A partition ID identifies a grouping of entities. The grouping is always by project and namespace, however the namespace ID may be empty.

A partition ID contains several dimensions: project ID and namespace ID.

Partition dimensions:

  • May be "".
  • Must be valid UTF-8 bytes.
  • Must have values that match regex [A-Za-z\d\.\-_]{1,100} If the value of any dimension matches regex __.*__, the partition is reserved/read-only. A reserved/read-only partition ID is forbidden in certain documented contexts.

Foreign partition IDs (in which the project ID does not match the context project ID ) are discouraged. Reads and writes of foreign partition IDs may fail if the project is not in an active state.

JSON representation
  "projectId": string,
  "namespaceId": string,


The ID of the project to which the entities belong.



If not empty, the ID of the namespace to which the entities belong.