Reverse Proxy Support (#1318)

* use configured server URL for all CallBuilder requests

Author: Ryang-21

CHANGELOG.md

@@ -12,7 +12,7 @@ A breaking change will get clearly marked in this log.
 
 ### Fixed
 * X-App-Name and X-App-Version headers are now included when using `CallBuilder.stream()` ([#1317](https://github.com/stellar/js-stellar-sdk/pull/1317)).
-
+* `CallBuilder` now correctly uses the configured server URL for all requests, including pagination and linked resources. Previously, URLs returned by Horizon in `_links` would bypass reverse proxies ([#1318](https://github.com/stellar/js-stellar-sdk/pull/1318)).
 
 ## [v14.4.3](https://github.com/stellar/js-stellar-sdk/compare/v14.4.2...v14.4.3)
 

src/horizon/call_builder.ts

@@ -398,13 +398,9 @@ export class CallBuilder<
   private async _sendNormalRequest(initialUrl: URI) {
     let url = initialUrl;
 
-    if (url.authority() === "") {
-      url = url.authority(this.url.authority());
-    }
-
-    if (url.protocol() === "") {
-      url = url.protocol(this.url.protocol());
-    }
+    // Always use the configured server's authority and protocol.
+    // Horizon returns absolute URLs in _links that would bypass reverse proxies.
+    url = url.authority(this.url.authority()).protocol(this.url.protocol());
 
     return this.httpClient
       .get(url.toString())

test/integration/client_headers.test.ts

@@ -127,6 +127,91 @@ describe("integration tests: client headers", () => {
       .call();
   });
 
+  it("uses configured server URL for pagination links (reverse proxy support)", async () => {
+    let server: http.Server;
+    let requestCount = 0;
+
+    const requestHandler = (
+      _request: http.IncomingMessage,
+      response: http.ServerResponse,
+    ) => {
+      requestCount++;
+
+      if (requestCount === 1) {
+        // First request: return a response with _links pointing to a DIFFERENT host
+        // This simulates what Horizon does - it returns its own hostname in links
+        response.setHeader("Content-Type", "application/json");
+        response.end(
+          JSON.stringify({
+            _embedded: {
+              records: [{ id: "1", paging_token: "token1" }],
+            },
+            _links: {
+              // These links point to a different host (horizon.stellar.org)
+              // The SDK should rewrite these to use localhost:${port}
+              next: {
+                href: `https://horizon.stellar.org/operations?cursor=token1`,
+              },
+              prev: {
+                href: `https://horizon.stellar.org/operations?cursor=token0`,
+              },
+            },
+          }),
+        );
+      } else if (requestCount === 2) {
+        // Second request (pagination): verify it came to our server, not horizon.stellar.org
+        response.setHeader("Content-Type", "application/json");
+        response.end(
+          JSON.stringify({
+            _embedded: {
+              records: [{ id: "2", paging_token: "token2" }],
+            },
+            _links: {
+              next: {
+                href: `https://horizon.stellar.org/operations?cursor=token2`,
+              },
+              prev: {
+                href: `https://horizon.stellar.org/operations?cursor=token1`,
+              },
+            },
+          }),
+        );
+        server.close();
+      }
+    };
+
+    server = http.createServer(requestHandler);
+
+    await new Promise<void>((resolve, reject) => {
+      server.listen(port, (err?: Error) => {
+        if (err) {
+          reject(err);
+          return;
+        }
+        resolve();
+      });
+    });
+
+    const horizonServer = new Horizon.Server(`http://localhost:${port}`, {
+      allowHttp: true,
+    });
+
+    // First request
+    const firstPage = await horizonServer.operations().call();
+    expect(firstPage.records).toHaveLength(1);
+    expect(firstPage.records[0]!.id).toBe("1");
+
+    // Second request via .next() - this should go to localhost, not horizon.stellar.org
+    // If the fix works, requestCount will be 2. If not, this will timeout/fail
+    // because the request would go to horizon.stellar.org instead of our mock server
+    const secondPage = await firstPage.next();
+    expect(secondPage.records).toHaveLength(1);
+    expect(secondPage.records[0]!.id).toBe("2");
+
+    // Verify both requests came to our server
+    expect(requestCount).toBe(2);
+  });
+
   it("sends appName and appVersion via headers for HTTP requests", async () => {
     let server: http.Server;
 

test/unit/server/horizon/server.test.ts

@@ -802,7 +802,7 @@ describe("server.js non-transaction tests", () => {
             }
             if (
               url.match(
-                /^https:\/\/horizon.stellar.org\/transactions\/c585b8764b28be678c482f8b6e87e76e4b5f28043c53f4dcb7b724b4b2efebc1\/operations/,
+                /^https:\/\/horizon-live\.stellar\.org:1337\/transactions\/c585b8764b28be678c482f8b6e87e76e4b5f28043c53f4dcb7b724b4b2efebc1\/operations/,
               )
             ) {
               return Promise.resolve({ data: { operations: [] } });
@@ -830,6 +830,7 @@ describe("server.js non-transaction tests", () => {
       describe("with options", () => {
         it("requests the correct endpoint", async () => {
           mockGet.mockImplementation((url: string) => {
+            console.log("URL called:", url);
             if (
               url.includes(
                 "https://horizon-live.stellar.org:1337/ledgers/7952722/transactions?cursor=b&limit=1&order=asc",
@@ -839,7 +840,7 @@ describe("server.js non-transaction tests", () => {
             }
             if (
               url.match(
-                /^https:\/\/horizon.stellar.org\/transactions\/c585b8764b28be678c482f8b6e87e76e4b5f28043c53f4dcb7b724b4b2efebc1\/operations\?limit=1/,
+                /^https:\/\/horizon-live\.stellar\.org:1337\/transactions\/c585b8764b28be678c482f8b6e87e76e4b5f28043c53f4dcb7b724b4b2efebc1\/operations\?limit=1/,
               )
             ) {
               return Promise.resolve({ data: { operations: [] } });
@@ -940,7 +941,7 @@ describe("server.js non-transaction tests", () => {
         mockGet.mockImplementation((url: string) => {
           if (
             url.includes(
-              "https://horizon-live.stellar.org:1337/transactions/6bbd8cbd90498a26210a21ec599702bead8f908f412455da300318aba36831b0",
+              "https://horizon-live.stellar\.org:1337/transactions/6bbd8cbd90498a26210a21ec599702bead8f908f412455da300318aba36831b0",
             )
           ) {
             return Promise.resolve({ data: singleTranssactionResponse });