fix: fix root request path encoding

CHANGELOG.md

@@ -3,6 +3,7 @@
 ## Pending
 
 ### Update
+- fix: make `RootRequestBuilder` request the Horizon root endpoint as `/` instead of the percent-encoded `/%2F` path.
 - fix: make Horizon request builder URL generation idempotent so repeated `buildUri()` or `execute()` calls on the same builder do not duplicate path segments.
 - docs: add an [Agent Skill](https://agentskills.io/) for the Java Stellar SDK under `skills/`, plus Claude Code plugin manifests in `.claude-plugin/`. The skill gives AI coding agents concise, Stellar-specific guidance (transactions, operations, Horizon, Soroban, XDR/SCVal, and SEP protocols) when generating application code with `stellar-sdk`.
 - feat: add SEP-0046, SEP-0047, and SEP-0048 contract introspection support. New `ContractMeta`, `ContractSpec`, and `ContractInfo` wrappers under `org.stellar.sdk.contract` parse contract Wasm metadata and interface specs locally. `SorobanServer` adds `getContractWasm`, `getContractWasmByHash`, `getContractMeta`, `getContractSpec`, and `getContractInfo` for RPC-backed retrieval.

src/main/java/org/stellar/sdk/requests/RootRequestBuilder.java

@@ -9,7 +9,7 @@
 /** Builds requests connected to root. */
 public class RootRequestBuilder extends RequestBuilder {
   public RootRequestBuilder(OkHttpClient httpClient, HttpUrl serverURI) {
-    super(httpClient, serverURI, "/");
+    super(httpClient, serverURI, null);
   }
 
   /**

src/test/java/org/stellar/sdk/requests/RootRequestBuilderTest.java

@@ -0,0 +1,45 @@
+package org.stellar.sdk.requests;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import java.io.IOException;
+import okhttp3.mockwebserver.MockResponse;
+import okhttp3.mockwebserver.MockWebServer;
+import okhttp3.mockwebserver.RecordedRequest;
+import org.junit.Test;
+import org.stellar.sdk.Server;
+import org.stellar.sdk.exception.BadRequestException;
+
+public class RootRequestBuilderTest {
+  @Test
+  public void testRoot() {
+    Server server = new Server("https://horizon-testnet.stellar.org");
+
+    assertEquals("https://horizon-testnet.stellar.org/", server.root().buildUri().toString());
+
+    server.close();
+  }
+
+  @Test
+  public void testRootRequestPath() throws IOException, InterruptedException {
+    MockWebServer mockWebServer = new MockWebServer();
+    mockWebServer.enqueue(new MockResponse().setResponseCode(404));
+    mockWebServer.start();
+    Server server = new Server(mockWebServer.url("").toString());
+
+    try {
+      server.root().execute();
+      fail("expected root request to return 404");
+    } catch (BadRequestException e) {
+      assertEquals(404, e.getCode().intValue());
+
+      RecordedRequest request = mockWebServer.takeRequest();
+      assertEquals("GET", request.getMethod());
+      assertEquals("/", request.getPath());
+    } finally {
+      server.close();
+      mockWebServer.shutdown();
+    }
+  }
+}