Mirrors provides regression testing for AI agents. Teams shipping agents constantly change prompts, models, and tools, and there's no way to test any of it.
Mirrors is a Y Combinator company in the Fall 2026 batch. Its directory entry describes it as: Give AI agents the right context at the right moment. The founder listed is Aryan Singhal (Founder/CEO) (Y Combinator directory entry, September 10, 2026).
Sell to companies like Mirrors? Enter your website and see 10 with a filed reason to buy from you this month. Free.
Opens in a new tab. No signup.
New accelerator entry · 2026-09-10 · the record
Pitching, partnering or investing alongside them? See who really runs and owns Mirrors.
Free to see. No signup.
More on Mirrors and the records around it.
Same batch, B2B first.
Get an email when Mirrors changes status, grows its team or files a funding notice. One email first to confirm; nothing else until you click it. At most one a day, one click to stop. Free for up to 3 companies.
We'll show it in your MentionFox inbox when Mirrors raises, hires or launches. No email unless you switch it on.
Watch Mirrors →Get the full cited report on Mirrors
Example from a real report (our sample on Target): “The Q2 2026 earnings report, published August 19, 2026, showed adjusted EPS of $2.46 against an expected $2.33” Source: CNBC
A Full Report on Mirrors: verified, sourced, every claim cited, ready in a few minutes. See pricing.
Saved here on this device in the meantime, so nothing is lost either way.
Mirrors provides regression testing for AI agents. Teams shipping agents constantly change prompts, models, and tools, and there's no way to test any of it. Agents call bespoke internal tools and APIs no test framework can reproduce, so most teams ship on vibes. Mirrors rebuilds the tools your agent calls from your own production traces, then replays real sessions against every change before it merges. You see which tool calls changed, which arguments moved, and where state landed differently. And when something fails, we tell you whether your agent regressed or something upstream moved. Built for teams whose agents take irreversible actions. Refunds, record updates, outbound email. Runs in your CI on every PR.
Checked away from the directory entry. Neither line below comes from the company's Y Combinator page.
Mirrors builds a runnable twin of the systems your AI agents call from their traces, then replays real sessions against every prompt, tool or model change.
The title and description the site itself served, answering 200. Not a cached copy and not the company's directory entry — what was live when we asked.
Counted only where a thread links to this company's own site, announces it by name on that forum, or names it beside its own Y Combinator batch. A thread whose title merely carries the words is not counted — a name is not an identifier. More may exist than the one page of results read here. Hacker News is not us, and nothing above is our opinion of the company.
Founders, titles and bios as the company published them. Photographs are our own copies of the ones on that record, so they do not break when the original link expires.
No investor is drawn from a Form D — the form states how many invested and never who. The one investor on this graph is named because a batch has exactly one.
Weighing a deal with Mirrors? A company due diligence report brings its funding, leadership changes, layoffs and warning signs together, with every claim linked to its source.
Example from a real report (our sample on Target): “The Q2 2026 earnings report, published August 19, 2026, showed adjusted EPS of $2.46 against an expected $2.33” Source: CNBC
A Full Report on Mirrors: verified, sourced, every claim cited, ready in a few minutes. See pricing.
What the Full Report on Mirrors covers
Plus the sections for what you are deciding, which you pick after ordering.
A real finished report, first screen. Opens in a new tab.
Not ready to order yet? Keep this snapshot.
Sends this preview to you once; we won't add you to any list
You land back on this company when you are in.
Not ready to upgrade? Keep this one in view instead.
Watchlist MirrorsYou get an alert in MentionFox the next time this company shows up.
If you're behind Mirrors: acceptance into a YC batch is one of the few weeks a young company gets looked up by people who matter — investors, other founders, press. FoxPlug turns the commits, deploys, and releases you're already making into that story automatically, so anyone who looks finds something current. GetFoxChat puts a guide on your own site so the people YC's own page just sent you don't read one line and leave.
Sourced from the company's Y Combinator directory entry, from the company's own site, read directly on 2026-09-10 (runmirrors.com), and from Hacker News, where 3 threads met the matching rule stated beside the count.
Each opens in a new tab, filled in for Mirrors. With no account yet, you sign up free and land on the result.
Share the news. Sharing needs no account.
https://mentionfox.com/funding/yc-mirrors