Agentic commerce is here. Let's secure it together.

McKinsey predicts agentic commerce will bring $3 trillion+ in new revenue (yes, trillion). You can be damn sure that executives will jump without looking twice to get a piece of that pie. Priority #1 will be to optimize for millions of new website "shoppers". Defending against millions of new website attackers will be left for security teams as an after-thought.

The technical instruments to deal with this do not exist yet. The era of detecting "are you a human" is over. The era of detecting "are you acting on behalf of a human" is here. And that means catching whether those agents act on behalf of a human with good intentions (to purchase) or bad intentions (scrape content, find vulns., test stolen credit cards).

We're a small startup of security engineers. After building in the client-side space (monitoring what happens in the browser) for years, we're taking on this "agentic trust" challenge. And we want every code commit to be grounded in community insight from practitioners like you.

Simon Wijckmans
Simon Wijckmans, Founder, cside
January, 2026

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Private users will be invited to test our MVP for free. Your feedback will shape what we ship.

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cside is backed by top VCs

Uncork Capital
Mantis VC
Scribble Ventures
See What We've Built ↓

Agents are already on your website.

Good "consumer" agents need guidance on your website. For example, on a checkout page, how should an agent handle selecting upsells?

Proper optimization leads to more revenue. Poor optimization leads to angry calls to the bank saying "your website tricked my AI agent into buying more than I asked for".

Morgan Stanley predicts 20% of digital commerce will be agentic by 2030
In 2025, VISA & Mastercard launched tools to accept agentic payments
AI agent detection graphic

We tested bot detection tools.
None of them worked for AI agents.

8/10 times they failed to detect our malicious AI agents. And we were barely trying. In fact we intentionally tried to get caught and still slipped through most times.

This made it clear to us that "bot detection" tools are not ready for:

Pirates: Scraping premium content at scale (video streaming, music, art)
Hackers: Brute force scanning for vulnerabilities, creating false accounts
Payment Fraudsters: Credit card testing, chargeback abuse

Our vision for client-side security & governance of AI agents:

Agents will interface with APIs and MCPs, but most activity is happening on the client-side. That is, agents are accessing your website via a "browser" in (mostly) the same way a human user would.

Network-level monitoring (most web security tools) does not see what happens in the browser. We're building a client-side AI agent governance layer that can be added onto your stack without ripping out current infra.

cside client-side vision architecture

About cside

We're a fully funded, developer-centric startup building the next generation of web security. Established vendors don't take client-side security seriously, so we're filling the gap.

Members of our team have contributed to: Bootstrap, Tailwind CSS, Servo, W3C

We regularly sponsor developer events like CSIDES, BSIDES and EMF Camp.

cside team

cside in the news:

Get Private Access to AI Bot Detection

Private users will be invited to test our MVP for free. Your feedback will shape what we ship.

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