chore: add EU API URl to docs & infer web URL (#883)

* Add API URL of new EU instance to READMEs:
https://docs.smith.langchain.com/reference/cloud_architecture_and_scalability#architecture
* Infer the web/host URL from the EU API URL

js/README.md

@@ -53,6 +53,7 @@ Tracing can be activated by setting the following environment variables or by ma
 ```typescript
 process.env["LANGSMITH_TRACING"] = "true";
 process.env["LANGCHAIN_ENDPOINT"] = "https://api.smith.langchain.com";
+// process.env["LANGCHAIN_ENDPOINT"] = "https://eu.api.smith.langchain.com"; // If signed up in the EU region
 process.env["LANGCHAIN_API_KEY"] = "<YOUR-LANGSMITH-API-KEY>";
 // process.env["LANGCHAIN_PROJECT"] = "My Project Name"; // Optional: "default" is used if not set
 ```

js/package.json

@@ -261,4 +261,4 @@
     },
     "./package.json": "./package.json"
   }
-}
+}

js/src/client.ts

@@ -481,6 +481,9 @@ export class Client {
     } else if (this.apiUrl.split(".", 1)[0].includes("dev")) {
       this.webUrl = "https://dev.smith.langchain.com";
       return this.webUrl;
+    } else if (this.apiUrl.split(".", 1)[0].includes("eu")) {
+      this.webUrl = "https://eu.smith.langchain.com";
+      return this.webUrl;
     } else {
       this.webUrl = "https://smith.langchain.com";
       return this.webUrl;

js/src/tests/client.test.ts

@@ -115,6 +115,15 @@ describe("Client", () => {
       expect(result).toBe("https://dev.smith.langchain.com");
     });
 
+    it("should return 'https://eu.smith.langchain.com' if apiUrl contains 'eu'", () => {
+      const client = new Client({
+        apiUrl: "https://eu.smith.langchain.com/api",
+        apiKey: "test-api-key",
+      });
+      const result = (client as any).getHostUrl();
+      expect(result).toBe("https://eu.smith.langchain.com");
+    });
+
     it("should return 'https://smith.langchain.com' for any other apiUrl", () => {
       const client = new Client({
         apiUrl: "https://smith.langchain.com/api",

python/README.md

@@ -70,6 +70,7 @@ Tracing can be activated by setting the following environment variables or by ma
 import os
 os.environ["LANGSMITH_TRACING_V2"] = "true"
 os.environ["LANGSMITH_ENDPOINT"] = "https://api.smith.langchain.com"
+# os.environ["LANGSMITH_ENDPOINT"] = "https://eu.api.smith.langchain.com" # If signed up in the EU region
 os.environ["LANGSMITH_API_KEY"] = "<YOUR-LANGSMITH-API-KEY>"
 # os.environ["LANGSMITH_PROJECT"] = "My Project Name" # Optional: "default" is used if not set
 ```

python/langsmith/client.py

@@ -654,6 +654,8 @@ def _host_url(self) -> str:
             elif parsed_url.path.endswith("/api"):
                 new_path = parsed_url.path.rsplit("/api", 1)[0]
                 link = urllib_parse.urlunparse(parsed_url._replace(path=new_path))
+            elif parsed_url.netloc.startswith("eu."):
+                link = "https://eu.smith.langchain.com"
             elif parsed_url.netloc.startswith("dev."):
                 link = "https://dev.smith.langchain.com"
             else:

python/tests/unit_tests/test_client.py

@@ -898,6 +898,9 @@ def test_host_url(_: MagicMock) -> None:
     client = Client(api_url="http://localhost:8000", api_key="API_KEY")
     assert client._host_url == "http://localhost"
 
+    client = Client(api_url="https://eu.api.smith.langchain.com", api_key="API_KEY")
+    assert client._host_url == "https://eu.smith.langchain.com"
+
     client = Client(api_url="https://dev.api.smith.langchain.com", api_key="API_KEY")
     assert client._host_url == "https://dev.smith.langchain.com"