Phantasos — Operator Manual

Sovereign AI image generation. Type a prompt, get a 1024² render on canvas. A module of the Livyatan Design Suite; licensed PolyForm Small Business. Everything runs on the machine Phantasos is launched on — no network, no remote host, no account.

Hardware

Needs a real GPU. The backend is stable-diffusion.cpp's Vulkan build, so it runs on any GPU that backend supports (AMD, Intel, NVIDIA) — not tied to one vendor.

Measured floor (NVIDIA T1000 8GB, FLUX.1 Schnell q4, 1024×1024, 4 steps): first render ~6.5 min including model load, ~5 min per render after — sampling is ~4.5 min of that. The card must be otherwise free: the diffusion weights alone are 6.9GB, so 8GB is the working minimum. Text encoding runs on the CPU and VAE decode is tiled by default, which is what makes 8GB cards work at all; bigger cards pay a few seconds for the same defaults. FLUX.2 dev wants more headroom and patience — it renders one-shot with CPU offload and takes minutes even on large cards.

Quickstart

sudo apt install ./phantasos_<version>_amd64.deb
phantasos

1. Build stable-diffusion.cpp (Vulkan backend) and put sd-server/sd-cli on your PATH — or set PHANTASOS_SD_DIR to the directory holding them.
2. Get weights (FLUX.1 Schnell — Apache-2.0 — and optionally FLUX.2 dev) into PHANTASOS_MODEL_DIR, default ~/.local/share/phantasos/models. Weights are licensed by their publishers, not by this tool — check their terms (FLUX.2 dev carries Black Forest Labs' non-commercial license).
3. Run phantasos. Type a prompt, press Shape (or Enter). First render pays the model load; after that it's resident and stays fast.
4. The render fills the canvas and joins the folio strip on the right. Open in gimp (or whatever's current) hands the full-res PNG to an editor; swap cycles editors; Fit to monitor opens a monitor-sized copy.

Headless, same pipeline (prints the output path; --seed makes it reproducible):

phantasos shape "a lighthouse at dusk" out.png
phantasos shape "a lighthouse at dusk" out.png --model flux2dev --seed 42

Other suite modules use this seam too: GilgaMESH's words mode and Kish's folio plates render through phantasos shape when it's on your PATH.

What it is

A standalone Rust app — one window, one binary. It is the image half of "image + report": Phantasos makes the picture, Kish makes the report. It made every Livyatan module splash and the LIVYATAN masthead.

No web tech. No Python UI. One binary, one window, your own GPU.

Features

• Canvas + folio — big canvas shows the latest render; every render joins the folio (thumbnail strip, newest on top). Click a thumbnail to bring it back.
• Model picker — Model: button cycles the two offered models, persisted to ~/.config/phantasos/model:
  • Schnell (FLUX.1 Schnell, Apache-2.0) — 4 steps, fast. Resident: stays loaded between renders.
  • FLUX.2 dev — 20 steps, higher quality. Non-resident, one-shot (slow by design).
• Local execution only — the resident model runs behind a local sd-server Phantasos starts and keeps warm on loopback; the non-resident model runs one-shot via a local sd-cli call. No network calls leave the machine.
• Open in… — hands the current render to gimp/krita/inkscape/gthumb/eog/feh/nomacs; first installed wins, swap cycles, choice persisted to ~/.config/phantasos/editor.
• Fit to monitor — native Lanczos resize to the monitor the window is on (up or down), then opens the copy in the editor.

Using it

• Render: pick a model, type, Shape. The hourglass takes the canvas while the render runs, its sand paced to the learned time for your machine; the status line says what's happening, then the image lands.
• Cold start: first render after Phantasos starts or a model switch blocks while it loads the model (idempotent — a no-op if that model is already resident, otherwise it swaps servers and waits for "listening on" or fails loud).
• Model switch: cycling the Model button is free; the load cost is paid on the next Shape.
• Revisit: click any folio thumbnail — canvas swaps back, Open/Fit act on it.
• Files: everything is a plain PNG in PHANTASOS_OUT_DIR (default ~/Phantasos).

Known limits

• Fixed 1024² and fixed steps — steps/size control is the next small add.
• FLUX.2 dev is slow one-shot by design — its long CPU-offload first step outlasts a kept-open server connection, so it can't ride the resident path.
• Cold-start tax — first render after Phantasos starts or a model switch pays the full model load from disk. Every fresh launch reloads on first render.
• No negative prompt; no seed field in the window — window renders are random-seed today (headless phantasos shape --seed is reproducible).
• Chroma1-HD and FLUX.1 dev aren't offered — both weave a cross-hatch artifact on constrained-VRAM Vulkan paths across every setting tried.

Queued

• Steps/size control in the prompt row.
• Seed field in the window; negative prompt.
• Progress feedback during long shapes.