Generate AI images and videos via the LetzAI API. Images with Nano Banana Pro, Seedream 5, Flux 2, GPT Image 2; videos with Veo 3.1, Kling V3, Seedance 2.0. Includes context editing, upscaling, asset uploads, and custom @model training. Use for content creation apps and automation.

LetzAI API Integration Skill Overview Helps you integrate the LetzAI public API for AI image and video generation, editing, upscaling, asset uploads, and custom model (LoRA) training. Custom trained models for persons, objects and styles are referenced inside prompts with @modelname . Authentication Base URL: https://api.letz.ai Auth: Authorization: Bearer YOUR API KEY Get an API key: [letz.ai/subscription](https://letz.ai/subscription) Swagger (source of truth): [api.letz.ai/doc](https://api.letz.ai/doc) — machine readable at /doc json and /doc yaml Do not confuse the public API with the private one. https://api.letz.ai is the public developer API described here. https://private api.letz.ai powers the LetzAI web app and has different route names ( /upscales , /image completions , /video edits ). Those routes 404 on the public API. Unknown field rejection The API validates request bodies strictly. Sending a field that is not in the schema returns 400 . In particular there is no negativePrompt , seed or aspectRatio on POST /images — aspect ratio is expressed via width / height . Core Workflows 1. Image Generation — POST /images Parameter Type Default Notes prompt string — Required. May contain @modelname tags. baseModel string account default See model table below. mode string model default Resolution tier — allowed values differ per model. width int 1600 480–2160 height int 1600 480–2160 quality int 2 1–6 creativity int 2 1–6 hasWatermark bool true systemVersion int account default 2 or 3 hideFromUserProfile bool false webhookUrl string — POSTed when the job finishes. organizationId UUID — Bill credits to an org you belong to. Image models mode is the resolution tier , and the accepted values are model specific. Model baseModel mode values Credits (generate) Credits (edit) Nano Banana Pro (Google) gemini 3 pro image default (1K) · 2k (HD) · 4k 80 / 160 / 240 80 / 160 / 240 Nano Banana 2 (Google) nbf inferencesh default (1K) · 2k (HD) · 4k 40 / 80 / 160 50 / 100 / 150 Nano Banana 2 Lite (Google) nano banana 2 lite default (1K) 20 25 Seedream 5 Pro (ByteDance) seedream 5 0 pro 2k (HD) · 4k 80 / 160 80 / 160 Seedream 4.5 (ByteDance) seedream 4 5 251128 2k (HD) · 4k 80 / 160 80 / 160 Flux 2 (Black Forest Labs) flux2 1k · hd 60 / 120 60 / 120 GPT Image 2 (OpenAI) gpt image 2 1k · hd · 4k 160 / 240 / 480 160 / 240 / 480 WAN 2.7 Image Pro (Alibaba) wan 2 7 image pro 1k · 2k 10 10 Aliases are accepted, e.g. gemini 3 pro image preview still resolves to Nano Banana Pro. The live catalogue with pricing lives at [letz.ai/docs/models.json](https://letz.ai/docs/models.json). Workflow 1. POST /images 2. Read id from the response 3. Poll GET /images/{id} every 3 s 4. On status === "ready" , read imageVersions.original See [examples/image generation.js](examples/image generation.js). 2. Video Generation — POST /videos Parameter Type Notes prompt string Required. originalImageCompletionId UUID Animate a previously generated LetzAI image. imageUrl string Animate a public image URL. imageUrls string[] Multi frame: [0] = first frame, [1] = last frame. prompts object[] Multi shot storyboards ( video kling3 ): [{ prompt, duration }] . baseModel string Optional; settings.mode is the usual selector. width / height / resolution number Optional output sizing. settings object Model + duration + audio (below). webhookUrl string hidePrompt bool organizationId UUID Image input is optional — omit all of originalImageCompletionId / imageUrl / imageUrls for pure text to video. settings Field Notes mode Video model key — see table. duration Seconds, clamped to the model's allowed values. withSound Enable native audio where supported. highQuality Higher resolution tier; usually doubles the price. resolution "720p" , "1080p" , "4k" for per second priced models. Video models Use the video prefixed key as settings.mode . Model settings.mode Duration Credits Google Veo 3.1 video veo31 8 s (fixed) 1500 · ×2 with audio · ×2 at 1080p Kling V3 video kling3 3–15 s 150 · 300 with audio Kling V2.6 video kling26 5 or 10 s 150 · ×2 with audio · ×2 at 1080p WAN 2.5 video wan25 5 or 10 s 110 · ×2 at 1080p (image to video only) Seedance 2.0 video seedance2 4–15 s per second: 105 @480p · 210 @720p · 500 @1080p · 1000 @4K (audio always on) Seedance 2.0 Enterprise video seedance2 enterprise 4–15 s same as Seedance 2.0; requires organizationId only available to Enterprise Customers with an active organization Gemini Omni Flash video gemini omni 3–10 s 100 per second (audio always on) Workflow 1. POST /videos 2. Poll GET /videos/{id} every 2–3 s 3. On status === "ready" , read videoVersions.original See [examples/video generation.py](examples/video generation.py). 3. Image Editing — POST /image edits Parameter Type Notes mode string Required. context (AI editing) or skin (skin fix). prompt string Edit instruction. May contain @modelname tags. imageUrl string Single source image URL. inputImageUrls string[] Multi reference source images (up to 9 in practice). originalImageCompletionId UUID Edit a previously generated LetzAI image. originalImageCompletionIds UUID[] Several LetzAI images as sources. baseModel string Same identifiers as image generation. settings object { resolution, aspect ratio, model } imageCompletionsCount int Variations to generate (1–5, default 1). Not used by skin . mask string Base64 mask, legacy inpainting only. width / height number Target dimensions. webhookUrl , organizationId , hidePrompt settings : resolution : "2k" (HD) or "4k" (Ultra HD) aspect ratio : "1:1" , "16:9" , "9:16" , "4:3" , "3:4" , "21:9" , "9:21" model : same identifiers as baseModel Provide at least one source: imageUrl , inputImageUrls , originalImageCompletionId or originalImageCompletionIds . Prefer the top level baseModel . Server side queue routing reads baseModel ; settings.model is forwarded to the worker. Setting both to the same value is safest. Workflow 1. POST /image edits 2. Poll GET /image edits/{id} every 3 s 3. On status === "ready" , read generatedImageCompletion.imageVersions.original mode: "in" (inpainting) and mode: "out" (outpainting) are deprecated — use context . 4. Upscaling — POST /upscale The public route is /upscale (singular). /upscales is the private web app route and returns 404 here. Parameter Type Default Notes imageId UUID — A LetzAI image completion ID. imageUrl string — Public image URL. Use instead of imageId . To upscale your own file, upload it via /user assets and pass the returned imageUrl . mode string default Upscaler model — see table. size number — 2–12; output tier — see table. strength number 1 1–5. prompt string — Optional guidance for creative upscalers. webhookUrl , organizationId mode Upscaler size → output Credits nano banana pro Google Gemini 3 Pro 4 → 1K · 8 → 2K · 12 → 4K 80 / 160 / 240 nano banana 2 Google Gemini 3.1 Flash 4 → 1K · 8 → 2K · 12 → 4K 50 / 100 / 150 gpt image 2 OpenAI GPT Image 2 4 → 1K · 8 → 2K · 12 → 4K 160 / 240 / 480 pruna Pruna P Image Upscale 4 → 1 MP · 8 → 4 MP · 12 → 16 MP 20 / 40 / 80 default LetzAI in house — 20 Workflow 1. POST /upscale 2. Poll GET /upscale/{id} every 3 s 3. On status === "ready" , read imageVersions.original 5. Uploading Your Own Files — POST /user assets Two step pre signed S3 upload. Use this to get a public URL for a local file before feeding it to /image edits , /videos or /upscale . 1. POST /user assets with { extension } (plus optional originalFilename , mimeType , fileSize , caption , metadata , numberOfImages ). 2. PUT the raw file bytes to the returned uploadUrl with the matching Content Type header. No Authorization header — the URL is already signed. 3. The file is then reachable at imageUrl from the step 1 response. Allowed extension values: jpg , jpeg , png , gif , webp , mp4 , webm , mov , avi , mp3 , wav , ogg , m4a , aac , flac . POST /user images is the older image/video only variant of the same flow; prefer /user assets , which also accepts audio. See [examples/uploads and training.md](examples/uploads and training.md). 6. Custom AI Models ( @modelname ) Trained models for persons, objects and styles. Tag them inside any image or edit prompt: @john doe on the beach at sunset . List: GET /models — query params page , limit , sortBy , sortOrder , search , name , userId , username , class ( person object style ), type , description , privacy ( public private licensed ), systemVersion , isActive , status . Pagination is reported through the X Total Count , X Current Page , X Per Page and X Total Pages response headers. Get one: GET /models/{id} Train a new model: POST /models — this is available over the API (Enterprise plans). Parameter Notes name Required. Alphanumeric, and . , max 50 chars. Becomes the @tag . class Required. person \ style \ object privacy public \ private \ licensed type Optional; auto generated when omitted. trainingDataUrls 1–50 public image URLs. Upload via /user assets first. trainingMode e.g. default , slow settings e.g. ["NO ADULT CONTENT", "NO VIOLENCE"] description , website , webhookUrl , organizationId Optional. Training starts automatically. Poll GET /models/{id} until status is available . Manage: PATCH /models/{id} , DELETE /models/{id} , PUT /models/{id}/thumbnail . Workflow Decision Tree Create an image → pick baseModel + mode from the model table → POST /images → poll GET /images/{id} → imageVersions.original . Use a trained model → GET /models?class=person to find the name → put @name in the prompt → generate normally. Edit an image → get a source (URL, /user assets upload, or a LetzAI completion id) → POST /image edits with mode: "context" → poll → generatedImageCompletion.imageVersions.original . Create a video → optional source image → POST /videos with settings.mode = a video key → poll → videoVersions.original . Upscale → POST /upscale with imageId or imageUrl → poll → imageVersions.original . Train a model → upload images via /user assets → POST /models with trainingDataUrls → poll GET /models/{id} until available . Status Polling Every generation endpoint is asynchronous: the POST returns an id , and you poll the matching GET until a terminal status. Resource Statuses Images new · generating · ready · failed · interrupted · not allowed · hidden Videos new · generating · ready · saved · failed · interrupted Image edits new · generating · ready · saved · failed · interrupted Upscales new · generating · ready · failed Models new · pen

letzai-api