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🌟 Introduction

ZapCap is a REST API for programmatically adding high-quality animated subtitles to videos. Process videos in 48 languages with up to 99.9% transcription accuracy, and transform them using 20+ designer templates.

Quick example using jq and curl: Add animated subtitles to a video

# First, upload the video and get the ID
VIDEO_ID=$(curl -X POST "https://api.zapcap.ai/videos" \
  -H "x-api-key: YOUR_API_KEY" \
  -F "file=@video.mp4" | jq -r .id)

# Then create the task using the video ID
curl -X POST "https://api.zapcap.ai/videos/$VIDEO_ID/task" \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "templateId": "template_id",
    "autoApprove": true
  }'

For complete examples in Node.js, Python, and curl, see our Caption a Video Guide

Why Choose ZapCap?​

  • High-Performance Processing: Process 4k videos in minutes
  • Enterprise-Ready: Scale to thousands of videos with 99.9% uptime SLA
  • Developer-First: Well-documented REST API with examples in multiple languages
  • Production-Tested: Powers subtitle generation for Fortune 500 companies and leading content creators

🛠 Core Features​

📝 Advanced Transcription Engine​

  • 99.9% accuracy across 48 languages
  • Automatic punctuation and formatting
  • Custom vocabulary handling

🎨 Powerful Template System​

// Customize templates programmatically
{
  "renderOptions": {
    "subsOptions": {
      "emoji": true,
      "animation": true,
      "emphasizeKeywords": true
    },
    "styleOptions": {
      "fontSize": 46,
      "fontColor": "#ffffff"
    }
  }
}

⚡ Built for Scale​

  • Asynchronous processing with webhooks
  • Regional edge processing
  • Automatic content delivery via CDN

🎯 Common Use Cases​

1. Content Management Systems​

Automatically generate subtitles when videos are uploaded to your CMS:

// Server-side webhook handler (Express.js)
app.post("/video-uploaded", async (req, res) => {
  const { videoUrl } = req.body;

  // Upload video to ZapCap
  const uploadRes = await fetch("https://api.zapcap.ai/videos/url", {
    method: "POST",
    headers: {
      "x-api-key": process.env.ZAPCAP_API_KEY,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({ url: videoUrl }),
  });
  const { id: videoId } = await uploadRes.json();

  // Create captioning task
  await fetch(`https://api.zapcap.ai/videos/${videoId}/task`, {
    method: "POST",
    headers: {
      "x-api-key": process.env.ZAPCAP_API_KEY,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({
      templateId: process.env.TEMPLATE_ID,
      autoApprove: true,
    }),
  });

  res.json({ status: "processing" });
});

2. Video Editing Platforms​

Add a backend endpoint that your frontend calls:

// Server-side API route - never expose API keys to the client
app.post("/api/add-subtitles", async (req, res) => {
  const { videoId, templateId } = req.body;

  const response = await fetch(`https://api.zapcap.ai/videos/${videoId}/task`, {
    method: "POST",
    headers: {
      "x-api-key": process.env.ZAPCAP_API_KEY,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({ templateId, autoApprove: true }),
  });

  res.json(await response.json());
});

3. Multi-Language Distribution​

Create translated versions of your video for different markets:

// Server-side batch translation
async function createTranslations(videoId, templateId, languages) {
  const tasks = await Promise.all(
    languages.map((language) =>
      fetch(`https://api.zapcap.ai/videos/${videoId}/task`, {
        method: "POST",
        headers: {
          "x-api-key": process.env.ZAPCAP_API_KEY,
          "Content-Type": "application/json",
        },
        body: JSON.stringify({
          templateId,
          translateTo: language,
          autoApprove: true,
        }),
      }).then((res) => res.json())
    )
  );
  return tasks;
}

// Usage: Create Spanish, French, and German versions
createTranslations(videoId, "template_id", ["es", "fr", "de"]);

🚀 Get Started​

  1. Get your API key
  2. Follow our 5-minute quickstart
  3. Explore the full API reference

📚 Resources​