# HookFindr Caption SRT Export

> HookFindr Caption SRT Export is a paid API for AI agents from api.hookfindr.com, paid per call via x402, $0.05/call, status unknown (last checked 2026-09-13).

Exports video captions as a broadcast-standard SRT subtitle file from TikTok, YouTube, Instagram, X, or Twitch URLs

## Facts

- Endpoint: POST https://api.hookfindr.com/api/x402/caption.srt
- Price: $0.05/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/hookfindr-caption-srt-export-990ea8f3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Eix3s1VijOQWv_PvEYUW-

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability hookfindr-caption-srt-export-990ea8f3 -d '<json body>'
```

Example prompt: Can you grab the captions from this TikTok video and export them as an SRT subtitle file I can upload to YouTube? Here's the URL: https://www.tiktok.com/@example/video/123456789

## When to prefer this

Choose this endpoint when you need a ready-to-upload SRT file specifically formatted to broadcast standards (42-char lines, 1-2s groupings) from a social video URL. Prefer it over raw transcription endpoints when the output destination is a video platform subtitle uploader rather than a text document or database. It covers TikTok, YouTube, Instagram, X, and Twitch natively via yt-dlp.

## Known failure modes

- Video URL is private or age-restricted — returns error indicating inaccessible content
- Platform not supported or URL malformed — returns validation error
- Video has no audio track or captions — returns empty or error response
- Network timeout on long videos — may require retry
- Rate limiting or payment failure — 402 Payment Required if USDC balance insufficient

## How this service works

Export video captions as SRT subtitles — TikTok, YouTube, Instagram, X, Twitch. Broadcast-quality SRT subtitle file ready to upload to YouTube, IG Reels, TikTok, or any subtitle player. Word-level timestamps grouped into ~1-2s caption lines capped at 42 chars (broadcast standard).

## Output

A broadcast-standard SRT subtitle file with word-level timestamps grouped into caption lines of approximately 1-2 seconds duration, capped at 42 characters per line per broadcast convention, ready to upload directly to YouTube, Instagram Reels, TikTok, or any subtitle player.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "POST"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "url"
     ],
     "properties": {
      "url": {
       "type": "string",
       "description": "Public URL of a short-form video. Supports TikTok, YouTube, YouTube Shorts, Instagram Reels, Twitter/X, Twitch clips, Facebook, and ~1000 other platforms via yt-dlp."
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/hookfindr-caption-srt-export-990ea8f3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.hookfindr.com](https://www.zero.xyz/host/api.hookfindr.com/llms.txt)