Validate changes in Saved Object types

This page covers testing model versions, ensuring safe Saved Object type definition changes, and troubleshooting validation failures. It applies to type definitions (the code you register), not to validating Saved Object instances at runtime.

Model version definitions are more structured than legacy migration functions. The @kbn/core-test-helpers-model-versions package provides utilities to test the behavior of model versions and their transformations.

The createModelVersionTestMigrator helper creates a test migrator that applies the same transformations the migration algorithm uses during an upgrade.

Example:

import {
  createModelVersionTestMigrator,
  type ModelVersionTestMigrator
} from '@kbn/core-test-helpers-model-versions';

const mySoTypeDefinition = someSoType();

describe('mySoTypeDefinition model version transformations', () => {
  let migrator: ModelVersionTestMigrator;

  beforeEach(() => {
    migrator = createModelVersionTestMigrator({ type: mySoTypeDefinition });
  });

  describe('Model version 2', () => {
    it('properly backfill the expected fields when converting from v1 to v2', () => {
      const obj = createSomeSavedObject();

      const migrated = migrator.migrate({
        document: obj,
        fromVersion: 1,
        toVersion: 2,
      });

      expect(migrated.properties).toEqual(expectedV2Properties);
    });

    it('properly removes the expected fields when converting from v2 to v1', () => {
      const obj = createSomeSavedObject();

      const migrated = migrator.migrate({
        document: obj,
        fromVersion: 2,
        toVersion: 1,
      });

      expect(migrated.properties).toEqual(expectedV1Properties);
    });
  });
});
		

With a real Elasticsearch cluster you can test Saved Object documents in a production-like way and simulate two Kibana instances with different model versions.

Use createModelVersionTestBed to set up a full test bed: start/stop Elasticsearch and run migrations between the versions under test.

Example:

import {
  createModelVersionTestBed,
  type ModelVersionTestKit
} from '@kbn/core-test-helpers-model-versions';

describe('myIntegrationTest', () => {
  const testbed = createModelVersionTestBed();
  let testkit: ModelVersionTestKit;

  beforeAll(async () => {
    await testbed.startES();
  });

  afterAll(async () => {
    await testbed.stopES();
  });

  beforeEach(async () => {
    testkit = await testbed.prepareTestKit({
      savedObjectDefinitions: [{
        definition: mySoTypeDefinition,
        modelVersionBefore: 1,
        modelVersionAfter: 2,
      }]
    })
  });

  afterEach(async () => {
    if(testkit) {
      await testkit.tearDown();
    }
  });

  it('can be used to test model version cohabitation', async () => {
    const repositoryV1 = testkit.repositoryBefore;
    const repositoryV2 = testkit.repositoryAfter;

    await repositoryV1.create(someAttrs, { id });
    const v2docReadFromV1 = await repositoryV2.get('my-type', id);
    expect(v2docReadFromV1.attributes).toEqual(whatIExpect);
  });
});
		

Limitations:

The test bed only instantiates the parts of Core needed for the two SO repositories and does not load all plugins:

• No extensions (no security, encryption, or spaces).
• All SO types use the same SO index.

Saved Object type definitions drive migrations and the shape of the Saved Objects API. Changes to them must meet strict safety criteria to avoid:

• Data corruption.
• Unsupported mapping changes.
• Rollback failures.

Validation runs automatically in CI on pull_request and on-merge. You can also run it locally.

Run the check from your PR branch:

# Get your current commit
git log -n 1

# Get the merge-base with main (or your base branch)
git merge-base -a <lastCommitId> main

# Run the script (validates against that merge-base)
node scripts/check_saved_objects --baseline <mergeBase> --fix
		

If you get validation errors, see Troubleshooting below.

• Existing model versions/migrations — Once defined, they cannot be changed or deleted. This keeps environments that have already upgraded consistent with those that have not.
• Deleting versions — You cannot delete model versions; you can only add new ones.

• Consecutive versions — Model versions must be consecutive integers starting at 1. No gaps.
• One model version per PR — A single PR cannot add more than one model version for the same type. Multi-step rollouts must ship in separate Serverless releases. The on-merge pipeline compares against the current Serverless release.
• No new legacy migrations — Do not add new versions via the deprecated migrations property.

• Mapping changes need a new version — Any change to mappings must be reflected in a new model version (e.g. with mappings_addition).
• Backward compatible mappings — Updates must be done in place without reindexing. Elasticsearch does not allow breaking changes such as removing fields or changing field types (e.g. integer to text).
• Mandatory schemas — New model versions must include both create and forwardCompatibility schemas.

For Serverless rollback guarantees, the validation script requires data fixtures for any updated Saved Object types. These represent the state before and after the upgrade.

The script runs:

1. Simulate Upgrade → Simulate Rollback → Simulate Second Upgrade.
2. At each step it reads documents via the SavedObjectsRepository.
3. It checks that the document shape matches the corresponding fixture.

Providing fixtures and defining mandatory create and forwardCompatibility schemas for each new model version allows type owners to validate both migration and rollback behavior.

Some fields in migrated documents — such as IDs generated by uuidv4 or uuidv5 — cannot be hardcoded in fixture files because they change with every baseline run. For these cases, a fixture document can use a special { "$match": "<type>" } marker object in place of a literal value:

{
  "tabs": [
    {
      "id": { "$match": "uuid" },
      "label": "Untitled",
      "attributes": { ... }
    }
  ]
}
		

Instead of requiring an exact value, the check asserts that the actual field satisfies the declared type constraint. The supported matchers are:

Matchers compose naturally with the rest of the fixture: you can use them at any depth inside arrays or objects, mixing them freely with exact literal values.

When the check fails and reports a diff, fields covered by a passing matcher are omitted from the diff output (they are silently substituted with the actual value). Fields covered by a failing matcher appear as <any uuid>, <any string>, etc., so the diff still points directly at the real problem.

If you are building a new Saved Object type whose schema and mappings are still evolving, the standard immutability constraints can slow down early iteration. The WIP types mechanism lets you iterate freely during development and then graduate the type to full constraints when it is production-ready.

There are two approaches depending on how the owning plugin is deployed.

Use this when the feature and its plugin are only enabled in dedicated dev or QA environments and are not deployed to production or Serverless by default.

Workflow:

1. Open a PR adding the type name to src/core/packages/saved-objects/server-internal/wip_types.json (reviewed by @elastic/kibana-core). This file is the gate that Core team reviews.

2. Add the type name to migrations.allowWipTypes in every kibana.yml where the plugin is enabled. Kibana will fail to start if the type is registered but absent from this list:

   migrations.allowWipTypes:
     - my_new_type
   		

3. Iterate freely. The CI SO check treats the type as perpetually new on every PR — the same checks that apply when first introducing a type always apply, but history-based immutability constraints (e.g. "existing model versions cannot change") are never enforced.

4. Graduation: when the type is stable and production-ready, open a PR removing it from wip_types.json and from all migrations.allowWipTypes entries. Full immutability constraints apply from that point forward.

Use this when the plugin is always enabled (including in Serverless production), but the SO type should only be registered when a feature flag or configuration option is turned on.

The no_conditional_saved_object_type_registration ESLint rule normally forbids conditional registration to avoid migration ON/OFF conflicts. For WIP types, suppress it with an inline comment and a TODO to remove it at graduation:

if (config.featureFlags.myFeatureEnabled) {
  // eslint-disable-next-line @kbn/eslint/no_conditional_saved_object_type_registration -- TODO: remove once my_new_type graduates from WIP
  core.savedObjects.registerType(myNewType);
}
		

Because the type is only registered when the flag is on, it is never registered in environments where the flag is off — so the CI SO check never sees it, and no wip_types.json entry or migrations.allowWipTypes config is needed.

Graduation: remove the conditional and the ESLint suppression. The type becomes unconditionally registered and is subject to full SO type constraints from that point forward.

CI validates Saved Object type definitions. When you add or change a type, the Check changes in saved objects step may fail. Use the errors below to identify the cause.

❌ Modifications have been detected in the '<soType>.migrations'. This property is deprected and no modifications are allowed.
		

Problem: The deprecated migrations property cannot be modified. Existing migrations must remain for importing old documents. Solution: Do not change migrations. If you did not change it, rebase and ensure your branch is up to date.

❌ Some modelVersions have been updated for SO type '<soType>' after they were defined: 5.
		

Problem: Existing modelVersions cannot be mutated; that would cause inconsistencies between deployments.

Scenario 1: You are adding a new model version, but someone else already added one that was released in Serverless (the comparison baseline). Scenario 2: You are fixing a bug in an existing version. Once a version is merged and released (e.g. in Serverless), it may already be in use. You generally need to add a new model version instead of editing the existing one.

❌ Some model versions have been deleted for SO type '<soType>'.
		

Problem: Model versions cannot be deleted. Your branch may be behind the current Serverless release and missing recent versions. Solution: Rebase and pull the latest SO type definitions.

❌ Invalid model version 'five' for SO type '<soType>'. Model versions must be consecutive integer numbers starting at 1.
❌ The '<soType>' SO type is missing model version '4'. Model versions defined: 1,2,3,5.
		

Problem: Version keys must be consecutive numeric strings (e.g. '1', '2', '3'). Solution: Use consecutive integers starting at 1 with no gaps.

❌ The '<soType>' SO type has changes in the mappings, but is missing a modelVersion that defines these changes.
		

Problem: Mapping changes must be declared in a model version so the migration logic can update the SO index. Solution: Add a new model version that includes a mappings_addition change and the corresponding schemas.forwardCompatibility (and create if applicable).

❌ The SO type '<soType>' is defining two (or more) new model versions.
		

Problem: Only one new model version per type per PR is allowed to support safe, incremental rollouts.

Scenario 1: You have several unrelated changes. If they do not require a multi-step rollout, combine them into a single model version. Scenario 2: You only added one new version but CI still fails. Validation uses two baselines: your PR merge-base (usually stable) and the current Serverless release. If Serverless was rolled back, the “current release” baseline may make your PR look like it defines multiple new versions. Wait for the release state to normalize, or contact the Kibana Core team.

❌ The following SO types are no longer registered: '<soType>'. Please run with --fix to update 'removed_types.json'.
		

Problem: A Saved Object type was removed but removed_types.json was not updated. Solution: Run node scripts/check_saved_objects --baseline <mergeBase> --fix, then commit the updated removed_types.json. See Delete for how to get the merge-base.

❌ Cannot re-register previously removed type(s): <soType>. Please use a different name.
		

Problem: The type name was used before and then removed. Type names in removed_types.json cannot be reused. Solution: Choose a different type name. Names in packages/kbn-check-saved-objects-cli/removed_types.json are permanently reserved.

Kibana cannot start because the following WIP saved object types are registered but not listed in 'migrations.allowWipTypes': [<soType>].
		

Problem: A type listed in wip_types.json is registered by a plugin but has not been explicitly allowed in the Kibana configuration. Solution: Add the type name to migrations.allowWipTypes in kibana.yml for every environment where the plugin is enabled:

migrations.allowWipTypes:
  - <soType>
		

If you did not intend to register a WIP type, check whether the plugin should be disabled in this environment. See Scenario A for the full workflow.