Buyer questions, answered from SalesBook rankings

Each page answers one question buyers ask AI assistants about agent infrastructure, with a ranked shortlist taken only from SalesBook's ranked data (methodology v0.3.0), a dated source for every company and a link to each profile. Ranks are never for sale.

1. Which companies provide identity and authorization for AI agents?10
2. Which browser-infrastructure vendors serve AI agents, and how do they compare?10
3. What are the best sandbox platforms for running AI agent code?10
4. Which MCP server hosting and tool-integration platforms lead for enterprises?10
5. Which startups offer payments or checkout rails for AI agents?10
6. Which agent infrastructure startups rank highest, and who are their investors?20
7. Which AI agent startups publish MCP servers or llms.txt?25
8. What does Agentery do, and who invested in it?4
9. Who are Noetive's investors and customers?8
10. What is Keycard (AI agent identity), and how is it funded?10