{"id":12584,"date":"2025-11-12T03:40:13","date_gmt":"2025-11-12T03:40:13","guid":{"rendered":"https:\/\/developer.rdkcentral.com\/documentation\/?page_id=12584"},"modified":"2025-11-26T07:34:30","modified_gmt":"2025-11-26T07:34:30","slug":"webconfig-metadata-for-supported-docs-and-versioning-of-groups","status":"publish","type":"page","link":"https:\/\/developer.rdkcentral.com\/documentation\/documentation\/device_management\/webconfig\/webconfig-metadata-for-supported-docs-and-versioning-of-groups\/","title":{"rendered":"Metadata Guide"},"content":{"rendered":"
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This document defines the mechanism by which the CPE communicates its supported features to the cloud. To ensure compatibility, especially in cases where the cloud introduces support for new groups or blobs not yet implemented in the CPE, RDK adopts a metadata-based approach.<\/p>\n\n

When the CPE contacts the cloud server to retrieve the latest version of documents, during either a forced sync or a bootup sync then it includes the header X-System-Supported-Docs:<\/em><\/strong> in the request. This header contains a bitmask string that indicates which features are supported in the CPE firmware.<\/p>\n\n

Within RDK, different features are managed by separate components. Accordingly, subdocs are organized into groups, each represented by a bit masked value. These values are comma-separated within the header. Each group’s position in the header is predefined and identified by its two most significant (MS) nibbles. The cloud can parse these bitstreams based on the group ID provided by RDK. Within each group’s bitmap, the cloud can check which bits are set to identify the supported features.<\/p>\n\n

RDK reserves two MS nibbles for identifying the group; these remain constant. The remaining bits are used to indicate whether a specific subdoc is supported.<\/p>\n\n

To specify the schema versions supported for each group, the metadata header X-System-Schema-Version<\/em><\/strong> is included. This header contains comma-separated entries, each combining a bitmask subdoc ID with its corresponding version number. This allows the cloud to determine the schema version supported by the CPE for each subdoc in a given firmware release. The order of versions in this header may differ from the bitstream order used in the supported-docs metadata. Since all subdoc versions begin at 1.0, RDK does not include this header or subdoc version information unless a version change has occurred.<\/p>\n\n

Both version and supported-docs information are generated at build time and remain unchanged during CPE runtime.<\/p>\n\n

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RDK Subdoc Group Placeholders<\/h2>\n<\/div>\n<\/div>\n<\/div>\n
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Metadata for supported features in CPE<\/h3>\n
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X-System-Supported-Docs: <Group1>,<Group2>,<Group3>,...,<GroupN><\/pre>\n<\/div>\n<\/div>\n
Points for future:<\/em><\/p>\n\n