Show Useful Waiting States for the Kling 4.0 API
A spinning circle says that something is happening. It does not tell a person whether their video request arrived, whether they can leave the page, or what to do if the circle is still there later. A useful waiting screen answers those questions without pretending to know the completion time.
For an image-to-video tool using the Kling 4.0 API, start with confirmed task states and add the application's own uncertainty separately. API means application programming interface: the way your application submits work to another service and reads its response. The service's state and the visitor's experience are related, but they are not the same thing.
The greenhouse project in this guide is an invented interface exercise. The images are conceptual illustrations, and the state examples are simulated. They are not screenshots or results from a live generation test.
A quiet loading symbol needs a clear message; elapsed time alone does not establish progress.
Replace the spinner's missing explanation
Imagine a creator wants a short movement in a greenhouse illustration. After they choose an image and write a prompt, the application starts a request. What they need next is less mysterious than a sophisticated animation: confirmation of what was submitted, a useful status, and a next action.
Keep a compact description visible, such as “Greenhouse window, five-second clip, 720p.” It helps the creator recognize the job when they return. Treat that as their request description, not a guarantee that the generated video will match the scene perfectly.
Do not display a percentage unless your application has a valid source for that measurement. The four documented task states do not themselves provide a completion percentage. A growing progress bar that advances only with elapsed time invents certainty the service did not return.
Similarly, avoid “Almost done” just because the request has been running for a while. A plain “The video is still processing. Check again later” gives less theater and more information.
Write one message and one action for each confirmed state
The documented states are submitted, processing, succeed, and failed. Use their actual meaning as the basis for your interface:
Confirmed task state | Possible visitor-facing message | Main action |
|---|---|---|
submitted | Your request was accepted and is waiting to be processed. | Check status |
processing | Your video is being generated. | Check status |
succeed | A result is available. Review the full clip before using it. | Open result |
failed | This generation failed. Review the request before starting another. | Review request |
These messages are writing suggestions for your application. They are not text supplied by the API, and they do not add a promised turnaround time. The distinction between submitted and processing is useful even if both share the same quiet loading symbol.
Use more than color to distinguish outcomes. Give each state a clear text label and a relevant button. A green circle without words is less helpful than “Result available”; an amber symbol without an explanation leaves someone guessing about whether their work was lost.
Give each confirmed state its own explanation and next action; these objects are not provider interface elements.
Give the application its own uncertainty states
Two important situations do not fit the four remote states.
The application has stopped waiting. A browser or server-side waiting limit has been reached, but the last confirmed remote state is still submitted or processing. Say that checking has paused. Preserve the job and offer a way to check the same task again. Do not relabel the generation as failed.
The latest status could not be read. Perhaps a connection failed or the application received a response it cannot interpret. Say that the current status is unavailable, and show the time of the last successful check if you recorded it. Keep “last checked” separate from “submitted at”; those timestamps answer different questions.
An unconfirmed submission is another case to handle carefully. If the connection ends before your server saves a usable task identifier, your application may not know whether a request was created. A Try again button that immediately sends another generation request can turn uncertainty into a duplicate charge. Route that case to investigation or an explicit recovery path rather than hiding it behind the ordinary failure screen.
Make a return visit possible before saying it is safe to leave
The documented task identifier gives your application a reference for later status queries. It does not automatically give your own site a saved job list. If you want to tell someone “You can leave this page and return later,” implement and verify that behavior first.
Save the job association on your application's server and restrict it to the correct user. Give the visitor a stable application page or a recent-jobs view. On return, load the saved record and query the existing task. Do not make reopening that page trigger another generation POST.
If you have not built persistent jobs yet, use a narrower message: “Keep this page available while this version of the tool is checking.” Do not promise recovery after a refresh when you have only kept an identifier in a temporary JavaScript variable.
A later visit should return to a saved job, rather than automatically create another request.
Test the decisions without generating a clip
A small state-to-message function can be tested with local fixtures before you connect the provider. Give it the last confirmed remote state and, separately, whether the latest read failed or the application stopped waiting. It should choose a message and an action, not start a new paid request.
Run through five practical cases:
- A submitted job becomes processing, then succeeds. The action changes to opening the result, while the job identity stays the same.
- A remote task returns failed. The interface offers review, rather than continuously querying a terminal outcome.
- The application stops waiting while the task is processing. Check again queries that same task; it does not resubmit it.
- The latest read fails after a previously confirmed processing state. The interface shows that the newest state is unavailable and retains the earlier observation as history.
- The result state is successful but the expected video location is missing or cannot be opened. The application explains the retrieval problem without pretending a usable download was already delivered.
Also inspect the actual page with a keyboard and with the loading animation disabled. The message and action should still communicate what is happening. An animation should support the explanation, not carry it alone.
Keep generation, delivery, and approval separate
The Flaq AI Kling 4.0 image-to-video API provides the submission, task identifier, and documented status-query workflow behind this example. Your application supplies job persistence, waiting messages, permissions, and the interface for reviewing a returned clip.
A completed task is not a creative approval. Before placing the result in a project, the creator still needs to watch the clip and check its movement, identity, and intended use. If the video location cannot be retrieved, say so; avoid replacing the job with a new generation simply to make the screen look successful.
Pay-as-you-go usage is another reason to make the next action explicit. Check status, Open result, and Start a new generation are different operations. “Unlimited” is not a reason to blur them: this guide establishes no unlimited quota, free retries, or unlimited concurrency.
A good waiting screen gives the visitor a truthful place to stand. They know which job they are looking at, what is actually known, and whether the next click checks, reviews, or creates work.
Disclosure: This guide is published by the Flaq AI team and includes our own service.