| Filename | Latest commit message | Latest commit date |
|---|---|---|
9561624ba9Bumps `mcp-kotlin` from 0.11.1 to 0.12.0. Updates `io.modelcontextprotocol:kotlin-sdk-client` from 0.11.1 to 0.12.0 <details> <summary>Release notes</summary> <p><em>Sourced from <a href="https://github.com/modelcontextprotocol/kotlin-sdk/releases">io.modelcontextprotocol:kotlin-sdk-client's releases</a>.</em></p> <blockquote> <h2>0.12.0</h2> <h2>Description</h2> <p>Adds sampling-with-tools per SEP-1577, JSON Schema dialect declaration on tool schemas, server-side tool name validation, and capability extensions; fixes SSE reconnect on the same session and stops swallowing <code>CancellationException</code>.</p> <h3>Breaking Changes</h3> <p><strong>Sampling messages can carry tool calls and results (SEP-1577)</strong> by <a href="https://github.com/devcrocod"><code>@devcrocod</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/718">#718</a></p> <p><code>SamplingMessage.content</code> is now typed as a new <code>SamplingMessageContent</code> supertype, with <code>MediaContent</code> (text/image/audio), <code>ToolUseContent</code>, and <code>ToolResultContent</code> as variants. <code>MediaContent</code> still exists and now extends <code>SamplingMessageContent</code>, so most source code that constructs sampling messages compiles unchanged — but the binary signatures of <code>SamplingMessage</code>, <code>CreateMessageResult</code>, and related types have changed. <code>ClientCapabilities.sampling</code> is also now a typed <code>Sampling</code> object instead of a raw <code>JsonObject</code>. Recompilation is required; consumers reading <code>sampling</code> as <code>JsonObject</code> must migrate to the typed accessors.</p> <p><strong><code>watchosX64</code> and <code>tvosX64</code> Kotlin/Native targets removed</strong> by <a href="https://github.com/devcrocod"><code>@devcrocod</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/727">#727</a></p> <p>These targets have been deprecated upstream. Migrate to the corresponding ARM/simulator targets (<code>watchosArm64</code>, <code>watchosSimulatorArm64</code>, <code>tvosArm64</code>, <code>tvosSimulatorArm64</code>).</p> <h3>Features</h3> <ul> <li>Add <code>$schema</code> field to <code>ToolSchema</code>, declaring JSON Schema 2020-12 as the default dialect (SEP-1613) by <a href="https://github.com/devcrocod"><code>@devcrocod</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/696">#696</a></li> <li>Validate tool names at registration time on the server, following the MCP tool naming standard (SEP-986) by <a href="https://github.com/devcrocod"><code>@devcrocod</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/695">#695</a></li> <li>Add <code>extensions</code> field to <code>ClientCapabilities</code> and <code>ServerCapabilities</code> for advertising supported MCP extensions during the initialize handshake by <a href="https://github.com/eritscher"><code>@eritscher</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/678">#678</a></li> </ul> <h3>Fixed</h3> <ul> <li>Validate the <code>mcp-protocol-version</code> HTTP header on initialization requests and correct <code>DEFAULT_NEGOTIATED_PROTOCOL_VERSION</code> to match the spec by <a href="https://github.com/devcrocod"><code>@devcrocod</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/697">#697</a></li> <li>Propagate <code>CancellationException</code> instead of logging it as an error by <a href="https://github.com/devcrocod"><code>@devcrocod</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/706">#706</a></li> <li>Evict stale GET SSE stream mapping on reconnect so a new GET on the same session is no longer silently rejected by the leftover entry from the previous stream by <a href="https://github.com/amr"><code>@amr</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/716">#716</a></li> </ul> <h3>Maintenance</h3> <ul> <li>Add <code>kotlinlang</code> MCP server sample with <code>search</code> and <code>get_page</code> tools by <a href="https://github.com/devcrocod"><code>@devcrocod</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/713">#713</a></li> <li>Migrate detekt to a <code>buildSrc</code> convention plugin with a fully explicit, version-locked YAML config by <a href="https://github.com/devcrocod"><code>@devcrocod</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/729">#729</a></li> <li>Add Streamable HTTP integration tests for pagination, bad-request handling, and logging by <a href="https://github.com/jskjw157"><code>@jskjw157</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/613">#613</a></li> <li>Remove unused OpenAPI Generator plugin and configuration by <a href="https://github.com/devcrocod"><code>@devcrocod</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/683">#683</a></li> <li>Remove Codecov configuration in favor of kover by <a href="https://github.com/devcrocod"><code>@devcrocod</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/691">#691</a></li> <li>Remove redundant JUnit XML report configuration by <a href="https://github.com/devcrocod"><code>@devcrocod</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/728">#728</a></li> <li>Remove IDEA files tied to the incompatible detekt IDE plugin by <a href="https://github.com/devcrocod"><code>@devcrocod</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/714">#714</a></li> <li>Add Node.js setup to the release workflow so TypeScript integration tests run on macOS runners by <a href="https://github.com/devcrocod"><code>@devcrocod</code></a> in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/684">#684</a></li> </ul> <h3>Dependencies</h3> <ul> <li>Kotlin to v2.3.21 in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/704">#704</a>, <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/723">#723</a></li> <li>kotlinx.serialization-json to v1.11.0 in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/687">#687</a></li> </ul> <h3>New Contributors</h3> <ul> <li><a href="https://github.com/eritscher"><code>@eritscher</code></a> made their first contribution in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/678">#678</a></li> <li><a href="https://github.com/amr"><code>@amr</code></a> made their first contribution in <a href="https://redirect.github.com/modelcontextprotocol/kotlin-sdk/pull/716">#716</a></li> </ul> <p><strong>Full Changelog</strong>: <a href="https://github.com/modelcontextprotocol/kotlin-sdk/compare/0.11.1...0.12.0">https://github.com/modelcontextprotocol/kotlin-sdk/compare/0.11.1...0.12.0</a></p> </blockquote> </details> <details> <summary>Commits</summary> <ul> <li><a href=" |
||
| .. | ||
| gradle | ||
| src | ||
| build.gradle.kts | ||
| gradle.properties | ||
| gradlew | ||
| gradlew.bat | ||
| mcp-inspector-config.json | ||
| README.md | ||
| settings.gradle.kts | ||
Kotlin MCP Server
A sample MCP server demonstrating multiple transport modes: STDIO, SSE (plain), and SSE (Ktor plugin).
Note: The SSE transport modes are provided for backward compatibility. For new projects, consider using the simple-streamable-server sample, which uses the recommended Streamable HTTP transport.
Overview
This sample registers a prompt, a tool, and a resource, then lets you choose how to expose them.
STDIO mode is the default and is best for process-based clients. The two SSE modes show how to
serve MCP over HTTP using either a manual Ktor routing setup or the built-in mcp { } Ktor plugin.
Prerequisites
- JDK 17+
- MCP Inspector (optional, for testing)
Build & Run
STDIO mode (default)
./gradlew run
Or explicitly:
./gradlew run --args="--stdio"
Connect with the MCP Inspector:
npx @modelcontextprotocol/inspector --config samples/kotlin-mcp-server/mcp-inspector-config.json --server stdio-server
SSE with Ktor plugin
./gradlew run --args="--sse-server-ktor 3002"
Connect with the MCP Inspector:
npx @modelcontextprotocol/inspector --config samples/kotlin-mcp-server/mcp-inspector-config.json --server sse-ktor-server
SSE with plain configuration
Known issue: This mode may not work correctly at this time.
./gradlew run --args="--sse-server 3001"
Connect with the MCP Inspector:
npx @modelcontextprotocol/inspector --config samples/kotlin-mcp-server/mcp-inspector-config.json --server sse-server
MCP Capabilities
Tools
| Name | Description |
|---|---|
kotlin-sdk-tool |
A test tool that returns a "Hello, world!" greeting. |
Prompts
| Name | Description |
|---|---|
Kotlin Developer |
Generates a prompt to develop a small Kotlin application for a given project name. |
Resources
| Name | URI | Description |
|---|---|---|
Web Search |
https://search.com/ |
A placeholder resource demonstrating resource handling. |