| name | video-blog-walkthrough |
| description | Create, revise, verify, and embed narrated technical walkthrough videos for developer blogs. Use when a request asks for a blog video, product walkthrough, source-code-and-application demo, subtitles/captions, narration, MP4/poster/SRT assets, or a local video embed that will later be replaced by YouTube. |
Video Blog Walkthrough
Produce a concise, reproducible video that demonstrates the real application and the source/configuration behind every material component.
Workflow
- Audit the blog and repository before scripting.
- Extract the core message, component list, runnable path, and limitations.
- Verify claims against current source and configuration.
- Define a scene for the app plus one for each important component.
- Create a scene plan with exact duration, visual source, narration, and subtitle text.
- Prefer 90 seconds to 4 minutes unless the user specifies otherwise.
- Start with outcome and architecture, then move through code/config, live app, data write, and recap.
- Keep subtitles to two lines, about 42 characters per line when practical.
- Capture authentic visuals.
- Use the appropriate browser skill for the live application.
- Show actual repository files for Java, JavaScript/TypeScript, YAML, SQL, or configuration.
- Use stable zoom and large text; crop out unrelated tabs, notifications, and personal information.
- Never show secrets,
.env values, wallets, tokens, passwords, private URLs, or browser account data.
- Build deterministic assets inside the project.
- Store the build source, narration text, subtitle file, poster, and final MP4 together under a clearly named
video/ directory.
- Prefer a repository-native build script so scenes can be regenerated when the blog changes.
- Use available local media tooling. On macOS, AVFoundation/AVKit plus
say is an acceptable dependency-light path.
- Add narration and captions.
- Narrate only what the current scene demonstrates.
- Produce an SRT or WebVTT sidecar even if subtitles are burned into the video.
- Use accessible contrast and keep burned captions inside title-safe margins.
- Verify before embedding.
- Play or inspect the complete video, not only individual frames.
- Confirm the MP4 has video and audio, expected dimensions/duration, readable code, synchronized narration, and no secret exposure.
- Run
scripts/audit_video.sh VIDEO SRT BLOG_HTML when working on macOS.
- Embed locally and preserve a YouTube migration path.
- Use responsive HTML5
<video controls preload="metadata" poster="...">.
- Include an MP4
<source> and caption <track kind="captions" ... default>.
- Add a concise fallback link to the MP4.
- Place the walkthrough near the article introduction and update nearby copy to match the demonstrated implementation.
- Re-run the blog’s publishing audit and project tests, then commit only scoped assets.
Quality Gates
- The live application visibly performs its central workflow.
- Every architecture component appears as application behavior, source, or configuration.
- Database writes shown in the video use test/demo data and are explicitly approved.
- Code is legible at normal playback size.
- Narration, burned subtitles, and sidecar captions convey the same meaning.
- No credential value or sensitive local path appears in frames, narration, captions, metadata, or committed files.
- Blog claims, commands, screenshots, and video all describe the same revision.
Reusable Script
Run scripts/audit_video.sh after rendering. It checks file presence, macOS media metadata, caption numbering/timestamps, blog embedding, and obvious secret-like text in captions.