Saved Objects Style Review

Use this skill when reviewing or changing Saved Object type registrations, especially code that calls savedObjects.registerType, edits mappings, or changes modelVersions.

Type Registration

Register Saved Object types systematically during plugin setup. We want to encourage—and, where possible, enforce—unconditional savedObjects.registerType calls rather than gating registration behind a configuration parameter or feature flag.

If registration is conditional, our CI Saved Object check is unlikely to detect the type. The check builds the current registry by starting Kibana; when the gate is off in CI, the type is never registered and the check cannot validate its definition or subsequent updates to mappings, modelVersions, or schemas. That bypasses safeguards that catch invalid migrations before they reach production, where bad changes can corrupt stored data or prevent Kibana from starting.

For early iteration that genuinely requires conditional registration, follow the documented WIP-type workflows in docs/extend/key-concepts/saved-objects/validate.md rather than ad hoc feature-flag gating.

Mapping Mindset

Saved Object mappings are search indexes, not a complete schema. Once added and released, mappings cannot be removed. Add mappings only for fields that Kibana must search, filter, sort, or aggregate on. Stored attributes do not need mappings just because they exist in the Saved Object payload.

Default to dynamic: false for object mappings so Elasticsearch stores unmapped attributes without indexing them. Do not use enabled: false or index: false; those choices are hard to change later.

Review Checklist

• If a new field is not queried, filtered, sorted, or aggregated, do not add a mapping, mappings_addition, or root mapping entry for it.
• If a new field is indexed, add it in both places: the latest type mappings and a modelVersions mappings_addition.
• Do not add a mappings_addition for a field that already existed in the type's root mappings before the change. Root mappings represent the latest complete mapping state; model version changes describe only what changed in that version.
• When adding an indexed field with a default value, pair mappingsaddition with databackfill. For a non-indexed field with a default, use only data_backfill.
• For new searchable behavior, prefer a two-release rollout: first add/backfill the indexed field, then depend on it in business logic in the next release.
• Keep create and forwardCompatibility schemas aligned with stored attributes. These schemas may include non-indexed fields even when mappings do not.

Common Review Findings

Check whether the proposed mapping already existed in the saved object root mappings (createdat, createdby etc.) before this change. Re-declaring an existing root-mapped field adds duplication and wastes resources.

References

• docs/extend/key-concepts/saved-objects/create.md
• docs/extend/key-concepts/saved-objects/update.md
• packages/kbn-check-saved-objects-cli/README.md
• docs/extend/key-concepts/saved-objects/validate.md