Agent-aware Markdown serving
The Serve SDK responds to recognized AI crawler requests, Markdown negotiation, or an `?onto` URL parameter with Markdown while leaving regular visitor responses unchanged.
Onto
Freemium
Onto helps website owners make pages easier for AI agents to read by serving clean Markdown at the same URL. It also provides agent-visit analytics and an AIO readability score. Developers can retrieve and process web content via its Read API or MCP server.
What is Onto?
Onto is a web-to-Markdown service for making website content readable by AI agents. Its Serve SDK identifies supported agent requests and serves a cleaned Markdown version while continuing to return the normal page to people. The service also records agent visits and provides an AIO score that identifies structural issues affecting agent readability.
For developers building agent workflows, Onto provides a Read API and MCP server. The API can read public web pages, PDFs, JSON, CSV, and plain text, then return cleaned content or declared page metadata. It supports individual reads, batch requests, site mapping, extraction, and optional scoring.
What can Onto do?
Read API
A POST request to the Read API returns clean Markdown, metadata, and size statistics for a public URL. Reads use one credit per URL, and failed reads are refunded.
AIO scoring
Onto scores agent readability from 0 to 100 and reports named structural faults, along with a low, medium, or high hallucination-risk label.
MCP server
Agents such as Claude, ChatGPT, or Cursor can use Onto tools, including `read_url`, through the hosted connector or a local `npx` server authenticated with an Onto key.
Batch and site operations
The API can read up to 50 URLs in a batch, map up to 1,000 site URLs from a sitemap or linked pages, and extract JSON-LD, OpenGraph, and meta data.
Agent analytics
The dashboard shows which recognized agents visited which pages, their source, and how much lighter the served response was. Serve Pro adds unknown-agent lists and CSV export.
Use Cases
“Preparing a site for AI discovery”
Install the Serve SDK so supported agents receive a cleaner representation of documentation or marketing pages without changing the page shown to human visitors.
“Building an agent or retrieval workflow”
Use the Read API to fetch public pages as Markdown, preserve declared metadata, and optionally score the result before passing it into an application.
“Auditing AI readability”
Run the free scanner or scoring route to find issues such as missing Markdown, blocked crawler access, absent JSON-LD, heading problems, or missing image alt text.
“Connecting an assistant to web content”
Add Onto’s MCP server so a compatible agent can call `read_url` and related tools when it needs to inspect a page.
“Measuring agent traffic”
Use Serve analytics to see which named or unknown agents access site routes and export the available data on higher Serve plans.
Frequently Asked Questions
What does Onto return to a normal website visitor?
The regular full page. The Serve SDK changes the response for recognized AI-agent requests, Markdown requests, or requests using the `?onto` parameter.
How does the Read API handle a URL?
It checks the API key, applies a credit, checks its one-hour cache unless a fresh read is requested, validates public hosts and redirects, checks robots.txt, fetches the page without running JavaScript, cleans it through Onto’s core engine, and returns the result as JSON or raw Markdown. Failed reads are refunded.
What content can the Read API process?
It can clean web pages, return text from PDFs up to 20 pages, pass through JSON, CSV, and plain text, extract declared JSON-LD, OpenGraph, and meta data, map site URLs, and process up to 50 URLs in a batch. Image-only PDFs fail because they contain no text to return.
How are Onto credits charged?
One URL read costs one credit. Batch requests charge one credit per URL, while scoring is free. On the free Read tier, requests stop with a quota error after the monthly allowance; paid tiers can use purchased credit packs for overage.
Does Onto run JavaScript on fetched pages?
No. The Read API fetches the publicly available response without running JavaScript. It also checks robots.txt and stops when the site blocks GPTBot or all crawlers.
Quick Facts
- Product type
- AI agent web-readability and content extraction service
- Primary users
- Website owners and developers building AI or retrieval workflows
- Delivery options
- Serve SDK, Read API, and MCP server
- Main output
- Clean Markdown with metadata; optional AIO score
- Read free tier
- 1,000 credits per month; no card required
- Serve SDK
- MIT-licensed, free on npm without a usage cap
Onto Traffic Analysis
Traffic data is for reference only.
- Domain Rating
- 5
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