seedance-2-prompt

name	seedance-2-prompt
description	Render a single 3-15s video clip via Seedance 2.0. Supports two backends: OpenRouter (default, model bytedance/seedance-2.0) and the official Volcengine ARK / BytePlus ModelArk endpoint (model doubao-seedance-2-0-260128 / dreamina-seedance-2-0-260128). Accepts a structured English video prompt, optional first-frame image, and optional identity/style reference image. Trigger when the user asks for AI video clip generation, 分镜视频, seedance, or wants a short cinematic shot from a prompt + frame.
provenance	{"origin":"clawhub-mit0","license":"MIT-0","upstream_url":"https://clawhub.ai/dandysuper/seedance-2-prompt-engineering-skill","upstream_version":"2.0.0","maintained_by":"AgentOS","modifications":"Added scripts/generate_video.py with dual-provider support: OpenRouter async /videos API and Volcengine ARK / BytePlus ModelArk /contents/generations/tasks. References kept from upstream."}
metadata	{"agentos":{"risk":"medium","capabilities":["network-read","filesystem-write"],"requires":{"anyBins":["python","python3"],"envAny":["OPENROUTER_API_KEY","ARK_API_KEY"]}}}
entrypoint	{"command":"python {baseDir}/scripts/generate_video.py","args":["--prompt","{{ with.prompt }}","--filename","{{ with.filename }}","--provider","{{ with.provider | default('openrouter') }}","--aspect-ratio","{{ with.aspect_ratio | default('9:16') }}","--duration","{{ with.duration | default(5) }}","--resolution","{{ with.resolution | default('720p') }}","--model","{{ with.model | default('') }}","--input-image","{{ with.input_image | default('') }}","--input-reference","{{ with.input_reference | default('') }}","--input-reference","{{ with.input_reference_2 | default('') }}","--max-retries","{{ with.max_retries | default(0) }}"],"parse":"text","timeout":1500}

seedance-2-prompt — Seedance 2.0 video clip generator (dual backend)

Submits a Seedance 2.0 generation job and downloads the resulting MP4. Two backends share one CLI, picked via with.provider:

with.provider	Endpoint	Auth env	Default model
openrouter (default)	https://openrouter.ai/api/v1/videos	OPENROUTER_API_KEY	bytedance/seedance-2.0
volcengine (CN)	https://ark.cn-beijing.volces.com/api/v3/contents/generations/tasks	ARK_API_KEY (or VOLC_ARK_API_KEY)	doubao-seedance-2-0-260128
byteplus (intl)	https://ark.ap-southeast.bytepluses.com/api/v3/contents/generations/tasks	ARK_API_KEY (or BYTEPLUS_API_KEY)	dreamina-seedance-2-0-260128

Both flavours follow submit-then-poll, but differ in request shape (OpenRouter uses a flat prompt field; ARK packs everything into a content[] array), polling URL (OpenRouter returns polling_url; ARK gets id and you construct /contents/generations/tasks/{id}), the terminal-success status (completed vs succeeded), and where the final MP4 URL sits (top-level unsigned_urls[0] vs content.video_url). This script normalises both into a single Python contract.

Inputs (with:)

key	required	default	notes
prompt	yes	—	Structured English video prompt (use this skill's recipes).
filename	yes	—	Output .mp4 path.
provider	no	openrouter	openrouter, volcengine, or byteplus.
aspect_ratio	no	9:16	9:16, 16:9, 1:1, 4:3, 3:4, 21:9.
duration	no	5	Seconds, 3-15. Provider enforces 4-15 typically.
resolution	no	720p	480p, 720p, 1080p. Ignored by OpenRouter.
model	no	provider default	Override model id. Empty means use provider default.
input_image	no	""	Strict first-frame path. If set, video starts from this image.
input_reference	no	""	Primary soft identity/style anchor path. Used only when input_image is empty. Same anchor passed across shots locks the character.
input_reference_2	no	""	Optional second reference (e.g. per-shot scene composition). Forwarded as a second --input-reference so the underlying provider sees both. Empty strings are filtered out before the API call.
max_retries	no	0	Extra retries on transient submit/poll/download failures or non-success terminal status. 0 = single attempt; 2 = up to 3 total attempts with exponential backoff (2s, 4s, 8s capped at 15s). Set this on flows that fall back to a still-image animator on final failure.

input_image vs input_reference — input_image becomes the literal first frame. input_reference is a softer style + identity hint the model uses without locking the frame. For multi-shot drama, pass the same input_reference to every shot; pass input_image only when you want a specific opening frame.

Prompt rules (from upstream + AgentOS tightening)

1. One major action per 3-5s segment. Don't pack multiple motions.
2. Identity continuity — repeat the main character's full description in every shot's prompt.
3. Specific over poetic — "a young woman in a red trench coat walks through rain-soaked neon streets" >> "a woman walking".
4. Negative constraints inline — append no watermark, no logo, no subtitles, no on-screen text.
5. IP-safe — invent original character/brand names.
6. Aspect ratio explicit — append aspect_ratio: 9:16.

See references/recipes.md, references/modes-and-recipes.md, references/camera-and-styles.md for the upstream playbook.

Auth

• openrouter provider API-key resolution order:
  1. --api-key CLI argument
  2. OPENROUTER_API_KEY env var
  3. AGENTOS_LLM_API_KEY env var, only when the effective AgentOS LLM provider resolves to openrouter
  4. llm.api_key or llm.api_key_env from the selected AgentOS TOML config. Config discovery matches GatewayConfig.load: explicit AGENTOS_GATEWAY_CONFIG_PATH first; otherwise ./agentos.toml, then default_agentos_home()/config.toml. AGENTOS_STATE_DIR changes default_agentos_home(), so a state-dir profile does not fall through to ~/.agentos. Config-file credentials are consumed only when the selected config's llm.provider is openrouter or omitted.
• volcengine / byteplus provider reads ARK_API_KEY (with provider- specific fallbacks VOLC_ARK_API_KEY / BYTEPLUS_API_KEY). No config-file fallback for these — the AgentOS [llm] config describes the agent's selected LLM provider, not ARK / BytePlus video credentials.
• All three send the key as Authorization: Bearer <key>.
• For OpenRouter the same bearer is also added when downloading the resulting unsigned_urls[0]. Volcengine returns pre-signed object store URLs that reject extra headers, so the downloader strips Authorization for non-OpenRouter hosts.

Output

Prints the absolute path of the saved .mp4 on stdout. Non-zero exit on any error; stderr carries the diagnostic.

Cost / latency

• OpenRouter bytedance/seedance-2.0 5s @ 9:16 720p: ≈30-90s wall, ≈$0.76.
• Volcengine official 5s 1080p: ≈30-120s wall, ≈$0.93.
• Volcengine doubao-seedance-2-0-fast-260128: roughly half cost and faster.
• The returned unsigned_urls / content.video_url expire 24 hours after success on the Volcengine path — this script downloads them before that window so the local mp4 is durable.

Multi-segment workflows (>15s)

Generate segments individually with duration ≤ 15, ending each on a stable hand-off frame. Stitch with the video-merger skill. See references/modes-and-recipes.md § "Multi-Segment Stitching".