Ele foi uma das primeiras implementações de um framework usando Python _type hints_ para declarar parâmetros e requisições que eu nunca vi (antes no NestJS e Molten). Eu encontrei ele mais ou menos na mesma época que o Hug. Mas o APIStar utilizava o padrão OpenAPI.

Ele tinha validação de dados automática, serialização de dados e geração de _schema_ OpenAPI baseado nos mesmos _type hints_ em vários locais.

      },
      "stopword_en_filter": {
        "type": "stop",
        "stopwords": "_english_"
      },
      "content_length_filter": {
        "type": "length",
        "max": 30
      },
      "limit_token_count_filter": {
        "type": "limit",
        "max_token_count": 2147483647
      },
      "stemmer_en_filter": {
        "type": "stemmer",
        "name": "english"
      },

      },
      "favorite_count": {
        "type": "long"
      },
      "filename": {
        "type": "keyword"
      },
      "filetype": {
        "type": "keyword"
      },
      "host": {
        "type": "keyword"
      },
      "lang": {
        "type": "keyword"
      },
      "last_modified": {
        "type": "date",
        "format": "date_optional_time"
      },

          <version>1.0.0+</version>
          <type>String</type>
          <description>The version of the dependency.</description>
        </field>
        <field>
          <name>type</name>
          <version>1.0.0+</version>
          <type>String</type>
          <defaultValue>jar</defaultValue>
          <description>The type of dependency.</description>
        </field>
      </fields>

        CURRENT = JAVA6;
      }
    }

    abstract Type newArrayType(Type componentType);

    abstract Type usedInGenericType(Type type);

    final ImmutableList<Type> usedInGenericType(Type[] types) {
      ImmutableList.Builder<Type> builder = ImmutableList.builder();
      for (Type type : types) {
        builder.add(usedInGenericType(type));
      }
      return builder.build();
    }

      },
      "hitCount": {
        "type": "long"
      },
      "hitCountRelation": {
        "type": "keyword"
      },
      "queryOffset": {
        "type": "integer"
      },
      "queryPageSize": {
        "type": "integer"
      },
      "userAgent": {
        "type": "keyword"
      },
      "referer": {
        "type": "keyword"
      },
      "clientIp": {
        "type": "keyword"

		}
	}
	return diffSlc
}

type srBucketMetaInfo struct {
	madmin.SRBucketInfo
	DeploymentID string
}

type srPolicy struct {
	madmin.SRIAMPolicy
	DeploymentID string
}

type srPolicyMapping struct {
	madmin.SRPolicyMapping
	DeploymentID string
}

type srUserInfo struct {
	madmin.UserInfo
	DeploymentID string
}

pkg os, method (FileMode) String() string
pkg os, type FileInfo interface { IsDir, ModTime, Mode, Name, Size, Sys }
pkg os, type FileInfo interface, IsDir() bool
pkg os, type FileInfo interface, ModTime() time.Time
pkg os, type FileInfo interface, Mode() FileMode
pkg os, type FileInfo interface, Name() string
pkg os, type FileInfo interface, Size() int64
pkg os, type FileInfo interface, Sys() interface{}
pkg os, type FileMode uint32
pkg os, type PathError struct

    /**
     * Casts an object to the specified type with type checking
     * @param <T> the target type
     * @param type the target class type
     * @param object the object to cast
     * @return object cast to type
     * @throws PACDecodingException if types are incompatible
     */
    public static <T> T as(final Class<T> type, final Object object) throws PACDecodingException {
        if (!type.isInstance(object)) {

pkg syscall (linux-386-cgo), type Credential struct, NoSetGroups bool
pkg syscall (linux-386-cgo), type SysProcAttr struct, AmbientCaps []uintptr
pkg syscall (linux-386), type Credential struct, NoSetGroups bool
pkg syscall (linux-386), type SysProcAttr struct, AmbientCaps []uintptr
pkg syscall (linux-amd64-cgo), type Credential struct, NoSetGroups bool