TikTok and Reels reward fast-tested creative more than any other paid surface. That means producing variants quickly is the bottleneck — not budget, not targeting. A team that ships 30 variants per week wins over one that ships 3.
This guide uses the same video creative API as the B2B video guide, but with `aspect_ratio: "9:16"`. Output is a 1080×1920 MP4 with cinematic AI footage, animated headlines, and a CTA card — vertical-native, not cropped from a 16:9 source.
Step by step
- 01
Vertical-native composition
Pass `aspect_ratio: "9:16"`. The script director composes scenes for vertical specifically — hero subjects centred top, headline animation middle, CTA card bottom. Cropping from 16:9 loses the headline; native 9:16 keeps it in safe zone.
- 02
Duration and pacing
Footage is 4–8 seconds. The motion-graphics overlay adds the headline animation and CTA card on top — final runtime is typically 6–10 seconds. TikTok feed surfaces 9–15 second ads best; if you need longer, you can chain two calls and stitch.
- 03
Upload directly
The MP4 is encoded H.264 + AAC silent track. Drops straight into TikTok Ads Manager, Meta Ads Manager (Reels placement), or YouTube Shorts. Add music in their post-upload editor or via the Creator Studio overlay if you need branded audio.
Example prompts
Copy, click, tweak — the CTA opens the terminal with the prompt pre-loaded.
5-second 9:16 vertical ad for a casual puzzle game. Headline: "1 minute. 100 levels." CTA: "Free on the App Store". Style: bright candy palette, fast cuts. Try →8-second 9:16 video for a portable espresso maker. Headline: "Real espresso. Anywhere." CTA: "Pre-order". Style: outdoor cinematic, shallow depth of field. Try →6-second 9:16 portrait video for a developer tooling startup. Headline: "Ship without writing CI YAML". CTA: "Try the beta". Style: clean studio, code visible on screen behind speaker. Try →API call
Standard REST. Bearer token, JSON body, URL response. Works in any HTTP client, n8n, Make, Zapier, or MCP agent.
curl -X POST https://api.42rows.com/v1/video-creative \
-H "Authorization: Bearer sk_..." \
-H "Content-Type: application/json" \
-d '{
"prompt": "5-second vertical ad for a casual puzzle game, CTA Free on the App Store",
"duration": 5,
"aspect_ratio": "9:16",
"resolution": "1080p"
}'Pricing
Pay-per-call, no subscription. Subscription plans are on the roadmap — they will not change pay-per-call rates.
FAQ
Can I add music or voice-over?
Not at the API layer yet. Output audio is a silent track. Add music in TikTok or Meta's post-upload editor — that path keeps you on the platform-native commercial library, which is usually licensing-safe by default.
How does TikTok feel about AI-generated footage?
TikTok requires AI-generated video to be labelled when it depicts realistic events, places, or people. Our outputs default to clearly stylised footage, but you should still tick the "AI-generated content" toggle in TikTok Ads Manager when uploading.
Does the MP4 work in Reels and Shorts too?
Yes. 1080×1920 H.264 is the universal vertical format — same file works on TikTok, Instagram Reels, Facebook Reels, YouTube Shorts. No re-encode.
How long does a vertical render take?
Same as 16:9: typically 3–5 minutes. The aspect ratio does not change render time meaningfully.
Can I preview before paying for the full render?
There is no preview-only mode currently. Each render is one call. The script director's output (the 3-scene plan) is logged but not exposed as a separate billable step.
Ship it
Use the first example prompt as a starter — the button opens the public terminal with it pre-filled.