ReelsBuilder API

Agent-Native Video Infrastructure

ReelsBuilder positions itself as Agent-Native Video Infrastructure: the agent-facing execution layer for programmatic short-form video. Prompts, articles, campaign briefs, and live system context from Claude, Codex, Cursor, LangGraph, CrewAI, or any custom runner come in; finished short-form video assets with captions, status truth, asset delivery, and prepaid USD-cent billing come out.

The broader category language is Autonomous Video Infrastructure — same product, longer horizon. We use that framing for board, fundraising, and ecosystem-level positioning; on these pages and in code we keep the clearer developer-facing label.

Three composable surfaces on one rail

1. Generation API — agent-callable branded short-form video, article-to-video, autoblog, and AI-influencer rendering. Returns a job handle plus a finished asset contract (video URL, captions, transcript) for downstream distribution by your stack.
2. Signals API — viral trend data, proven X hooks, brand DNA, and engagement intelligence. Free reads today (get_x_hooks, future get_trending, future get_brand_intelligence); the data side is structurally agent-friendly and survives the commoditization of raw video models.
3. Distribution handoff — paid renders return the completed asset to your stack with distribution.mode: "external_agent_distribution". We do not compete with Ayrshare, Buffer, or Hootsuite for the posting layer — we hand the asset to whichever publisher your agent already uses.

Two pricing layers, one platform

ReelsBuilder ships under two distinct economic models:

• Consumer / dashboard — subscription tokens at $0.0025 each, $14.99–$149.99/month tiers. Net effective cost per branded short-form: $0.15–$0.45 depending on tier, watermark, and annual prepay.
• M2M API — prepaid USD ledger, $10 minimum top-up, no subscription floor. Live rate: $0.50 per generate_video (or generate_and_post at $0.60, blog_to_video at $0.50, generate_article at $0.20). The 2× markup over consumer covers idempotency guarantees, MCP routing, agent retry semantics, and worker concurrency carve-out — mirroring the Anthropic API-vs-Plus split.

For full per-tool USD pricing see prepaid business model.

vs DIY (Veo / Sora / fal + ElevenLabs + your engineering)

A common ask: why pay $0.50 instead of stitching Veo 3 + ElevenLabs TTS + captions yourself for $0.10/second?

• Veo 3 raw: $0.50–$0.75/second video-only → $7.50–$11.25 for a 15s clip
• Veo 3.1 Fast / Lite: $0.05–$0.10/s → $0.75–$1.50 for 15s, silent
• Sora 2 (720p): $0.10/s → $1.50 for 15s, silent
• fal Seedance / Kling / Hailuo: $0.02–$0.30/s → $0.30–$4.50 for 15s, silent

That gets you a silent model clip. To match ReelsBuilder's output you still need: a script (OpenAI/Claude), TTS (ElevenLabs ~$0.018 per 500-char clip), word-level transcription for captions (ElevenLabs Scribe ~$0.008), caption rendering (your code or Submagic at $69/mo), clip selection (your library or a stock-clip API), music licensing, FFmpeg compute, CDN upload. Honest DIY total: $0.35–$1.20 per 15s render before your engineering time.

ReelsBuilder's $0.50 buys you that pipeline pre-assembled with idempotency, refund-on-failure, the Signals API as a side-channel input, and an MCP surface — at roughly DIY parity on cost and a fraction of the integration time. The moat is the bundle plus the USD ledger, not the raw rendering.

New to the API? Start with the 10-minute quickstart — sandbox key to live render in seven steps, including 402/409/429 handling and the MCP config for Claude Desktop and Codex.

Quickstart

ReelsBuilder exposes its full video, intelligence, and distribution stack as a single REST API. Authenticate with a Bearer token, send JSON, get back JSON or a webhook. Every mutating endpoint accepts an Idempotency-Key header so retries are safe. Every async job delivers an HMAC-signed webhook on completion.

Codex, Agents, and AgenticFlows

For autonomous systems, start with Agent Generate API. Live keys charge credits for real renders; sandbox keys prefixed with rb_test_ return safe fixtures. The API returns a durable job id and a completed video asset contract so your agent can decide whether to create a blog embed, CMS draft, social post, or approval queue item.

For article and autoblog workflows, use Autoblog Video API. Send the source URL plus extracted text or markdown, then attach the returned video asset to your CMS, customer report, or social queue.

Base URL

https://api.reelsbuilder.ai/api/v1

Your first request

curl -X POST https://api.reelsbuilder.ai/api/v1/hooks/generate \
  -H "Authorization: Bearer rb_your_api_key_here" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
    "topic": "AI startup productivity",
    "audience": "founders",
    "count": 5
  }'

Response (within ~500ms):

{
  "success": true,
  "data": {
    "hooks": [
      { "text": "The 3 AI tools my startup runs at 4am...", "score": 0.91 },
      { "text": "Why we deleted Notion last week.", "score": 0.87 },
      ...
    ]
  },
  "meta": { "request_id": "req_...", "credits_used": 1, "credits_remaining": 999 }
}

Get an API key

Generate one from the developer dashboard. Free accounts include fixed starter videos; API generation uses paid tokens or the card-verified trial proof render.

Key concepts

• Authentication — Bearer tokens prefixed with rb_. Hashed at rest with SHA-256.
• Idempotency — Opt-in Idempotency-Key header on POST. Replays within 24h return the original response without re-charging credits or re-running external work.
• Webhooks — Async jobs deliver completion events with an HMAC-SHA256 signature derived from your key. Retry with exponential backoff on non-2xx.
• Rate limits — Per-key, per-minute. Headers tell you exactly where you stand.
• Errors — Stable error code field separate from HTTP status. Machine-handleable.

Products

Every endpoint below has a dedicated reference page with curl, TypeScript, and Python examples. The full machine-readable OpenAPI 3.0 spec lives at api.reelsbuilder.ai/api-docs.json.

Status & changelog

Production status is visible at api.reelsbuilder.ai/health. Breaking changes ship to /api/v2/* with overlap windows. The current stable surface is v1.

Support

API support: admin@reelsbuilder.ai. SLA-backed responses available on Business and Enterprise plans (see pricing).