> ## Documentation Index > Fetch the complete documentation index at: https://testweb2-docs-openapi.test765.com/llms.txt > Use this file to discover all available pages before exploring further. > ## Agent Instructions > Five API is a video generation REST API. Base URL: https://api.fiveapi.ai. Authenticate with the header Authorization: Bearer ; read the key from the FIVEAPI_API_KEY environment variable and never hard-code it. > Every generation is an asynchronous task: POST /v1/{brand}/{version}/{task} returns a queued task, then poll GET /v1/tasks/{task_id} or receive a signed webhook, and download output.video.url before expires_at (7 days). > The OpenAPI spec is at https://docs.fiveapi.ai/api-reference/openapi.yaml. An installable agent skill: npx skills add https://docs.fiveapi.ai # Troubleshooting > Fixes for the most common problems: rejected URLs, credits, limits, webhooks and stuck tasks. > **400 url\_not\_allowed for a URL that opens in my browser** > > **Causes:** > > * The URL uses `http` instead of `https`. > * The host resolves to a private or reserved address (internal DNS, a VPN or a corporate proxy that rewrites DNS). > * The server doesn't answer `HEAD`, or answers without `Content-Length`. > * There are more than 3 redirects. > * The file is larger than the model's limit. > > **Fix:** serve the file from public object storage or a CDN (a presigned URL is fine), make sure `HEAD` answers `2xx` with a `Content-Length`, and keep the file within the [limits of the model](https://testweb2-docs-openapi.test765.com/concepts/input-files.md#limits-per-model). > **400 invalid\_parameter on duration or resolution** > > Not every model sells every combination of resolution and duration. Check the ranges of the model on its API reference page or with `GET /v1/models/{brand}/{version}/{task}`, and pick a combination the model offers. > **402 insufficient\_credits although my balance looks high enough** > > `balance.credits` doesn't include credits held by queued and processing tasks; those are in `balance.held` until the tasks finish. Wait for in-flight tasks, cancel the ones you no longer need, or top up on the **Billing** page. > **429 concurrency\_limit\_exceeded with only a few tasks running** > > The cap counts the queued and processing tasks of the **whole account**, across all keys. List them with `GET /v1/tasks?status=queued` and `GET /v1/tasks?status=processing`, and cancel the ones that are stale. > **401 invalid\_api\_key** > > Check that the header is exactly `Authorization: Bearer sk_live_...` (or `x-api-key: sk_live_...`), that no whitespace or quotes surround the key, and that the key wasn't revoked or expired in the console. > **403 account\_not\_active** > > New production accounts are reviewed before they can use the API. Email [support@fiveapi.ai](mailto:support@fiveapi.ai) with your account id if the review takes longer than expected. > **The webhook never arrives** > > **Causes:** the endpoint isn't `https` or isn't publicly reachable; it answers after more than 10 seconds; it redirects (a `3xx` stops the delivery); it answered non-`2xx` 9 times and the delivery stopped. > > **Fix:** answer `2xx` first and work afterwards, check the delivery log on the **Webhooks** page of the console and resend from there, and reconcile with `GET /v1/tasks/{task_id}`. > **Webhook signature verification fails** > > **Causes:** > > * You verify a re-serialized body instead of the raw bytes. > * You use the whole secret, including `whsec_`, as the key instead of the base64-decoded part after the prefix. > * You compare with only one `v1,` value while the header carries two during a rotation. > * Your server clock is more than 5 minutes off. > > **Fix:** run the [test vector](https://testweb2-docs-openapi.test765.com/concepts/webhooks.md#test-your-verifier) through your verifier. > **The task stays queued for a long time** > > The model's queue is busy; `queue.position` decreases as earlier tasks start. Tasks with input files also download and prepare them while queued. Keep waiting for the webhook, or cancel the task if you no longer need it: its credits are released at once. > **The task failed with input\_fetch\_failed** > > The input file couldn't be downloaded or processed after the task was accepted, often because a presigned URL expired. Make sure the URL stays valid for at least an hour and submit a new task. > **output is missing from a completed task** > > The output is removed at `expires_at`, 7 days after completion. Download results as soon as `task.completed` arrives. > **409 idempotency\_in\_progress** > > The first request with this `Idempotency-Key` is still running. Wait a moment and send the identical request again; it returns the stored answer. ## Still stuck? Email [support@fiveapi.ai](mailto:support@fiveapi.ai) with: * the `X-Request-Id` (or `error.request_id`) of the failing request, or the task `id`, * the time it happened, with time zone, * the model and, if relevant, the request body without your API key. This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.