higgsfield-seedance-2-5

# Higgsfield Seedance 2.5 Director

Seedance 2.5 is a **different dialect from Seedance 2.0**, not a version bump you can
prompt through by habit. 2.0 is a reference-driven shot generator with start/end frames
and a 4K lane. 2.5 is an **omni-reference production model**: up to 50 reference
materials, 30-second native runtime, and three non-generation modes — it can edit a video
you already have, and extend one forward or backward from its boundary frame.

The prompt grammar changes with it. Reference roles are declared in prose (`@Image 1
defines …`), audio and text get bracket syntax, long videos are staged with explicit end
states, and first/last frames are announced **inside the prompt** rather than selected as
a mode.

> **Model split — read this before writing anything.** 2.5 caps at **720p** and has no
> `start_image` / `end_image` media role, no `genre` hint, and no 4K lane. If the job
> needs 4K, a genre hint, or platform-level start/end frame pinning, it is a
> **Seedance 2.0** job — `../higgsfield-seedance/SKILL.md`. See § Choosing 2.0 vs 2.5.

## QUICK FACTS
*Generated-checked block (scripts/build_index.py verifies anchors). Routing aids — read the linked sections for the rules themselves.*
- Four modes, picked **before** writing: `t2v` · `omni_reference` · `video_edit` · `video_extension`; the mode changes what the prompt *is* [→](#the-mode-router)
- Higgsfield surface: **480p/720p only**, duration **4–30s**, no start/end-frame role, no genre hint, `extension_mode` required for (and only for) `video_extension` [→](#the-higgsfield-parameter-surface)
- `video_edit` **ignores** `duration` and `aspect_ratio` and bills by the source video's length; `video_extension` inherits the source's aspect ratio [→](#the-higgsfield-parameter-surface)
- Every reference material gets an explicit role **and** an exclusion — "what to use" plus "what not to use"; never let the model infer the mapping [→](#reference-roles-say-what-to-use-and-what-not-to-use)
- Each material also declares a **fidelity grade** — full-preserve / partial-preserve / attribute-transfer (name the target) / loose-guide; beat lines name characters (name + one visible marker), never handles [→](#fidelity-say-how-much-of-each-material-must-survive)
- Material budget: 30 images / 10 videos ≤30s total / 10 audio ≤30s total, 50 materials max; stability ranges are 1–8 subjects (images), 1–5 subjects at 5–10s (video/audio) [→](#material-budget)
- Multi-reference is a 5-step workflow — map → group → profile → select-by-scene, one line per subject; `@Images 1 through 4 define four characters` is the canonical failure [→](#multi-reference-the-five-step-workflow)
- Long videos are **staged**, not paragraphed: one primary change per stage + an explicit **end state**; timestamps allocate a budget, they are not frame-accurate edit points [→](#long-video-stages-and-end-states)
- Staging fixes too many EVENTS; two incompatible JOBS in one generation (physics + performance) is a separate cut — split into two prompts and stitch [→](#split-by-job-not-only-by-length)
- Bracket syntax: `()` music · `<>` SFX · `{}` dialogue · `【】` subtitles; non-Chinese dialogue needs a language line before the line [→](#audio-and-text-bracket-syntax)
- First/last frames and multi-keyframes are declared **in the prompt** (`@Image 1 is the first frame`) — aspect ratio locks to the first image; never merge the two anchors into one sentence [→](#first-last-frame-and-multi-keyframe-control)
- Editing needs a **sole editing master** + edit scope + Timeline Inheritance; extension needs the **boundary frame aligned before** any new content: `MODE-PLAYBOOKS.md`
- Storyboard grids, coarse-vs-fine blockouts, one-click video, seamless transitions: `MODE-PLAYBOOKS.md`
- **AI-VFX production pipeline** — model-per-asset-class routing, the size-ref frame, location batching, the `omni_reference` v2v lane (source ≥4s, duration = source), the four-batch rule, the slop catalog: `VFX-PIPELINE.md`
- Emotion needs 2–4 **observable** cues, not adjectives; niche camera terms get translated into a visible result [→](#emotional-direction-and-camera-terms)
- The real-person formula is 7 slots — and slot 1 is **role, never age**: the age-blind engine rule outranks the source guide's `[Age/Race]` label [→](#the-real-person-character-formula)
- Hard limits that must not be over-promised (frame accuracy, locked parameters, pixel-identical transitions) [→](#hard-limits-do-not-over-promise-these)
- Dreamina-product features that are **not** on the Higgsfield surface — Ultra Long Video 180s, mark-based editing, Clay Renderer [→](#dreamina-only-what-higgsfield-does-not-expose)

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## Provenance

Two independent sources, labelled throughout:

| Label | Source |
|---|---|
| `[OFFICIAL — Dreamina]` | ByteDance's *Dreamina Seedance 2.5 Prompt Guide* + *User Guide* — the model vendor's own prompt doctrine. Prompt grammar is model-side, so it carries across to Higgsfield's hosting. |
| `[OFFICIAL — platform]` | Higgsfield's live `models_explore` catalog, snapshot **2026-08-07** (`../../specs/model-specs.json`). Parameters, enums, and media roles come from here and nowhere else. |
| `[DREAMINA-ONLY]` | A Dreamina *product* feature with no Higgsfield parameter behind it. Never quote these as things the user can do here. |

Where the two disagree about what is *settable*, the platform snapshot wins — it is what
the API actually accepts.

---

## The Mode Router

Pick the mode first. The same sentence means different things in different modes, and two
of the four modes are not generation at all.

| The user wants | Mode | What the prompt is |
|---|---|---|
| A clip from a description, no materials | `t2v` | A scene brief — the core formula below |
| A clip built from images / videos / audio they supply | `omni_reference` | A **role map** plus a scene brief |
| To change something inside a video they already have | `video_edit` | An **edit order**: master + scope + preserve list |
| More footage before o