mold

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iPhone App ​

Mold for iPhone is a first-class remote studio for a Mold server. The phone does not run AI models itself: generation, model storage, downloads, queueing, and gallery files stay on one or more remote Mold hosts while the app provides an iPhone-native control surface.

Mold requires iOS 17 or later. The current build is distributed through the project's internal TestFlight group; there is not yet a public App Store listing.

Connect a host ​

Start a reachable server on the GPU machine. Use an API key whenever the server is reachable beyond localhost:

bash
MOLD_API_KEY='choose-a-long-secret' mold serve --bind 0.0.0.0 --port 7680

Open Machines on the iPhone and use one of these paths:

  • Tap Discover nearby to browse _mold._tcp services on the current LAN. Allow Local Network access when iOS asks.
  • Enter an IP address such as 192.168.1.10. Mold adds http:// and port 7680 when they are omitted.
  • Enter a DNS hostname, HTTPS URL, or Tailscale MagicDNS name.

Paste the same API key, then tap Test and save. Saved host metadata remains in the app's local storage, while the API key is kept separately in the iOS Keychain.

Tailscale ​

Tailscale is the simplest way to reach a private GPU host away from its LAN:

  1. Join the iPhone and GPU host to the same tailnet.
  2. Keep mold serve listening on an address the Tailscale interface can reach.
  3. Add the host by its MagicDNS name, for example plato or plato.example-tailnet.ts.net. Mold supplies port 7680 for a bare name.
  4. Include https:// and an explicit port only when your own reverse proxy provides TLS.

Bonjour discovery is LAN-local; Tailscale hosts are normally added by name. Mold uses the installed Tailscale network and does not manage tailnet login, ACLs, DNS, or certificates.

Create ​

Choose a host and one of its installed generation models. The form adapts to the selected model family and uses the same request contract and model defaults as desktop. The primary controls stay on the main screen; deeper options open in a full-screen Advanced sheet, and prompt style presets compose at submit without rewriting your prompt text.

The mobile composer includes:

  • Batch 1 quick prompt expansion with undo, Batch N prepared-variation review, and remote prompt history;
  • local templates that can be saved, searched, sorted, renamed, loaded, and deleted;
  • batch generation as independent queued jobs, each with its own progress and Cancel action;
  • source images and fit policies, Qwen edit target/reference images, masks, ControlNet, LoRA stacks and trigger words;
  • scheduler, CFG++, steps, guidance, output format, and post-generation upscaling where the selected family supports them;
  • validated video frames/FPS, audio, camera motion, source media, keyframes, retake, and LTX-2 pipeline/spatial/temporal controls; and
  • a host-aware memory estimate before submission.

Choose resolution through orientation, proportionally drawn aspect-ratio tiles, a resolution tier, or explicit custom dimensions. Seed has separate Random and Fixed modes, including one-tap reuse of the last generated seed.

When several jobs are submitted, the Queue section keeps them visible while you continue composing. Mold limits simultaneous streams so generation does not starve gallery or download requests.

Batch is also the expansion count. Batch 1 freezes the selected host through the next Develop while keeping quick undo. Batch 2 or greater first requests exactly N non-empty prompts from that host and opens an inline workspace where you can edit, intentionally remove, regenerate, refresh, or discard them before anything is queued. Reducing two prompts to one requires confirmation. Changes to the source prompt, model, family, Batch count, host endpoint, Keychain key, or server identity preserve the reviewed work with a specific stale reason and block Develop until you choose Refresh or Discard.

The same frozen host is used for expansion-model pulls, source preprocessing, and every sibling. Missing-model recovery stays inline with Connecting, Starting, Queued, percentage/bytes/files/ETA Pulling, Ready, and failure or cancellation retry states. The original inputs and route remain one immutable recovery record, and an attempt lease prevents a newer Models credential from redirecting the pull. Compatible Models work already in Starting is joined; every terminal, stale, superseded, or aborted attempt releases the lease before Retry reacquires the same frozen route. Editing/removing reviewed work cancels a pending replacement. Siblings remain independently cancellable and keep deterministic seeds, the source prompt, and durable batch position through long-video chains. A partial result names each failed variation and reviewed prompt, plus any separate unconfirmed-cancellation caveat, while keeping successful prints. Library shows Batch N of M and the source prompt when that provenance is present; prints from older servers remain unchanged.

Library ​

Library merges prints from every saved host, newest first. Unavailable hosts are reported without hiding media from hosts that did respond.

Tap a tile to open the full-screen viewer:

  • images are shown uncropped;
  • videos stream from their owning host with native playback and seeking;
  • swipe left or right to move through the loaded prints; and
  • use Use as prompt to restore recorded generation settings, or Use as source to attach a still to the next compatible generation.

Reusing settings switches to the print's host and restores the model when it is installed there. If the original model is unavailable, Mold clearly identifies the compatible fallback and removes non-portable adapter/component choices.

Authenticated hosts issue a short-lived read-only media ticket for the selected file. The app never puts a long-lived API key in a video URL or buffers an entire video into phone memory.

Models ​

Models combines installed models with live Hugging Face and Civitai results. You can search, filter All/Images/Video, filter by source or family, inspect download contents and installed components, and include NSFW entries explicitly.

The host selector controls where Models browses. Pulling a model can target a different ready host without changing the host selected in Create. With more than one target available, Mold opens a host picker.

Pull buttons reflect the server state immediately:

  • Connecting... while the download event stream opens
  • Starting... while the request is accepted
  • Queued while waiting for a download slot
  • Pulling N% during transfer

Active downloads stay pinned above results and can be cancelled. Installed model details offer Load on GPU, Unload from GPU, and a guarded Remove from host action.

Host details ​

Tap a saved host to inspect its current state. The detail screen shows:

  • GPU/VRAM, CPU, and RAM telemetry;
  • free and used storage for the models filesystem;
  • queued/running generation work and loaded models;
  • queued/active model downloads with progress; and
  • the models installed on that host.

From the same screen you can rename or retry the host, select it for Create, unload a model, open it in Models, or forget it. Forgetting a host also deletes its API key from the iOS Keychain.

Settings and themes ​

Open Settings from the sliders button in the header. Mobile settings currently cover:

  • Color family: the Mold Studio theme families, Mold or Safelight
  • Appearance: System, Dark, or Light
  • Remote hosts: saved-host count and a shortcut to manage them
  • About: app version, remote-only processing, and TestFlight updates

Fresh installs start with the Safelight color family and System appearance. Existing users keep any valid Mold or Safelight choice they already saved.

The appearance choice updates both the WebView and native iOS system chrome so status-bar content remains readable. Themes change the app chrome but never recolor generated photos or videos.

The app intentionally prevents WebKit input-focus and double-tap page magnification and suppresses rubber-band scrolling. The Library's horizontal swipe navigation remains enabled. iOS system-level accessibility Zoom is separate from WebView page zoom.

Updates and current boundaries ​

Internal TestFlight builds are created automatically after mobile-relevant changes pass the iOS workflow on main. The pipeline validates the bundled mobile index.html, Mold icon catalog, native archive, App Store Connect processing, and internal tester access before it is considered complete.

The initial iPhone release focuses on remote Create, Library, Models, Machines, and appearance settings. Use desktop or the CLI for a local engine, the full Chains authoring/jobs workspace, RunPod provisioning, engine configuration, and desktop Stable/Nightly self-update controls.

For server networking and deployment options, continue with Remote Workflows. For supported model-family controls, see Feature Support.

Troubleshooting ​

Discovery finds nothing ​

  • Confirm Local Network access is enabled for Mold in iOS Settings.
  • Confirm the phone and host are on the same LAN; Bonjour does not browse a remote tailnet.
  • Confirm the server was not started with --no-mdns or MOLD_MDNS=0.
  • Add the IP address or Tailscale MagicDNS name manually.

The host test fails ​

  • Open http://host:7680/health from another device on the same network.
  • Confirm the server listens on 0.0.0.0, not only 127.0.0.1.
  • Check the firewall, Tailscale ACL, port, scheme, and API key.

A video will not play ​

Update the remote Mold host. Current authenticated video playback needs the short-lived gallery media-ticket endpoint so iOS can make native Range requests without exposing the API key.