Video Agent - Short-form, Explainer & Demo Router
SkillDocs & knowledgeShort-form, explainer, and demo video generation via a key-optional 3-tier router. Composes scripts, oma-voice narration, oma-image/oma-slide/stock visuals, key-free captions, and a vendored Remotion compositor into reproducible run directories. Routes three modes — shorts/reels (9:16), explainer (16:9 README/code/data), and demo/walkthrough (screen capture, incl. supervised headed web-app capture of any URL). Use for video, shorts, reels, short-form, demo, explainer, walkthrough, screencast, web capture, video generation, 영상, 숏폼, 쇼츠, 릴스, 데모, 설명 영상.
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Connect ahel once, and every AI you use reads what you have installed.
Then ask your AI: use the Video Agent - Short-form, Explainer & Demo Router skill
What this skill tells your AI
The instructions your AI receives, as published by gracefullight/stock-checker in .agents/skills/oma-video/SKILL.md and read by ahel’s review.
Scheduling
Goal
Generate finished .mp4 videos through a key-optional, 3-tier (CLI-first / MCP / guided) provider router while preserving deterministic asset buses (script -> timing -> render-spec), reproducible manifests, cost controls, and capture-path safety.
Intent signature
- User asks for a short-form video, shorts/reels clip, TikTok/YouTube Short, explainer, demo, walkthrough, or screencast.
- User wants a topic, README, code, or data turned into a narrated, captioned video.
- Another skill needs shared video-generation infrastructure (script -> assets -> render).
When to use
- Generating short-form video (shorts / reels) from a topic or brief (
--mode shorts, 9:16) - Generating an explainer from a README, code, or data set (
--mode explainer, 16:9 / 9:16) - Producing a demo / walkthrough from a screen capture file (
--mode demo --source file, 16:9) - Supervised headed web-app capture of any URL (
--mode demo --source web --url <url>) — a human drives the on-screen flow; the tool only opens a headed browser and records. Example categories are equal and illustrative only: demo, walkthrough, onboarding clip, bug repro, app-review screencast. - Re-rendering an existing run deterministically from
render-spec.json - Other skills needing video-generation infrastructure (shared invocation via
--format json)
When NOT to use
- Generating a single still image -> use
oma-image - Generating a slide deck / presentation -> use
oma-slide(this skill calls it internally for explainer frames) - Generating speech audio only (no video) -> use
oma-voice - Non-linear video editing of an existing finished mp4 -> out of scope (OpenCut-MCP deferred)
- Supervised headed web capture is in-scope (
--source web); live streaming is out of scope
Expected inputs
- A brief (topic / README path / data) plus optional mode, aspect, locale, captions, visual, voice, music, duration, compositor, capture path, seed
- For
demo--source file: a screen-capture file path (--capture) or Cap availability - For
demo--source web: a target--url(any URL — local/staging/prod), optional--device/--ready-selector/--show-cursor/--polish/--capture-timeout; capture size is derived from--aspect/--device(no hardcoded size); a resolvable Playwright + an interactive TTY (else the run falls back to the guided protocol) - Authentication/environment state for oma-voice (Voicebox MCP), oma-image vendors, and optional Pexels / Pixelle keys
Expected outputs
- A run directory under
.agents/results/videos/<timestamp>-<shortid>-<mode>/ - Deterministic asset bus:
script.json,timing.json,render-spec.json audio/,visuals/,captions.srt/captions.vtt, the rendered<mode>-<slug>.mp4manifest.jsonwith providers, asset hashes, cost breakdown, and exit code
Dependencies
oma video generateCLI + central error module (exit codes aligned withoma search fetch)- oma-voice (Voicebox MCP), oma-image, oma-slide as key-free fallback providers
- Vendored Remotion project at
resources/remotion/(compositor) resources/vendor-matrix.md,resources/execution-protocol.md,resources/prompt-tips.md,config/video-config.yaml
Control-flow features
- Branches by mode (shorts / explainer / demo), aspect, visual strategy, provider availability, cost threshold, capture requirement, and path safety
- Runs a per-capability fallback chain (real key/resource -> key-free fallback) per backend rule 11
- Reads briefs/captures and writes assets, render-spec, and manifests
- Calls external resources: Voicebox MCP, oma-image vendors, Remotion toolchain, optional Pexels / Pixelle
Structural Flow
Entry
- Validate that the brief carries enough mode/topic signal (or infer the mode from keywords).
- For
demo, confirm a capture path exists (or Cap is available); otherwise enter the guided protocol. - Resolve defaults from
config/video-config.yaml-> env vars -> CLI flags; check output path safety and limits.
Scenes
- PREPARE: Resolve mode/aspect/locale, clarify or amplify the brief, choose the visual + compositor strategy.
- ACQUIRE: Probe provider availability (voice / visual / caption / compositor), validate capture path, check cost.
- ACT: Run the mode pipeline — script -> (voice ∥ visuals ∥ captions) -> render-spec -> compositor render.
- VERIFY: Validate every asset-bus schema, manifest hashes, exit code, and the output mp4.
- FINALIZE: Return the run-dir path, the mp4 path, and any provider/coverage warnings.
Transitions
- If the brief lacks a clear mode, infer from keywords (shorts/reels -> shorts; README/code -> explainer; capture -> demo) and show the user the inferred plan before generating.
- If the selected visual provider key is absent (Pexels / Pixelle), fall through the chain to the key-free oma-image stills + Ken Burns fallback and annotate coverage.
- If
demo--source webhas a--url, dispatch the headed web-capture path (human-driven flow, ENTER to stop); if Playwright is unresolvable OR there is no interactive TTY, fall back to the guided protocol (no hang). - If
demo--source filehas no capture and Cap is unavailable, emit the guided capture protocol and stop (exit code maps to capture-required). - If estimated cost (Pixelle / RunningHub credits) exceeds the guardrail, require confirmation unless bypassed.
Failure and recovery
- If a provider is unavailable, try the next provider in the capability's
order; only chain exhaustion is a stage failure. - If the Remotion toolchain is not bootstrapped, point the user to
oma video doctor; fall back to the MPT compositor where applicable. - If Voicebox MCP is down, fall back through voicebox-stt -> whisper.cpp -> estimated timing (still produces captions).
- If the brief locale is non-source, translate via oma-translator (key-free); if absent, warn and keep source text.
Exit
- Success:
<mode>-<slug>.mp4andmanifest.jsonexist in the run directory; all schemas validate. - Partial success: video renders with a key-free fallback in place of a paid provider; coverage is annotated in warnings.
- Failure: no video is produced and the route/cost/capture/auth/safety blocker is explicit in the exit code + manifest.
Logical Operations
Actions
| Action | SSL primitive | Evidence |
|---|---|---|
| Validate brief + mode | VALIDATE | Clarification protocol, mode inference |
| Select provider strategy | SELECT | Vendor matrix, providers.*.order, availability |
| Read brief / capture | READ | Brief text, --capture path |
| Generate script | CALL_TOOL | AgentScriptProvider -> script.json |
| Synthesize narration + timing | CALL_TOOL | oma-voice -> audio/*.wav + timing.json |
| Produce visuals | CALL_TOOL | oma-image / oma-slide / stock -> visuals/* |
| Build captions | WRITE | key-free captions.srt / .vtt from timing |
| Compose render-spec | WRITE | render-spec.json (determinism boundary) |
| Render video | CALL_TOOL | Remotion / MPT compositor -> <mode>-<slug>.mp4 |
| Validate result | VALIDATE | Schema parse, manifest hashes, exit code |
| Report output | NOTIFY | Run-dir + mp4 path summary |
Tools and instruments
oma video generate,oma video doctor,oma video list-providers,oma video render- Provider adapters: AgentScript, oma-voice, oma-image, oma-slide, Pexels, Pixelle, oma-captions, Cap, Remotion, MPT
- Vendored Remotion project (
resources/remotion/), prompt tips, vendor matrix, video config
Canonical command path
oma video doctor
oma video generate "<brief>" --mode shorts --aspect auto --captions tiktok --format json
Explainer from a README, with a deterministic seed:
oma video generate "explain this project" --mode explainer --aspect 16:9 --seed 42 --out ./out
Demo from a screen capture:
oma video generate "feature walkthrough" --mode demo --capture <absolute-path>.mp4
Deterministic re-render from an existing run:
oma video render .agents/results/videos/20260603-143052-ab12cd-shorts
Resource scope
| Scope | Resource target |
|---|---|
LOCAL_FS | Briefs, captures, assets, render-spec, run dir, manifests |
PROCESS | oma-image / oma-slide CLIs, Remotion / MPT, Cap CLI, Playwright web-capture driver (subprocess) |
NETWORK | Voicebox MCP (localhost), oma-image vendor APIs, the user-supplied --url for web capture (masked in logs/manifest), optional Pexels / Pixelle / RunningHub |
CREDENTIALS | oma-image vendor auth, optional PEXELS_API_KEY / RUNNINGHUB_API_KEY. Web capture handles NO credentials — a human logs in if the flow needs it; nothing is stored or printed. |
Preconditions
- Brief carries enough signal for the mode, or the user approves the inferred/amplified plan.
- Output path is inside
$PWD(or--allow-external-outis set). - For
demo--source file: the capture path exists, is absolute/$PWD-guarded, and is a valid format. - For
demo--source web: a--urlis supplied (elseSchemaValidationError); a resolvable Playwright + an interactive TTY exist (else the run falls back to the guided protocol). - Required provider availability holds for the chosen (non-fallback) path, or the fallback is acceptable.
Effects and side effects
- Creates a run directory with assets, render-spec, captions, mp4, and manifest.
- oma-voice plays narration on the speakers as a side effect of synthesis.
- May call paid or rate-limited providers (Pexels / Pixelle / RunningHub) only when keys are present.
Guardrails
- Clarify or infer before invoking: if the mode/topic is ambiguous, infer the mode from keywords and show the user the plan, or ask. Do NOT silently render from a vague brief. See
Clarification Protocolbelow. - Key-optional dispatch (backend rule 11): every external capability has a real (key/resource) path AND a key-free fallback. Paid providers (Pexels, Pixelle) auto-enable only when their env key is present; otherwise the chain falls through to oma-image stills + Ken Burns. Default providers (oma-voice local, oma-image, oma-slide, Remotion) are key-free, so auto-triggering on keywords is safe.
- Cost guardrail: confirm before runs whose estimated cost is >=
cost.guardrail_usd($0.20, configurable) or--max-usd.--yes/OMA_VIDEO_YES=1bypass. Local/free paths carry zero cost. - Path safety: output paths outside
$PWDrequire--allow-external-out.--captureis absolutized,$PWD-guarded, and format-validated; external assets are copied into the run dir and hashed (no URL refs). - Cancellable: SIGINT/SIGTERM aborts in-flight provider calls, the render, and the orchestrator.
- Deterministic outputs:
render-spec.json+ asset files (+ seed + embedded Pretendard font) are the determinism boundary. Re-rendering the same render-spec is byte-stable;OMA_VIDEO_MOCK=1replays golden fixtures. - Limits:
limits.max_duration_sec= 180,limits.max_scenes= 40 (wall-time + memory bound). - Community-MCP consent: Pixelle-MCP is off by default and requires one-time explicit consent + source review before connecting; RunningHub credits gate on
--max-usd. - Demo is human-in-the-loop: capture is performed by a human. For
--source filethe skill guides but does not screen-record autonomously; for--source webthe tool only opens a headed browser and records while the human drives the entire on-screen flow (interactive ENTER to stop). The mechanism prescribes nothing about what the flow is or what the recording is for. - Web-capture security: NO credential automation of any kind — if a flow needs a login, a human performs it. The driver runs as a subprocess under the resolved Playwright (never imported into the CLI). The
--urland any query tokens are masked in logs and inmanifest.json; credentials are never stored or printed. Recording and all outputs are confined to the run dir. On-screen sensitive input is captured as-is — the user controls the flow. Multi-page navigation (popup / new tab / redirect) is recorded generically, with no assumption about the flow's shape. - Web capture is key-optional + non-blocking: web capture is the real branch; the guided protocol is the fallback when Playwright is unresolvable OR there is no interactive TTY (CI /
-y/ no stdin) — the run falls back to guided and never hangs. Live capture is outside the determinism boundary, so the manifest recordsnondeterministic: true. - Exit codes align with
oma search fetch(0 ok, 1 generic, 2 safety, 3 not-found, 4 invalid-input, 5 auth-required, 6 timeout).
Clarification Protocol
Before invoking oma video generate, the calling agent runs this checklist. If any answer is "no / unknown", clarify or infer-and-confirm with the user first.
Required signal (must be present or inferable):
- Mode: shorts / explainer / demo? Infer from keywords (shorts/reels/쇼츠/릴스 -> shorts; README/code/data/explain/설명 -> explainer; demo/walkthrough/capture/데모 -> demo).
- Topic / source: what is the video about? (a topic, a README/code path, a capture file, or — for
demo--source web— a--url) - For
demo:--source file(a--capturepath) or--source web(a--url)? For--source web, state up front that a human drives the on-screen flow and that the tool never automates any login.
Strongly recommended (ask if absent AND not inferable):
- Aspect:
9:16(shorts/reels),16:9(explainer/demo),1:1, orauto(snaps to the mode default). - Locale: narration + caption language (default from config; translated via oma-translator when non-source).
- Captions:
tiktok(centered, animated),lower-third, ornone. - Duration: target seconds (<= 180) or
auto(derived from the script). - Voice / music: voice profile or
none; musicupbeat/calm/none.
Amplification shortcut. For a one-line brief (e.g. "shorts about Jeju coffee"), do not pop a questionnaire if the request is genuinely simple. Instead amplify inline and show the user the inferred plan before invoking:
User: "make a short about Jeju coffee" Agent: "I'll generate this as: mode
shorts, 9:16, ~30s, oma-image stills with Ken Burns, TikTok captions, localeen, calm music. Proceed, or adjust mode/aspect/voice?"
Skip clarification when the user authored a full brief (mode + topic + aspect + captions). Respect their flags verbatim.
Output language. Narration and on-screen text are authored in the requested locale. Image-generation prompts passed to oma-image are sent in English (image models are trained predominantly on English captions); translate the user's request and show the translated version during amplification.
Modes
| Mode | Aspect | Source | Default visual | Compositor | Output |
|---|---|---|---|---|---|
shorts | 9:16 | synthetic (topic) | oma-image stills + Ken Burns; Pexels (key) · Pixelle AIGC (key) opt | Remotion · MPT alt | shorts-<slug>.mp4 |
explainer | 16:9 / 9:16 | README · code · data | oma-slide frames + oma-image diagrams + code | Remotion (deterministic) | explainer-<slug>.mp4 |
demo | 16:9 | --source file (Cap / capture file) · --source web (headed browser at --url) | raw footage (default) · Remotion intro · zoom · callouts (--polish) | Remotion polish | demo-<slug>.mp4 |
3-Tier Integration
| Tier | Surface | Providers | Trigger |
|---|---|---|---|
| 1 | CLI-first (subprocess, deterministic) | Remotion render, MPT, oma-image, oma-slide, oma-voice | always available (key-free defaults) |
| 2 | MCP | Voicebox MCP (voice/timing), Pixelle-MCP (AIGC, off by default) | MCP server reachable; Pixelle needs explicit consent + key |
| 3 | Guided (human-in-the-loop) | Playwright headed web capture (--source web, human drives the flow), Cap (capture), openscreen fallback | demo mode; web capture needs a resolvable Playwright + a TTY (else guided protocol) |
Invocation
Standalone
/oma-video make a 30s short about Jeju coffee
/oma-video --mode explainer --aspect 16:9 explain this project from the README
/oma-video --mode demo --source file --capture ~/recordings/walkthrough.mp4 feature demo
/oma-video --mode demo --source web --url http://localhost:3000 record my app flow
/oma-video --mode demo --source web --url <url> --ready-selector "#app" --polish onboarding clip
Shell CLI
oma video generate "<brief>" [--mode shorts|explainer|demo] \
[--aspect 9:16|16:9|1:1|auto] [--locale <lang>] \
[--captions tiktok|lower-third|none] \
[--visual auto|generate|stock|aigc|slide] \
[--voice <profile>|none] [--music upbeat|calm|none] \
[--duration <sec>|auto] [--compositor remotion|mpt] \
[--capture <path>] \
[--source file|web] [--url <url>] [--device <name>] \
[--ready-selector <css>] [--show-cursor] [--polish] \
[--capture-timeout <sec>] [--capture-stop duration:<sec>|selector:<css>] \
[--out <dir>] [--allow-external-out] \
[--max-usd <n>] [--seed <n>] [--timeout 600] [-y] \
[--dry-run] [--format text|json] [--no-brief-in-manifest]
# --source web: headed browser at --url; capture size derived from --aspect/--device (no hardcoded size).
# A human drives the on-screen flow; press ENTER to stop. NO credential automation. --url/tokens masked.
# Non-interactive (CI / -y / no TTY) or unresolvable Playwright -> falls back to the guided protocol (no hang).
# --capture-stop gives CI a non-interactive stop (duration / selector) in place of the ENTER prompt.
oma video doctor # Node/Chromium/FFmpeg · Voicebox MCP · oma-image vendors · Pixelle-MCP · Cap · Playwright (web capture)
oma video doctor --install-playwright # one-time: npm i playwright + chromium (web capture)
oma video list-providers # availability + key/fallback status
oma video render <runDir> # re-render from render-spec.json (deterministic)
Shared Infrastructure (from other skills)
Other skills call oma video generate --format json and parse the JSON envelope ({exitCode, runDir, manifestPath, outputs}) from stdout. The deterministic boundary is render-spec.json + assets, so a downstream consumer can re-render via oma video render <runDir> without re-running script/voice/visual generation.
Output Layout
.agents/results/videos/
└── 20260603-143052-ab12cd-shorts/ # {timestamp}-{shortid}-{mode}
├── script.json # determinism boundary start
├── timing.json
├── render-spec.json # deterministic compute boundary
├── audio/
│ └── narration-01.wav …
├── visuals/
│ └── scene-01.jpg …
├── captions.srt
├── captions.vtt
├── shorts-<slug>.mp4
└── manifest.json # reproducibility record
References
Follow resources/execution-protocol.md step by step.
See resources/vendor-matrix.md for provider precheck + fallback-chain rules.
Use resources/prompt-tips.md for writing effective briefs per mode.
Before submitting, run resources/checklist.md.
The vendored Remotion compositor lives at resources/remotion/ (see its README.md).
The web-capture driver lives at resources/playwright/record.mjs (runs as a subprocess under the resolved Playwright; never imported into the CLI).
The MPT fallback compositor driver lives at resources/mpt/driver.py (consumed by the CLI's mpt-project internals).
Configuration
Project-specific settings: config/video-config.yaml.
Env vars: OMA_VIDEO_DEFAULT_MODE, OMA_VIDEO_DEFAULT_OUT, OMA_VIDEO_YES, PEXELS_API_KEY, RUNNINGHUB_API_KEY (+ POLLINATIONS_API_KEY via oma-image), OMA_VIDEO_MOCK, OMA_VIDEO_PLAYWRIGHT_DIR (web-capture Playwright override), OMA_VIDEO_PWTEST (opt-in web-capture e2e).
- Execution steps:
resources/execution-protocol.md - Vendor matrix:
resources/vendor-matrix.md - Prompt tips:
resources/prompt-tips.md - Checklist:
resources/checklist.md - Remotion compositor:
resources/remotion/README.md - Context loading:
../_shared/core/context-loading.md
Signals
- GitHub stars
- 44
- Forks
- 9
- Last commit
- Sep 2026
Advanced
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oma-video-gracefullight- Source
- github.com/gracefullight/stock-checker