We're thrilled to announce that Stainless is joining @AnthropicAI! Stainless was founded to make software better for everyone, and we're honored to continue that mission on the Anthropic team. Check out the announcement blog post for more: stainless.com/blog/stainless…

On April 2, we're teaming up with @KeycardLabs, @OpenAI, @vercel, and @Google for AX Night. Join us in SF for live demos and Q&A on everything your API needs for agents to integrate successfully. MCP (code mode), agent skills, CLIs, and more.

Big news… Stainless is expanding into rally racing! 🏎️ Just kidding. We recently worked with an old friend from Stripe, richö, on a security project. Instead of a typical payment, he asked if we’d sponsor his rally car (hard to say no to that). If you happen to see the Stainless logo flying down a gravel stage somewhere, now you know why.

🔍 Preview builds Every pull request to your docs repo generates a preview deployment. Review documentation changes in context before merging, just like code.

🎨 Styling improvements We rewrote the theming system during early access. Customize colors, typography, and UI styling using simple CSS variables. Update your accent color or fonts once, and the entire docs site updates.

🤖 Conversational AI chat Docs now include an AI assistant that can answer questions using your API reference and guides. - Streams markdown responses with syntax-highlighted code - Renders tables and structured docs content - Works alongside traditional search

🖼️ Automatically generated OG images Every page generates a branded OG image. - API endpoints render method signatures - Guides render titles + breadcrumbs - Light and dark variants supported

The Stainless Docs Platform is now in public beta! From the same OpenAPI spec that powers your SDKs, you can generate API reference, SDK examples, and prose guides. Start shipping docs that enable AI agents and delight developers.

The agent generates SDK code to generate the context it needs to respond to the prompt, which it then requests for the MCP server to execute. The results of the API request give the agent the information it needs.

An agent configured with an SDK code mode MCP server receives a prompt that can be satisfied by the MCP server. The agent starts with a docs_search tool call (or a few) to get information on the APIs it needs to operate.

"SDK code mode" enables operating an API via MCP with SotA accuracy and efficiency. It's how Stainless MCP servers already work today - learn more on the Stainless blog and in the thread 🧵

Headed to @HumanXCo? Join us at SFMOMA on April 8 for the biggest AI afterparty of the year. @browserbase | @resolveai | @WorkOS | @modal | @mintlify

MCP is approaching an inflection point, and the limiting factor is becoming obvious. Last week we held our first event in SF with @KeycardLabs, @Cloudflare, @temporalio, and @humanlayer_dev. We talked about what’s breaking in MCP right now, and what it will take to make agent-driven software robust. Some hard truths: - Many MCP servers work in demos but fail across real-world use cases. - “Giant agent skills” are becoming an anti-pattern with thousands of lines explaining things the model already knows, without clarity on the 5% it doesn’t. - Standard MCP approaches (one tool per endpoint or dynamic tools) scored ~50% correctness, but more advanced implementations reached ~70%. - The real kicker: when agents wrote code against production-grade SDKs, correctness jumped to 90–95%. But capability is only half the story. Control is the other half. An in-house Gmail MCP server was great for drafting emails… until it sent one unintentionally. The question isn’t just “can the agent do this?” but “what is it allowed to do?” OAuth scopes and coarse endpoint controls aren’t enough, and we’ll need fine-grained, programmable boundaries like: - Limit an agent to a single document - Cap refund amounts - Prevent broad, unintended actions If AI interfaces are going to replace dashboards, the underlying systems need to behave like an operating system kernel, not a shell script. Capability gets attention. Control earns trust. Trust is what scales.

Java SDK builds now come with a hosted Maven repo for early testing. When a build succeeds, Stainless automatically generates a shareable Maven repository so you can test and distribute pre-release versions before a formal release. The same pre-release testing workflow is supported for Python and TypeScript as well. stainless.com/changelog/stag…

You can now iterate on your SDKs locally with the Stainless Language Server ⚡ It brings all of the editing capabilities of the Stainless Studio directly into your local environment - VS Code, Cursor, Neovim, Zed, and more. The LSP supports: ✱ Real-time diagnostics with one-click autofixes ✱ Context-aware completions powered by your OpenAPI spec ✱ Go-to-definition + find references across config and spec ✱ Inline codelenses to see SDK coverage in your API ✱ Live Transforms updates as you edit Tighter feedback loops without ever leaving your editor.

What makes this different from raw HTTP extensions? * Type-safe composite types (not JSONB blobs) * Smart pagination with recursive CTEs that auto-short-circuit based on LIMIT for efficiency * Auto-generated from your OpenAPI spec * Easy configuration via DB params