Image with ComfyUI

Call a user-defined ComfyUI server to generate or edit images and videos, or turn an image into a 3D mesh. Qwen-Image 2.1 Turbo (id qwen21t) is the default model for both T2I and I2I; the earlier Qwen-Image 2.1 (id qwen21, 25-step), Z-Image / SD3.5 (T2I), Qwen Image Edit 2511 (single-image edit), MiniMax H3 (I2V h3_i2v, default / T2V h3_t2v), Wan2.2 (I2V), and Pixal3D / Trellis2 (I2M, default image → 3D GLB) are available. The older Hunyuan 3D v2.1 (I2M) is still available under the hyi2m entry point. If no ComfyUI server is reachable, the script exits with setup instructions — that is an environment/ops issue, not something to solve with your own requests (see README.md).

• T2I (Text → Image) → Qwen-Image 2.1 Turbo (qwen21t, default) or Qwen-Image 2.1 legacy (qwen21) / Z-Image / SD3.5 Medium
• I2I (Image → Image / Edit / Multi-image, up to 16 refs) → Qwen-Image 2.1 Turbo (qwen21t, default) or Qwen-Image 2.1 legacy (qwen21) / Qwen Image Edit (2511, single image)
• I2V (Image → Video) → MiniMax H3 (h3_i2v, default); Wan2.2 is still available under wan2.2
• T2V (Text → Video) → MiniMax H3 (h3_t2v)
• Cutout (extract the main subject or any image element) → Qwen-Image 2.1 — redraws the target on a transparent background, producing a clean, alpha-only image; see Cutout below.
• I2M (Image → 3D Mesh) → Pixal3D / Trellis2 (default) — the source image feeds straight in (the graph removes its own background internally), generates a GLB, and zips it for delivery. The older Hunyuan 3D v2.1 is available via hyi2m — it extracts the main character first (transparent PNG), generates a GLB, scales it ×3000, and zips it.

config.json at the skill root holds every default. The agent never reads, manages, or overrides the ComfyUI endpoint, API key, or poll settings by hand — the script loads those automatically at call time (env COMFYUI_URL / COMFYUI_APIKEY and config.json, as configured). The agent's entire job is: call one subcommand, then read the local output paths the script prints.

Cutout — Extract the Subject

Note: cutout is a genuine image-generation task, not a simple non-generation tweak — use it when the user wants to isolate the subject or any image element from its surroundings.

Qwen-Image 2.1 can cut out / extract the main subject (or a specified element) from an image and return it on a transparent background. The output is a clean PNG with alpha only — it re-draws the target rather than doing a hard pixel mask, so it works well for organic shapes (people, animals, products, characters) and can target a specific described element (e.g. "extract just the red car", "isolate the vase") via the prompt.

• Use the i2i subcommand with --image <path> and a prompt that names the subject to extract. Keep the prompt focused on what to keep, not what to remove.
• The result is transparent (alpha-only). Deliver it as-is — never convert to JPG (which has no alpha channel, so it would flatten transparency onto white).
• This is the same redraw-to-transparent step that I2M runs first (see the i2m rules), but here it is used on its own to produce a standalone cutout image.

When to Use

• Generate images from text → t2i
• Edit one image, or compose 2–16 reference images → i2i (--image order = slot order = <image1>, <image2> …)
• Turn an image into a short video → MiniMax H3 (h3_i2v, default) or wan2.2
• Turn a text prompt into a short video → MiniMax H3 (h3_t2v)
• Turn the character in an image into a 3D mesh (GLB) → pi2m (Pixal3D / Trellis2, default) — the source image feeds straight in (the graph removes its own background internally). i2m is an alias for pi2m — the two names are interchangeable and both route to Pixal3D. For the older Hunyuan 3D v2.1 extraction path (character extraction + ×3000 delivery), use hyi2m. See the I2M Model Selection table below.
• Hybrid input (text prompt plus a source image as the conditioning frame / seed) → h3_i2v, not h3_t2v. The source image drives the video; the prompt describes its motion. A --seed flag alone is not a way to feed an image in (it wants an integer).
• Text only → h3_t2v.
• The user sends an image, then within 2 minutes asks to edit or animate it → image-first mode, see references/image-first.md

I2M Model Selection (which entry point matches your need)

Three I2M paths exist; pick by the extraction + delivery need, not by default:

Want	Use	Why	Notes
Just mesh it (image feeds straight in, auto background removal)	pi2m	Pixal3D/Trellis2, --image is the only input, no redraw step	Delivery scale ×1 (real units baked in — no upscale). __MAX resolution 512__ (config mesh.pi2m.default_resolution).
Clean cutout first, not redraw, then mesh	hyi2m --extract rembg	Non-generative u2net human cutout, done as a discrete step before the mesh	Best for humans; u2net is poor on non-humans.
Image is already a clean cutout, skip extraction	hyi2m --extract none	Feed the image straight in — only if it is already a clean cutout	No extraction run at all.
Highest detail + normalized-unit ×3000 delivery	hyi2m (Hunyuan 3D v2.1)	Default resolution 4096, --resolution up to 8192, delivery scale ×3000	Only Hunyuan scales ×3000.
User asked for ×3000 scale	hyi2m	×3000 is the Hunyuan normalized-unit convention — the rule is ×3000 ⇒ hyi2m	Never pass --scale 3000 to pi2m (see trap below).
Redrawing first is fine / preferred for extraction	hyi2m (default --extract auto)	Default extraction is i2i (Qwen-Image 2.1 redraws the character centered, transparent)	New users: hyi2m redraws the source before meshing unless --extract rembg/none.

⚠️ Never pass --scale 3000 (or any large --scale) to pi2m. pi2m's default scale is ×1 because the Trellis2 mesh carries its own real-world units — --scale 3000 would blow it up ~3000× (kilometres). --scale N is a real lever only on hyi2m, where the raw Hunyuan mesh is at a normalized unit scale (character ≈ 2 units) and needs the ×3000 in-place upscale before zipping (--scale 1 keeps it unscaled).

⚠️ i2m = pi2m. The i2m subcommand is an alias for the Pixal3D / Trellis2 pi2m path (default I2M). It is not the Hunyuan path — if you want Hunyuan 3D v2.1 (character extraction + ×3000 delivery), use hyi2m.

• pi2m default --resolution 512 (Pixal3D/Trellis2 mesh at real units, delivery scale ×1 by default) — override with --resolution N if the node allows a larger latent grid; there is no documented maximum in this skill, so read the actual node cap from the workflow if a higher value is needed.
• hyi2m (Hunyuan 3D v2.1) default --resolution 4096; --resolution can go up to 8192 (the highest value shown in the cli-reference; treat it as the working cap).

How the agent runs this (read first — this is the only thing that matters)

One command per job. That is the whole interaction.

The script is self-contained: it reads config.json + the env-supplied COMFYUI_URL / COMFYUI_APIKEY (auth header) automatically, submits the workflow, polls ComfyUI for progress on the agent's behalf, downloads and saves the results to output_dir, then prints those local paths. The agent never touches the API key, never curls ComfyUI, and never polls /queue or /history by hand — that is 150 lines the script already does internally.

• Never write your own curl http://host:port/history/<id> / /queue / /object_info / upload requests. The equivalent is the subcommand you run directly.
• Never cat the API key or put it in a header. It lives in the env that the script was started with; the script carries it into every request.
• If the script exits with configuration/setup instructions, the ComfyUI endpoint or key is misconfigured at the environment level — that is an ops fix (the COMFYUI_URL / COMFYUI_APIKEY env the script is launched under), not something to solve by building your own requests.
• For every model/flag, timeout, and delivery detail, see the reference files linked below instead of guessing.

Data & Privacy (what actually goes over the wire)

• What is transmitted: prompts and the workflow JSON go to the configured endpoint for every mode; I2I, I2V and I2M additionally upload the full source image. The agent cannot control what the script transmits — it can only decide whether to run.
• Endpoint / key: loaded automatically from the environment (COMFYUI_URL /
  COMFYUI_APIKEY and config.json). A non-local host prints a data-flow warning on every run. If no server answers, the script exits with setup instructions instead of a raw timeout.
• Written to disk: generated media is saved under output_dir (config.json or COMFYUI_OUTPUT_DIR). Don't submit sensitive content if the endpoint or disk is a concern.
• Secrets: the API key is handled entirely inside the script (it is never printed, never logged, never part of the agent's output). The agent must not echo it into any message, URL, or log.

Workflow Files

Mode	Workflow	File
T2I (Qwen-Image 2.1 Turbo, default qwen21t)	Qwen-Image 2.1 Turbo	workflows/qwen_image_2.1_turbo_api.json
I2I (Qwen-Image 2.1 Turbo, default qwen21t, incl. multi-image)	same file, switch ON	workflows/qwen_image_2.1_turbo_api.json
T2I (Qwen-Image 2.1, legacy qwen21)	Qwen-Image 2.1 dual-mode	workflows/qwen_image_2.1_api.json
I2I (Qwen-Image 2.1, legacy)	same file, switch ON	workflows/qwen_image_2.1_api.json
T2I (Z-Image)	Z-Image	workflows/z-image_t2i_api.json
T2I (SD3.5)	SD3.5 Medium	workflows/sd3.5-med_t2i_api.json
I2I (legacy)	Qwen Image Edit (2511)	workflows/qwen_image-edit_api.json
I2V (default h3_i2v)	MiniMax H3 Image-to-Video (8-step FastH3, int8_convrot — 4090-safe)	workflows/h3_fasth3_i2v_api.json
T2V (h3_t2v)	MiniMax H3 Text-to-Video	workflows/h3_fasth3_t2v_api.json
I2V (legacy)	Wan2.2 Image-to-Video	workflows/wan2.2_i2v_api.json
I2M (Image → 3D Mesh) — default	Pixal3D / Trellis2	workflows/trellis2-pixal3d_i2m_api.json
I2M (Image → 3D Mesh) — Hunyuan 3D v2.1 (hyi2m)	Hunyuan 3D v2.1	workflows/hunyuan3d-v2.1_i2m_api.json

Each workflow is an adapted version of a real ComfyUI graph. Original source + exactly what was changed → references/attribution.md.

CLI Usage

⚠️ The prompt is MANDATORY and must be passed via --prompt — never as a positional word.

Every subcommand (t2i, i2i, h3_t2v, h3_i2v, wan2.2) reads the prompt from --prompt "...". Passing the prompt as a bare positional word fails immediately with exit code 2: python3 image_with_comfyui.py t2i "some description" → t2i: error: the following arguments are required: --prompt

This is a 100%-avoidable failure loop — the command never reaches ComfyUI, so the model can't help. Always write the prompt through --prompt on the first attempt.

The default I2M entry point is pi2m (Pixal3D / Trellis2, no prompt — the character image is the condition; --image is its only required flag). i2m is an alias for pi2m — use either name, they are identical. hyi2m is the separate Hunyuan 3D v2.1 path (--extract + ×3000). pi2m/hyi2m/i2m take no prompt.

Full commands and the timeout table → references/cli-reference.md

Prompt Formatting

Per-model guidance (formulas, rules, example prompts) lives in references/prompts.md. The English prose is there; example prompts keep their bilingual keyword pairs where the original was bilingual (e.g. blurry 模糊).

• Qwen-Image 2.1 Turbo (T2I + I2I default, qwen21t) / legacy Qwen-Image 2.1 (qwen21): natural-language prompts. CFG locked to 1.0 (distilled) — never pass --cfg. Optional --negative supported in both T2I and I2I (keep it short); I2I prompts stay concise, in the user's language. Turbo (qwen21t) is the 8-step fast default; force the 25-step legacy with --model qwen21.
• SD3.5 Medium: natural language + optional --negative; default 1:1 (1024×1024), 20 steps, CFG 4.01.
• Z-Image / Qwen-Image 2.1: --aspect is optional — T2I omits it and the output defaults to 1:1 (1024×1024); I2I omits it and the output canvas matches the first reference image's size (workflow latent switch ON). Pass --aspect 16:9, 9:16, etc. to force a shape — in I2I this flips the latent switch to route the canvas through the ResolutionSelector (reference stays at native size, never stretched).
• Z-Image: natural language — no negative prompts.
• Qwen Image Edit (2511): concise, positive-only, user's exact words.
• MiniMax H3 (h3_t2v / h3_i2v, default 2v): motion/action prompts (same style as Wan2.2). Default duration 15 s (t2v) / 10 s (i2v) from config; --length overrides; --aspect optional for t2v. 8-step FastH3 int8_convrot diffusion + GGUF text encoder loaded via CLIPLoaderGGUF (type qwen_image, Nif00 ComfyUI-GGUF fork) — see MODEL_URL.txt [7].
• Wan2.2 (I2V): motion/action prompts; default 81 frames, 4 steps, CFG 4.5.
• pi2m (Pixal3D / Trellis2, default I2M, no prompt): the only input is the character image (--image). The trellis2 graph removes its own background internally (birefnet), so no client-side extraction is done and the image is fed straight in. Delivery scale defaults to ×1 — the Trellis2 mesh already carries its own real-world units (no normalized-unit upscale). i2m is an alias for pi2m — identical command, identical defaults (resolution 512, delivery scale ×1).
• hyi2m (Hunyuan 3D v2.1, no prompt) is the separate older path. It runs a character-extraction step first: default extraction is i2i (Qwen-Image 2.1 redraws the main character centered on a transparent background, saved as PNG); --extract rembg for a non-generative u2net human cutout; or --extract none to feed the image straight in (only if it's already a clean cutout). Defaults: resolution 4096, 30 steps, CFG 5.0, delivery scale ×3000 — the raw Hunyuan 3D v2.1 mesh is at a normalized unit scale (character ≈ 2 units, no declared units), so the GLB is scaled in place before zipping (--scale 1 keeps it unscaled).

Error Handling

The script auto-detects three categories of server-side problems and reports them with install/source guidance, and t2i/i2i run through a runtime fallback chain when the default model fails. Details → references/error-handling.md:

1. Missing nodes — reports which node, its package, and a pinned GitHub install hint (the script never runs git clone itself).
2. Missing models — substitutes a compatible model (e.g. SD3.5 medium variants → SD3.5 large).
3. Non-critical utility nodes (e.g. UnloadAllModels) — bypassed automatically without interrupting generation.
4. Runtime fallback chain — t2i/i2i auto-descend through alternate models (and, for t2i, any available checkpoint) on runtime failures; config problems (missing files/nodes) abort instead of degrading. Disable with --no-fallback.

Output Delivery

Send the generated file — do not just describe it. Deliver in the user's original session, never raw paths/URLs. Per-channel prefixes and the staging/cleanup routine → references/delivery.md

Output format: generated images default to JPG (config.json → image.output_format). Routing rule: if the user asks for a PNG image/file, or an RGBA image with transparency/alpha, always pass --format png and deliver the PNG file as-is — never convert to JPG (JPEG has no alpha channel; the conversion would flatten transparency onto white). PNG output passes the server's PNG bytes through unchanged, so transparency is preserved byte-for-byte. Otherwise --format jpg --jpg-quality N is available per run; JPG conversion happens client-side (ComfyUI always saves PNG server-side). i2m delivery rules (3D output): the mesh is always packaged as a zip (i2m_<timestamp>.zip) and delivered as the zip, never the raw .glb. (a) For the default pi2m (Pixal3D / Trellis2) there is no extraction step — the character image is the model's own condition, not a separate file, so just deliver the zip. (b) For hyi2m (Hunyuan 3D v2.1) the raw mesh is at a normalized unit scale (character ≈ 2 units, no declared units), so the script scales the GLB in place by the delivery factor (default ×3000; --scale 1 keeps it unscaled) before zipping; optionally also attach the extracted character image if the user needs it. (c) never render the mesh — no GLB → image/video conversion and no 3D-viewer screenshots (a third-party viewer link is fine to share). Format conversion never applies to 3D files.

Execution Discipline — Fast Path

The measured GPU sampling time is ~12–20s. When a task takes minutes, the delay is not inference — it's either a model cold-reload or agent-side overhead. Kill the waste: 0. Never poll or check status by hand. The script submits, polls ComfyUI for progress, and fetches+saves the results itself — then prints the local output paths. There is no agent-side step like curl .../queue, .../history/<id>, or .../object_info; that is the whole command you already ran. If a task is long, let the one command run (background it for i2m/video) and read the printed paths — do not spin around the ComfyUI API.

i2m exception: 3D generation is legitimately long (cold checkpoint load + 30 sampling steps + voxel decode ≈ minutes on a 4090). Run it once in the background (exec with a generous timeoutSeconds), report the queue state, and when it completes deliver the character image + the GLB zip per the i2m delivery rules above — don't spin tool calls around it.

1. Never re-read on repeat. Don't re-read SKILL.md, config.json, or the script for a known config / repeat / same-model job. Defaults are baked in; --aspect / --steps / --cfg are in the links above.

Long-running jobs — use exec background mode (read this; this is where the skill trips up)

Two of these jobs are legitimately long, not overhead — do not treat them as stuck:

• i2m / I2M (3D GLB): cold checkpoint load + 30 sampling steps + voxel decode ≈ minutes on a 4090.
• video (wan2.2 / h3_t2v / h3_i2v): 5–15 s clips usually take 2–200 minutes on a 4090.

For these, run the one command in exec background mode and let it finish, then deliver per the i2m / delivery rules above. Do not sit on the foreground command and do not spin tool calls around ComfyUI.

❌ The #1 mistake here: starting the job yourself with nohup python3 image_with_comfyui.py … & inside a normal foreground exec command, then letting that command return.

That is exactly how every turn on this skill gets wasted, and it is not a ComfyUI problem — it is a process-group problem:

1. You background the generation inside a foreground exec command; the & attaches the generation process to that exec session's process group.
2. The foreground command returns a few lines later, and the session sees the command as done.
3. The session end recycles the whole process group — including the nohup'd generation, because it is still a child of that session. nohup only blocks the normal "shell exit" signal; it does not survive a process-group recycle.
4. Result: your 120-minute generation dies at second ~10, the log stays empty, the process vanishes, and you have nothing. Nothing was ComfyUI's fault.

✅ Use exec's built-in background mode instead. That mode launches the command as a session that stays alive past the command and returns the output when it completes — it is the correct tool for "run something long and get the result later." One command, the generation runs to completion on its own, results come back on finish. t2v / video / i2m succeed this way every time; the nohup…& approach fails every time.

3. At most one pre-check merge. Gather any needed info in a single batched command, or skip it entirely for trivial repeat jobs.
4. Run immediately after one check. Don't inspect, second-guess, or add tool calls between knowing the prompt and running.
5. Verify only the minimum. After the run, check only what the user asked (size / seed / file exists).
6. Golden rule: sampling is ~12–20s. Anything longer = reload or overhead — never pile on tool calls before the image exists.
7. Prompt-flag trap: pass --prompt "..." on the first attempt; a positional word wastes a whole turn.

References (index)

• references/image-first.md — image-then-edit detection rules + multi-image reference composition
• references/attribution.md — original source + modifications per workflow
• references/cli-reference.md — full commands + timeout reference
• references/prompts.md — per-model prompt guidance
• references/error-handling.md — auto-handled error categories
• references/delivery.md — per-channel delivery + staging