Migrate from Stainless to APIMatic — Free Assessment + 50% Off First YearSkip to content<br>For Stainless customersSpecs are forever. Platforms aren't.<br>Migrate from Stainless to APIMatic, the original CodeGen<br>Your Stainless SDKs are yours to keep. APIMatic helps you keep the pipeline that maintains them — SDKs, docs, MCP servers, and CLIs generated from one OpenAPI spec. Free migration assessment, plus 50% off your first year, for paying Stainless customers.<br>Request your migration assessment →Talk to our migration team

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Your generated SDK code — yours to modify, relicense, fork, or maintain independently

Your stainless.yaml config files — yours to keep (though they only operate with Stainless tooling)

Your published packages on npm, PyPI, Maven, and other registries — already live in the ecosystem

—Auto-regeneration when your OpenAPI spec changes — every API change becomes a manual port across every SDK language

—Package publishing pipeline — no more automated releases to npm, PyPI, Maven, NuGet on merge

—Support and accountability — there's no SDK platform team to file issues against

PathWhere it fitsWhat to plan forManual maintenance Small APIs, 1–2 SDK languages0.5–1.5 FTE of senior engineering time; cross-language drift; single-person dependencyAgentic coding tools (Claude Code Actions, Cursor, etc.)One-shot edits to a single SDK at a timeCross-language consistency; custom-code preservation across regenerations; senior review per PR; no SLA when output breaks productionOpen-source generators (TypeSpec, OpenAPI Generator)Teams with strong internal build-engineering capacityFunctional but less idiomatic output; limited customization vs. a managed platform; ongoing maintenance of the generator integration in your build

SDKs in 7 languages<br>Idiomatic SDKs in each language. Auto-regenerated when your OpenAPI spec changes. Published to npm, PyPI, Maven, etc.<br>TSPythonJavaC#RubyPHP

Docs Portal<br>Interactive API reference, narrative guides, and code samples in every SDK language. Stays in sync with your OpenAPI spec automatically. Self-host or deploy to APIMatic-managed hosting.

AI Context Plugin<br>Drop-in context for Claude Code, Cursor, and other agentic coding tools so AI agents using your API generate correct, idiomatic code on the first try.

MCP Server Generator Coming soon<br>Generate Model Context Protocol servers from the same OpenAPI spec. Token-efficient, ready for Claude, Cursor, ChatGPT, and other agent clients.

CLI Generator Coming soon<br>A scriptable command-line interface for your API, generated alongside your SDKs. Same spec, same custom-code model.

// one specOpenAPI in → everything out.<br>The same source of truth drives SDKs, docs, agent context, MCP, and CLI — so the surface stays coherent without per-language drift.

// track record10years.1,000,000+OpenAPI specs.<br>APIMatic has been generating SDKs since 2015. Our platform has processed more than a million OpenAPI specifications for teams shipping production APIs to developers around the world.<br>"A modern developer experience site needs several essentials: clear business value within the API, a usable code sandbox/playground, and SDKs in different languages to support developers in their preferred environment. APIMatic checked a lot of those boxes for us."

Available as managed SaaS or on-premises deployment for regulated and enterprise environments.

01Submit your OpenAPI spec and Stainless config.<br>Send us the artifacts you already have. No engineering work required on your side.

02Receive your migration plan.<br>A written report from APIMatic's SDK engineering team — scope, mapping, and quote.

03Implementation.<br>A dedicated engineer sets up the SDK generation pipeline alongside your team.

04Validate & ship.<br>Regenerate, publish to your registries, and cut over before September 1.

The migration assessment is a written report, not a sample SDK generation. We recommend starting at least 4–6 weeks before September 1, 2026, to allow time for assessment, implementation, and validation.

FreeFree Migration Assessment<br>A written report and migration plan based on your OpenAPI spec and Stainless config. Delivered by APIMatic's SDK engineering team.

Discount50% off your first year<br>Paying Stainless customers who migrate to APIMatic receive 50% off their first-year subscription on any plan.

White-gloveDedicated engineer<br>Every customer gets a dedicated engineer who will review their configuration and help setup the SDK Generation pipeline.

Request your migration assessment →Talk to our migration team

Why not use Claude Code GitHub Actions to maintain our SDKs?Claude Code Actions can suggest changes to a single SDK reasonably well. APIMatic generates seven idiomatic SDKs from one OpenAPI spec, preserves your custom code across regenerations, and publishes packages to every major registry — at the same time, automatically. The two solve different problems. For teams running multiple production SDKs across more...