Quickstart
Your first Flux API request, in a few simple steps.
1. Create a key
Create a key in API Key and save it as a server-side environment variable.
export FLUX_API_KEY="YOUR_FLUX_API_KEY"2. Check your connection
This request reads your balance and does not spend credits.
curl https://api.flux-context.org/api/v1/balance \
-H "Authorization: Bearer $FLUX_API_KEY"3. Create a generation
Choose a model to see its parameters and a complete request example.
Text-to-image and image-to-image
Text-to-image and image-to-image
Text-to-image and image-to-image
Text and references to video
Text and references to video
Text and references to video
Text and references to video
Text and references to video
Text-to-image and image-to-image
Text-to-image and image-to-image
4. Poll and download
Save the returned request ID and query approximately every 10 seconds. Background work continues even when you stop polling.
curl https://api.flux-context.org/api/v1/generations/REQUEST_ID \
-H "Authorization: Bearer $FLUX_API_KEY"When status is succeeded, download each URL in results. Response excerpt:
{
"id": "REQUEST_ID",
"status": "succeeded",
"results": [
{
"url": "https://api.flux-context.org/api/v1/files/SIGNED_TOKEN",
"url_expires_at": "2026-09-10T11:42:18Z",
"expires_at": "2026-10-10T10:42:18Z",
"expired": false,
"media_type": "image",
"content_type": "image/png",
"size_bytes": 1234567,
"width": 1024,
"height": 1024
}
]
}Stop polling when the status is succeeded or failed. For failed tasks, read error and billing for the reason and final credit settlement.
Download links last one hour. Query again for a fresh link. Files are retained for 30 days after transfer; file expiry does not change generation or billing records. Video results use media_type video and content_type video/mp4; save them with a .mp4 extension. Downloads support HEAD and single byte-range requests for playback and resuming.
curl --fail --location "$RESULT_URL" --output result.pngCredits and settlement
No subscription is required. API generations spend subscription credits first, then purchased credits. Gift credits cannot be used, including for additional video charges. GET /balance returns credits_available for these eligible pools only; breakdown.giftRemaining is informational and is not included. Refunds follow the original charge.
Fixed requests are charged upfront. Seedance 2.5 editing reserves credits and settles automatically after generation. Billing includes credits_precharged, credits_additional, credits_refunded, credits_final and settlement_status. credits_charged remains the total debited before refunds. credits_final is null while pending. If settlement_mode is precharge_retained, the precharge remains debited and results are available while billing awaits review.
Missing final billing data stays pending and is retried in the background. No manual log checks are required. Results are available after settlement. File expiry does not refund a successful generation.
Reference media
Supply public HTTPS URLs, without duration fields. Flux measures MP4/MOV video and MP3/WAV/M4A audio before charging. References must stay available until generation finishes. Requests use up to 3 concurrent probes, a 20-second deadline, an 8 MiB metadata budget per file and 32 MiB in total. Range support is recommended; small files also work without it.
INVALID_REFERENCE_MEDIA (HTTP 400) means media could not be read reliably or exceeded a model constraint. No task was created or credits charged. Check the URL, file format and duration, then retry.
Common request headers
| Header | Usage |
|---|---|
AuthorizationRequired | Bearer YOUR_FLUX_API_KEY. Keep this key on your server. Access changes are synchronized automatically. Status reads may take up to five minutes to reflect a permission change. Existing download links keep their original expiry. |
Content-TypeRequired for POST | application/json |
Idempotency-KeyOptional · POST | For automatic retries, reuse the same value and body for one business request. The original task is returned without another charge. If omitted, every POST creates an independent task. Use 1–128 letters, digits, dots, colons, underscores, or hyphens. |
A network timeout does not prove creation failed. Use the optional retry header when automatically retrying POST requests. The Python example handles it for you.
Errors & limits
各HTTPリクエストには、`request_id`と`X-Request-Id`ヘッダーが含まれます。同じ`Idempotency-Key`を使用し、リクエストボディが変更されていない場合、再試行しても生成IDは変わりません。ステータスの照会にはFluxの生成IDを使用してください。`provider_task_id`はサポート用の任意のリファレンスであり、Fluxの検索キーではありません。
エラーが発生した場合、Fluxの`error.code`が保持され、利用可能な場合はソースとプロバイダーの詳細が追加されます。プロバイダーのビジネスコード、失敗コード、HTTPステータスは、FluxのHTTPステータスとは異なります。ステータスの照会が成功しても、生成が成功したとは限りません。
再試行する前に、エラーの説明と課金状態をご確認ください。無効な入力は修正し、レート制限の場合は待機してください。結果が不明な場合は、元のタスクを照会します。上流のアカウントや設定に関するエラーの場合は、新しいFlux APIキーや追加のFluxクレジットではなく、Fluxのサポートが必要です。
サポートが必要な場合は、APIログからトラブルシューティング情報をコピーしてください。HTTPリクエストID、Flux生成ID、および利用可能な場合はプロバイダータスクIDを必ず含めてください。APIキー、Authorizationヘッダー、プライベートな入力データは決して共有しないでください。
| Operation | Limit |
|---|---|
| Create requests | 60 / minute / account |
| Read requests | 300 / minute / account |
| Generation concurrency (queued and processing) | 20 / account |
These are default limits. Your effective limits appear in Overview and GET /balance. All keys share the account limit. HTTP 429 includes Retry-After: 60 and a limit object with scope and value. For TOO_MANY_TASKS, wait for existing generations to finish; 60 seconds does not guarantee a slot.
| HTTP | What to check |
|---|---|
| 400 | Request parameters or an invalid optional header. |
| 401 | A missing, invalid, or revoked API key. |
| 402 | Available credits. |
| 403 | Account access is restricted or disabled. |
| 404 | The request ID and its owning account. |
| 409 | A retry identifier was reused with different parameters. |
| 410 | The result is no longer retained. |
| 503 | Temporary unavailability or an unconfirmed submission. |
SUBMISSION_NOT_CONFIRMED is not a confirmed failure. Keep the original request ID and query its status. Temporary query errors do not trigger refunds.