Changelog

Sorbet type definitions are stable with improved autocomplete for models.

Stainless Ruby SDKs are among the first to support type annotations without relying on sorbet-runtime, giving you static analysis without the extra overhead.

It’s also the first to offer Sorbet, RBS, and YARD docs with full generics.

Stainless can now generate an MCP server for your API. The feature is currently experimental and is free to all users.

Get the full details in the launch blog.

The SDK Studio features an improved editor. This provides a more consistent coding experience and comes with improved autocomplete and cmd+click navigation.

Users with code snippets enabled in their Stainless config can toggle a feature in the Studio UI to make their documented OpenAPI spec downloadable via a public URL.

For APIs where the base URL includes dynamic segments like a region subdomain (https://{region}.acme.com), you can map client options to them with the server_variable property in your Stainless config.

This allows your SDK users to set region directly without constructing custom baseURLs.

// now
const client = new Acme({ region: 'us-east-2' })
// before
const client = new Acme({ baseURL: 'https://us-east-2.amazonaws.com' })

# Stainless config
client_settings:
	opts:
		region:
			type: string
			env: ACME_REGION
			nullable: false
			server_variable: region

You can now generate a Ruby SDK for your API using Stainless. Once your project is configured, follow this guide to get started.

See it in action here: Modern Treasury Ruby SDK.

For any feedback or feature requests, ping hao@.

Java and Kotlin SDKs come with hosted API docs—Javadocs and KDocs are published to javadoc.io and linked from the README.

Stainless docs now have an “Integrations” section with guides on integrating with other platforms. Check out the first integration guide with bump.sh.

The Java/Kotlin SDKs are now generally available in the Stainless Studio.

Stainless now outputs Java/Kotlin code snippets, which will be read by API reference documentation providers and displayed in your documentation.

Here is an example (binary response handling) of the code snippets:

package com.example.api.example;

import com.example.api.client.TestOrgClient;
import com.example.api.client.okhttp.TestOrgOkHttpClient;
import com.example.api.core.http.HttpResponse;
import com.example.api.models.FileContentParams;

public final class Main {
    private Main() {}

    public static void main(String[] args) {
      // Configures using the `EXAMPLE_API_KEY` environment variable
      TestOrgClient client = TestOrgOkHttpClient.fromEnv();

      FileContentParams params = FileContentParams.builder()
          .fileId("file_id")
          .build();
      HttpResponse response = client.files().content(params);
    }
}

The SDK Studio is now served from app.stainless.com, with the homepage updated to stainless.com (formerly stainlessapi.com).

The SDK Studio now shows Terraform schemas and snippets in the SDK preview pane.

Stainless automatically resolves more repetitive, low-risk merge conflicts with a syntax-aware merge algorithm.

When generating code snippets for documentation providers, Stainless will prioritize the first example in your OpenAPI spec’s request examples.

Generate a Terraform Provider for your API using Stainless to allow your customers to automatically provision resources in your API. Follow this guide to get started. To see an example in action, try the Cloudflare v5 Terraform Provider.

For any feedback or feature requests, ping dackerman@.

You can now ignore specific diagnostics in the SDK Studio to better prioritize build-critical ones.

See changes you’re making to the Stainless Config and the OpenAPI spec before you save them.

Setting max_retries to 0 is now supported across our SDKs. Use this setting if retries are not compatible with your API.

When deprecating a schema, SDKs will include a message. In your OpenAPI spec, add x-stainless-deprecation-message: <your message> alongside deprecated: true to use this feature.

SDKs now support endpoints that return JSONL responses. Mark your endpoint’s content type as application/jsonl or application/x-jsonl to use this feature.

The SDK Studio now features a redesigned preview pane with an improved look and feel. Use the preview pane to review complete language-specific content including method signatures, parameters, types, and more.

Use Cmd+S (Ctrl+S on Linux/Windows) to save your progress in the SDK Studio.

The project dashboard page displays the status of each SDK, release configuration, and build history.

The Java and Kotlin SDKs support logging requests when setting a <OrgName>_LOG environment variable to info or debug depending on the desired verbosity.

This is also available in Python and TypeScript.

The Java and Kotlin SDKs now use custom, SDK-specific code instead of Guava, reducing generated JAR size by 10% (3 MB).

The Java and Kotlin SDKs automatically prevent accidental memory leaks. If a user forgets to close an HTTP response or client, then it will be automatically closed when it becomes phantom reachable.

SDKs now include an X-Stainless-Retry-Count header in every request to indicate the current retry attempt. This provides better visibility into why requests are being sent to your API.

Stainless now seamlessly integrates with JSR, a multi-platform package manager for TypeScript developed by the Deno team.