feat! Add context to server call handlers (#515)

## Motivation and Context

Adds a `ClientConnection` context receiver to server call handlers,
which provides access to the client communication channel. This is
necessary to allow tools to send notifications, logging, elicitations,
etc.

Supersedes https://github.com/modelcontextprotocol/kotlin-sdk/pull/144,
discussed in
https://github.com/modelcontextprotocol/kotlin-sdk/issues/295.

## How Has This Been Tested?

With the added integration test.

## Breaking Changes

It breaks binary compatibility and breaks source compatibility for tool
handlers that already use `this`.

If you care a lot about maintaining compatibility, I could add some
overloads to ease the transition. But the new methods would likely need
to be named differently for resolution.

Future compatibility should be easier to maintain - `Context` is an
interface (with experimental opt-in subclassing), so new fields can be
added without breaking compatibility. Different types could also be
introduced for different handles without breaking compatibility, as long
as they extend `ClientConnection`.

## Types of changes
<!-- What types of changes does your code introduce? Put an `x` in all
the boxes that apply: -->
- [ ] Bug fix (non-breaking change which fixes an issue)
- [x] New feature (non-breaking change which adds functionality)
- [x] Breaking change (fix or feature that would cause existing
functionality to change)
- [ ] Documentation update

## Checklist
<!-- Go over all the following points, and put an `x` in all the boxes
that apply. -->
- [x] I have read the [MCP
Documentation](https://modelcontextprotocol.io)
- [x] My code follows the repository's style guidelines
- [x] New and existing tests pass locally
- [x] I have added appropriate error handling
- [x] I have added or updated documentation as needed

## Additional context
<!-- Add any other context, implementation notes, or design decisions
-->

---------

Co-authored-by: Konstantin Pavlov <1517853+kpavlov@users.noreply.github.com>
This commit is contained in:
Ryan Nett 2026-02-23 06:30:15 -08:00 • committed by GitHub
commit 4a08959121
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
8 changed files with 1585 additions and 253 deletions

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@ -32,7 +32,6 @@
<ID>LongMethod:KotlinServerForTsClientSse.kt:HttpServerTransport$suspend fun handleRequest</ID>
<ID>LongMethod:KotlinServerForTsClientSse.kt:KotlinServerForTsClient$fun createMcpServer: Server</ID>
<ID>LongMethod:KotlinServerForTsClientSse.kt:KotlinServerForTsClient$fun start</ID>
<ID>LongMethod:KotlinTestBase.kt:KotlinTestBase$protected fun setupServer</ID>
<ID>LongMethod:ServerResourcesNotificationSubscribeTest.kt:ServerResourcesNotificationSubscribeTest$@Test fun `should send resource notifications`</ID>
<ID>LongMethod:TsEdgeCasesTestSse.kt:TsEdgeCasesTestSse$@Test @Timeout(30, unit = TimeUnit.SECONDS) fun testComplexConcurrentRequests: Unit</ID>
<ID>MatchingDeclarationName:PromptIntegrationTestSse.kt:SchemaPromptIntegrationTestSse : AbstractPromptIntegrationTest</ID>

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@ -1,9 +1,16 @@
package io.modelcontextprotocol.kotlin.sdk.server
import io.modelcontextprotocol.kotlin.sdk.client.Client
import io.modelcontextprotocol.kotlin.sdk.client.ClientOptions
import io.modelcontextprotocol.kotlin.sdk.shared.InMemoryTransport
import io.modelcontextprotocol.kotlin.sdk.types.CallToolResult
import io.modelcontextprotocol.kotlin.sdk.types.ClientCapabilities
import io.modelcontextprotocol.kotlin.sdk.types.GetPromptResult
import io.modelcontextprotocol.kotlin.sdk.types.Implementation
import io.modelcontextprotocol.kotlin.sdk.types.ReadResourceResult
import io.modelcontextprotocol.kotlin.sdk.types.ServerCapabilities
import io.modelcontextprotocol.kotlin.sdk.types.TextContent
import io.modelcontextprotocol.kotlin.sdk.types.TextResourceContents
import kotlinx.coroutines.launch
import kotlinx.coroutines.runBlocking
import org.junit.jupiter.api.BeforeEach
@ -13,8 +20,31 @@ abstract class AbstractServerFeaturesTest {
protected lateinit var server: Server
protected lateinit var client: Client
protected fun addTool(name: String, block: suspend ClientConnection.() -> Unit) {
server.addTool(name, "Test $name") {
block()
CallToolResult(listOf(TextContent("Success")))
}
}
protected fun addPrompt(name: String, block: suspend ClientConnection.() -> Unit) {
server.addPrompt(name, "Test $name") {
block()
GetPromptResult(messages = emptyList())
}
}
protected fun addResource(uri: String, block: suspend ClientConnection.() -> Unit) {
server.addResource(uri, uri, "Test resource $uri") {
block()
ReadResourceResult(contents = listOf(TextResourceContents(text = "content", uri = uri)))
}
}
abstract fun getServerCapabilities(): ServerCapabilities
protected open fun getClientCapabilities(): ClientCapabilities = ClientCapabilities()
protected open fun getServerInstructionsProvider(): (() -> String)? = null
@BeforeEach
@ -33,6 +63,9 @@ abstract class AbstractServerFeaturesTest {
client = Client(
clientInfo = Implementation(name = "test client", version = "1.0"),
options = ClientOptions(
capabilities = getClientCapabilities(),
),
)
runBlocking {

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@ -0,0 +1,172 @@
package io.modelcontextprotocol.kotlin.sdk.server
import io.kotest.matchers.collections.shouldBeEmpty
import io.kotest.matchers.collections.shouldHaveSize
import io.kotest.matchers.shouldBe
import io.modelcontextprotocol.kotlin.sdk.types.CallToolRequest
import io.modelcontextprotocol.kotlin.sdk.types.CallToolRequestParams
import io.modelcontextprotocol.kotlin.sdk.types.LoggingLevel
import io.modelcontextprotocol.kotlin.sdk.types.LoggingMessageNotification
import io.modelcontextprotocol.kotlin.sdk.types.LoggingMessageNotificationParams
import io.modelcontextprotocol.kotlin.sdk.types.Method
import io.modelcontextprotocol.kotlin.sdk.types.ServerCapabilities
import kotlinx.coroutines.CompletableDeferred
import kotlinx.coroutines.runBlocking
import kotlinx.serialization.json.JsonObject
import kotlinx.serialization.json.JsonPrimitive
import org.junit.jupiter.api.Test
import org.junit.jupiter.params.ParameterizedTest
import org.junit.jupiter.params.provider.EnumSource
class ClientConnectionLoggingTest : AbstractServerFeaturesTest() {
override fun getServerCapabilities(): ServerCapabilities = ServerCapabilities(
tools = ServerCapabilities.Tools(listChanged = true),
logging = JsonObject(emptyMap()),
)
@Test
fun `notification should send logging message to client`(): Unit = runBlocking {
val notificationReceived = CompletableDeferred<LoggingMessageNotification>()
client.setNotificationHandler<LoggingMessageNotification>(Method.Defined.NotificationsMessage) {
notificationReceived.complete(it)
CompletableDeferred(Unit)
}
val expectedLevel = LoggingLevel.Info
val expectedData = JsonPrimitive("test-data-sample")
addTool("test-notification") {
notification(
LoggingMessageNotification(
LoggingMessageNotificationParams(
level = expectedLevel,
data = expectedData,
),
),
)
}
client.callTool(CallToolRequest(CallToolRequestParams("test-notification")))
val received = notificationReceived.await()
received.params.level shouldBe expectedLevel
received.params.data shouldBe expectedData
}
@ParameterizedTest
@EnumSource(LoggingLevel::class)
fun `notification should filter logging messages below level`(minLevel: LoggingLevel): Unit = runBlocking {
val receivedMessages = mutableListOf<LoggingMessageNotification>()
client.setNotificationHandler<LoggingMessageNotification>(Method.Defined.NotificationsMessage) {
receivedMessages.add(it)
CompletableDeferred(Unit)
}
client.setLoggingLevel(minLevel)
addTool("test-notification-filtered") {
LoggingLevel.entries.forEach { level ->
notification(
LoggingMessageNotification(
LoggingMessageNotificationParams(
level = level,
data = JsonPrimitive(level.name),
),
),
)
}
}
client.callTool(CallToolRequest(CallToolRequestParams("test-notification-filtered")))
val expectedLevels = LoggingLevel.entries.filter { it >= minLevel }
receivedMessages shouldHaveSize expectedLevels.size
receivedMessages.map { it.params.level } shouldBe expectedLevels
}
@ParameterizedTest
@EnumSource(LoggingLevel::class)
fun `sendLoggingMessage should send message at level`(expectedLevel: LoggingLevel): Unit = runBlocking {
val notificationReceived = CompletableDeferred<LoggingMessageNotification>()
client.setNotificationHandler<LoggingMessageNotification>(Method.Defined.NotificationsMessage) {
notificationReceived.complete(it)
CompletableDeferred(Unit)
}
val expectedData = JsonObject(mapOf("key" to JsonPrimitive("value")))
addTool("test-logging") {
sendLoggingMessage(
LoggingMessageNotification(
LoggingMessageNotificationParams(
level = expectedLevel,
data = expectedData,
),
),
)
}
client.callTool(CallToolRequest(CallToolRequestParams("test-logging")))
val received = notificationReceived.await()
received.params.level shouldBe expectedLevel
received.params.data shouldBe expectedData
}
@ParameterizedTest
@EnumSource(LoggingLevel::class)
fun `sendLoggingMessage should filter messages below level`(minLevel: LoggingLevel): Unit = runBlocking {
val receivedMessages = mutableListOf<LoggingMessageNotification>()
client.setNotificationHandler<LoggingMessageNotification>(Method.Defined.NotificationsMessage) {
receivedMessages.add(it)
CompletableDeferred(Unit)
}
client.setLoggingLevel(minLevel)
addTool("test-logging-level") {
LoggingLevel.entries.forEach { level ->
sendLoggingMessage(
LoggingMessageNotification(
LoggingMessageNotificationParams(
level = level,
data = JsonPrimitive(level.name),
),
),
)
}
}
client.callTool(CallToolRequest(CallToolRequestParams("test-logging-level")))
val expectedLevels = LoggingLevel.entries.filter { it >= minLevel }
receivedMessages shouldHaveSize expectedLevels.size
receivedMessages.map { it.params.level } shouldBe expectedLevels
}
@Test
fun `sendLoggingMessage should send no messages when level is set to highest`(): Unit = runBlocking {
val receivedMessages = mutableListOf<LoggingMessageNotification>()
client.setNotificationHandler<LoggingMessageNotification>(Method.Defined.NotificationsMessage) {
receivedMessages.add(it)
CompletableDeferred(Unit)
}
client.setLoggingLevel(LoggingLevel.Emergency)
addTool("test-logging-highest") {
LoggingLevel.entries.dropLast(1).forEach { level ->
sendLoggingMessage(
LoggingMessageNotification(
LoggingMessageNotificationParams(
level = level,
data = JsonPrimitive(level.name),
),
),
)
}
}
client.callTool(CallToolRequest(CallToolRequestParams("test-logging-highest")))
receivedMessages.shouldBeEmpty()
}
}

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@ -0,0 +1,163 @@
package io.modelcontextprotocol.kotlin.sdk.server
import io.kotest.assertions.assertSoftly
import io.kotest.assertions.withClue
import io.kotest.matchers.shouldBe
import io.kotest.matchers.string.shouldNotBeBlank
import io.modelcontextprotocol.kotlin.sdk.types.CallToolRequest
import io.modelcontextprotocol.kotlin.sdk.types.CallToolRequestParams
import io.modelcontextprotocol.kotlin.sdk.types.ClientCapabilities
import io.modelcontextprotocol.kotlin.sdk.types.GetPromptRequest
import io.modelcontextprotocol.kotlin.sdk.types.GetPromptRequestParams
import io.modelcontextprotocol.kotlin.sdk.types.ListRootsRequest
import io.modelcontextprotocol.kotlin.sdk.types.ListRootsResult
import io.modelcontextprotocol.kotlin.sdk.types.LoggingLevel
import io.modelcontextprotocol.kotlin.sdk.types.LoggingMessageNotification
import io.modelcontextprotocol.kotlin.sdk.types.LoggingMessageNotificationParams
import io.modelcontextprotocol.kotlin.sdk.types.Method
import io.modelcontextprotocol.kotlin.sdk.types.Notification
import io.modelcontextprotocol.kotlin.sdk.types.PromptListChangedNotification
import io.modelcontextprotocol.kotlin.sdk.types.ReadResourceRequest
import io.modelcontextprotocol.kotlin.sdk.types.ReadResourceRequestParams
import io.modelcontextprotocol.kotlin.sdk.types.Request
import io.modelcontextprotocol.kotlin.sdk.types.RequestResult
import io.modelcontextprotocol.kotlin.sdk.types.ResourceListChangedNotification
import io.modelcontextprotocol.kotlin.sdk.types.ResourceUpdatedNotification
import io.modelcontextprotocol.kotlin.sdk.types.ResourceUpdatedNotificationParams
import io.modelcontextprotocol.kotlin.sdk.types.Root
import io.modelcontextprotocol.kotlin.sdk.types.ServerCapabilities
import io.modelcontextprotocol.kotlin.sdk.types.ToolListChangedNotification
import kotlinx.coroutines.CompletableDeferred
import kotlinx.coroutines.test.runTest
import kotlinx.serialization.json.JsonPrimitive
import org.junit.jupiter.api.Test
class ClientConnectionTest : AbstractServerFeaturesTest() {
private inline fun <reified T : Notification> onClientNotification(method: Method): CompletableDeferred<T> {
val deferred = CompletableDeferred<T>()
client.setNotificationHandler<T>(method) {
deferred.complete(it)
CompletableDeferred(Unit)
}
return deferred
}
private inline fun <reified Req : Request, reified Res : RequestResult> onClientRequest(
method: Method,
crossinline response: (Req) -> Res,
) {
client.setRequestHandler<Req>(method) { req, _ -> response(req) }
}
override fun getServerCapabilities(): ServerCapabilities = ServerCapabilities(
tools = ServerCapabilities.Tools(listChanged = true),
prompts = ServerCapabilities.Prompts(listChanged = true),
resources = ServerCapabilities.Resources(listChanged = true),
logging = ServerCapabilities.Logging,
)
override fun getClientCapabilities(): ClientCapabilities = ClientCapabilities(
roots = ClientCapabilities.Roots(listChanged = true),
)
private val sampleRoots = listOf(Root("file:///project", "Project Root"))
/** Holds all deferreds that capture what a server-side handler emits during [callAllMethods]. */
private inner class Captures {
val pingComplete = CompletableDeferred<Unit>()
val rootsResult = CompletableDeferred<ListRootsResult>()
val sessionId = CompletableDeferred<String>()
val toolListChanged =
onClientNotification<ToolListChangedNotification>(Method.Defined.NotificationsToolsListChanged)
val resourceListChanged =
onClientNotification<ResourceListChangedNotification>(Method.Defined.NotificationsResourcesListChanged)
val promptListChanged =
onClientNotification<PromptListChangedNotification>(Method.Defined.NotificationsPromptsListChanged)
val loggingMessage = onClientNotification<LoggingMessageNotification>(Method.Defined.NotificationsMessage)
val resourceUpdated =
onClientNotification<ResourceUpdatedNotification>(Method.Defined.NotificationsResourcesUpdated)
init {
onClientRequest<ListRootsRequest, ListRootsResult>(Method.Defined.RootsList) {
ListRootsResult(sampleRoots)
}
}
suspend fun assertAll() {
val roots = rootsResult.await()
val log = loggingMessage.await()
val resourceUri = resourceUpdated.await().params.uri
val capturedSessionId = sessionId.await()
assertSoftly {
withClue("ping() was not called inside the handler") {
pingComplete.isCompleted shouldBe true
}
roots.roots shouldBe sampleRoots
withClue("sendToolListChanged() did not deliver a notification to the client") {
toolListChanged.isCompleted shouldBe true
}
withClue("sendResourceListChanged() did not deliver a notification to the client") {
resourceListChanged.isCompleted shouldBe true
}
withClue("sendPromptListChanged() did not deliver a notification to the client") {
promptListChanged.isCompleted shouldBe true
}
withClue("sendLoggingMessage() delivered unexpected payload") {
log.params.data shouldBe JsonPrimitive("log")
}
withClue("sendResourceUpdated() delivered wrong URI") {
resourceUri shouldBe "test://res"
}
capturedSessionId.shouldNotBeBlank()
}
}
}
/** Exercises every [ClientConnection] method, recording results into [cap]. */
private suspend fun ClientConnection.callAllMethods(cap: Captures) {
ping()
cap.pingComplete.complete(Unit)
cap.rootsResult.complete(listRoots())
sendToolListChanged()
sendResourceListChanged()
sendPromptListChanged()
sendLoggingMessage(
LoggingMessageNotification(
LoggingMessageNotificationParams(level = LoggingLevel.Info, data = JsonPrimitive("log")),
),
)
sendResourceUpdated(ResourceUpdatedNotification(ResourceUpdatedNotificationParams("test://res")))
cap.sessionId.complete(sessionId)
}
@Test
fun `all ClientConnection methods are callable from tool handler`() = runTest {
val cap = Captures()
addTool("test") { callAllMethods(cap) }
client.callTool(CallToolRequest(CallToolRequestParams("test")))
cap.assertAll()
}
@Test
fun `all ClientConnection methods are callable from prompt handler`() = runTest {
val cap = Captures()
addPrompt("test") { callAllMethods(cap) }
client.getPrompt(GetPromptRequest(GetPromptRequestParams("test")))
cap.assertAll()
}
@Test
fun `all ClientConnection methods are callable from resource handler`() = runTest {
val cap = Captures()
addResource("test://resource") { callAllMethods(cap) }
client.readResource(ReadResourceRequest(ReadResourceRequestParams("test://resource")))
cap.assertAll()
}
}

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@ -0,0 +1,183 @@
package io.modelcontextprotocol.kotlin.sdk.server
import io.kotest.matchers.collections.shouldBeEmpty
import io.kotest.matchers.collections.shouldContainExactlyInAnyOrder
import io.kotest.matchers.collections.shouldHaveSize
import io.kotest.matchers.shouldBe
import io.modelcontextprotocol.kotlin.sdk.types.CallToolResult
import io.modelcontextprotocol.kotlin.sdk.types.GetPromptResult
import io.modelcontextprotocol.kotlin.sdk.types.Prompt
import io.modelcontextprotocol.kotlin.sdk.types.ReadResourceResult
import io.modelcontextprotocol.kotlin.sdk.types.Resource
import io.modelcontextprotocol.kotlin.sdk.types.ServerCapabilities
import io.modelcontextprotocol.kotlin.sdk.types.Tool
import io.modelcontextprotocol.kotlin.sdk.types.ToolSchema
import kotlinx.coroutines.test.runTest
import org.junit.jupiter.api.Test
class ServerBulkFeaturesTest : AbstractServerFeaturesTest() {
override fun getServerCapabilities(): ServerCapabilities = ServerCapabilities(
tools = ServerCapabilities.Tools(listChanged = null),
prompts = ServerCapabilities.Prompts(listChanged = null),
resources = ServerCapabilities.Resources(listChanged = null, subscribe = null),
)
// ── addTools ───────────────────────────────────────────────────────────────
@Test
fun `addTools should register all provided tools`() = runTest {
server.addTools(
listOf(
RegisteredTool(Tool("bulk-a", ToolSchema(), "Tool A")) { CallToolResult(emptyList()) },
RegisteredTool(Tool("bulk-b", ToolSchema(), "Tool B")) { CallToolResult(emptyList()) },
RegisteredTool(Tool("bulk-c", ToolSchema(), "Tool C")) { CallToolResult(emptyList()) },
),
)
val tools = client.listTools().tools
tools shouldHaveSize 3
tools.map { it.name } shouldContainExactlyInAnyOrder listOf("bulk-a", "bulk-b", "bulk-c")
}
@Test
fun `addTools should append to existing tools`() = runTest {
server.addTool("existing", "Existing") { CallToolResult(emptyList()) }
server.addTools(
listOf(
RegisteredTool(Tool("new-a", ToolSchema())) { CallToolResult(emptyList()) },
RegisteredTool(Tool("new-b", ToolSchema())) { CallToolResult(emptyList()) },
),
)
val tools = client.listTools().tools
tools shouldHaveSize 3
tools.map { it.name } shouldContainExactlyInAnyOrder listOf("existing", "new-a", "new-b")
}
// ── addPrompts ─────────────────────────────────────────────────────────────
@Test
fun `addPrompts should register all provided prompts`() = runTest {
server.addPrompts(
listOf(
RegisteredPrompt(Prompt("bulk-p1", "Prompt 1")) { GetPromptResult(messages = emptyList()) },
RegisteredPrompt(Prompt("bulk-p2", "Prompt 2")) { GetPromptResult(messages = emptyList()) },
),
)
val prompts = client.listPrompts().prompts
prompts shouldHaveSize 2
prompts.map { it.name } shouldContainExactlyInAnyOrder listOf("bulk-p1", "bulk-p2")
}
@Test
fun `addPrompts should append to existing prompts`() = runTest {
server.addPrompt("existing-prompt", "Existing") { GetPromptResult(messages = emptyList()) }
server.addPrompts(
listOf(
RegisteredPrompt(Prompt("new-p")) { GetPromptResult(messages = emptyList()) },
),
)
val prompts = client.listPrompts().prompts
prompts shouldHaveSize 2
prompts.map { it.name } shouldContainExactlyInAnyOrder listOf("existing-prompt", "new-p")
}
// ── addResources ───────────────────────────────────────────────────────────
@Test
fun `addResources should register all provided resources`() = runTest {
server.addResources(
listOf(
RegisteredResource(Resource("test://bulk-r1", "Resource 1")) { ReadResourceResult(emptyList()) },
RegisteredResource(Resource("test://bulk-r2", "Resource 2")) { ReadResourceResult(emptyList()) },
),
)
val resources = client.listResources().resources
resources shouldHaveSize 2
resources.map { it.uri } shouldContainExactlyInAnyOrder listOf("test://bulk-r1", "test://bulk-r2")
}
@Test
fun `addResources should append to existing resources`() = runTest {
server.addResource("test://existing-res", "Existing", "Existing resource") {
ReadResourceResult(emptyList())
}
server.addResources(
listOf(
RegisteredResource(Resource("test://new-res", "New")) { ReadResourceResult(emptyList()) },
),
)
val resources = client.listResources().resources
resources shouldHaveSize 2
resources.map { it.uri } shouldContainExactlyInAnyOrder listOf("test://existing-res", "test://new-res")
}
// ── Partial-batch remove ───────────────────────────────────────────────────
@Test
fun `removeTools should return count of actually removed tools`() = runTest {
server.addTool("present", "Present") { CallToolResult(emptyList()) }
client.listTools().tools shouldHaveSize 1
val count = server.removeTools(listOf("present", "absent-1", "absent-2"))
count shouldBe 1
client.listTools().tools.shouldBeEmpty()
}
@Test
fun `removeTools on empty list should return zero`() = runTest {
val count = server.removeTools(emptyList())
count shouldBe 0
}
@Test
fun `removePrompts should return count of actually removed prompts`() = runTest {
server.addPrompt("present-p", "Present") { GetPromptResult(messages = emptyList()) }
client.listPrompts().prompts shouldHaveSize 1
val count = server.removePrompts(listOf("present-p", "absent-p"))
count shouldBe 1
client.listPrompts().prompts.shouldBeEmpty()
}
@Test
fun `removePrompts on empty list should return zero`() = runTest {
val count = server.removePrompts(emptyList())
count shouldBe 0
}
@Test
fun `removeResources should return count of actually removed resources`() = runTest {
server.addResource("test://present-r", "Present", "Present resource") {
ReadResourceResult(emptyList())
}
client.listResources().resources shouldHaveSize 1
val count = server.removeResources(listOf("test://present-r", "test://absent-r"))
count shouldBe 1
client.listResources().resources.shouldBeEmpty()
}
@Test
fun `removeResources on empty list should return zero`() = runTest {
val count = server.removeResources(emptyList())
count shouldBe 0
}
}

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@ -0,0 +1,222 @@
package io.modelcontextprotocol.kotlin.sdk.server
import io.kotest.assertions.assertSoftly
import io.kotest.matchers.collections.shouldHaveSize
import io.kotest.matchers.shouldBe
import io.kotest.matchers.shouldNotBe
import io.modelcontextprotocol.kotlin.sdk.types.CallToolRequest
import io.modelcontextprotocol.kotlin.sdk.types.CallToolRequestParams
import io.modelcontextprotocol.kotlin.sdk.types.CallToolResult
import io.modelcontextprotocol.kotlin.sdk.types.GetPromptRequest
import io.modelcontextprotocol.kotlin.sdk.types.GetPromptRequestParams
import io.modelcontextprotocol.kotlin.sdk.types.GetPromptResult
import io.modelcontextprotocol.kotlin.sdk.types.McpException
import io.modelcontextprotocol.kotlin.sdk.types.PromptMessage
import io.modelcontextprotocol.kotlin.sdk.types.ReadResourceRequest
import io.modelcontextprotocol.kotlin.sdk.types.ReadResourceRequestParams
import io.modelcontextprotocol.kotlin.sdk.types.ReadResourceResult
import io.modelcontextprotocol.kotlin.sdk.types.Role
import io.modelcontextprotocol.kotlin.sdk.types.ServerCapabilities
import io.modelcontextprotocol.kotlin.sdk.types.TextContent
import io.modelcontextprotocol.kotlin.sdk.types.TextResourceContents
import kotlinx.coroutines.CompletableDeferred
import kotlinx.coroutines.test.runTest
import kotlinx.serialization.json.JsonObject
import kotlinx.serialization.json.JsonPrimitive
import kotlinx.serialization.json.jsonPrimitive
import org.junit.jupiter.api.Test
import kotlin.test.assertFailsWith
class ServerFeaturesInvocationTest : AbstractServerFeaturesTest() {
override fun getServerCapabilities(): ServerCapabilities = ServerCapabilities(
tools = ServerCapabilities.Tools(listChanged = null),
prompts = ServerCapabilities.Prompts(listChanged = null),
resources = ServerCapabilities.Resources(listChanged = null, subscribe = null),
)
// ── Tool invocation ────────────────────────────────────────────────────────
@Test
fun `callTool should return tool result content`() = runTest {
server.addTool("echo", "Echo tool") {
CallToolResult(listOf(TextContent("echo response")))
}
val result = client.callTool(CallToolRequest(CallToolRequestParams("echo")))
assertSoftly(result) {
isError shouldNotBe true
(content.single() as TextContent).text shouldBe "echo response"
}
}
@Test
fun `callTool should pass arguments to handler`() = runTest {
server.addTool("greet", "Greeting tool") { request ->
val name = request.params.arguments?.get("name")?.jsonPrimitive?.content ?: "stranger"
CallToolResult(listOf(TextContent("Hello, $name!")))
}
val result = client.callTool(
CallToolRequest(
CallToolRequestParams(
name = "greet",
arguments = JsonObject(mapOf("name" to JsonPrimitive("World"))),
),
),
)
(result.content.single() as TextContent).text shouldBe "Hello, World!"
}
@Test
fun `callTool should return error result when tool not found`() = runTest {
val result = client.callTool(CallToolRequest(CallToolRequestParams("nonexistent")))
assertSoftly(result) {
isError shouldBe true
(content.single() as TextContent).text shouldBe "Tool nonexistent not found"
}
}
@Test
fun `callTool should return error result when handler throws`() = runTest {
server.addTool("failing", "Failing tool") {
throw IllegalStateException("handler failure")
}
val result = client.callTool(CallToolRequest(CallToolRequestParams("failing")))
assertSoftly(result) {
isError shouldBe true
(content.single() as TextContent).text shouldBe "Error executing tool failing: handler failure"
}
}
@Test
fun `callTool should pass empty arguments map to handler`() = runTest {
server.addTool("greet", "Greeting tool") { request ->
val name = request.params.arguments?.get("name")?.jsonPrimitive?.content ?: "stranger"
CallToolResult(listOf(TextContent("Hello, $name!")))
}
val result = client.callTool(
CallToolRequest(
CallToolRequestParams(
name = "greet",
arguments = JsonObject(emptyMap()),
),
),
)
(result.content.single() as TextContent).text shouldBe "Hello, stranger!"
}
// ── Prompt invocation ──────────────────────────────────────────────────────
@Test
fun `getPrompt should return prompt description and messages`() = runTest {
server.addPrompt("my-prompt", "My prompt") {
GetPromptResult(
description = "Prompt result description",
messages = listOf(
PromptMessage(role = Role.User, content = TextContent("User message")),
),
)
}
val result = client.getPrompt(GetPromptRequest(GetPromptRequestParams("my-prompt")))
assertSoftly(result) {
description shouldBe "Prompt result description"
messages shouldHaveSize 1
(messages.single().content as TextContent).text shouldBe "User message"
}
}
@Test
fun `getPrompt should pass arguments to handler`() = runTest {
server.addPrompt("templated", "Templated prompt") { request ->
val topic = request.params.arguments?.get("topic") ?: "unknown"
GetPromptResult(
messages = listOf(
PromptMessage(role = Role.User, content = TextContent("Tell me about $topic")),
),
)
}
val result = client.getPrompt(
GetPromptRequest(
GetPromptRequestParams(
name = "templated",
arguments = mapOf("topic" to "Kotlin coroutines"),
),
),
)
(result.messages.single().content as TextContent).text shouldBe "Tell me about Kotlin coroutines"
}
@Test
fun `getPrompt should use default when arguments are absent`() = runTest {
server.addPrompt("templated", "Templated prompt") { request ->
val topic = request.params.arguments?.get("topic") ?: "unknown"
GetPromptResult(
messages = listOf(
PromptMessage(role = Role.User, content = TextContent("Tell me about $topic")),
),
)
}
val result = client.getPrompt(GetPromptRequest(GetPromptRequestParams("templated")))
(result.messages.single().content as TextContent).text shouldBe "Tell me about unknown"
}
@Test
fun `getPrompt should throw when prompt not found`() = runTest {
assertFailsWith<McpException> {
client.getPrompt(GetPromptRequest(GetPromptRequestParams("nonexistent")))
}
}
// ── Resource invocation ────────────────────────────────────────────────────
@Test
fun `readResource should return resource content`() = runTest {
val uri = "test://my-resource"
server.addResource(uri, "My Resource", "Test resource") {
ReadResourceResult(
contents = listOf(TextResourceContents(text = "resource content", uri = uri)),
)
}
val result = client.readResource(ReadResourceRequest(ReadResourceRequestParams(uri)))
(result.contents.single() as TextResourceContents).text shouldBe "resource content"
}
@Test
fun `readResource should pass request URI to handler`() = runTest {
val uri = "test://uri-check"
val receivedUri = CompletableDeferred<String>()
server.addResource(uri, "URI Check", "Test") { request ->
receivedUri.complete(request.params.uri)
ReadResourceResult(
contents = listOf(TextResourceContents(text = "ok", uri = uri)),
)
}
client.readResource(ReadResourceRequest(ReadResourceRequestParams(uri)))
receivedUri.await() shouldBe uri
}
@Test
fun `readResource should throw when resource not found`() = runTest {
assertFailsWith<McpException> {
client.readResource(ReadResourceRequest(ReadResourceRequestParams("test://nonexistent")))
}
}
}

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package io.modelcontextprotocol.kotlin.sdk.server
import io.kotest.assertions.assertSoftly
import io.kotest.matchers.collections.shouldBeEmpty
import io.kotest.matchers.collections.shouldContainExactlyInAnyOrder
import io.kotest.matchers.collections.shouldHaveSize
import io.kotest.matchers.nulls.shouldNotBeNull
import io.kotest.matchers.shouldBe
import io.modelcontextprotocol.kotlin.sdk.types.CallToolResult
import io.modelcontextprotocol.kotlin.sdk.types.GetPromptResult
import io.modelcontextprotocol.kotlin.sdk.types.ListResourceTemplatesRequest
import io.modelcontextprotocol.kotlin.sdk.types.PromptArgument
import io.modelcontextprotocol.kotlin.sdk.types.ReadResourceResult
import io.modelcontextprotocol.kotlin.sdk.types.Resource
import io.modelcontextprotocol.kotlin.sdk.types.ServerCapabilities
import kotlinx.coroutines.test.runTest
import org.junit.jupiter.api.Test
class ServerFeaturesListTest : AbstractServerFeaturesTest() {
override fun getServerCapabilities(): ServerCapabilities = ServerCapabilities(
tools = ServerCapabilities.Tools(listChanged = null),
prompts = ServerCapabilities.Prompts(listChanged = null),
resources = ServerCapabilities.Resources(listChanged = null, subscribe = null),
)
// ── listTools ──────────────────────────────────────────────────────────────
@Test
fun `listTools should return empty list when no tools registered`() = runTest {
client.listTools().tools.shouldBeEmpty()
}
@Test
fun `listTools should return all registered tools`() = runTest {
server.addTool("alpha", "First tool") { CallToolResult(emptyList()) }
server.addTool("beta", "Second tool") { CallToolResult(emptyList()) }
val tools = client.listTools().tools
tools shouldHaveSize 2
tools.map { it.name } shouldContainExactlyInAnyOrder listOf("alpha", "beta")
}
@Test
fun `listTools should expose tool name and description`() = runTest {
server.addTool("my-tool", "Detailed description") { CallToolResult(emptyList()) }
val tool = client.listTools().tools.single()
assertSoftly(tool) {
name shouldBe "my-tool"
description shouldBe "Detailed description"
}
}
@Test
fun `listTools should reflect tool removal`() = runTest {
server.addTool("keep", "Kept") { CallToolResult(emptyList()) }
server.addTool("drop", "Dropped") { CallToolResult(emptyList()) }
client.listTools().tools shouldHaveSize 2
server.removeTool("drop") shouldBe true
val tools = client.listTools().tools
tools shouldHaveSize 1
tools.single().name shouldBe "keep"
}
@Test
fun `removeTool should return false when tool not found`() = runTest {
server.removeTool("ghost") shouldBe false
}
// ── listPrompts ────────────────────────────────────────────────────────────
@Test
fun `listPrompts should return empty list when no prompts registered`() = runTest {
client.listPrompts().prompts.shouldBeEmpty()
}
@Test
fun `listPrompts should return all registered prompts`() = runTest {
server.addPrompt("prompt-a", "First prompt") { GetPromptResult(messages = emptyList()) }
server.addPrompt("prompt-b", "Second prompt") { GetPromptResult(messages = emptyList()) }
val prompts = client.listPrompts().prompts
prompts shouldHaveSize 2
prompts.map { it.name } shouldContainExactlyInAnyOrder listOf("prompt-a", "prompt-b")
}
@Test
fun `listPrompts should expose prompt description`() = runTest {
server.addPrompt("my-prompt", "Helpful context prompt") { GetPromptResult(messages = emptyList()) }
val prompt = client.listPrompts().prompts.single()
assertSoftly(prompt) {
name shouldBe "my-prompt"
description shouldBe "Helpful context prompt"
}
}
@Test
fun `listPrompts should include prompt arguments`() = runTest {
val args = listOf(
PromptArgument(name = "topic", description = "The topic to discuss", required = true),
PromptArgument(name = "tone", description = "Tone of voice", required = false),
)
server.addPrompt("templated", "A templated prompt", args) { GetPromptResult(messages = emptyList()) }
val prompt = client.listPrompts().prompts.single()
val promptArgs = prompt.arguments.shouldNotBeNull()
promptArgs shouldHaveSize 2
promptArgs.map { it.name } shouldContainExactlyInAnyOrder listOf("topic", "tone")
promptArgs.first { it.name == "topic" }.required shouldBe true
promptArgs.first { it.name == "tone" }.required shouldBe false
}
@Test
fun `listPrompts should expose null description`() = runTest {
server.addPrompt("no-desc", null) { GetPromptResult(messages = emptyList()) }
client.listPrompts().prompts.single().description shouldBe null
}
@Test
fun `listPrompts should reflect prompt removal`() = runTest {
server.addPrompt("keep", "Kept") { GetPromptResult(messages = emptyList()) }
server.addPrompt("drop", "Dropped") { GetPromptResult(messages = emptyList()) }
client.listPrompts().prompts shouldHaveSize 2
server.removePrompt("drop") shouldBe true
val prompts = client.listPrompts().prompts
prompts shouldHaveSize 1
prompts.single().name shouldBe "keep"
}
@Test
fun `removePrompt should return false when prompt not found`() = runTest {
server.removePrompt("ghost") shouldBe false
}
// ── listResources ──────────────────────────────────────────────────────────
@Test
fun `listResources should return empty list when no resources registered`() = runTest {
client.listResources().resources.shouldBeEmpty()
}
@Test
fun `listResources should return all registered resources`() = runTest {
server.addResource("test://res-1", "Resource 1", "First") { ReadResourceResult(emptyList()) }
server.addResource("test://res-2", "Resource 2", "Second") { ReadResourceResult(emptyList()) }
val resources = client.listResources().resources
resources shouldHaveSize 2
resources.map { it.uri } shouldContainExactlyInAnyOrder listOf("test://res-1", "test://res-2")
}
@Test
fun `listResources should expose resource metadata`() = runTest {
server.addResource("test://my-res", "My Resource", "A detailed resource", "application/json") {
ReadResourceResult(emptyList())
}
val resource = client.listResources().resources.single()
assertSoftly(resource) {
uri shouldBe "test://my-res"
name shouldBe "My Resource"
description shouldBe "A detailed resource"
mimeType shouldBe "application/json"
}
}
@Test
fun `listResources should expose resource without mimeType`() = runTest {
server.addResources(
listOf(
RegisteredResource(Resource("test://no-mime", "No Mime")) {
ReadResourceResult(emptyList())
},
),
)
client.listResources().resources.single().mimeType shouldBe null
}
@Test
fun `listResources should reflect resource removal`() = runTest {
server.addResource("test://keep", "Keep", "Kept") { ReadResourceResult(emptyList()) }
server.addResource("test://drop", "Drop", "Dropped") { ReadResourceResult(emptyList()) }
client.listResources().resources shouldHaveSize 2
server.removeResource("test://drop") shouldBe true
val resources = client.listResources().resources
resources shouldHaveSize 1
resources.single().uri shouldBe "test://keep"
}
@Test
fun `removeResource should return false when resource not found`() = runTest {
server.removeResource("test://ghost") shouldBe false
}
// ── listResourceTemplates ──────────────────────────────────────────────────
@Test
fun `listResourceTemplates should return empty list`() = runTest {
client.listResourceTemplates(ListResourceTemplatesRequest()).resourceTemplates.shouldBeEmpty()
}
}

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package io.modelcontextprotocol.kotlin.sdk.server
import io.kotest.matchers.shouldBe
import io.modelcontextprotocol.kotlin.sdk.types.CallToolRequest
import io.modelcontextprotocol.kotlin.sdk.types.CallToolRequestParams
import io.modelcontextprotocol.kotlin.sdk.types.CallToolResult
import io.modelcontextprotocol.kotlin.sdk.types.GetPromptRequest
import io.modelcontextprotocol.kotlin.sdk.types.GetPromptRequestParams
import io.modelcontextprotocol.kotlin.sdk.types.GetPromptResult
import io.modelcontextprotocol.kotlin.sdk.types.LoggingLevel
import io.modelcontextprotocol.kotlin.sdk.types.LoggingMessageNotification
import io.modelcontextprotocol.kotlin.sdk.types.LoggingMessageNotificationParams
import io.modelcontextprotocol.kotlin.sdk.types.Method
import io.modelcontextprotocol.kotlin.sdk.types.ReadResourceRequest
import io.modelcontextprotocol.kotlin.sdk.types.ReadResourceRequestParams
import io.modelcontextprotocol.kotlin.sdk.types.ReadResourceResult
import io.modelcontextprotocol.kotlin.sdk.types.ServerCapabilities
import io.modelcontextprotocol.kotlin.sdk.types.TextContent
import io.modelcontextprotocol.kotlin.sdk.types.TextResourceContents
import kotlinx.coroutines.CompletableDeferred
import kotlinx.coroutines.test.runTest
import kotlinx.serialization.json.JsonObject
import kotlinx.serialization.json.JsonPrimitive
import org.junit.jupiter.api.Test
class ServerHandlerNotificationTest : AbstractServerFeaturesTest() {
override fun getServerCapabilities(): ServerCapabilities = ServerCapabilities(
tools = ServerCapabilities.Tools(true),
prompts = ServerCapabilities.Prompts(true),
resources = ServerCapabilities.Resources(true, null),
logging = JsonObject(emptyMap()),
)
@Test
fun `tool handler can send notification to client`() = runTest {
val notificationReceived = CompletableDeferred<LoggingMessageNotification>()
client.setNotificationHandler<LoggingMessageNotification>(Method.Defined.NotificationsMessage) { notification ->
notificationReceived.complete(notification)
CompletableDeferred(Unit)
}
val notificationText = "Notification from tool"
server.addTool("notify-tool", "A tool that notifies") {
sendLoggingMessage(
LoggingMessageNotification(
LoggingMessageNotificationParams(
level = LoggingLevel.Info,
data = JsonPrimitive(notificationText),
),
),
)
CallToolResult(listOf(TextContent("Tool executed")))
}
val result = client.callTool(CallToolRequest(CallToolRequestParams(name = "notify-tool")))
(result.content[0] as TextContent).text shouldBe "Tool executed"
val received = notificationReceived.await()
received.params.level shouldBe LoggingLevel.Info
received.params.data shouldBe JsonPrimitive(notificationText)
}
@Test
fun `prompt handler can send notification to client`() = runTest {
val notificationReceived = CompletableDeferred<LoggingMessageNotification>()
client.setNotificationHandler<LoggingMessageNotification>(Method.Defined.NotificationsMessage) { notification ->
notificationReceived.complete(notification)
CompletableDeferred(Unit)
}
val notificationText = "Notification from prompt"
server.addPrompt("notify-prompt", "A prompt that notifies") {
sendLoggingMessage(
LoggingMessageNotification(
LoggingMessageNotificationParams(
level = LoggingLevel.Info,
data = JsonPrimitive(notificationText),
),
),
)
GetPromptResult(messages = listOf(), description = "Prompt executed")
}
val result = client.getPrompt(GetPromptRequest(GetPromptRequestParams(name = "notify-prompt")))
result.description shouldBe "Prompt executed"
val received = notificationReceived.await()
received.params.level shouldBe LoggingLevel.Info
received.params.data shouldBe JsonPrimitive(notificationText)
}
@Test
fun `resource handler can send notification to client`() = runTest {
val notificationReceived = CompletableDeferred<LoggingMessageNotification>()
client.setNotificationHandler<LoggingMessageNotification>(Method.Defined.NotificationsMessage) { notification ->
notificationReceived.complete(notification)
CompletableDeferred(Unit)
}
val resourceUri = "test://notify-resource"
val notificationText = "Notification from resource"
server.addResource(resourceUri, "Notify Resource", "A resource that notifies") {
sendLoggingMessage(
LoggingMessageNotification(
LoggingMessageNotificationParams(
level = LoggingLevel.Info,
data = JsonPrimitive(notificationText),
),
),
)
ReadResourceResult(
contents = listOf(TextResourceContents(uri = resourceUri, text = "Resource read")),
)
}
val result = client.readResource(ReadResourceRequest(ReadResourceRequestParams(uri = resourceUri)))
(result.contents[0] as TextResourceContents).text shouldBe "Resource read"
val received = notificationReceived.await()
received.params.level shouldBe LoggingLevel.Info
received.params.data shouldBe JsonPrimitive(notificationText)
}
}