The share of 'Forbidden' responses served to AI agents has roughly doubled since the summer

a16z's This Week in Charts on 16 October 2026 cites Cloudflare data showing that the share of 403 'Forbidden' responses received by agents and bots has grown considerably since the summer, to about double what it once was. a16z links this partly to big e-tailers such as Amazon blocking agent shoppers, since retailers do not want to lose customer relationships or the advertising revenue that comes from customer eyeballs. It notes that how much of the rise is a response to agentic commerce specifically is a separate question.

What it means Agents that shop or browse on a user's behalf will hit more blocks, which pushes builders toward sanctioned APIs and merchant partnerships.