generate_video
Generate AI videos from text, images, or reference clips. Choose from multiple models like Seedance, Happyhorse, Veo, and Grok with custom duration and resolution.
Instructions
Generate a video using AI via MeiGen platform. Supports text-to-video, image-to-video (first/last frame), and reference-video continuation (Seedance 2.0 only — pass referenceVideo URL + referenceVideoDuration together, and prompt must explicitly say "extend / continue"). Available models include Seedance 2.0 (mini/fast/pro tiers, mini is the cheapest default, 4-15s), Happyhorse 1.0 (cost-effective, 3-15s), Veo 3.1 (fast/pro tiers, 4/6/8s, native audio), and Grok Video 1.5 (grok-video, xAI — IMAGE-TO-VIDEO ONLY, firstFrame required, native audio, 4-15s, 480p/720p). Pricing varies — seedance/happyhorse/grok are per-second, veo is per-generation by tier × duration. See https://www.meigen.ai/model-comparison for the current schedule. With a reference video (seedance only), billable seconds = max(reference_duration + duration, min_billable[duration]); total often higher than direct generation. Generation typically takes 1–5 minutes (veo at 4k can take up to ~8 min).
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| prompt | Yes | The video generation prompt. Describe motion, scene, and style — not just the still image. | |
| model | Yes | Video model ID. Use list_models to see available video models. Common (as of writing): "seedance-2-0" (multi-tier general purpose), "happyhorse-1.0" (cost-effective i2v/t2v), "veo-3.1" (Google Veo with two tiers, 4/6/8s, native audio), "grok-video" (xAI Grok Imagine 1.5 — IMAGE-TO-VIDEO ONLY: firstFrame REQUIRED, pure text-to-video is rejected; native audio; 4-15s; 480p/720p). | |
| tier | No | Quality tier — only for models that support tiers. seedance-2-0 accepts "mini" (default, cheapest; 480p/720p, no reference video), "fast" (480p/720p), or "pro" (highest fidelity; native 1080p and 4K); veo-3.1 accepts "fast" (default) or "pro". Tiers may be added by the platform — call list_models to see what each model exposes. | |
| duration | No | Video duration in seconds. seedance-2-0 / happyhorse-1.0 currently accept ~3–15s (any integer in range). veo-3.1 accepts exactly 4, 6, or 8 (default 4) — other values will be rejected. Defaults to the model's default duration. Call list_models for the current allowed values per model. | |
| resolution | No | Output resolution. Common: "480p" / "720p" / "1080p" / "4k" (model-dependent; e.g. Seedance Pro adds 1080p and 4k, while Fast/Mini are 480p/720p only). Use list_models to see what each model supports. Higher resolutions cost more credits per second. | |
| aspectRatio | No | Aspect ratio: "16:9", "9:16", "1:1", "4:3", "3:4", "21:9", "auto", "adaptive" (model-dependent). Defaults to "auto" when omitted. | |
| firstFrame | No | First-frame image to control where the video starts. Accepts public URL or local file path (auto-uploaded). REQUIRED for grok-video (image-to-video only — backend rejects it without a firstFrame). For seedance/happyhorse/veo it is optional: with no first frame they do pure text-to-video. | |
| lastFrame | No | Optional last-frame image to also control where the video ends. Used by seedance-2-0 and veo-3.1; happyhorse-1.0 ignores this field. Accepts public URL or local file path. Requires firstFrame to also be provided — passing lastFrame alone is rejected. | |
| referenceVideo | No | Optional reference video URL for Seedance 2.0 "video continuation". Must be a publicly accessible HTTPS URL (typically a previous generation result `videoUrl`); local paths are not supported. Only seedance-2-0 accepts this — passing it with other models will fail. IMPORTANT — prompt requirement: to make the new clip semantically continue the reference, the `prompt` MUST explicitly say "extend" / "continue" (e.g. prefix with "Extend this video with the following plot:"). Without that, the model treats the video as visual reference only and the new clip may drift from a true continuation. Output behavior: the output is ONLY your `duration` seconds (4-15s) of new content — the reference video is NOT concatenated into the output. To get a single "original + new" clip the user must stitch them locally. Billing: credits are charged at the With-reference-video rate, with `billable_seconds = max(reference_duration + duration, min_billable[duration])`. Total cost is often higher than direct generation of the same output length. Always pass `referenceVideoDuration` alongside this field — omitting it causes underbilling and broken continuation behavior. | |
| referenceVideoDuration | No | Duration of the reference video in seconds (typically 2–15 — backend validates the current allowed range). REQUIRED whenever `referenceVideo` is set; if omitted the backend treats it as 0, leading to undercharged credits and misconfigured generation. Pass the actual duration of the clip at `referenceVideo`. |