/byted-bp-seedance-viral-creative-rewrite-skill

name: byted-bp-seedance-viral-creative-rewrite-skill
description: Guide a user conversationally through generating a new ad video from a template video and a user-provided product image. The host agent performs video understanding, detailed analysis, and rewrite planning; BytePlus Seedance is used only for final video generation with local product images as generation references.

Viral Creative Rewrite Skill

What This Skill Does

This skill helps a user create a stronger ad video from:

• a template video, provided by the user as a local path or accessible URL
• a user-provided product image, defaulting to `./assets/examples/source_product.jpg`

The template video provides creative structure: hook, pacing, visual rhythm, CTA style. The product image provides the product identity, packaging, visual anchors, and confirmed selling points. The final video should keep the product image identity and borrow only the template's creative pattern.

Reference Loading

• Read `references/state_machine.md` when changing or auditing frontstage state transitions, opening prompts, detailed-analysis behavior, confirmation gates, missing-key behavior, bilingual parity, or transcript regressions.
• Read `references/workflow.md` when changing or auditing the user flow, confirmation gates, setup/prepare/execute behavior, review outputs, or local product image handling.
• Read `references/prompt_alignment.md` when changing analysis schemas, rewrite-planning prompts, prompt-package structure, or compatibility with earlier creative rewrite prompt patterns.
• Read `references/chain_contract.md` when changing or auditing cross-layer behavior: state, prepared artifacts, renderers, prompt compiler, execution gate, bilingual parity, and badcase regression coverage.

Hard Gates

• Treat "正式生成", "直接生成", or similar user wording as intent to enter the real-generation path, not permission to submit Seedance immediately.
• Always run or present the analysis/brief confirmation gate before real generation. The user must see the template logic, product-image anchors, rewrite strategy, forbidden carryover, prompt preview, audio setting, and cost/time warning before Seedance is called.
• Treat the conversation as a state machine. `references/state_machine.md` is the source of truth for frontstage state transitions, allowed output, forbidden output, and transcript regression invariants. Do not expose later-state actions in earlier-state messages:
• `START_OPENING`: explain the skill, two media roles, default assets, category/face guidance, and ask for grouped inputs. Forbidden in this state: "确认生成", "confirm generation", `--confirmed-brief`, or any instruction that asks the user to approve final generation.
• `BRIEF_READY`: after analysis/brief exists, show the compact brief, detailed-analysis option, edit option, and only then expose the generation-confirmation action.
• `DETAIL_VIEW`: when the user asks for detailed analysis, print the full detailed-analysis sections and return to edit/confirm options.
• `GENERATION_CONFIRMED`: after the user confirms the prepared brief, run `scripts/confirm_generation.py`; do not hand-write the result.
• `MISSING_KEY_FULL_GUIDANCE`: if the confirmed runner path lacks `ARK_API_KEY`, show the reusable brief state, no-cost/no-call state, Seedance advantages, playable examples, and account/key setup.
• Support both Chinese and English user flows. Keep user-facing messages, compact brief text, detailed-analysis text, setup/missing-key guidance, and prompt preview in the user's language. Use `ui_language: "zh"` or `ui_language: "en"` when the language is explicit; use `auto` only when it is safe to infer from the user's request. This UI language is separate from the template spoken-language rule.
• For conversation language selection, the latest user turn wins. If the latest invocation/request is in English, including a local-path invocation such as `/path/to/byted-bp-seedance-viral-creative-rewrite-skill use this skill`, start and continue the frontstage flow in English even if earlier thread history is Chinese. If the latest invocation/request is in Chinese, use Chinese. Do not let old thread context override the language of the current invocation.
• Before planning the rewrite, classify the template into a template profile. This profile decides which signals are allowed to become hard generation constraints:
• `visual_product_texture`: drinks, food, product static shots, material/texture demos, ingredient/product-state ads. Borrow shot order, camera pacing, product state changes, texture/satisfaction points, scene mood, and music mood. Do not add voiceover, lip sync, person ethnicity/appearance constraints, or subtitle logic unless the user explicitly asks.
• `human_demo`: visible human demonstration, try-on, hand-use, or presenter action without a strong voiceover. Borrow human framing, action sequence, expression/eye-contact when structurally important, product-human relationship, and real scene context. Do not invent voiceover.
• `human_voiceover`: presenter/creator video with spoken explanation. Borrow broad person appearance/market visual context, original template spoken language, voiceover rhythm, mouth/gesture synchronization, real scene, and action order. Generate a new non-identical person and original wording.
• `platform_cta`: platform/account/search/CTA pages. Borrow only the closing function; do not inherit platform UI, account, watermark, search page, captions, or blank ending.
• `mixed`: use only when several mechanisms are equally central, then expose the active transfer slots in the brief before asking for confirmation.
• Keep no-cost rehearsal and real prepare frontstage readouts aligned. They may differ in provider/cost wording, but they must use the same user-facing structure: status, brief summary, detailed-analysis option, edit option, confirmation option, and result-display expectation.
• Do not call Seedance until the user explic