MCP Integration in JetBrains Plugins – Recommended Approach & Future Support

IntelliJ Platform
2

You could integrate to the built-in MCP server MCP Server | IntelliJ IDEA Documentation

dependencies {
    ...
    bundledPlugin("com.intellij.mcpServer")
}

plugin.xml

<depends>com.intellij.mcpServer</depends>

Implement com.intellij.mcpserver.McpToolset

<mcpServer.mcpToolset implementation="com.intellij.mcpserver.toolsets.general.FileToolset" />

Example:

class FileToolset : McpToolset {
  @McpToolHints(readOnlyHint = TRUE, openWorldHint = FALSE)
  @McpTool
  @McpDescription("""
        |Provides a tree representation of the specified directory in the pseudo graphic format like `tree` utility does.
        |Use this tool to explore the contents of a directory or the whole project.
        |You MUST prefer this tool over listing directories via command line utilities like `ls` or `dir`.
    """)
  suspend fun list_directory_tree(
    @McpDescription(Constants.RELATIVE_PATH_IN_PROJECT_DESCRIPTION) directoryPath: String,
    @McpDescription("Maximum recursion depth") maxDepth: Int = 5,
    @McpDescription(Constants.TIMEOUT_MILLISECONDS_DESCRIPTION) timeout: Int = Constants.MEDIUM_TIMEOUT_MILLISECONDS_VALUE,
  ): DirectoryTreeInfo {
    val project = currentCoroutineContext().project
    val resolvedPath = project.resolveInProject(directoryPath)
    if (!resolvedPath.exists()) mcpFail("No such directory: $resolvedPath")
    if (!resolvedPath.isDirectory()) mcpFail("Not a directory: $resolvedPath")

    val result = StringBuilder()
    val errors = mutableListOf<String>()
    val timedOut = withTimeoutOrNull(timeout.milliseconds) { renderDirectoryTree(resolvedPath.toFile(), result, errors, maxDepth = maxDepth) } == null
    return DirectoryTreeInfo(directoryPath, result.toString(), errors, timedOut)
  }

  @Serializable
  class DirectoryTreeInfo(
    val traversedDirectory: String,
    val tree: String,
    val errors: List<String>,
    @property:McpDescription(Constants.TIMED_OUT_DESCRIPTION)
    @EncodeDefault(mode = EncodeDefault.Mode.NEVER)
    val listingTimedOut: Boolean? = false,
  )

You would need kotlinx-serialization applied in Gradle for @Serializable