Resources

• Use resource(uri) for a fixed resource, or resourceTemplate(uriTemplate) for a {variable} URI template.

• Add metadata: name, title, description, mimeType, size.

• Provide the read logic, returning Either[ResourceError, List[ResourceContents]]:

  • handle — synchronous read logic.

  • handleWithHeaders — synchronous read logic that also receives the request headers.

  • serverLogic — effectful read logic, with the request headers.

• Register with .addResource / .addResourceTemplate. Subscriptions are wired with .withSubscriptions.

import chimp.server.*
import chimp.protocol.ResourceContents

val readme = resource("file:///readme.txt")
  .name("readme")
  .mimeType("text/plain")
  .handle(() => Right(List(ResourceContents.Text(uri = "file:///readme.txt", text = "Hello!", mimeType = Some("text/plain")))))

val item = resourceTemplate("item://{id}")
  .name("item")
  .handle((vars, uri) => Right(List(ResourceContents.Text(uri = uri, text = s"item ${vars("id")}"))))

val endpoint = McpServer(resources = List(readme), resourceTemplates = List(item)).endpoint(List("mcp"))

Returning Left(ResourceError(...)) (or reading an unknown URI) responds with a JSON-RPC error carrying the offending uri.