Changes only the fields present in the request body; omitted fields keep their current value. A field sent as null counts as omitted; send an empty string to clear a text field, or an empty array to clear label or projectMeta. A body with no updatable field is rejected with 400. When name is present it must not be blank. When label or projectMeta is present it replaces the current set. File metadata is preserved automatically; do not include FILE entries in the body — they are rejected with 400, and each projectMeta entry must state metaType explicitly (entries without one are treated as FILE). Changes to name or longname are recorded in the project's journal log; when label is present, labels no longer used by any project or protocol in the group are deleted. Use the PUT call to replace the whole project.

The name field sets the Internal Project ID shown in eLab (the field integrations usually key on), while longname sets the project's display name.