Onto Documentation
The AI compatibility layer for the web. Read any site cleanly, serve your own site cleanly.
api.buildonto.dev. The Serve SDK is published as @ontosdk/next. Sign up for free credits at app.buildonto.dev/signup.Onto solves two ends of the same problem. AI agents read modern websites poorly because every HTML payload is mostly framework noise — Tailwind classes, hydration scripts, animation wrappers. The actual semantic content is buried.
The Read API fixes this from the agent's side: any developer can call POST /v1/read with a URL and get back clean Markdown plus an AIO score flagging hallucination risk. The Serve SDK fixes it from the site's side: install @ontosdk/next and AI crawlers get clean Markdown at the edge while humans still see the full HTML page.
What you can build
Two products, one platform
Read and Serve are billed independently — pick one or both — and share a single sign-in. The dashboard surfaces both: /read/* for your API keys and usage, /serve/* for the sites running the SDK.
| Read API (for AI developers) | Serve SDK (for site owners) | |
|---|---|---|
| What it does | Read any URL on the public web cleanly | Serve your site cleanly to AI bots |
| Auth | Per-user API key (Bearer token) | Per-site API key in env var |
| Hosted at | api.buildonto.dev | Your own deployment (Vercel, etc.) |
| Free tier | 1,000 requests / month | 1 site, basic analytics |
| Paid from | $9 / mo (Starter) | $19 / mo (Pro) |
Pricing at a glance
Full breakdown on the public pricing page. Headline numbers:
| Plan | Read API | Serve |
|---|---|---|
| Free | 1k requests / 2 concurrent | 1 site / basic analytics |
| Starter | $9 — 10k / 5 concurrent | — |
| Pro | — | $19 — 1 site / advanced analytics / per-route injection |
| Growth | $49 — 100k / 20 concurrent | — |
| Business | — | $99 — 10 sites / all features |
| Scale | $250 — 500k / 50 concurrent | — |
| Enterprise | Custom | Custom |