Inside Stainless, The Developer Tools Startup Anthropic Just Bought for $300 Million

The transcript of AI & I with Stainless CEO Alex Rattray is below. Watch on X or YouTube, or listen on Spotify or Apple Podcasts. [Disclosure: I’m a small investor in Stainless.]

Timestamps

1. Introduction: 00:01:15
2. APIs and MCP, the connectors of the new internet: 00:05:09
3. Why MCP exists: 00:11:00
4. Why MCP servers are hard to get right: 00:17:15
5. Design principles for reliable MCP servers: 00:20:24
6. Using MCP for business ops at Stainless: 00:25:06
7. Alex’s take on the security model for MCP: 00:40:57
8. How one-off AI actions become permanent production software: 00:44:42

Dan Shipper

The internet runs on computers talking to each other, but its entire architecture was built for a pre-AI world. Now we’re trying to hook AI up to the internet with MCP—Model Context Protocol—which turns any website or web service into a set of tools that an AI can use natively to get work done. And the software companies that learn how to do MCP well are going to win over the next decade.

That’s why I brought Alex Rattray, the founder and CEO of Stainless, onto the show. Stainless’s job is to help computers talk to each other. They make the APIs and SDKs for all the big companies you know about, like OpenAI and Anthropic, and they’re starting to build MCP servers too. Alex and I get into the nitty-gritty of what the future of MCP looks like, how to design good MCPs, why MCPs are actually really hard to scale and possibly insecure, and we try to figure out together what a better model for allowing AIs to use the internet might look like.

This is a great episode. Alex is a good friend of mine. Let’s dive in.

Alex, welcome to the show.