生成 SDK

Install the Fern CLI

$
npm install -g fern-api

Initialize the fern folder

Initialize the fern folder with your existing OpenAPI specification. Specify your organization name using the --organization flag.

$
fern init --openapi path/to/openapi.yml \
>
--organization <YourOrganization>

This creates a fern folder in your current directory.

Validate your API definition

Check that your API definition is valid, and fix errors before proceeding:

$
fern check

添加 SDK 生成器

运行以下命令将 Java SDK 生成器添加到 generators.yml：

$
fern add fern-java-sdk --group {{GROUP_NAME}}

此命令向 generators.yml 添加以下 group：

1
  java-sdk: # group name
2
    generators:
3
      - name: fern-java-sdk
4
        version: 4.10.1
5
        output:
6
          location: local-file-system
7
          path: ../sdks/java

生成 SDK

运行以下命令生成您的 SDK：

$
fern generate --group java-sdk

$
fern generate --group java-sdk --api your-api-name

The first time you run fern generate, you must log in. Confirm the prompt and choose any of the login methods to authenticate, then generation continues automatically.

fern generate creates a sdks folder in your current directory. The resulting folder structure looks like this:

Set up GitHub repositories

Fern uses a multi-repo structure: your source repository contains the fern/ folder, and each SDK gets its own separate repository.

1. Create a source repository for your fern/ folder if you don’t have one already (e.g., your-org/your-api-definitions).
2. Create an SDK repository for your SDK (e.g., your-org/your-api-java-sdk).
3. Install the Fern GitHub App on both repositories.

发布到 Maven Central

按照发布到 Maven Central 指南配置您的包并通过 GitHub Actions 设置自动发布。