diff --git a/src/lib/openapi/spec/export-result-schema.ts b/src/lib/openapi/spec/export-result-schema.ts
index 9b0c744539..b6389ee43b 100644
--- a/src/lib/openapi/spec/export-result-schema.ts
+++ b/src/lib/openapi/spec/export-result-schema.ts
@@ -18,6 +18,7 @@ import { releasePlanMilestoneSchema } from './release-plan-milestone-schema.js';
 import { releasePlanMilestoneStrategySchema } from './release-plan-milestone-strategy-schema.js';
 import { createFeatureStrategySchema } from './create-feature-strategy-schema.js';
 import { createStrategyVariantSchema } from './create-strategy-variant-schema.js';
+import { transitionConditionSchema } from './transition-condition-schema.js';
 import { dependentFeatureSchema } from './dependent-feature-schema.js';
 import { tagSchema } from './tag-schema.js';
 import { featureLinksSchema } from './feature-links-schema.js';
@@ -217,6 +218,7 @@ export const exportResultSchema = {
             releasePlanMilestoneStrategySchema,
             createFeatureStrategySchema,
             createStrategyVariantSchema,
+            transitionConditionSchema,
         },
     },
 } as const;
diff --git a/src/lib/openapi/spec/feature-environment-schema.ts b/src/lib/openapi/spec/feature-environment-schema.ts
index eefc2ea666..b735c53244 100644
--- a/src/lib/openapi/spec/feature-environment-schema.ts
+++ b/src/lib/openapi/spec/feature-environment-schema.ts
@@ -9,6 +9,7 @@ import { releasePlanMilestoneSchema } from './release-plan-milestone-schema.js';
 import { releasePlanMilestoneStrategySchema } from './release-plan-milestone-strategy-schema.js';
 import { createFeatureStrategySchema } from './create-feature-strategy-schema.js';
 import { createStrategyVariantSchema } from './create-strategy-variant-schema.js';
+import { transitionConditionSchema } from './transition-condition-schema.js';
 
 export const featureEnvironmentSchema = {
     $id: '#/components/schemas/featureEnvironmentSchema',
@@ -132,6 +133,7 @@ export const featureEnvironmentSchema = {
             releasePlanMilestoneStrategySchema,
             createFeatureStrategySchema,
             createStrategyVariantSchema,
+            transitionConditionSchema,
         },
     },
 } as const;
diff --git a/src/lib/openapi/spec/feature-schema.ts b/src/lib/openapi/spec/feature-schema.ts
index 5c8f2939fa..93442886a0 100644
--- a/src/lib/openapi/spec/feature-schema.ts
+++ b/src/lib/openapi/spec/feature-schema.ts
@@ -12,6 +12,7 @@ import { releasePlanMilestoneSchema } from './release-plan-milestone-schema.js';
 import { releasePlanMilestoneStrategySchema } from './release-plan-milestone-strategy-schema.js';
 import { createFeatureStrategySchema } from './create-feature-strategy-schema.js';
 import { createStrategyVariantSchema } from './create-strategy-variant-schema.js';
+import { transitionConditionSchema } from './transition-condition-schema.js';
 
 export const featureSchema = {
     $id: '#/components/schemas/featureSchema',
@@ -298,6 +299,7 @@ export const featureSchema = {
             releasePlanMilestoneStrategySchema,
             createFeatureStrategySchema,
             createStrategyVariantSchema,
+            transitionConditionSchema,
         },
     },
 } as const;
diff --git a/src/lib/openapi/spec/feature-search-environment-schema.ts b/src/lib/openapi/spec/feature-search-environment-schema.ts
index 431f9dcb4e..d1a2d3484d 100644
--- a/src/lib/openapi/spec/feature-search-environment-schema.ts
+++ b/src/lib/openapi/spec/feature-search-environment-schema.ts
@@ -10,6 +10,7 @@ import { releasePlanMilestoneSchema } from './release-plan-milestone-schema.js';
 import { releasePlanMilestoneStrategySchema } from './release-plan-milestone-strategy-schema.js';
 import { createFeatureStrategySchema } from './create-feature-strategy-schema.js';
 import { createStrategyVariantSchema } from './create-strategy-variant-schema.js';
+import { transitionConditionSchema } from './transition-condition-schema.js';
 
 export const featureSearchEnvironmentSchema = {
     $id: '#/components/schemas/featureSearchEnvironmentSchema',
@@ -45,6 +46,7 @@ export const featureSearchEnvironmentSchema = {
             releasePlanSchema,
             releasePlanMilestoneSchema,
             releasePlanMilestoneStrategySchema,
+            transitionConditionSchema,
             createFeatureStrategySchema,
             createStrategyVariantSchema,
         },
diff --git a/src/lib/openapi/spec/health-overview-schema.ts b/src/lib/openapi/spec/health-overview-schema.ts
index d88232648f..1068aecc29 100644
--- a/src/lib/openapi/spec/health-overview-schema.ts
+++ b/src/lib/openapi/spec/health-overview-schema.ts
@@ -13,6 +13,7 @@ import { projectEnvironmentSchema } from './project-environment-schema.js';
 import { releasePlanSchema } from './release-plan-schema.js';
 import { releasePlanMilestoneSchema } from './release-plan-milestone-schema.js';
 import { releasePlanMilestoneStrategySchema } from './release-plan-milestone-strategy-schema.js';
+import { transitionConditionSchema } from './transition-condition-schema.js';
 import { createStrategyVariantSchema } from './create-strategy-variant-schema.js';
 import { strategyVariantSchema } from './strategy-variant-schema.js';
 import { createFeatureNamingPatternSchema } from './create-feature-naming-pattern-schema.js';
@@ -150,6 +151,7 @@ export const healthOverviewSchema = {
             releasePlanSchema,
             releasePlanMilestoneSchema,
             releasePlanMilestoneStrategySchema,
+            transitionConditionSchema,
             strategyVariantSchema,
             variantSchema,
             projectStatsSchema,
diff --git a/src/lib/openapi/spec/import-toggles-schema.ts b/src/lib/openapi/spec/import-toggles-schema.ts
index f545a0174f..4db59e612c 100644
--- a/src/lib/openapi/spec/import-toggles-schema.ts
+++ b/src/lib/openapi/spec/import-toggles-schema.ts
@@ -18,6 +18,7 @@ import { releasePlanMilestoneSchema } from './release-plan-milestone-schema.js';
 import { releasePlanMilestoneStrategySchema } from './release-plan-milestone-strategy-schema.js';
 import { createFeatureStrategySchema } from './create-feature-strategy-schema.js';
 import { createStrategyVariantSchema } from './create-strategy-variant-schema.js';
+import { transitionConditionSchema } from './transition-condition-schema.js';
 import { strategyVariantSchema } from './strategy-variant-schema.js';
 import { featureDependenciesSchema } from './feature-dependencies-schema.js';
 import { dependentFeatureSchema } from './dependent-feature-schema.js';
@@ -63,6 +64,7 @@ export const importTogglesSchema = {
             releasePlanMilestoneStrategySchema,
             createFeatureStrategySchema,
             createStrategyVariantSchema,
+            transitionConditionSchema,
             variantsSchema,
             variantSchema,
             overrideSchema,
diff --git a/src/lib/openapi/spec/index.ts b/src/lib/openapi/spec/index.ts
index 7e41d833a3..b7d69c8ee2 100644
--- a/src/lib/openapi/spec/index.ts
+++ b/src/lib/openapi/spec/index.ts
@@ -205,6 +205,7 @@ export * from './telemetry-settings-schema.js';
 export * from './toggle-maintenance-schema.js';
 export * from './token-string-list-schema.js';
 export * from './token-user-schema.js';
+export * from './transition-condition-schema.js';
 export * from './ui-config-schema.js';
 export * from './unknown-flag-schema.js';
 export * from './unknown-flags-response-schema.js';
diff --git a/src/lib/openapi/spec/project-overview-schema.ts b/src/lib/openapi/spec/project-overview-schema.ts
index b38504fff3..c821b3b6d7 100644
--- a/src/lib/openapi/spec/project-overview-schema.ts
+++ b/src/lib/openapi/spec/project-overview-schema.ts
@@ -18,6 +18,7 @@ import { projectLinkTemplateSchema } from './project-link-template-schema.js';
 import { releasePlanSchema } from './release-plan-schema.js';
 import { releasePlanMilestoneSchema } from './release-plan-milestone-schema.js';
 import { releasePlanMilestoneStrategySchema } from './release-plan-milestone-strategy-schema.js';
+import { transitionConditionSchema } from './transition-condition-schema.js';
 
 export const projectOverviewSchema = {
     $id: '#/components/schemas/projectOverviewSchema',
@@ -208,6 +209,7 @@ export const projectOverviewSchema = {
             releasePlanSchema,
             releasePlanMilestoneSchema,
             releasePlanMilestoneStrategySchema,
+            transitionConditionSchema,
             projectStatsSchema,
             createFeatureNamingPatternSchema,
             featureTypeCountSchema,
diff --git a/src/lib/openapi/spec/release-plan-milestone-schema.ts b/src/lib/openapi/spec/release-plan-milestone-schema.ts
index f5e08c34b9..3e38249eb0 100644
--- a/src/lib/openapi/spec/release-plan-milestone-schema.ts
+++ b/src/lib/openapi/spec/release-plan-milestone-schema.ts
@@ -4,6 +4,7 @@ import { createFeatureStrategySchema } from './create-feature-strategy-schema.js
 import { parametersSchema } from './parameters-schema.js';
 import { constraintSchema } from './constraint-schema.js';
 import { createStrategyVariantSchema } from './create-strategy-variant-schema.js';
+import { transitionConditionSchema } from './transition-condition-schema.js';
 
 export const releasePlanMilestoneSchema = {
     $id: '#/components/schemas/releasePlanMilestoneSchema',
@@ -43,11 +44,8 @@ export const releasePlanMilestoneSchema = {
             nullable: true,
         },
         transitionCondition: {
-            type: 'object',
-            description:
-                'The transition condition for the next automated milestone progression.',
-            additionalProperties: true,
-            nullable: true,
+            description: 'The condition configuration for the transition',
+            $ref: '#/components/schemas/transitionConditionSchema',
         },
         progressionExecutedAt: {
             type: 'string',
@@ -73,6 +71,7 @@ export const releasePlanMilestoneSchema = {
             parametersSchema,
             constraintSchema,
             createStrategyVariantSchema,
+            transitionConditionSchema,
         },
     },
 } as const;
diff --git a/src/lib/openapi/spec/transition-condition-schema.ts b/src/lib/openapi/spec/transition-condition-schema.ts
new file mode 100644
index 0000000000..1cb016534d
--- /dev/null
+++ b/src/lib/openapi/spec/transition-condition-schema.ts
@@ -0,0 +1,21 @@
+import type { FromSchema } from 'json-schema-to-ts';
+
+export const transitionConditionSchema = {
+    $id: '#/components/schemas/transitionConditionSchema',
+    type: 'object',
+    additionalProperties: false,
+    required: ['intervalMinutes'],
+    description: 'A transition condition for milestone progression',
+    properties: {
+        intervalMinutes: {
+            type: 'number',
+            description: 'The interval in minutes before transitioning',
+            example: 30,
+        },
+    },
+    components: {},
+} as const;
+
+export type TransitionConditionSchema = FromSchema<
+    typeof transitionConditionSchema
+>;