diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 06bedfb84a..8c3c6c7f35 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -82,6 +82,10 @@ ktor-serialization = { group = "io.ktor", name = "ktor-serialization", version.r
 ktor-serialization-json = { group = "io.ktor", name = "ktor-serialization-kotlinx-json", version.ref = "ktor" }
 
 keycloak-authz-client = { group = "org.keycloak", name = "keycloak-authz-client", version = "25.0.1" }
+
+kotest-assertions-coreJvm = { group = "io.kotest", name = "kotest-assertions-core-jvm", version = "5.9.1" }
+kotest-assertions-ktor = { group = "io.kotest.extensions", name = "kotest-assertions-ktor", version = "2.0.0" }
+
 guava = { group = "com.google.guava", name = "guava", version = "33.2.1-jre" }
 org-json = { group = "org.json", name = "json", version = "20240303" }
 google-oauth-client = { group = "com.google.oauth-client", name = "google-oauth-client", version = "1.36.0" }
diff --git a/model-server-openapi/specifications/model-server-v2.yaml b/model-server-openapi/specifications/model-server-v2.yaml
index 526cd94f83..2f408a91e2 100644
--- a/model-server-openapi/specifications/model-server-v2.yaml
+++ b/model-server-openapi/specifications/model-server-v2.yaml
@@ -140,15 +140,36 @@ paths:
           required: true
           schema:
             type: string
+      x-modelix-media-type-handlers:
+        - v1:
+            - 'application/x.modelix.branch+json;version=1'
+        - delta:
+            - 'application/x-modelix-objects-v2'
+            - 'application/x-modelix-objects'
+            - 'application/json'
+            - 'text/plain'
+            - '*/*'
       responses:
         "404":
           $ref: '#/components/responses/404'
         "200":
-          $ref: '#/components/responses/versionDelta'
-#          content:
-#            '*/*':
-#              schema:
-#                $ref: "#/components/schemas/VersionDelta"
+          description: "Information about a branch for content type `application/x.modelix.branch+json;version=*'. Else all model data of the branch in version delta format."
+          content:
+            'application/x.modelix.branch+json;version=1':
+              schema:
+                $ref: "#/components/schemas/BranchV1"
+            'application/x-modelix-objects-v2':
+              schema:
+                type: string
+            'application/x-modelix-objects':
+              schema:
+                type: string
+            'application/json':
+              schema:
+                type: object
+            'text/plain':
+              schema:
+                type: string
         default:
           $ref: '#/components/responses/GeneralError'
     post:
@@ -538,3 +559,15 @@ components:
           type: string
         value2:
           type: string
+    BranchV1:
+      x-modelix-media-type: 'application/x.modelix.branch+json;version=1'
+      type: object
+      properties:
+        name:
+          type: string
+        current_hash:
+          type: string
+          example: 7fQeo*xrdfZuHZtaKhbp0OosarV5tVR8N3pW8JPkl7ZE
+      required:
+        - name
+        - current_hash
diff --git a/model-server/build.gradle.kts b/model-server/build.gradle.kts
index 583a492065..318b3ab661 100644
--- a/model-server/build.gradle.kts
+++ b/model-server/build.gradle.kts
@@ -66,6 +66,8 @@ dependencies {
 
     testImplementation(libs.bundles.apache.cxf)
     testImplementation(libs.junit)
+    testImplementation(libs.kotest.assertions.coreJvm)
+    testImplementation(libs.kotest.assertions.ktor)
     testImplementation(libs.cucumber.java)
     testImplementation(libs.ktor.server.test.host)
     testImplementation(libs.kotlin.coroutines.test)
diff --git a/model-server/src/main/kotlin/org/modelix/model/server/Main.kt b/model-server/src/main/kotlin/org/modelix/model/server/Main.kt
index d68632916b..eaf59e4042 100644
--- a/model-server/src/main/kotlin/org/modelix/model/server/Main.kt
+++ b/model-server/src/main/kotlin/org/modelix/model/server/Main.kt
@@ -55,6 +55,7 @@ import kotlinx.serialization.json.Json
 import org.apache.commons.io.FileUtils
 import org.apache.ignite.Ignition
 import org.modelix.api.v1.Problem
+import org.modelix.api.v2.Paths.registerJsonTypes
 import org.modelix.authorization.KeycloakUtils
 import org.modelix.authorization.NoPermissionException
 import org.modelix.authorization.NotLoggedInException
@@ -203,6 +204,7 @@ object Main {
                 }
                 install(ContentNegotiation) {
                     json()
+                    registerJsonTypes()
                 }
                 install(CORS) {
                     anyHost()
diff --git a/model-server/src/main/kotlin/org/modelix/model/server/handlers/ModelReplicationServer.kt b/model-server/src/main/kotlin/org/modelix/model/server/handlers/ModelReplicationServer.kt
index a656561822..3d15d19180 100644
--- a/model-server/src/main/kotlin/org/modelix/model/server/handlers/ModelReplicationServer.kt
+++ b/model-server/src/main/kotlin/org/modelix/model/server/handlers/ModelReplicationServer.kt
@@ -39,6 +39,7 @@ import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.flow.onEmpty
 import kotlinx.coroutines.flow.withIndex
 import kotlinx.coroutines.withContext
+import org.modelix.api.v2.BranchV1
 import org.modelix.api.v2.DefaultApi
 import org.modelix.authorization.getUserName
 import org.modelix.model.InMemoryModels
@@ -94,7 +95,9 @@ class ModelReplicationServer(
         }
     }
 
-    private fun repositoryId(paramValue: String?) = RepositoryId(checkNotNull(paramValue) { "Parameter 'repository' not available" })
+    private fun repositoryId(paramValue: String?) =
+        RepositoryId(checkNotNull(paramValue) { "Parameter 'repository' not available" })
+
     private suspend fun <R> runWithRepository(repository: String, body: suspend () -> R): R {
         return repositoriesManager.runWithRepository(repositoryId(repository), body)
     }
@@ -107,7 +110,7 @@ class ModelReplicationServer(
         call.respondText(repositoriesManager.getBranchNames(repositoryId(repository)).joinToString("\n"))
     }
 
-    override suspend fun PipelineContext<Unit, ApplicationCall>.getRepositoryBranch(
+    override suspend fun PipelineContext<Unit, ApplicationCall>.getRepositoryBranchDelta(
         repository: String,
         branch: String,
         lastKnown: String?,
@@ -119,6 +122,18 @@ class ModelReplicationServer(
         }
     }
 
+    override suspend fun PipelineContext<Unit, ApplicationCall>.getRepositoryBranchV1(
+        repository: String,
+        branch: String,
+        lastKnown: String?,
+    ) {
+        runWithRepository(repository) {
+            val branchRef = repositoryId(repository).getBranchReference(branch)
+            val versionHash = repositoriesManager.getVersionHash(branchRef) ?: throw BranchNotFoundException(branchRef)
+            call.respond(BranchV1(branch, versionHash))
+        }
+    }
+
     override suspend fun PipelineContext<Unit, ApplicationCall>.deleteRepositoryBranch(
         repository: String,
         branch: String,
diff --git a/model-server/src/main/resources/openapi/templates/Paths.kt.mustache b/model-server/src/main/resources/openapi/templates/Paths.kt.mustache
index 11a429ea45..7e05b4e43b 100644
--- a/model-server/src/main/resources/openapi/templates/Paths.kt.mustache
+++ b/model-server/src/main/resources/openapi/templates/Paths.kt.mustache
@@ -3,6 +3,10 @@ package {{packageName}}
 
 import io.ktor.resources.*
 import kotlinx.serialization.*
+import io.ktor.http.ContentType
+import io.ktor.serialization.kotlinx.KotlinxSerializationConverter
+import io.ktor.serialization.kotlinx.json.DefaultJson
+import io.ktor.server.plugins.contentnegotiation.ContentNegotiationConfig
 {{#imports}}import {{import}}
 {{/imports}}
 
@@ -26,5 +30,22 @@ object Paths {
     {{/operation}}
 {{/operations}}
 {{/apis}}
+
+    /**
+     * Registers all models from /components/schemas with an x-modelix-media-type vendor extension to be serializable
+     * as JSON for that media type.
+     */
+    fun ContentNegotiationConfig.registerJsonTypes() {
+    {{#models}}
+        {{#model}}
+            {{#vendorExtensions}}
+                {{#x-modelix-media-type}}
+        register(ContentType.parse("{{{.}}}"), KotlinxSerializationConverter(DefaultJson))
+                {{/x-modelix-media-type}}
+            {{/vendorExtensions}}
+        {{/model}}
+    {{/models}}
+    }
+
 }
 {{/apiInfo}}
diff --git a/model-server/src/main/resources/openapi/templates/api.mustache b/model-server/src/main/resources/openapi/templates/api.mustache
index bca88a6ea3..4d47a3c227 100644
--- a/model-server/src/main/resources/openapi/templates/api.mustache
+++ b/model-server/src/main/resources/openapi/templates/api.mustache
@@ -3,6 +3,7 @@ package {{apiPackage}}
 
 import io.ktor.http.*
 import io.ktor.server.application.*
+import io.ktor.server.request.*
 import io.ktor.server.response.*
 {{#featureResources}}
 import {{packageName}}.Paths
@@ -22,6 +23,11 @@ import io.ktor.util.pipeline.PipelineContext
 abstract class {{classname}} {
 {{#operations}}
     {{#operation}}
+
+        {{#vendorExtensions}}
+            {{#x-modelix-media-type-handlers}}
+                {{#entrySet}}
+
     /**{{#summary}}
      * {{.}}{{/summary}}
      *
@@ -29,14 +35,38 @@ abstract class {{classname}} {
      *
      * {{httpMethod}} {{path}}
      *
-    {{#allParams}}* @param {{paramName}} {{description}} {{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}
-    {{/allParams}}
+     {{#allParams}}
+     * @param {{paramName}} {{description}} {{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}
+     {{/allParams}}
+     */
+     {{#isDeprecated}}
+     @Deprecated("deprecated flag is set in the OpenAPI specification")
+     {{/isDeprecated}}
+    abstract suspend fun PipelineContext<Unit, ApplicationCall>.{{operationId}}{{#lambda.titlecase}}{{key}}{{/lambda.titlecase}}({{#allParams}}{{paramName}}: {{{dataType}}}{{^required}}?{{/required}}{{#required}}{{#isNullable}}?{{/isNullable}}{{/required}}{{^-last}}, {{/-last}}{{/allParams}})
+
+                {{/entrySet}}
+            {{/x-modelix-media-type-handlers}}
+            {{^x-modelix-media-type-handlers}}
+
+    /**{{#summary}}
+     * {{.}}{{/summary}}
+     *
+     * {{unescapedNotes}}
+     *
+     * {{httpMethod}} {{path}}
+     *
+     {{#allParams}}
+     * @param {{paramName}} {{description}} {{^required}}(optional{{#defaultValue}}, default to {{{.}}}{{/defaultValue}}){{/required}}
+     {{/allParams}}
      */
     {{#isDeprecated}}
     @Deprecated("deprecated flag is set in the OpenAPI specification")
     {{/isDeprecated}}
     abstract suspend fun PipelineContext<Unit, ApplicationCall>.{{operationId}}({{#allParams}}{{paramName}}: {{{dataType}}}{{^required}}?{{/required}}{{#required}}{{#isNullable}}?{{/isNullable}}{{/required}}{{^-last}}, {{/-last}}{{/allParams}})
 
+            {{/x-modelix-media-type-handlers}}
+        {{/vendorExtensions}}
+
     {{/operation}}
 {{/operations}}
 
@@ -55,9 +85,30 @@ abstract class {{classname}} {
     {{#operations}}
     {{#operation}}
     protected open fun Route.install_{{operationId}}() {
+        {{#vendorExtensions}}
+            {{#x-modelix-media-type-handlers}}
+                {{#entrySet}}
+
+                    accept(
+                        {{#value}}
+                            ContentType.parse("{{{.}}}"),
+                        {{/value}}
+                    ) {
+                        {{#lambda.lowercase}}{{httpMethod}}{{/lambda.lowercase}}<Paths.{{operationId}}> { parameters ->
+                            {{operationId}}{{#lambda.titlecase}}{{key}}{{/lambda.titlecase}}({{#allParams}}parameters.{{paramName}}{{^-last}}, {{/-last}}{{/allParams}})
+                        }
+                    }
+
+                {{/entrySet}}
+            {{/x-modelix-media-type-handlers}}
+            {{^x-modelix-media-type-handlers}}
+
         {{#lambda.lowercase}}{{httpMethod}}{{/lambda.lowercase}}<Paths.{{operationId}}> { parameters ->
-            {{#lambda.indented_8}}{{operationId}}({{#allParams}}parameters.{{paramName}}{{^-last}}, {{/-last}}{{/allParams}}){{/lambda.indented_8}}
+            {{operationId}}({{#allParams}}parameters.{{paramName}}{{^-last}}, {{/-last}}{{/allParams}})
         }
+
+            {{/x-modelix-media-type-handlers}}
+        {{/vendorExtensions}}
     }
     {{/operation}}
     {{/operations}}
diff --git a/model-server/src/test/kotlin/org/modelix/model/server/ModelServerTestUtil.kt b/model-server/src/test/kotlin/org/modelix/model/server/ModelServerTestUtil.kt
index 6e9e91e74f..86fde1494f 100644
--- a/model-server/src/test/kotlin/org/modelix/model/server/ModelServerTestUtil.kt
+++ b/model-server/src/test/kotlin/org/modelix/model/server/ModelServerTestUtil.kt
@@ -27,6 +27,7 @@ import io.ktor.server.routing.IgnoreTrailingSlash
 import io.ktor.server.testing.ApplicationTestBuilder
 import io.ktor.server.websocket.WebSockets
 import kotlinx.coroutines.runBlocking
+import org.modelix.api.v2.Paths.registerJsonTypes
 import org.modelix.authorization.installAuthentication
 import org.modelix.model.client2.ModelClientV2
 import org.modelix.model.server.Main.installStatusPages
@@ -38,7 +39,10 @@ suspend fun ApplicationTestBuilder.createModelClient(): ModelClientV2 {
 
 fun Application.installDefaultServerPlugins() {
     install(WebSockets)
-    install(ContentNegotiation) { json() }
+    install(ContentNegotiation) {
+        json()
+        registerJsonTypes()
+    }
     install(Resources)
     install(IgnoreTrailingSlash)
     installStatusPages()
diff --git a/model-server/src/test/kotlin/org/modelix/model/server/handlers/ModelReplicationServerTest.kt b/model-server/src/test/kotlin/org/modelix/model/server/handlers/ModelReplicationServerTest.kt
index c6e67882bd..9844c83085 100644
--- a/model-server/src/test/kotlin/org/modelix/model/server/handlers/ModelReplicationServerTest.kt
+++ b/model-server/src/test/kotlin/org/modelix/model/server/handlers/ModelReplicationServerTest.kt
@@ -15,11 +15,17 @@
 
 package org.modelix.model.server.handlers
 
+import com.google.api.client.http.HttpStatusCodes
+import io.kotest.assertions.ktor.client.shouldHaveContentType
+import io.kotest.assertions.ktor.client.shouldHaveStatus
+import io.kotest.matchers.shouldBe
 import io.ktor.client.HttpClient
 import io.ktor.client.call.body
 import io.ktor.client.engine.cio.CIO
 import io.ktor.client.plugins.HttpTimeout
+import io.ktor.client.plugins.contentnegotiation.ContentNegotiation
 import io.ktor.client.plugins.defaultRequest
+import io.ktor.client.request.accept
 import io.ktor.client.request.delete
 import io.ktor.client.request.get
 import io.ktor.client.statement.bodyAsText
@@ -29,6 +35,9 @@ import io.ktor.http.HttpStatusCode
 import io.ktor.http.appendPathSegments
 import io.ktor.http.contentType
 import io.ktor.http.takeFrom
+import io.ktor.http.withCharset
+import io.ktor.serialization.kotlinx.KotlinxSerializationConverter
+import io.ktor.serialization.kotlinx.json.DefaultJson
 import io.ktor.serialization.kotlinx.json.json
 import io.ktor.server.application.Application
 import io.ktor.server.netty.NettyApplicationEngine
@@ -42,6 +51,7 @@ import kotlinx.coroutines.flow.flow
 import kotlinx.coroutines.test.runTest
 import kotlinx.coroutines.withTimeout
 import org.modelix.api.v1.Problem
+import org.modelix.api.v2.BranchV1
 import org.modelix.authorization.installAuthentication
 import org.modelix.model.InMemoryModels
 import org.modelix.model.api.IConceptReference
@@ -51,6 +61,7 @@ import org.modelix.model.client2.runWrite
 import org.modelix.model.client2.useVersionStreamFormat
 import org.modelix.model.lazy.RepositoryId
 import org.modelix.model.server.api.v2.VersionDeltaStream
+import org.modelix.model.server.api.v2.VersionDeltaStreamV2
 import org.modelix.model.server.installDefaultServerPlugins
 import org.modelix.model.server.runWithNettyServer
 import org.modelix.model.server.store.InMemoryStoreClient
@@ -222,7 +233,14 @@ class ModelReplicationServerTest {
         val repositoryId = RepositoryId("repo1")
         val branchRef = repositoryId.getBranchReference()
 
-        runWithTestModelServer(Fixture(storeClient, modelClient, faultyRepositoriesManager, modelReplicationServer)) { _, _ ->
+        runWithTestModelServer(
+            Fixture(
+                storeClient,
+                modelClient,
+                faultyRepositoriesManager,
+                modelReplicationServer,
+            ),
+        ) { _, _ ->
             repositoriesManager.createRepository(repositoryId, null)
 
             // Act
@@ -365,4 +383,53 @@ class ModelReplicationServerTest {
             )
         }
     }
+
+    @Test
+    fun `getRepositoryBranch responds with version delta v2 if requested`() {
+        val repositoryId = RepositoryId("repo1")
+
+        runWithTestModelServer { _, fixture ->
+            fixture.repositoriesManager.createRepository(repositoryId, null)
+
+            val response = client.get {
+                url {
+                    appendPathSegments("v2", "repositories", repositoryId.id, "branches", "master")
+                }
+                accept(VersionDeltaStreamV2.CONTENT_TYPE)
+            }
+
+            response shouldHaveStatus HttpStatusCodes.STATUS_CODE_OK
+            response.shouldHaveContentType(VersionDeltaStreamV2.CONTENT_TYPE)
+        }
+    }
+
+    @Test
+    fun `getRepositoryBranch responds with v1 branch if requested`() {
+        val repositoryId = RepositoryId("repo1")
+        val branchV1ContentType =
+            ContentType.parse("application/x.modelix.branch+json;version=1").withCharset(Charsets.UTF_8)
+
+        runWithTestModelServer { _, fixture ->
+            fixture.repositoriesManager.createRepository(repositoryId, null)
+            val client = createClient {
+                install(ContentNegotiation) {
+                    json()
+                    register(branchV1ContentType, KotlinxSerializationConverter(DefaultJson))
+                }
+            }
+
+            val response = client.get {
+                url {
+                    appendPathSegments("v2", "repositories", repositoryId.id, "branches", "master")
+                }
+                accept(branchV1ContentType)
+            }
+
+            response.shouldHaveContentType(branchV1ContentType)
+            response.body<BranchV1>() shouldBe BranchV1(
+                "master",
+                fixture.repositoriesManager.pollVersionHash(repositoryId.getBranchReference("master"), null),
+            )
+        }
+    }
 }