Kling 4.0's API opens to developers in early access
Kling's own documentation calls the release early access while its pricing table and developer page still say the 4.0 API is coming soon.
Key takeaways
- Kling's own API documentation says Kling 4.0 is available for early access, while its pricing table and developer landing page still say the 4.0 API is coming soon.
- A SelfyzAI press release dated October 23, 2026 says the Kling 4.0 API service officially launched on October 22, 2026, a day later than the rollout Kling announced on X.
- Kling has not published an official launch date or per-second pricing for the Kling 4.0 API, and its only published rates are marked not usable before launch.
- Kling 4.0 makes 3 to 30 second clips in one run, with up to 10 keyframes and up to 15 combined reference inputs across images, video, voice and elements.
Kuaishou's Kling AI said on October 21, 2026 that the Kling 4.0 API is rolling out, and its own documentation now offers early access rather than general availability.
Kling announced the rollout in a post on its X account on October 21, 2026, the date Creators Toolbox reports for the post. A banner now sits above every page of Kling's own API documentation, reading "Kling 4.0 API Is Now Available for Early Access," next to a "Get Early Access" button.
Kling's own pages disagree about how far the rollout has gone. The table on Kling's video pricing page still marks Kling 4.0 "Coming Soon," and a note above it says Kling 4.0 API access is not yet available and that the rates shown are for preview purposes only. The developer landing page still reads "Kling 4.0 API Coming Soon" and shows Kling 4.0 with a Preview badge.
A third party dated the launch a day later. A SelfyzAI press release dated October 23, 2026 says the Kling 4.0 API service officially launched on October 22, 2026 and is gradually opening to enterprise customers and developers worldwide. TokenPost reported the same gradual expansion on October 22. Kling has not posted a general availability date.
Kling AI is the AI video platform from Kuaishou Technology. The Kling 4.0 model itself shipped earlier in October. Kling's own release note says the model "will officially launch in October" and gives no date, and it does not mention the API at all. Two integrators, OrcaRouter and Wireflow, date full availability to October 15, 2026.
That gap is what SLOP TV flagged on October 20, when the model's 30-second clips could not yet be called from code. The API opening changes how developers reach Kling 4.0, not the model itself.
Kling 4.0 generates 3 to 30 second clips in one run, takes up to 10 keyframes and up to 15 combined reference inputs across images, video, voice and elements, and outputs two-channel stereo audio with lip-synced speech. It renders at 720p, 1080p or 4K in aspect ratios including 21:9, 16:9, 1:1 and 9:16, and accepts prompts up to 8,000 tokens.
Early access means an application and a wait rather than a rate card. The pricing page lists preview rates for 720p and 1080p that it says cannot be used to submit requests before launch, and it says the official launch date and pricing will be announced separately.
To ask for access, sign in to Kling's developer console at kling.ai/dev and open an API key, or use the business inquiry form on the same page; Kling has not published a date for wider availability.