# Security · Onto > Onto's security posture with a source for every claim: how API keys are stored, what's encrypted, what we don't claim, and how to report a vulnerability. **Source:** /legal/security **Extracted:** 2026-09-24T18:14:20.450Z --- Security ## Every claim on this page _has a receipt._ Each line states a control and cites the file that implements it or the measurement that confirms it. The last section is the same list with nothing to cite: the things we don't have. Written and current · checked 24 Sep 2026 Report a vulnerability [founder@buildonto.dev](mailto:founder@buildonto.dev) First response Within one business day Machine-readable [security.txt](/.well-known/security.txt) 13 Controls, each with a source 6 Processors 6 Things we don't claim Keys and access ### Everything that decides whether a request is yours. 1. A Read API key is shown once, when it's made. Only its SHA-256 digest is stored, with the prefix every key shares (onto\_sk\_live), so it can't be recovered by us or by anyone with the database. _Implemented in_`onto-api/lib/auth.ts · hashKey()` 2. Replacing a key revokes the old one on its next request. Every call looks the key up and needs it active; nothing caches that answer. _Implemented in_`onto-api/lib/auth.ts · status !== 'active'` 3. Dashboard sign-in is Supabase Auth: GitHub, Google, or email and password. Supabase hashes the password; Onto's code passes it through and never stores it. _Implemented in_`onto-dashboard/src/app/(auth)/actions.ts` 4. The MCP connector signs you in through Onto's own OAuth server. PKCE with S256 is required; access tokens last an hour, refresh tokens 30 days, and a refresh token is replaced every time it's used. _Implemented in_`onto-api/lib/mcp/oauth.ts · oauth-handlers.ts` 5. The connector's calls to the API carry a signed token minted per user that expires after two minutes and is verified on arrival. _Implemented in_`onto-api/lib/connector-token.ts · HS256, 2m` 6. Quota is counted per account per calendar month (UTC) and resets on the 1st. The free tier stops at 1,000 credits; it can't overspend. _Implemented in_`onto-api/lib/rate-limit.ts · TIER_LIMITS` In transit and at rest ### Where your data goes, and what protects it there. 1. TLS 1.3 with a valid certificate chain and HTTP/2 on buildonto.dev, app.buildonto.dev and api.buildonto.dev. _Measured_`openssl s_client · 24 Sep 2026` 2. Records live in one Postgres database on Supabase. Vercel KV holds the short-lived rest: the hour's page cache, this month's quota counters, MCP sign-in grants, and the keyless reader's per-IP counts. There's no analytics warehouse. _Implemented in_`@supabase/supabase-js · @vercel/kv` 3. A read's result is cached for one hour under a SHA-256 key of the engine version and the URL, then expires. It holds the public page, not your account data. _Implemented in_`onto-api/lib/cache.ts · TTL_SECONDS = 3600` 4. Encryption at rest is Supabase's and Vercel's, under their own published controls. We don't add a second layer, and would rather say so than imply one. _Measured_`Provider-managed` What we send to other sites ### Onto makes requests to other people's sites for you. This is how. 1. The API's fetcher names itself Onto-Reader/1.0 and links to a page saying what it does. (The free scanner on buildonto.dev fetches as a browser and as GPTBot instead; the Onto-Reader page says so.) _Implemented in_`onto-api/lib/fetch-and-clean.ts · USER_AGENT` 2. robots.txt is read before every fetch. A site-wide Disallow for GPTBot or \* stops it before the page is requested. If robots.txt can't be fetched, that's taken as allowed. _Implemented in_`onto-api/lib/fetch-and-clean.ts · checkRobots()` 3. A read sends at most four requests, waits 15 seconds for the page, runs no JavaScript and keeps no cookies. It only visits more of a site when a customer asks it to map or batch one. _Implemented in_`onto-api/lib/fetch-and-clean.ts · crawl.ts` Every request, and the robots.txt that actually stops it, is on [About Onto-Reader](/about-bot). Processors ### Everyone who touches your data. Read off the services the code actually calls. Checked 24 Sep 2026. 1. [**Vercel**Their privacy policy](https://vercel.com/legal/privacy-policy) Hosting, and Vercel KV (run by Upstash) for short-lived dataEvery request in transit; page payloads cached for an hour; monthly quota counters; MCP sign-in grants; the keyless reader's per-IP counts; cookieless page analytics on buildonto.dev`next, @vercel/kv, @vercel/analytics` 2. [**Supabase**Their privacy policy](https://supabase.com/privacy) The database, and dashboard sign-inAccount (email, name and company if you gave them), sign-in identity, API key digests, usage records per call, Serve visit records, pages your SDK uploads, reports you save`@supabase/supabase-js` 3. [**Polar**Their privacy policy](https://polar.sh/legal/privacy) Billing and subscriptionsYour email, plan and purchases. Card details stay with Polar`@polar-sh/sdk` 4. [**Resend**Their privacy policy](https://resend.com/legal/privacy-policy) EmailYour email and first name for the welcome email; your message, email and plan when you contact support`resend` 5. [**Notion**Their privacy policy](https://www.notion.so/notion/Privacy-Policy) The old waitlistEmail addresses left on the waitlist before signup opened on 5 June 2026`@notionhq/client` 6. [**Google Fonts**Their privacy policy](https://policies.google.com/privacy) Fonts on the reader pagesYour IP address and browser details when you open a page at md.buildonto.dev`fonts.googleapis.com` What we don't claim ### The same list, with nothing to cite. A vendor who won't say what they lack hasn't really told you what they have. 1. SOC 2 Type II. Not attested, not in an observation window. _Evidence_`none` 2. ISO 27001. Same. _Evidence_`none` 3. A third-party penetration test. None commissioned yet. _Evidence_`none` 4. A 24/7 on-call rotation. Onto is a small team in one timezone; response is best effort. _Evidence_`none` 5. An uptime SLA. We haven't run long enough to have a number we'd sign. _Evidence_`none` 6. A bug bounty. Reports get a reply and credit if you want it, not money. _Evidence_`none` Disclosure ### Found something? Tell us directly. **Email founder@buildonto.dev**With steps to reproduce. You'll hear back within one business day from someone who can fix it. We won't threaten you, and we'll credit you publicly if you want it. **Please don't scan the API**Automated scanners against api.buildonto.dev mostly test the rate limiter, and the counters are shared. Tell us what you want to test instead. [**Privacy**What we collect, how long we keep it, and how to have it deleted._Read it_](/legal/privacy) Related ### How the fetcher behaves toward your site. The outbound half of this page, in full: what it sends, who can trigger it, and the robots.txt that stops it. [About Onto-Reader](/about-bot) [Privacy Policy](/legal/privacy) --- ## Structured Data (JSON-LD) ```json { "@context": "https://schema.org", "@graph": [ { "@type": "Organization", "@id": "https://buildonto.dev/#org", "name": "Onto", "url": "https://buildonto.dev", "logo": "https://buildonto.dev/icon.png", "sameAs": [ "https://x.com/buildonto", "https://github.com/ravixalgorithm/ontosdk" ] }, { "@type": "WebSite", "@id": "https://buildonto.dev/#site", "url": "https://buildonto.dev", "name": "Onto", "publisher": { "@id": "https://buildonto.dev/#org" } }, { "@type": "SoftwareApplication", "name": "Onto", "applicationCategory": "DeveloperApplication", "operatingSystem": "Web", "url": "https://buildonto.dev", "description": "Onto serves AI agents clean Markdown from your own site, at the same URL, and shows you which agents came. Plus the AIO score, a Read API and an MCP server.", "publisher": { "@id": "https://buildonto.dev/#org" }, "offers": { "@type": "Offer", "price": "0", "priceCurrency": "USD", "description": "Free tier: 1,000 credits / month" } } ] } ```