO, …)
GRPC_BACKEND_HOST	0.0.0.0	Host the backend gRPC server binds to
GRPC_BACKEND_PORT	50051	Port the backend gRPC server listens on
GRPC_TLS_ENABLED	0	1 = enable TLS on the gRPC socket
GRPC_TLS_REQUIRE_CLIENT_AUTH	0	1 = require client mTLS certificate
WEIGHTSLAB_CERTS_DIR	~/.weightslab-certs	Directory containing cert/key files
GRPC_AUTH_TOKEN	(unset)	Optional metadata-token auth (on top of mTLS)
GRPC_MAX_MESSAGE_BYTES	268435456	Raise for large tensors / image batches
WEIGHTSLAB_DISABLE_WATCHDOGS	0	1 = disable watchdogs (use with breakpoints)

UI server environment variables (set before weightslab start)

Variable	Default	Description
WEIGHTSLAB_UI_HOST	0.0.0.0	Interface the UI server binds to
WEIGHTSLAB_UI_PORT	8080	HTTP port (--port flag overrides)
GRPC_BACKEND_HOST	localhost	Backend gRPC host to proxy to
GRPC_BACKEND_PORT	50051	Backend gRPC port to proxy to
WEIGHTSLAB_CERTS_DIR	~/.weightslab-certs	Certs dir (read when --certs)
WEIGHTSLAB_OPENCODE_PORT | 4096		Port the agent (OpenCode) server is started on; falls back to a free port if taken
OPENCODE_URL	(unset)	Adopt an already-running agent server instead of spawning one (shared with the SDK agent)

Frontend runtime feature toggles

These are injected as window.* globals when the UI is served. Set them as environment variables before weightslab start.

Variable	Default	Effect when 0 / false
ENABLE_PLOTS	1	Remove plots board + Signals card
ENABLE_DATA_EXPLORATION	1	Remove data grid + metadata/details panel
ENABLE_HYPERPARAMETERS_OPTIMIZATION | 1		Remove Hyperparameters section (read-only HPs)
ENABLE_AGENT	1	Remove agent chat bar
WS_HISTOGRAM_MAX_BINS	512	Cap on metadata histogram bars
BB_THUMB_RENDER	10	Max bounding boxes per thumbnail (per overlay)
BB_MODAL_RENDER	100	Max bounding boxes per modal image (per overlay)