How to use the Showcase Video Maker agent skill (showcase-video)

What the skill makes the agent do

Agent skills are folders of instructions that an AI agent loads when a task matches them. This one covers the full path from gameplay to finished video: scripting a repeatable take, recording only the game window with the game's own audio, picking moments from timestamped contact sheets, and assembling the result from a JSON edit list.

The skill's toolchain is the um command-line tool, which uses ffmpeg and Pillow. The commands it names are um win record (capture), um video contact (look at frames) and um video compile (edit).

• Records the game window only, not the whole desktop
• Captures game audio only, with no Spotify or notifications
• Builds contact sheets so the agent can choose in and out points
• Edits with one-line animated titles, creator credits, transitions, music, a watermark and a fade-out

Install the showcase-video skill

Download the ZIP for the showcase-video skill from this page, then choose one of two routes. For a personal setup, unzip it into ~/.claude/skills/. For a single project, unzip it into that project's .claude/skills/ folder. The skill ships as a single file, SKILL.md.

If you use the Claude apps, you can instead upload the skill under Settings → Capabilities → Skills.

• Personal: unzip into ~/.claude/skills/
• Project only: unzip into the project's .claude/skills/
• Claude apps: Settings → Capabilities → Skills, then upload

Install the tools the skill depends on

The skill does not work on its own. It calls the um command-line tool, ffmpeg and Pillow, and it expects a Windows machine with a game window to capture. Install these before you ask for a video. The source does not give installation commands for um, so check its own documentation for that step.

• um command-line tool (um win record, um video, um fal music)
• ffmpeg
• Pillow
• Windows with a running game window
• Optional: NVENC, AMF or QSV for hardware encoding
• Optional: a music generation service through um fal music, which implies a fal account or API key (the skill does not specify the details)

Trigger the skill with a natural request

You do not need special syntax. The skill loads when your request asks for a demo video, trailer, clip or montage of a mod, or for combining existing clips into a styled video. Say what you want and what you have.

Good requests name the mod, the game executable if you know it, the length you want, and any clips or music you plan to use.

• "Make a 30-second demo video of my mod from the Terraria game window."
• "Record a take of Game.exe for 40 seconds and cut a trailer from it."
• "Combine these three clips I have permission to use into a styled montage with titles and credits."
• "Put a watermark and fade-out on my mod showcase."

Follow the workflow the skill describes

The skill walks the agent through four stages. First, make the take repeatable: script the action, restore the world before each take with um backup, and set a clean frame. Second, record the window and audio, then mux them with a sync offset. Third, look at contact sheets and pick peak moments. Fourth, write an EDL JSON and compile it.

Here is an example of the recording commands the skill uses:

• Restore the game world before each take so every take starts the same
• Use --offset in the mux step when audio and video drift, matching a visual flash with its sound
• Preview with --preview before a full render
• Look at a contact sheet of the finished video before sharing it

Edit with an EDL JSON file

The edit is described in a JSON file, called an EDL here, which you pass to um video compile. The skill's example sets the frame size, frame rate, accent colour, a default fade transition, clip volume, background music, a corner watermark and a list of segments. Each segment names a clip, an in point, a duration, and optionally a title, hook or transition. A segment can also be a title card.

The full format is documented in um video --help, according to the skill.

• Transitions: any ffmpeg xfade type (fade, pixelize, slideleft, circleopen and others) or cut
• Fills for non-16:9 clips: blur, crop or pad
• Per clip: speed, volume, zoom and crop
• Music: set bpm and use beats instead of dur to cut on the beat

Safety notes: scripts and network

The skill runs scripts and uses the network. Its recording step uses a WASAPI process loopback script, um/ps1/ProcLoopback.ps1, to capture the game's audio. The optional music step sends a request to a music generation service. Review the scripts and the tool before you run the skill, especially on a machine with sensitive data.

The skill asks you to credit other creators and to get permission for promotional use, but it does not enforce either rule. Only download public posts, and only the clips you will actually use.

• Runs scripts: yes (including ProcLoopback.ps1)
• Uses network: yes (for example, the optional music service)
• Permission and crediting are advice, not enforced by the skill

Tips for a better showcase

The skill gives concrete style advice. Keep titles to one line that names what is on screen, and leave out captions about how the video was made; put that in the post text instead. Get into gameplay within 2-3 seconds, keep menus under 3 seconds, and keep clips to about 3-5 seconds each. End on the mod name or URL and fade out.

Keep the game's own audio, because it sells impacts. In a compilation, put music under the clips and set clip audio around 0.5 to 0.8.

• Titles: one line, naming the thing on screen
• Pace: gameplay within 2-3 s, clips 3-5 s each
• Sound: keep game audio; music under compilations
• Compilations: credit every creator on screen and in the post