Dance

/dance — Image-to-dance-video in one command

Drop a photo of a person, pick a dance style, get back a clean 5-second mp4 (plus a shareable looping gif). Powered by ByteDance Seedance 2.0 through the BlockRun x402 gateway.

What this skill does

Calls mcp__blockrun__blockrun_video with image_url set to the user's photo, model="bytedance/seedance-2.0-fast", and a choreography prompt from the Dance style variants section at the bottom of this file. The MCP tool blocks while polling internally for 60–180 seconds, then returns a permanent mp4 URL. The skill downloads the mp4 to ./blockrun-out/{ts}-dance/dance.mp4 and renders a GIF preview.

Inputs

If the user says "make a dance video" without a photo, ask for the photo path.

Workflow (Claude executes strictly in order)

Step 0 — Verify the BlockRun MCP server is registered

Before any tool call, confirm mcp__blockrun__blockrun_video and mcp__blockrun__blockrun_wallet are available. If not, surface this exact message and stop:

"The BlockRun MCP server isn't registered with Claude Code yet, so /dance can't run. Please run once:

claude mcp add blockrun -s user -- npx -y @blockrun/mcp@latest

Then restart Claude Code and try /dance again. (Full install guide: INSTALL.md in the Claude Code-GPT-IMAGE2-SeeDance-BlockRun bundle.)"

Do not proceed to the wallet preflight or video call if the MCP tools are missing.

Step 1 — Wallet preflight

Call mcp__blockrun__blockrun_wallet with {"action": "status"}.

• Required balance: 0.15 × duration_seconds USDC plus a small buffer. For default 5s, require ≥ $1.00 USDC.
• If too low, pause and tell the user:

  "Your BlockRun wallet balance is too low. /dance with 5s Seedance 2.0-fast costs ~$0.75. Run blockrun_wallet action: setup to top up Base USDC." Do not proceed.

Step 2 — Image accessibility

The Seedance image-to-video flow needs a publicly fetchable URL or the MCP tool will accept a hosted image. The current MCP blockrun_video tool's image_url parameter expects a URL.

• If the user gave a URL: pass through.
• If the user gave a local file path:
  1. Verify the file exists with Read.
  2. Confirm size < 10 MB and dimensions are reasonable (Seedance prefers ≥ 720px on the short side).
  3. Local-file fallback: Use mcp__blockrun__blockrun_image with action="edit" and a no-op-style prompt (e.g. "return the image unchanged, no edits") to upload-and-host the photo — the response URL is a permanent BlockRun CDN URL we can pass to blockrun_video.image_url. Cost ≈ $0.06 extra.
  4. Alternatively, instruct the user to upload to a host they control and supply the URL.

Step 3 — Prepare prompt

Use the master template from the Dance style variants section at the bottom of this file. Pick the block matching {style} (default tiktok-trend) and substitute its slots into the master template. For freestyle-from-music, splice the user's --music argument into {user_music_description}.

Step 4 — Call BlockRun MCP (the slow one)

Tool: mcp__blockrun__blockrun_video
Arguments:
{
  "prompt": "<filled template from Step 3>",
  "image_url": "<URL from Step 2>",
  "duration_seconds": <int, default 5>,
  "model": "bytedance/seedance-2.0-fast"
}

Tell the user before calling:

"Submitting to Seedance 2.0-fast. This blocks for 60–180s while polling. Sit tight."

The MCP tool handles all polling internally with a 300s hard cap. When the call returns, expect either:

• Success: response.structuredContent.url is a permanent mp4 URL.
• Timeout (did not complete within 300s): no charge — offer a retry.

Step 5 — Download mp4 and render GIF

1. Timestamp: date -u +"%Y-%m-%dT%H%M%SZ".
2. Output dir: ${BLOCKRUN_OUT_DIR:-./blockrun-out}/{ts}-dance/.
3. mkdir -p the dir.
4. curl -sSL "<url>" -o <out_dir>/dance.mp4.
5. Render shareable looping GIF (best-effort — skip if ffmpeg is missing):

   ffmpeg -i <out_dir>/dance.mp4 \
     -vf "fps=15,scale=540:-1:flags=lanczos,split[s0][s1];[s0]palettegen[p];[s1][p]paletteuse" \
     -loop 0 <out_dir>/dance.gif
   

   If ffmpeg is not installed, omit the GIF and tell the user brew install ffmpeg would unlock it.
6. Confirm files are non-empty (ls -la).

Step 6 — Report to user

✅ Dance video ready

  Video:    {relative path to .mp4}
  GIF:      {relative path to .gif}   (if rendered)
  Style:    {style}
  Duration: {duration} s
  Model:    bytedance/seedance-2.0-fast
  Cost:     ~${0.15 × duration} (settled on Base via x402)

Play it: open {relative path to .mp4}

If a GIF was generated, suggest the user attach it to a social post.

Failure handling

Cost

Plus a one-time ~$0.06 if we used the upload-via-blockrun_image fallback. Settled on Base USDC via x402. No charge if Seedance times out or fails.

Examples

/dance ./me.jpg
/dance ./me.jpg --style hiphop
/dance ./me.jpg --style terracotta-disco
/dance ./me.jpg --style freestyle-from-music --music "lo-fi jazz 75 bpm"
/dance ./me.jpg --duration_seconds 8 --style kpop

Master template (Seedance 2.0-fast, image-to-video)

The person from the input image performs {style} dance choreography.
Full body remains visible throughout. Smooth, fluid motion synchronized to
an implied {bpm} BPM beat. Camera: {camera_motion}. Setting:
{environment}. Lighting: {lighting}. The person's facial identity, body
proportions, hairstyle, and clothing remain consistent across every frame.

Avoid: extra limbs, identity drift, hands distorting, motion blur on face,
wardrobe morphing mid-shot.

Dance style variants

Pick one by --style (or ask). Each block fills the master template's variables.

hiphop (urban + crisp pops)

{style}: crisp street hip-hop — chest pops, body rolls, shoulder isolations,
         a confident two-step groove with clean weight transfers
{bpm}: 95
{camera_motion}: slow circular dolly around subject, ending with a gentle
                 push-in on the final pose
{environment}: neon-lit urban underpass with subtle rain reflections OR
               graffiti-tagged warehouse interior
{lighting}: cyan + magenta neon spill, hard rim light from behind

ballet (graceful, classical)

{style}: classical ballet — a single grand jeté leading into a piqué turn
         and finishing in fourth position arabesque
{bpm}: 60
{camera_motion}: smooth slow-mo tracking shot, low angle that sweeps to eye
                 level on the final pose
{environment}: bright minimalist dance studio with floor-to-ceiling windows
               OR a gilded baroque theater stage with red velvet drapes
{lighting}: soft natural daylight from camera-left OR warm theatrical key
            with a faint backlight

contemporary (emotional, expressive)

{style}: contemporary modern — flowing arm extensions, a controlled fall to
         the floor, then a slow rebound rise; focus on emotional fluidity
{bpm}: 70
{camera_motion}: handheld-but-stable, drifts in and out subtly
{environment}: empty industrial loft with shafts of dust-lit light OR a
               minimalist concrete plaza at golden hour
{lighting}: single hard key from a high window, deep falloff to shadow

kpop (synchronized, idol-stage energy)

{style}: K-pop idol-style point choreography — sharp arm hits, hair flips,
         crisp footwork, a charismatic finishing pose facing camera
{bpm}: 120
{camera_motion}: dynamic — quick zoom on the final beat, slight whip-pan
                 mid-routine
{environment}: glossy black-mirror stage with LED panel walls flashing
               brand colors
{lighting}: stage spots, strobing accent lights, lens flares on hits

terracotta-disco (兵马俑迪斯科 — viral meme combo)

{style}: Tang Dynasty terracotta warrior comes alive and dances disco —
         stiff-then-loose shoulder shimmies, retro point-and-pose moves, a
         signature hip drop
{bpm}: 110
{camera_motion}: slow orbit revealing the underground tomb opening up into
                 a 1970s disco
{environment}: terracotta army pit with disco ball descending from above,
               other warriors frozen mid-pose in the background
{lighting}: warm tungsten torches transitioning into rotating disco-ball
            sparkles + colored gels

tiktok-trend (default — current viral choreography wedge)

{style}: a clean tight 5-second TikTok-style routine — two distinct
         8-counts of upper-body choreography with one signature move on
         the final beat that begs to be looped
{bpm}: 105
{camera_motion}: locked tripod, vertical 9:16-friendly framing
{environment}: a bright bedroom OR minimalist white wall (let the camera
               feel native to the platform)
{lighting}: soft front ring-light look, natural skin tones, slight peach
            warmth

freestyle-from-music (when the user provides a music description)

{style}: choreography that responds to the following music: {user_music_description}
{bpm}: {inferred_or_user_supplied}
{camera_motion}: matched to musical phrasing — calm during verses, dynamic
                 on hits
{environment}: chosen to match the music's mood (let the model interpret)
{lighting}: matched to mood

Common Seedance pitfalls + retry addenda

Identity drift (face changes mid-clip)

Append:

The person's face is locked to the source image. Do not interpret or
restyle the face. Lip movement, eye direction, and head orientation may
change naturally, but underlying facial structure and skin tone must be
identical to the source frame.

Hands warping into 6+ fingers

Append:

Render hands clearly with five fingers each at all times. If a hand passes
behind the body, it should reappear with anatomically correct fingers.

Wardrobe morphing

Append:

Clothing remains identical to the source frame for the entire 5 seconds:
same garment type, same color, same fit. Do not introduce accessories or
patterns not present in the source.

"Static feeling" (low motion energy)

Append:

Increase motion energy. Limbs should travel through clear arcs, the upper
body should rotate, weight should shift visibly between feet at least
twice in 5 seconds.