# Runflow

> Start AI image and video runs with one HTTP call, then receive results by callback or polling. The Runflow API exposes a curated catalog of models from Runflow, Google, Alibaba, OpenAI, and others. Auth: HTTP Bearer.

## Resources

- [Public OpenAPI](https://docs.runflow.io/api/openapi.public.json): customer integration spec
- [API reference](https://docs.runflow.io/api-reference/models/search-models): generated from the public OpenAPI spec
- [Models catalog](https://www.runflow.io/models-catalog.json): the canonical model list
- [Agent skill](https://www.runflow.io/.well-known/agent-skills/runflow/SKILL.md): integration guide for AI coding assistants
- [llms-full.txt](https://docs.runflow.io/llms-full.txt): full docs corpus for one-shot ingestion

## Get started

- [Runflow](https://docs.runflow.io/): Start AI image and video runs with one HTTP call, then receive results by callback or polling. 50 models, one auth header.
- [Quickstart](https://docs.runflow.io/quickstart): Run your first Runflow model in under 5 minutes.

## Concepts

- [Authentication](https://docs.runflow.io/concepts/authentication): Pass an HTTP Bearer token on every Runflow API request.
- [Callbacks](https://docs.runflow.io/concepts/callbacks): Receive run results via HTTP webhook. Signing, retries, redelivery.
- [Clients](https://docs.runflow.io/concepts/clients): There are no official SDKs yet. Generate one from the public OpenAPI.
- [Errors](https://docs.runflow.io/concepts/errors): HTTP status codes Runflow returns and the error envelope shape.
- [Pricing](https://docs.runflow.io/concepts/pricing): How Runflow bills runs. Per-request, per-second, per-megapixel.
- [Rate limits](https://docs.runflow.io/concepts/rate-limits): How Runflow throttles requests, the headers we set, and how to back off.
- [Requests](https://docs.runflow.io/concepts/requests): Base URL, content types, pagination, filtering, and field projection.
- [Runs](https://docs.runflow.io/concepts/runs): A run is one model invocation. Lifecycle, logs, and how to fetch the result.

## Models

- [Models](https://docs.runflow.io/models): Browse the Runflow model catalog. One endpoint per model.
- [Happy Horse Image-to-Video](https://docs.runflow.io/models/alibaba/happy-horse/image-to-video): Alibaba's #1-ranked Happy Horse 1.0 - generate 1080p video with synchronized native audio and multilingual lip-sync from text prompts or images.
- [Happy Horse Reference-to-Video](https://docs.runflow.io/models/alibaba/happy-horse/reference-to-video): Generate 1080p video with synchronized native audio from a text prompt and references. Aspect ratios: 16:9, 9:16, 1:1, 4:3, 3:4. Duration: 3–15s.
- [Happy Horse Text-to-Video](https://docs.runflow.io/models/alibaba/happy-horse/text-to-video): Generate 1080p video with synchronized native audio from a text prompt. Aspect ratios: 16:9, 9:16, 1:1, 4:3, 3:4. Duration: 3–15s.
- [Happy Horse Video Edit](https://docs.runflow.io/models/alibaba/happy-horse/video-edit): HappyHorse video editing supports advanced video editing through natural language instructions. It allows for local or global editing of video elements using up to 5 reference images.
- [Qwen Image Edit 2511](https://docs.runflow.io/models/alibaba/qwen-image-edit-2511): Advanced image editing model from Alibaba. Qwen Image Edit 2511 delivers superior text editing capabilities, multi-image support, and precise visual modifications through natural language instructions. Supports style transfer, object editing, and creative compositions.
- [Wan 2.7 - Image to Video](https://docs.runflow.io/models/alibaba/wan/v2.7/image-to-video): Wan 2.7 delivers enhanced motion smoothness, superior scene fidelity, and greater visual coherence.
- [Wan 2.7 Pro Edit](https://docs.runflow.io/models/alibaba/wan/v2.7/pro/edit): Edit and transform images using text instructions with the WAN 2.7 Pro model for precise, professional-grade image modifications.
- [Wan 2.7 Text to Video](https://docs.runflow.io/models/alibaba/wan/v2.7/text-to-video): Wan 2.7 is the latest generation AI video model, delivering enhanced motion smoothness, superior scene fidelity, and greater visual coherence.
- [FLUX.2 [klein] 4B](https://docs.runflow.io/models/black-forest-labs/flux-2-klein-4b): Compact 4-billion parameter text-to-image model from Black Forest Labs. Step-distilled to 4 inference steps for sub-second generation. Unifies text-to-image and image editing in a single architecture with Apache 2.0 licensing.
- [FLUX.2 [klein] 9B](https://docs.runflow.io/models/black-forest-labs/flux-2-klein-9b): Text-to-image generation with FLUX.2 [klein] 9B from Black Forest Labs. Enhanced realism, crisper text generation, and native editing capabilities.
- [FLUX.2 [klein] 9B - Edit](https://docs.runflow.io/models/black-forest-labs/flux-2-klein-9b/edit): Image-to-image editing with FLUX.2 [klein] 9B from Black Forest Labs. Precise modifications using natural language descriptions and hex color control.
- [FLUX Kontext](https://docs.runflow.io/models/black-forest-labs/flux-pro/kontext): FLUX.1 Kontext [pro] handles both text and reference images as inputs, seamlessly enabling targeted, local edits and complex transformations of entire scenes.
- [Bria Background Remove](https://docs.runflow.io/models/bria/background/remove): Bria RMBG 2.0 enables seamless removal of backgrounds from images, ideal for professional editing tasks. Trained exclusively on licensed data for safe and risk-free commercial use.
- [Seedance 2.0 Fast Text to Video](https://docs.runflow.io/models/bytedance/seedance/2.0/fast/text-to-video): Fast variant of Seedance 2.0 for quicker text-to-video generation with synchronized audio support.
- [Seedance 2.0 Image to Video](https://docs.runflow.io/models/bytedance/seedance/2.0/image-to-video): Seedance 2.0 animates a starting frame image into video, with optional end frame for controlled transitions. Supports synchronized audio generation.
- [Seedance 2.0 Text to Video](https://docs.runflow.io/models/bytedance/seedance/2.0/text-to-video): Seedance 2.0 generates high-quality videos from text prompts with synchronized audio including sound effects, ambient sounds, and lip-synced speech.
- [ElevenLabs TTS v3](https://docs.runflow.io/models/elevenlabs/tts/eleven-v3): Generate text-to-speech audio using Eleven-v3 from ElevenLabs.
- [Gemini TTS](https://docs.runflow.io/models/google/gemini-tts): Google's Gemini TTS converts text to realistic audio. 30 voice presets, multi-speaker synthesis (up to 10 speakers), 24+ languages, and inline style markers for expressive control.
- [Nano Banana 2](https://docs.runflow.io/models/google/nano-banana-2): Nano Banana 2 is Google's new state-of-the-art fast image generation and editing model
- [Nano Banana 2 - Edit](https://docs.runflow.io/models/google/nano-banana-2/edit): Nano Banana 2 is Google's new state-of-the-art image generation and editing model
- [Nano Banana Pro](https://docs.runflow.io/models/google/nano-banana-pro): Nano Banana Pro is Google's new state-of-the-art image generation and editing model
- [Nano Banana Pro - Edit](https://docs.runflow.io/models/google/nano-banana-pro/edit): Nano Banana Pro is Google's new state-of-the-art image generation and editing model
- [Veo 3.1](https://docs.runflow.io/models/google/veo3.1): Veo 3.1 by Google, the most advanced AI video generation model in the world. With sound on!
- [Veo 3.1 Fast](https://docs.runflow.io/models/google/veo3.1/fast): Faster and more cost effective version of Google's Veo 3.1!
- [Veo 3.1 Fast - Image to Video](https://docs.runflow.io/models/google/veo3.1/fast/image-to-video): Generate videos from your image prompts using Veo 3.1 fast.
- [Veo 3.1 - Image to Video](https://docs.runflow.io/models/google/veo3.1/image-to-video): Veo 3.1 is the latest state-of-the art video generation model from Google DeepMind
- [Veo 3.1 Lite](https://docs.runflow.io/models/google/veo3.1/lite): Veo 3.1 Lite balances practical utility with professional capabilities.
- [HeyGen Video Agent V3](https://docs.runflow.io/models/heygen/v3/video-agent): Generate videos with a single prompt. Describe what you want in plain text, and the agent handles avatar selection, scripting, scene composition - all in one.
- [Ideogram v3](https://docs.runflow.io/models/ideogram/v3): Generate high-quality images, posters, and logos with Ideogram V3. Features exceptional typography handling and realistic outputs optimized for commercial and creative use.
- [Kling v3 Pro - Image to Video](https://docs.runflow.io/models/kuaishou/kling-video/v3/pro/image-to-video): Kling 3.0 Pro: Top-tier image-to-video with cinematic visuals, fluid motion, and native audio generation, with custom element support.
- [Kling v3 Pro - Text to Video](https://docs.runflow.io/models/kuaishou/kling-video/v3/pro/text-to-video): Kling 3.0 Pro: Top-tier text-to-video with cinematic visuals, fluid motion, and native audio generation, with multi-shot support.
- [SAM 3](https://docs.runflow.io/models/meta/sam-3/image): SAM 3 is a unified foundation model for promptable segmentation in images and videos.
- [GPT Image 1.5](https://docs.runflow.io/models/openai/gpt-image-1.5): GPT Image 1.5 generates high-fidelity images with strong prompt adherence, preserving composition, lighting, and fine-grained detail.
- [GPT Image 2](https://docs.runflow.io/models/openai/gpt-image-2): GPT Image 2.0, OpenAI's latest image model, is capable of creating extremely detailed images with fine typography.
- [GPT Image 2 Edit](https://docs.runflow.io/models/openai/gpt-image-2/edit): GPT Image 2.0, OpenAI's latest image model, is capable of making fine-grained, detailed edits to images.
- [Reve Edit](https://docs.runflow.io/models/reve/edit): Reve's edit model lets you upload an existing image and then transform it via a text prompt.
- [Background Color](https://docs.runflow.io/models/runflow/background-color): Replace the background of a portrait or product shot with a flat color. Pick any RGB value; shading_percent baked at 30% for soft falloff.
- [Background Removal](https://docs.runflow.io/models/runflow/background-removal): Remove the background from an image and return a clean cutout with a transparent alpha channel. Built for e-commerce product shots, portraits, and batch cleanup pipelines.
- [Background Replace](https://docs.runflow.io/models/runflow/background-replace): Swap the background of any product photo for a new scene defined by a reference image and a short prompt. The model preserves the foreground subject while matching camera angle and lighting to the new background.
- [Eye Color](https://docs.runflow.io/models/runflow/eye-color): Recolor the irises in a portrait. The customer describes the target eye color (e.g. \"blue\", \"emerald green\", \"amber\") - that drives the inpaint guidance. Optional RGB lets you tint the overlay precisely.
- [Model Removal](https://docs.runflow.io/models/runflow/model-removal): Remove the human model from a garment or apparel photo and recover a clean flat-lay or ghost-mannequin view. Designed for fashion catalogs and PDP hero shots.
- [Object Removal](https://docs.runflow.io/models/runflow/object-removal): Remove an unwanted object or region from a photo. Mark the area to remove with a black-and-white mask. The model rebuilds the background using surrounding context.
- [Outpaint (Expand)](https://docs.runflow.io/models/runflow/outpaint): Expand the canvas of an image with AI-generated content that matches the existing scene. Specify percent expand on each side - required so the customer is intentional.
- [Outpaint (Aspect Ratio)](https://docs.runflow.io/models/runflow/outpaint/aspect-ratio): Expand the canvas of an image to a target aspect ratio (e.g. 16:9, 1:1, 9:16). The model decides where to add content - no need to specify per-side expand percentages.
- [Product Isolation](https://docs.runflow.io/models/runflow/product-isolation): Isolate the main product from a busy scene onto a clean background, using an optional text prompt to disambiguate the subject. Built for studio-grade product photography at scale.
- [Reference Inpaint](https://docs.runflow.io/models/runflow/reference-inpaint): Inpaint a region of a target photo using a reference image as the visual guide. Provide the target, a black-and-white mask of the area to fill, and a reference image. The model paints the masked region with content matching the reference.
- [Skin Fix](https://docs.runflow.io/models/runflow/skin-fix): Cleanup pass for portrait photography. Smoothes skin texture, fixes blemishes, preserves natural detail.
- [Smart Resize](https://docs.runflow.io/models/runflow/smart-resize): Resize an image to a target aspect ratio + resolution (1K, 2K, 4K) without distortion or cropping. Uses generative reframing to recompose the subject into the new frame.
- [Tag Removal](https://docs.runflow.io/models/runflow/tag-removal): Remove price tags, stickers, and labels from product images while preserving the underlying material and lighting. Ideal for re-listing inventory or cleaning up user-submitted photography.
- [Topaz Upscale - Image](https://docs.runflow.io/models/topaz/upscale/image): Use the powerful and accurate topaz image enhancer to enhance your images.

## Guides

- [Batch process media](https://docs.runflow.io/guides/batch-process-media): Run one model on many inputs in a single request, get one callback when the batch finishes.
- [Handle async callbacks](https://docs.runflow.io/guides/handle-async-callbacks): Build a webhook handler for Runflow runs. Express + FastAPI examples.
- [Pick a model](https://docs.runflow.io/guides/pick-a-model): Decision tree from task to Runflow model.
- [Upload large files](https://docs.runflow.io/guides/upload-large-files): Three-step presigned upload for files too large for a JSON body.
- [Verify callback signatures](https://docs.runflow.io/guides/verify-callback-signatures): HMAC-SHA256 verification for inbound Runflow callbacks. Express + FastAPI.

## For agents

- [For agents](https://docs.runflow.io/agents): Front door for AI agents integrating Runflow. Skill, llms.txt, OpenAPI, API catalog.
- [API catalog](https://docs.runflow.io/agents/api-catalog): RFC 9727 linkset that points at every machine-readable Runflow surface.
- [llms.txt](https://docs.runflow.io/agents/llms-txt): Runflow's llmstxt.org-formatted index of this site, plus the full corpus.
- [OpenAPI](https://docs.runflow.io/agents/openapi): Runflow OpenAPI specs, in OpenAPI 3.1, with codegen recipes.
- [Agent skills](https://docs.runflow.io/agents/skills): Runflow ships one agentskills.io v0.2.0 skill: integration guide for AI coding assistants.