COMPANY PROFILE · /stainless
S

Stainless

Stainless is a New York-based developer-tools company that uses an artificial-intelligence-powered compiler to automatically generate software development kits (SDKs), documentation, command-line interfaces (CLIs), Terraform providers, and Model Context Protocol (MCP) servers from a customer's OpenAPI specification. Founded in 2022 by former Stripe engineer Alex Rattray, the company powers official client libraries for major AI platforms including OpenAI, Anthropic, Google, Meta's Llama Stack, and Cloudflare. In May 2026, Stainless announced it was being acquired by Anthropic in a deal reported to be worth more than $300 million, and began winding down its hosted products for external customers.

stainless.com· New York, New York, United States· founded 2022reported
Fresh · 9d ago
Latest valuation
$150M
Annual Recurring Revenue
~$1M Annual Recurring Revenue (ARR) at time of Series A (December 2024)
Headcount
Funding total
$28.5M
OVERVIEW

In May 2026, Anthropic announced the acquisition of Stainless for a reported $300M+ — roughly 2x its $150M December 2024 Series A valuation. Founder Alex Rattray and team are joining Anthropic, and Stainless began directing existing customers to a transition portal as hosted products wind down. The acquisition follows Anthropic's pattern of buying developer-tooling and agent-infrastructure companies (Bun, Vercept, Coefficient Bio). Prior to acquisition, Stainless reported that millions of AI developers downloaded its generated SDKs each week, and customers included OpenAI, Anthropic, Google, Meta, Cloudflare, Runway, Cerebras, Groq, LangChain, and Writer.

Status
acquired
Tier
master-list
Profitability
Reported near-profitable at Series A (December 2024)
Pricing
Freemium with paid tiers ranging from approximately $250/month to $30,000/year; custom enterprise plans (legacy pricing, products being wound down post-acquisition)
FUNDING HISTORY · 0
No funding rounds on file.
PRODUCTS · 5
Stainless SDK Generator
SDK generation
Takes an OpenAPI specification as input and uses an AI-powered compiler to automatically produce idiomatic, typed client libraries (software development kits) in multiple programming languages, keeping them synchronized as the underlying API evolves.
Stainless MCP Server Generator
Agent infrastructure
Generates Model Context Protocol (MCP) servers from an OpenAPI specification, exposing a customer's API as tools that large language model (LLM) agents like Claude and other MCP clients can invoke.
Stainless Documentation Sites
API documentation
Generates hosted developer documentation sites directly from a customer's OpenAPI specification, kept in sync with their SDKs.
Stainless CLI Generator
Developer tools
Generates command-line interface tools for an API from its OpenAPI specification.
Stainless Terraform Provider Generator
Infrastructure as code
Generates Terraform providers from a customer's OpenAPI specification so that their API resources can be managed via infrastructure-as-code workflows.
TEAM · 0 key people

No people linked.

SOURCES · 19 cited
  1. 01Stainless Secures $25 Million in Series A Funding to Revolutionize AI-Driven SDK Generation - Fundraise Insider · fundraiseinsider.comreported
  2. 02Stainless Software gets $25M in funding to bring AI-generated SDKs to developers - SiliconANGLE · siliconangle.comreported
  3. 03Stainless - Crunchbase Company Profile & Funding · crunchbase.comreported
  4. 04Stainless - Blog - Towards the API platform we always wanted: why we raised our $25M Series A · stainless.comreported
  5. 05Anthropic Acquires SDK Platform Stainless for at Least $300M, Locking Out OpenAI and Google · opentools.aireported
  6. 06Stainless - Company · stainless.comreported
  7. 07Anthropic Buying Stainless: 300 Million Dollar SDK Deal Targets OpenAI | Let's Data Science · letsdatascience.comreported
  8. 08Anthropic Stainless Acquisition: How a $300M+ Developer Tools Deal Could Hand Anthropic Control Over Its Rivals' SDKs · entrepreneurloop.comreported
  9. 09Anthropic Acquires SDK Startup Stainless for Over $300M, Cutting Off Key Tool Used by OpenAI and Google · theaiinsider.techreported
  10. 10MCP Server Generator - Stainless MCP Portal · stainless.comreported
  11. 11Anthropic acquires SDK-generator Stainless to widen Claude agent reach · resultsense.comreported
  12. 12Stainless - Production-ready MCP servers optimized for agentic coding and context limits · stainless.comreported
  13. 13Generate MCP servers from OpenAPI specs | Stainless docs · stainless.comreported
  14. 14Create an MCP server from your OpenAPI specification | Stainless · stainless.comreported
  15. 15Generate MCP servers with OpenAPI specs | Stainless docs · app.stainless.comreported
  16. 16Stainless - SDK Generator from OpenAPI Spec | EveryDev.ai · everydev.aireported
  17. 17Standalone MCP server generation | Speakeasy · speakeasy.comreported
  18. 18Stainless - MCP servers · stainless.comreported
  19. 19Auto-generating an MCP server & client - Stytch · stytch.comreported