Runway Dev Kling Integration: Build AI Video Apps Step by Step

Runway's developer platform now hosts Kling video generation models. This tutorial walks through API setup, model selection, and building your first text-to-video application.

The New Runway Dev Ecosystem

On October 13, 2026, Runway AI announced that Kling video generation models are now available on its developer platform, Runway Dev. This integration gives developers access to Kuaishou's Kling 2.5 Turbo Pro, Kling 3.0 family, and Kling O3 family through a unified API, alongside Runway's existing video and image generation tools. For developers building AI video applications, this significantly expands the available model catalog without requiring multiple API integrations.

This tutorial covers account setup, model selection, text-to-video generation, image-to-video workflows, and cost optimization. By the end, you will have a working Python script that generates video clips using Kling through Runway's API.

Step 1: Account and API Key Setup

First, create a Runway Dev account at dev.runwayml.com. Navigate to the API Keys section and generate a new key. Store this key securely; Runway bills API usage in credits, and the key grants access to your account balance.

Runway Dev uses a credit-based billing system. Kling 2.5 Turbo Pro costs 12 credits per second. Kling 3.0 Standard costs 9 credits per second without audio and 13 with audio; Kling 3.0 Pro costs 12 and 17 credits per second respectively; Kling 3.0 4K costs 43 credits per second. Kling O3 variants match the 3.0 pricing structure for Standard and Pro, with O3 4K also at 43 credits per second. Image-to-video with O3 supports up to 7 reference images.

Step 2: Model Selection Guide

Choosing the right Kling model depends on your use case. Kling 2.5 Turbo Pro is the fastest option, generating 5-10 second clips from text or a start frame with optional last frame. It supports 1920x1080, 1440x1440, and 1080x1920 aspect ratios. Use this model for rapid prototyping and social media content.

Kling 3.0 Standard generates 3-15 second clips with optional audio and supports multishot prompts via providerSettings.multiPrompt for up to 6 segments. Ratios include 1280x720, 720x1280, and 960x960. Kling 3.0 Pro adds 1920x1080, 1080x1920, and 1440x1440 ratios. Kling 3.0 4K outputs at 3840x2160, 2160x3840, or 2880x2880 for premium productions.

Kling O3 variants add video-to-video editing for clips up to 10 seconds and accept up to 7 reference images on image-to-video tasks. Use O3 when you need precise control over existing footage or want to blend multiple visual references.

Step 3: Text-to-Video Generation

Runway Dev provides text-to-video, image-to-video, and video-to-video endpoints. For text-to-video with Kling 2.5 Turbo Pro, send a POST request to the text-to-video endpoint with your prompt, selected model, ratio, and duration. The API returns a generation ID. Poll the status endpoint until the video is ready, then download the result.

The cfgScale parameter, available on Kling 2.5 Turbo Pro and Kling 3.0, ranges from 0 to 1 with a default of 0.5. Lower values produce more literal interpretations of prompts; higher values increase creativity at the cost of prompt adherence. For commercial content where brand consistency matters, start with 0.3-0.4. For artistic exploration, try 0.6-0.7.

Step 4: Image-to-Video and Keyframes

For image-to-video, supply a promptImage URL as the first frame. Kling O3 supports up to 7 reference images including keyframes. Define keyframes to control character states, scene transitions, and story beats precisely. The model interpolates motion between keyframes while respecting the overall prompt.

When using multishot prompts with Kling 3.0 or O3, structure each segment with its own duration (3-15 seconds per segment, 3-15 seconds total). This enables complex narrative sequences in a single API call.

Step 5: Cost Optimization

For development and testing, use Kling 2.5 Turbo Pro at 12 credits per second with 5-second outputs. Each test generation costs 60 credits. For production social media content, Kling 3.0 Standard without audio at 9 credits per second offers the best quality-to-cost ratio. Reserve 4K models for final deliverables where resolution is client-specified.

Runway Dev's unified billing means you can combine Kling video generation with Ideogram 4.5 image generation and Runway's native video tools under one account, simplifying both accounting and integration architecture.

Sources: Releasebot Runway API Updates, Runway Dev Documentation, Kling AI Official