Getting Started

Introduction

Captapi gives you structured data from public social media through one consistent REST API. Send a public URL from YouTube, TikTok, Instagram, Facebook, and more and get back clean JSON — profiles, posts, transcripts, AI summaries, comments, search results, and ad-library data. No OAuth, no per-platform SDKs, no data-collection infrastructure to maintain.

• • One API key works across all 33 platforms.
• • Pass cache=true to serve from the 24h shared cache (0 credits on hit). Default is always fresh.
• • You are only charged for successful requests.

Quickstart

After signing up and copying your API key from the dashboard, make your first request:

curl "https://api.captapi.com/v1/youtube/transcript?url=https%3A%2F%2Fyoutube.com%2Fwatch%3Fv%3DdQw4w9WgXcQ" \
  -H "Authorization: Bearer capt_live_..."

Machine-readable: OpenAPI 3.1 spec (parameters, response schemas, errors, credit cost per endpoint), one-line endpoint list, and llms.txt.

Authentication

All requests are authenticated with a Bearer token. Generate keys in your dashboard and send them in the Authorization header. Keep keys secret — never expose capt_live_ keys in client-side code.

Authorization: Bearer capt_live_xxxxxxxxxxxxxxxxxxxx

Making Requests

Most endpoints take a url or q query parameter. Some need a different identifier instead — for example userId, username, repo, advertiser, or comment_id. Check each endpoint's docs for the exact params. When building a query string, you must URL-encode URL values so they aren't misinterpreted as multiple parameters.

# URL-encode the target URL before passing it
urlencode "https://youtube.com/watch?v=dQw4w9WgXcQ"

Response Format

Every response is JSON with a top-level success boolean and a data object.

{
  "success": true,
  "data": {
    "language": "en",
    "segments": [
      { "start": 0.0, "end": 4.12, "text": "Hey everyone, welcome back." }
    ],
    "text": "Hey everyone, welcome back."
  }
}

HTTP/1.1 502 Bad Gateway
Retry-After: 60

{
  "success": false,
  "error": {
    "code": "UPSTREAM_UNAVAILABLE",
    "message": "The upstream data source failed for this request. Retry shortly.",
    "retryable": true
  }
}

Credits & Caching

Credits are the unit of billing. Cost is per endpoint (see each docs page) — typically 1–4 for simple lookups; many list/search/comment endpoints are a flat 2 credits per call, while some list endpoints still scale with results (often higher). Failed requests are never charged.

Empty results are free on many endpoints. On many list and search endpoints, a call that ran but found nothing costs 0 credits, for example an ad-library or profile search with no matches. Where an empty result is still billed, the endpoint page says so: Google Maps business search bills its one page because the lookup ran. The X-Captapi-Credits response header always shows what a call actually cost.

A few endpoints cost more when a slower fallback path serves the call, for example when the platform's own page does not load. Their pages state the rule and the range we have observed: TikTok Song Details, LinkedIn Company Posts, and TikTok Shop Products.

By default every data request fetches fresh data (cache=false). Pass cache=true to serve from the shared 24h response cache at 0 credits.

Errors

Errors return a non-2xx status and an error object with a stable code, a human-readable message, and retryable. Retry only when retryable is true, after the Retry-After header. Failed requests are never charged. Match on code exactly: casing differs between codes. The table lists the common ones; endpoint pages list their specific codes.

Rate Limits

Rate limits scale with your plan and are returned on every response via X-RateLimit-Limit, X-RateLimit-Remaining, and X-RateLimit-Reset headers. When you exceed the limit you'll get a 429 — back off and retry after the reset window.

API Reference

179 endpoints across 36 groups. Click any endpoint for full parameters, examples, and FAQs.

The read-side companion to publishing and scheduling tools: pass any supported post, video, or reel URL (YouTube, TikTok, Instagram, Facebook, X, Reddit, Threads, Bluesky, Pinterest, LinkedIn, or Rumble) and get one normalized metrics object — views, likes, comments, shares, saves, interactions, and engagementRate — with the platform auto-detected. Fields a network does not expose stay null (YouTube has no public share/save counts).

# Platform is auto-detected from the URL
curl "https://api.captapi.com/v1/analytics/post?url=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DdQw4w9WgXcQ" \
  -H "Authorization: Bearer capt_live_..."

# Compare several posts in one call (same metrics shape per URL)
curl "https://api.captapi.com/v1/analytics/compare?urls=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DdQw4w9WgXcQ,https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DjNQXAC9IVRw" \
  -H "Authorization: Bearer capt_live_..."

Integrations