black-forest-labs/flux-2-flex/text-to-image9 點數起 /張· 生成圖片

FLUX.2 Flex 是 FLUX.2 裡專為字很關鍵的版面準備的模型。加引號的標題、標語和標籤文字會按原文出現,十六進位制色號能引導配色,改圖最多用三張原圖。

在 POST /jobs/createTask 把模型名稱填成 black-forest-labs/flux-2-flex/text-to-image 就能呼叫,9 點數/張起(US$0.09)。新帳戶送 30 點數,可以先在 Playground 免費試用。

  • 生成圖片
  • 編輯圖片
  • 最高 2K
  • 最多 3 張參考圖
  • 9 種畫面比例
模型名稱black-forest-labs/flux-2-flex/text-to-image
端點POST https://api.popnow.ai/api/v1/jobs/createTask
# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $IDEMPOTENCY_KEY" \
  -d '{
  "model": "black-forest-labs/flux-2-flex/text-to-image",
  "input": {
    "prompt": "A ceramic teapot on a linen cloth, soft window light, muted palette",
    "aspect_ratio": "1:1",
    "resolution": "1k"
  }
}'

# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

input 依下方的 Schema 產生,原樣就能通過驗證。把提示詞和連結換成你自己的即可。

價格

選項點數 /張≈ 美元
resolution 1K8.67US$0.087
resolution 2K13.21US$0.13

1 點數 = $0.01 · 全部選項及價格:GET /models/black-forest-labs/flux-2-flex/text-to-image

每個任務會無條件進位到整數點數,所以最低檔跑一次是 9 點數/張(US$0.09)。

限制

解析度
1K · 2K
畫面比例
1:1 · 16:9 · 9:16 · 4:3 · 3:4 · 3:2 +3
提示詞長度(字元)
5,000

參數

這些欄位來自我們驗證每個請求所用的同一份 Schema。沒列出的欄位會被拒絕。

  • promptstring必填

    Describe the subject, setting, light and style in plain sentences.

    範圍
    1 – 5000 chars
  • aspect_ratiostring選填

    畫面形狀:橫式、方形或直式。

    預設值
    "1:1"
    可用值
    "1:1""16:9""9:16""4:3""3:4""3:2""2:3""21:9""9:21"
  • resolutionstring選填影響價格

    輸出尺寸。越大越清晰,價格也越高。

    預設值
    "1k"
    可用值
    "1k""2k"
  • seedinteger選填

    用同一個數字,結果就能重現。

    範圍
    0 – 2147483647
原始 JSON Schema
{
  "type": "object",
  "required": [
    "prompt"
  ],
  "properties": {
    "seed": {
      "type": "integer",
      "maximum": 2147483647,
      "minimum": 0,
      "description": "Random seed for controlled comparisons."
    },
    "prompt": {
      "type": "string",
      "maxLength": 5000,
      "minLength": 1,
      "description": "Describe the subject, setting, light and style in plain sentences."
    },
    "resolution": {
      "enum": [
        "1k",
        "2k"
      ],
      "type": "string",
      "default": "1k",
      "description": "Output size tier: 1k is about one megapixel, 2k is 2048 pixels on the long side."
    },
    "aspect_ratio": {
      "enum": [
        "1:1",
        "16:9",
        "9:16",
        "4:3",
        "3:4",
        "3:2",
        "2:3",
        "21:9",
        "9:21"
      ],
      "type": "string",
      "default": "1:1",
      "description": "Output aspect ratio."
    }
  },
  "additionalProperties": false
}

FLUX.2 Flex 的真實成品

Tea tin label
提示詞Product photograph of a cylindrical tea tin painted matte deep green #1F3B2D with a cream #F3E9D2 paper label, standing on a light oak kitchen shelf beside a white porcelain cup with a curl of steam, soft morning window light from the left. The label is framed by a thin gold #C9A227 border and reads, in elegant typography: "KESTREL & FERN" in small spaced capitals at the top, "Smoked Earl Grey" in a large flowing script in the middle, and "LOOSE LEAF · 100 g" in small capitals at the bottom. Crisp focus on the label, shallow depth of field. No other text.
透過 API 送出的同一個請求
{
  "model": "black-forest-labs/flux-2-flex/text-to-image",
  "input": {
    "prompt": "Product photograph of a cylindrical tea tin painted matte deep green #1F3B2D with a cream #F3E9D2 paper label, standing on a light oak kitchen shelf beside a white porcelain cup with a curl of steam, soft morning window light from the left. The label is framed by a thin gold #C9A227 border and reads, in elegant typography: \"KESTREL & FERN\" in small spaced capitals at the top, \"Smoked Earl Grey\" in a large flowing script in the middle, and \"LOOSE LEAF · 100 g\" in small capitals at the bottom. Crisp focus on the label, shallow depth of field. No other text.",
    "aspect_ratio": "4:3",
    "resolution": "2k",
    "seed": 3130
  }
}

回應、輪詢與回呼

所有模型的用法都一樣:先建立任務,再輪詢,或等待回呼。

先報價

cURL
curl -X POST https://api.popnow.ai/api/v1/jobs/quote \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "model": "black-forest-labs/flux-2-flex/text-to-image",
  "input": {
    "prompt": "A ceramic teapot on a linen cloth, soft window light, muted palette",
    "aspect_ratio": "1:1",
    "resolution": "1k"
  }
}'

請求內容和 createTask 相同。它回傳預估扣款和最高可能扣款,不會真的執行。

已受理

HTTP
HTTP/1.1 202 Accepted

{
  "code": 200,
  "msg": "success",
  "data": {
    "taskId": "task_01k3m8x9q2z4v7n5p6r8s0t1w3",
    "state": "queued"
  },
  "request_id": "req_example_create"
}

HTTP 202 代表任務已受理,點數先凍結、尚未扣除。最終扣款不會超過凍結額。

查詢狀態

cURL
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

每隔幾秒查詢一次並逐步拉長間隔,state 變成 succeeded、failed、canceled 或 expired 時停止。

完成的任務

JSON
{
  "code": 200,
  "msg": "success",
  "data": {
    "taskId": "task_01k3m8x9q2z4v7n5p6r8s0t1w3",
    "model": "black-forest-labs/flux-2-flex/text-to-image",
    "state": "succeeded",
    "output": {
      "assets": [
        {
          "url": "https://cdn.popnow.ai/tasks/task_01k3m8x9q2z4v7n5p6r8s0t1w3/output.png?signature=FROM_RESPONSE",
          "expiresAt": "2026-10-17T12:20:00Z",
          "mime": "image/png",
          "width": 1024,
          "height": 1024
        }
      ]
    },
    "settled": true
  },
  "request_id": "req_example_record"
}

請在 expiresAt 之前從 url 下載。之後需要新連結,請呼叫 POST /common/download-url。

驗證回呼

Node.js
import { createHash, createHmac, timingSafeEqual } from "node:crypto";
import express from "express";

const app = express();
// express.raw keeps the exact bytes that were signed; express.json would not match.
app.post("/hooks/popnow", express.raw({ type: "application/json" }), (req, res) => {
  const timestamp = req.header("X-Webhook-Timestamp");
  const signature = req.header("X-Webhook-Signature") ?? "";
  const body = JSON.parse(req.body.toString("utf8"));
  const taskId = body.data?.taskId ?? body.task_id;
  const digest = createHash("sha256").update(req.body).digest("hex");
  const expected = createHmac("sha256", process.env.POPNOW_WEBHOOK_SECRET)
    .update(`${taskId}.${timestamp}.${digest}`)
    .digest("base64");
  const ok = expected.length === signature.length && timingSafeEqual(Buffer.from(expected), Buffer.from(signature));
  // Check the signature first, then reject anything older than five minutes.
  if (!ok || Math.abs(Date.now() / 1000 - Number(timestamp)) > 300) return res.status(401).end();
  res.status(200).end(); // answer fast, then fetch the task and store its files
});

設定 callBackUrl 後,我們會把完成的任務送給你。先用原始請求內容驗證簽名,再信任它。

上傳本機檔案

cURL
curl -X POST https://api.popnow.ai/api/v1/common/upload-url \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"contentType": "image/png", "bytes": 482113}'

# PUT the file bytes to data.uploadUrl with every header in data.headers, then commit it:
curl -X POST https://api.popnow.ai/api/v1/files/$FILE_ID/commit \
  -H "Authorization: Bearer $POPNOW_API_KEY"
# The commit returns a popnow://f/... reference. Put it in any image, video or
# audio field of the task input instead of a public https URL.

公開的 https 連結可以直接用。本機檔案要先經過 upload-url 和 commit。