diff --git a/packages/app/api-contracts/src/sse/dualModeContracts.ts b/packages/app/api-contracts/src/sse/dualModeContracts.ts
index aaa7235dd..cf070d5f7 100644
--- a/packages/app/api-contracts/src/sse/dualModeContracts.ts
+++ b/packages/app/api-contracts/src/sse/dualModeContracts.ts
@@ -1,5 +1,5 @@
 import type { z } from 'zod/v4'
-import type { RoutePathResolver } from '../apiContracts.ts'
+import type { CommonRouteDefinitionMetadata, RoutePathResolver } from '../apiContracts.ts'
 import type { HttpStatusCode } from '../HttpStatusCodes.ts'
 import type { SSEMethod } from './sseContracts.ts'
 import type { SSEEventSchemas } from './sseTypes.ts'
@@ -55,6 +55,10 @@ export type DualModeContractDefinition<
   responseBodySchemasByStatusCode?: ResponseSchemasByStatusCode
   serverSentEventSchemas: Events
   isDualMode: true
+  metadata?: CommonRouteDefinitionMetadata
+  description?: string
+  summary?: string
+  tags?: readonly string[]
 }
 
 /**
@@ -75,4 +79,8 @@ export type AnyDualModeContractDefinition = {
   responseBodySchemasByStatusCode?: Partial<Record<HttpStatusCode, z.ZodTypeAny>>
   serverSentEventSchemas: SSEEventSchemas
   isDualMode: true
+  metadata?: CommonRouteDefinitionMetadata
+  description?: string
+  summary?: string
+  tags?: readonly string[]
 }
diff --git a/packages/app/api-contracts/src/sse/sseContractBuilders.metadata.spec.ts b/packages/app/api-contracts/src/sse/sseContractBuilders.metadata.spec.ts
new file mode 100644
index 000000000..6b0f068ca
--- /dev/null
+++ b/packages/app/api-contracts/src/sse/sseContractBuilders.metadata.spec.ts
@@ -0,0 +1,173 @@
+import { describe, expect, expectTypeOf, it } from 'vitest'
+import { z } from 'zod/v4'
+import { buildSseContract } from './sseContractBuilders.ts'
+
+const SCHEMA = z.object({})
+const EVENTS = { data: z.object({ value: z.string() }) }
+
+type Metadata = {
+  myTestProp?: string[]
+  mySecondTestProp?: number
+}
+
+declare module '../apiContracts.ts' {
+  interface CommonRouteDefinitionMetadata extends Metadata {}
+}
+
+describe('buildSseContract metadata augmentation', () => {
+  describe('SSE GET route', () => {
+    it('should respect metadata type and reflect it on contract', () => {
+      const contract = buildSseContract({
+        method: 'get',
+        pathResolver: () => '/',
+        serverSentEventSchemas: EVENTS,
+        metadata: {
+          myTestProp: ['test'],
+          mySecondTestProp: 1,
+          extra: 'extra field',
+        },
+      })
+
+      expectTypeOf(contract.metadata).toMatchTypeOf<Metadata | undefined>()
+      expect(contract.metadata).toEqual({
+        myTestProp: ['test'],
+        mySecondTestProp: 1,
+        extra: 'extra field',
+      })
+    })
+
+    it('should reflect description, summary, and tags on contract', () => {
+      const contract = buildSseContract({
+        method: 'get',
+        pathResolver: () => '/',
+        serverSentEventSchemas: EVENTS,
+        description: 'Stream events',
+        summary: 'Event stream',
+        tags: ['streaming', 'sse'],
+      })
+
+      expect(contract.description).toBe('Stream events')
+      expect(contract.summary).toBe('Event stream')
+      expect(contract.tags).toEqual(['streaming', 'sse'])
+    })
+  })
+
+  describe('SSE POST route', () => {
+    it('should respect metadata type and reflect it on contract', () => {
+      const contract = buildSseContract({
+        method: 'post',
+        pathResolver: () => '/',
+        requestBodySchema: SCHEMA,
+        serverSentEventSchemas: EVENTS,
+        metadata: {
+          myTestProp: ['test2'],
+          mySecondTestProp: 2,
+          extra: 'extra field2',
+        },
+      })
+
+      expectTypeOf(contract.metadata).toMatchTypeOf<Metadata | undefined>()
+      expect(contract.metadata).toEqual({
+        myTestProp: ['test2'],
+        mySecondTestProp: 2,
+        extra: 'extra field2',
+      })
+    })
+
+    it('should reflect description, summary, and tags on contract', () => {
+      const contract = buildSseContract({
+        method: 'post',
+        pathResolver: () => '/',
+        requestBodySchema: SCHEMA,
+        serverSentEventSchemas: EVENTS,
+        description: 'Stream with body',
+        summary: 'Body stream',
+        tags: ['streaming'],
+      })
+
+      expect(contract.description).toBe('Stream with body')
+      expect(contract.summary).toBe('Body stream')
+      expect(contract.tags).toEqual(['streaming'])
+    })
+  })
+
+  describe('Dual-mode GET route', () => {
+    it('should respect metadata type and reflect it on contract', () => {
+      const contract = buildSseContract({
+        method: 'get',
+        pathResolver: () => '/',
+        successResponseBodySchema: SCHEMA,
+        serverSentEventSchemas: EVENTS,
+        metadata: {
+          myTestProp: ['test3'],
+          mySecondTestProp: 3,
+          extra: 'extra field3',
+        },
+      })
+
+      expectTypeOf(contract.metadata).toMatchTypeOf<Metadata | undefined>()
+      expect(contract.metadata).toEqual({
+        myTestProp: ['test3'],
+        mySecondTestProp: 3,
+        extra: 'extra field3',
+      })
+    })
+
+    it('should reflect description, summary, and tags on contract', () => {
+      const contract = buildSseContract({
+        method: 'get',
+        pathResolver: () => '/',
+        successResponseBodySchema: SCHEMA,
+        serverSentEventSchemas: EVENTS,
+        description: 'Dual-mode GET',
+        summary: 'GET dual',
+        tags: ['dual-mode', 'sse'],
+      })
+
+      expect(contract.description).toBe('Dual-mode GET')
+      expect(contract.summary).toBe('GET dual')
+      expect(contract.tags).toEqual(['dual-mode', 'sse'])
+    })
+  })
+
+  describe('Dual-mode POST route', () => {
+    it('should respect metadata type and reflect it on contract', () => {
+      const contract = buildSseContract({
+        method: 'post',
+        pathResolver: () => '/',
+        requestBodySchema: SCHEMA,
+        successResponseBodySchema: SCHEMA,
+        serverSentEventSchemas: EVENTS,
+        metadata: {
+          myTestProp: ['test4'],
+          mySecondTestProp: 4,
+          extra: 'extra field4',
+        },
+      })
+
+      expectTypeOf(contract.metadata).toMatchTypeOf<Metadata | undefined>()
+      expect(contract.metadata).toEqual({
+        myTestProp: ['test4'],
+        mySecondTestProp: 4,
+        extra: 'extra field4',
+      })
+    })
+
+    it('should reflect description, summary, and tags on contract', () => {
+      const contract = buildSseContract({
+        method: 'post',
+        pathResolver: () => '/',
+        requestBodySchema: SCHEMA,
+        successResponseBodySchema: SCHEMA,
+        serverSentEventSchemas: EVENTS,
+        description: 'Dual-mode POST',
+        summary: 'POST dual',
+        tags: ['dual-mode'],
+      })
+
+      expect(contract.description).toBe('Dual-mode POST')
+      expect(contract.summary).toBe('POST dual')
+      expect(contract.tags).toEqual(['dual-mode'])
+    })
+  })
+})
diff --git a/packages/app/api-contracts/src/sse/sseContractBuilders.ts b/packages/app/api-contracts/src/sse/sseContractBuilders.ts
index 1a3608aba..c76123fb3 100644
--- a/packages/app/api-contracts/src/sse/sseContractBuilders.ts
+++ b/packages/app/api-contracts/src/sse/sseContractBuilders.ts
@@ -1,5 +1,5 @@
 import type { z } from 'zod/v4'
-import type { RoutePathResolver } from '../apiContracts.ts'
+import type { CommonRouteDefinitionMetadata, RoutePathResolver } from '../apiContracts.ts'
 import type { HttpStatusCode } from '../HttpStatusCodes.ts'
 import type { DualModeContractDefinition } from './dualModeContracts.ts'
 import type { SSEContractDefinition } from './sseContracts.ts'
@@ -40,6 +40,10 @@ export type SSEGetContractConfig<
   responseBodySchemasByStatusCode?: ResponseSchemasByStatusCode
   requestBodySchema?: never
   successResponseBodySchema?: never
+  metadata?: CommonRouteDefinitionMetadata
+  description?: string
+  summary?: string
+  tags?: readonly string[]
 }
 
 /**
@@ -78,6 +82,10 @@ export type SSEPayloadContractConfig<
    */
   responseBodySchemasByStatusCode?: ResponseSchemasByStatusCode
   successResponseBodySchema?: never
+  metadata?: CommonRouteDefinitionMetadata
+  description?: string
+  summary?: string
+  tags?: readonly string[]
 }
 
 /**
@@ -130,6 +138,10 @@ export type DualModeGetContractConfig<
   responseBodySchemasByStatusCode?: ResponseSchemasByStatusCode
   serverSentEventSchemas: Events
   requestBodySchema?: never
+  metadata?: CommonRouteDefinitionMetadata
+  description?: string
+  summary?: string
+  tags?: readonly string[]
 }
 
 /**
@@ -183,6 +195,10 @@ export type DualModePayloadContractConfig<
    */
   responseBodySchemasByStatusCode?: ResponseSchemasByStatusCode
   serverSentEventSchemas: Events
+  metadata?: CommonRouteDefinitionMetadata
+  description?: string
+  summary?: string
+  tags?: readonly string[]
 }
 
 /**
@@ -250,6 +266,10 @@ function buildBaseFields(config: any, hasBody: boolean) {
     requestHeaderSchema: config.requestHeaderSchema,
     requestBodySchema: hasBody ? config.requestBodySchema : undefined,
     serverSentEventSchemas: config.serverSentEventSchemas,
+    metadata: config.metadata,
+    description: config.description,
+    summary: config.summary,
+    tags: config.tags,
   }
 }
 
diff --git a/packages/app/api-contracts/src/sse/sseContracts.ts b/packages/app/api-contracts/src/sse/sseContracts.ts
index 41d41011c..20d8af6f5 100644
--- a/packages/app/api-contracts/src/sse/sseContracts.ts
+++ b/packages/app/api-contracts/src/sse/sseContracts.ts
@@ -1,5 +1,5 @@
 import type { z } from 'zod/v4'
-import type { RoutePathResolver } from '../apiContracts.ts'
+import type { CommonRouteDefinitionMetadata, RoutePathResolver } from '../apiContracts.ts'
 import type { HttpStatusCode } from '../HttpStatusCodes.ts'
 import type { SSEEventSchemas } from './sseTypes.ts'
 
@@ -58,6 +58,10 @@ export type SSEContractDefinition<
    */
   responseBodySchemasByStatusCode?: ResponseSchemasByStatusCode
   isSSE: true
+  metadata?: CommonRouteDefinitionMetadata
+  description?: string
+  summary?: string
+  tags?: readonly string[]
 }
 
 /**
@@ -75,4 +79,8 @@ export type AnySSEContractDefinition = {
   serverSentEventSchemas: SSEEventSchemas
   responseBodySchemasByStatusCode?: Partial<Record<HttpStatusCode, z.ZodTypeAny>>
   isSSE: true
+  metadata?: CommonRouteDefinitionMetadata
+  description?: string
+  summary?: string
+  tags?: readonly string[]
 }