Practical Course Producer

Job

Turn a real tool workflow into a teachable, reviewable course video. The video is the lesson: its scenes, demonstrations, narration, pauses, and checks must carry the complete teaching sequence. Planning files are production intermediates, not substitutes for the finished media.

Never fabricate hands-on evidence with echo, Write-Host, print, scripted terminal text, or a long one-shot prompt presented as interactive work.

The product boundary is any workflow with a real starting state, observable action, resulting state change, and verification. Read references/product-boundary.md before accepting an unfamiliar course topic or when the request might belong to Manim, deck generation, ordinary video editing, or marketing media. A pure concept explainer is outside this Skill even if it could be presented inside a fake terminal.

Inputs

Collect or locate only what the requested phase needs:

• learning goal, audience, target duration, and language;
• the real workflow, repository, CLI, browser tool, or source artifacts;
• existing recordings, narration, slides, subtitles, or prior audit reports;
• output directory and any locked sections that must not change;
• optional voice, branding, or publishing constraints.

Do not request credentials in chat. Use existing authenticated sessions or environment variables. Never write API keys, tokens, cookies, private recordings, or raw model logs into the skill package or generated reports.

Outputs

The primary deliverable is a versioned, publishable course video. Produce the smallest set of intermediate artifacts needed to make that video reproducible:

1. Final media: a versioned course video plus short check clips when review is needed.
2. lesson-plan.md: the video's learning outcome, scene spine, and acceptance evidence.
3. interaction-plan.md: short user turns, expected tool actions, and why each turn exists.
4. recording-checklist.md: scenes, commands, files, failures, corrections, and retests that must be captured.
5. narration.md: spoken explanation aligned to observable actions.
6. audit.md: commands run, frame/audio checks, known issues, and verdict.

Use stable, descriptive filenames. Keep generated runs outside the installed skill directory.

Workflow

Keep one course-project.json as the production status source. Start from assets/course-project.json, replace its placeholders, and keep every artifact path relative to the project directory. Do not enter a later stage because a draft video happens to exist.

1. Audit before planning

• Inspect the latest real artifacts, repository state, and previous audit.
• State what is confirmed, missing, locked, and unsafe to change.
• Confirm the requested final format, duration, aspect ratio, and publishing constraints before committing to a render plan.

2. Build the lesson spine

Design a small number of meaningful stages:

1. Explain the method or tool.
2. State the task and success evidence.
3. Create or run the first version.
4. Inspect files or output.
5. Show one real failure or weakness.
6. Give focused feedback and rerun.
7. Verify the final artifact with a real check.

Keep the method central. Treat the example as evidence, not the course topic.

Create lesson-plan.md, interaction-plan.md, recording-checklist.md, and narration.md, then require the planning gate to pass:

python scripts/validate_course_project.py path\to\course-project.json --gate plan

3. Plan real interaction

• Use short, natural user messages with one logical purpose each.
• Record what the tool actually returns; do not prewrite its response.
• Explain what was asked, why it was phrased that way, what changed, and what evidence proves the change.
• Keep useful mistakes. Cut only dead waiting after preserving enough reading time.

Read references/recording-workflow.md before recording a terminal, browser, or AI coding session.

4. Record or collect evidence

• Prefer a browser-mirrored local terminal when foreground recording would disrupt the user's desktop.
• Enter interactive tools normally, then type messages inside the session.
• Capture file inspection, validator failure, repair, and retest when relevant.
• Stop if the real tool cannot run. Report the blocker instead of simulating it.

After the scene plan references actual source recordings, require the recording gate to pass. Missing or empty recordings are a project blocker, not an editing task:

python scripts/validate_course_project.py path\to\course-project.json --gate record

Generate Chinese narration with Volcengine TTS HTTP Chunked v3 by default and Edge TTS as the fallback. Set VOLCENGINE_TTS_API_KEY in the environment; optionally override VOLCENGINE_TTS_SPEAKER and VOLCENGINE_TTS_RESOURCE_ID together. Never put credentials in a project file or command. If the key is missing or rejected, direct the user to https://console.volcengine.com/speech/new/setting/apikeys?projectName=default to obtain or replace it; do not ask them to paste it into chat. The primary request enables provider timestamps, protects the sentence start, and writes the actual provider and any fallback reason beside the audio:

Protocol family: https://www.volcengine.com/docs/6561/1719100?lang=zh. The offline adapter uses its HTTP Chunked counterpart at /api/v3/tts/unidirectional.

python scripts/synthesize_narration.py path\to\narration.md `
  --output path\to\audio\narration.mp3 `
  --timeline path\to\audio\narration.timeline.json

Use --voice only to change the Edge fallback voice. Use --fallback-provider none when a project must fail closed instead of falling back. A fallback is never silent: requested_provider, provider, fallback_used, and fallback_reason are written to the timeline. If both providers fail after bounded retries, stop at the narration blocker; never accelerate speech.

Reference the generated timeline as captions in each narrated scene. Captions must follow the spoken sentence boundaries and remain inside the safe lower margin without covering the command or validation evidence being discussed.

5. Assemble in locked passes

• Keep every meaningful render versioned.
• Replace only the target region when earlier sections are locked.
• Do not accelerate narration to force alignment. Adjust scene duration or trim verified dead waiting.
• Use local zoom only on the content viewport; keep titles and course framing fixed.

When real source recordings are ready, read references/scene-plan.md and advance the project through the render gate:

python scripts/advance_course_project.py path\to\course-project.json --to render

The project runner checks the record gate, calls scripts/build_course_video.py, updates final_video and run_manifest atomically, and checks the render gate. Use the builder directly only when diagnosing an isolated scene plan. Do not use either script to fabricate demonstrations or replace missing evidence.

Do not begin visual or audio polishing unless the runner reports that the render gate passed.

Read references/editing-audit.md before editing or validating media.

6. Verify before delivery

Verification must match the claimed output:

• final video: it teaches the complete workflow without requiring the viewer to read the intermediate planning files;
• lesson plan: every stage has a learning purpose and observable evidence;
• interaction plan: every user turn is short, necessary, and testable;
• recording: commands and model/tool output are genuine and readable;
• media: inspect changed-region clips, representative frames, duration, audio, and stream hashes when claiming untouched regions stayed unchanged;
• final report: list exact artifacts, tests, remaining risks, and next action.

Do not call a project complete because files merely exist.

Generate audit.md and representative frames from the rendered project, then require the final project gate to pass:

python scripts/advance_course_project.py path\to\course-project.json --to release

The release transition requires the rendered duration to stay within 20% of the project target, then records ffprobe structure, SHA-256, silence intervals, tool versions, and three representative frames. These deterministic checks do not replace human review of teaching accuracy, readability, or narration alignment; record that verdict in the generated audit.md before delivery.

Dependencies

• Planning and audit only: no external dependency.
• Media inspection/editing: ffmpeg and ffprobe on PATH.
• Browser-terminal recording: a local terminal bridge and an authenticated tool session chosen by the user.
• Default narration: Volcengine TTS HTTP Chunked v3 plus network access and VOLCENGINE_TTS_API_KEY. Obtain or replace a missing/rejected key at https://console.volcengine.com/speech/new/setting/apikeys?projectName=default. The packaged public default is zh_female_vv_uranus_bigtts with seed-tts-2.0; cloned voices must override both speaker and matching resource ID. Edge TTS is the packaged fallback; install it with python -m pip install edge-tts.
• Optional ASR, alternate TTS, or avatar services: user-provided access through environment configuration; never persist secrets.

If a dependency is missing, complete unaffected planning/audit work and report the blocked phase precisely.

Failure Rules

• Missing source evidence: do not invent a workflow; request or locate evidence.
• Tool or provider failure: preserve the real error and decide whether it teaches the workflow; never replace it with fake success output.
• Missing or rejected Volcengine key: report the environment variable and the official API Key console URL; use the configured Edge fallback or stop when fallback is disabled.
• Dirty repository: do not mix unrelated changes; use a clean worktree or a separate staging directory.
• Unclear alignment: inspect several consecutive frames and audio boundaries before editing.
• No measurable improvement: leave a verified no-op instead of polishing wording.

Voice

For Chinese narration, use compact spoken language. Prefer observable actions such as "我现在看文件" over abstract claims such as "形成闭环". When TTS misreads a filename, use a natural spoken form such as "graph 文件".

Maintainer Verification

From the repository root, run the strict skill validator and any bundled tests. The package must contain no credentials, private source media, local caches, or absolute paths. Script changes require a smoke test.

From the skill directory, run the deterministic media smoke tests with:

python -m unittest discover -s tests -p "test_*.py" -v

Run the portable end-to-end project smoke from any working directory with:

python scripts/smoke_course_project.py

See examples/verified-cli-workflow.md for the public example and RELEASE_NOTES.md for the packaged release scope and verification record.

Release Exit Boundary

After automated tests, evals, security checks, and repository integration pass, run exactly one fresh forward test on a practical topic not used during Skill development. Start from a normal user request and do not reuse prepared media or historical course scripts. Deliver the resulting video and audit for human review, then stop autonomous iteration.

Treat explicit user approval such as "satisfied", "ready to publish", or "leave it there" as the hard completion signal. If the user reports a blocking defect, make only the requested correction and repeat the same acceptance case. Do not switch topics, add speculative features, or continue polishing after approval.