Happy Video Gen Skill for Claude

happy-video-gen

Generates short videos (text-to-video or image-to-video) across 10 providers through one CLI: bun scripts/main.ts .... All providers are async — the CLI submits a job, polls until the provider finishes, then downloads the MP4 / WebM.

Quick usage

# Text-to-video
bun scripts/main.ts --prompt "camera slowly pushes into a calico cat on grass" --ar 16:9 --duration 5 --video ./out.mp4

# Image-to-video (first frame)
bun scripts/main.ts --prompt "subtle zoom, leaves swaying" --image ./keyframe.png --duration 5 --video ./out.mp4

# Image-to-video with last-frame control (provider-dependent)
bun scripts/main.ts --prompt "seamless morph" --image ./a.png --last-frame ./b.png --video ./out.mp4

When to invoke this skill

• User asks to generate / create / make / synthesize a video from text.
• User asks to animate a still image, or provides a first-frame path.
• User names any video model family (Sora, Veo, Runway, Kling, Wan, Seedance, Hailuo, Pika, Dream Machine, Vidu).

Route to happy-dreamina if the user explicitly mentions 即梦 / Jimeng / dreamina CLI. Route to happy-image-gen if the user actually wants a still image.

Step 0: Preflight (BLOCKING)

• Locate EXTEND.md (same resolution order as happy-image-gen):
• ./.happy-skills/happy-video-gen/EXTEND.md
• $XDG_CONFIG_HOME/happy-skills/happy-video-gen/EXTEND.md
• ~/.happy-skills/happy-video-gen/EXTEND.md

If none, run bun scripts/main.ts --setup and walk the user through references/config/first-time-setup.md.

• Verify one provider has credentials. Check env vars in the order the CLI auto-detects (see providers.md). Do not proceed without one usable provider.

• Verify Bun. Fall back to npx -y bun if missing.

• Warn about cost. Video generation is 10–100× more expensive per call than images. If the user asks for HD 1080P / 10-second clips, confirm before firing — show them the expected provider cost bracket from references/providers.md.

Step 1: Choose provider

Preference order:

• --provider <id> explicitly passed.
• EXTEND.md default_provider.
• Auto-detect from env vars: fal > ark > minimax > runway > luma > pika > vidu > google > bailian > openai.

Pick by strength of the actual task:

• Chinese prompts / Chinese text in frame → ark (Seedance) or bailian (Wanx).
• Photorealistic portraits → google (Veo 3) or runway (Gen-4).
• Anime / stylized → fal (Kling) or luma.
• Cheap draft → ark Seedance Lite, fal Kling v2.5 turbo, vidu Q1.
• Voice-synced dialogue video (if applicable) → google Veo 3, openai Sora 2.

Step 2: Fill parameters

• --prompt: always double-quote.
• --image <path> / --last-frame <path>: local paths, will be base64-encoded as data URIs automatically. --last-frame only accepted by Luma and a few FAL endpoints.
• --duration <seconds>: 5 is universal default. Caps: Sora-2 / Kling up to 10; Seedance up to 10; Luma up to 9.
• --ar <ratio>: 16:9 / 9:16 / 1:1 / 4:3 / 3:4. See references/aspect_ratio_map.md for provider-specific quirks.
• --resolution: 480p / 720p / 1080p. Not all providers honour it; most cap at 720p on cheap tiers.
• --poll-timeout: default 600s (10 min). Increase for 1080P or >5s clips.

Step 3: Submit and wait

bun scripts/main.ts \
  --prompt "..." \
  --video ./out.mp4 \
  --provider ark \
  --duration 5 \
  --ar 16:9 \
  --resolution 720p

While waiting, do not fire another job on the same provider — concurrency caps on cheap tiers are strict (often 1). On success the CLI writes the MP4 and reports size + path. JSON output:

{ "success": true, "provider": "ark", "model": "doubao-seedance-1-0-lite-t2v-250408", "video": "/abs/out.mp4", "size_bytes": 4823456, "format": "mp4" }

Step 4: Timeouts and recovery

If polling exceeds --poll-timeout, the CLI throws with the provider-specific external id (task id / job id / operation name / request id). Capture it from stderr and resume later with provider-specific tooling. See references/async-protocol.md for the per-provider id format and manual resume commands.

References

• references/providers.md — all 10 providers with env vars, defaults, cost notes, feature matrix.
• references/async-protocol.md — external id format per provider + how to resume a stuck task.
• references/aspect_ratio_map.md — --ar mapping per provider.
• references/error_codes.md — common errors and fixes.
• references/config/first-time-setup.md — setup walkthrough.
• references/config/extend-schema.md — EXTEND.md schema.
• assets/EXTEND.template.md — config template.