Documentation for Nexus Standalone operations

docs/develop/java/index.mdx

@@ -66,6 +66,7 @@ From there, you can dive deeper into any of the Temporal primitives to start bui
 
 - [Quickstart](/develop/java/nexus/quickstart)
 - [Feature guide](/develop/java/nexus/feature-guide)
+- [Standalone Operations](/develop/java/nexus/standalone-operations)
 
 ## [Platform](/develop/java/platform)
 

docs/develop/java/nexus/index.mdx

@@ -25,4 +25,5 @@ Temporal Java SDK support for Nexus is [Generally Available](/evaluate/developme
 
 - [Quickstart](/develop/java/nexus/quickstart)
 - [Feature guide](/develop/java/nexus/feature-guide)
+- [Standalone Operations](/develop/java/nexus/standalone-operations)
 - [Nexus sync tutorial](https://learn.temporal.io/tutorials/nexus/nexus-sync-tutorial/)

docs/develop/java/nexus/standalone-operations.mdx

@@ -0,0 +1,165 @@
+---
+id: standalone-operations
+title: Standalone Nexus Operations - Java SDK
+sidebar_label: Standalone Operations
+toc_max_heading_level: 4
+keywords:
+  - standalone nexus operation
+  - nexus operation execution
+  - execute nexus operation
+  - nexus operation handle
+  - list nexus operations
+  - count nexus operations
+  - java sdk
+tags:
+  - Nexus
+  - Temporal Client
+  - Java SDK
+  - Temporal SDKs
+description: Execute Nexus Operations independently without a Workflow using the Temporal Java SDK.
+---
+
+:::tip SUPPORT, STABILITY, and DEPENDENCY INFO
+
+Temporal Java SDK support for Standalone Nexus Operations is at
+[Pre-release](/evaluate/development-production-features/release-stages#pre-release).
+
+All APIs are experimental and may be subject to backwards-incompatible changes.
+
+:::
+
+[Standalone Nexus Operations](/standalone-nexus-operation) let you run Nexus Operation Executions independently, without
+being orchestrated by a Workflow. Instead of calling a Nexus Operation from within a Workflow Definition using
+`Workflow.newNexusServiceStub()`, you execute a Standalone Nexus Operation directly from a Nexus service client created
+on the Temporal Client using `NexusServiceClient.newInstance()`.
+
+Standalone Nexus Operations use the same Nexus Service contract, Operation handlers, and Worker setup as
+Workflow-driven Operations — only the execution path differs. See the [Nexus feature guide](/develop/java/nexus/feature-guide) for details on
+[defining a Service contract](/develop/java/nexus/feature-guide#define-nexus-service-contract),
+[developing Operation handlers](/develop/java/nexus/feature-guide#develop-nexus-service-operation-handlers), and
+[registering a Service in a Worker](/develop/java/nexus/feature-guide#register-a-nexus-service-in-a-worker).
+
+This page focuses on the client-side APIs that are unique to Standalone Nexus Operations:
+
+- [Execute a Standalone Nexus Operation](#execute-operation)
+- [Start a Standalone Nexus Operation and Wait for the Result](#get-operation-result)
+- [List Standalone Nexus Operations](#list-operations)
+- [Count Standalone Nexus Operations](#count-operations)
+
+:::note
+This documentation uses source code from the
+[Java Nexus Standalone sample](https://github.com/temporalio/samples-java/tree/main/core/src/main/java/io/temporal/samples/nexusstandalone).
+
+:::
+
+## Execute a Standalone Nexus Operation {/* #execute-operation */}
+
+To execute a Standalone Nexus Operation, first create a
+[`NexusServiceClient`](https://www.javadoc.io/doc/io.temporal/temporal-sdk/latest/io/temporal/client/NexusServiceClient.html)
+using `NexusServiceClient.newInstance()`, bound to a specific Nexus Endpoint and Service. The endpoint must be
+pre-created on the server. Then call `start()` or `execute()` from application code (for example, a starter program),
+not from inside a Workflow Definition.
+
+`execute()` waits for the Operation to complete and returns the result.
+Both methods take a [`StartNexusOperationOptions`](https://www.javadoc.io/doc/io.temporal/temporal-sdk/latest/io/temporal/client/StartNexusOperationOptions.html)
+whose `id` is required — the SDK never generates one for you. `scheduleToCloseTimeout` is optional and defaults to the
+maximum allowed by the Temporal server.
+
+```java
+NexusServiceClient<GreetingNexusService> nexusClient =
+    NexusServiceClient.newInstance(GreetingNexusService.class, ENDPOINT_NAME, stubs, options);
+
+// Block until the operation completes and return its result.
+GreetingOutput greeting =
+    nexusClient.execute(
+        GreetingNexusService::greet,
+        new GreetingInput("World"),
+        StartNexusOperationOptions.newBuilder()
+            .setId("greet-" + UUID.randomUUID())
+            .setScheduleToCloseTimeout(Duration.ofSeconds(10))
+            .build());
+```
+
+`executeAsync()` is the same but returns a `CompletableFuture` instead of blocking.
+
+```java
+CompletableFuture<GreetingOutput> future =
+    nexusClient.executeAsync(
+        GreetingNexusService::greet, new GreetingInput("World"), options);
+GreetingOutput greeting = future.get();
+```
+
+See the full
+[starter sample](https://github.com/temporalio/samples-java/blob/main/core/src/main/java/io/temporal/samples/nexusstandalone/StandaloneClientStarter.java)
+for a complete example that executes both synchronous and asynchronous Operations, gets their results, and lists and
+counts Operations.
+
+## Start a Standalone Nexus Operation and Wait for the Result {/* #get-operation-result */}
+
+`start()` returns a
+[`NexusOperationHandle`](https://www.javadoc.io/doc/io.temporal/temporal-sdk/latest/io/temporal/client/NexusOperationHandle.html).
+Use `NexusOperationHandle.getResult()` to wait until the Operation completes and retrieve its result. This works for
+both synchronous and asynchronous Operations.
+
+```java
+// Start an operation and get a NexusOperationHandle.
+NexusOperationHandle<GreetingOutput> handle =
+    nexusClient.start(
+        GreetingNexusService::startGreeting, new GreetingInput("World"), options);
+
+// Block until the operation completes and retrieve its result.
+GreetingOutput greeting = handle.getResult();
+```
+
+If the Operation completed successfully, the result is returned. If the Operation failed, the failure is thrown as a
+`NexusOperationException`. Use `getResultAsync()` for a non-blocking `CompletableFuture`, or
+`getResult(long timeout, TimeUnit unit)` to bound the wait.
+
+## List Standalone Nexus Operations {/* #list-operations */}
+
+Use [`NexusClient.listNexusOperationExecutions()`](https://www.javadoc.io/doc/io.temporal/temporal-sdk/latest/io/temporal/client/NexusClient.html)
+to list Standalone Nexus Operation Executions that match a [List Filter](/list-filter) query. The result is a `Stream`
+of operation metadata entries.
+
+Note that `listNexusOperationExecutions()` is called on a `NexusClient`, not on the typed `NexusServiceClient`.
+
+```java
+String query = "Endpoint = \"" + ENDPOINT_NAME + "\"";
+nexusClient
+    .listNexusOperationExecutions(query)
+    .forEach(
+        op ->
+            System.out.printf(
+                "OperationId: %s, Operation: %s, Status: %s%n",
+                op.getOperationId(), op.getOperation(), op.getStatus()));
+```
+
+The `query` parameter accepts [List Filter](/list-filter) syntax. For example,
+`"Endpoint = 'my-endpoint' AND ExecutionStatus = 'Running'"`.
+
+## Count Standalone Nexus Operations {/* #count-operations */}
+
+Use [`NexusClient.countNexusOperationExecutions()`](https://www.javadoc.io/doc/io.temporal/temporal-sdk/latest/io/temporal/client/NexusClient.html)
+to count Standalone Nexus Operation Executions that match a [List Filter](/list-filter) query.
+
+Note that `countNexusOperationExecutions()` is called on a `NexusClient`, not on the typed `NexusServiceClient`.
+
+```java
+String query = "Endpoint = \"" + ENDPOINT_NAME + "\"";
+NexusOperationExecutionCount count = nexusClient.countNexusOperationExecutions(query);
+System.out.println("Total Nexus operations: " + count.getCount());
+```
+
+Passing a `GROUP BY` query (for example, `"GROUP BY ExecutionStatus"`) returns a count per group, available through
+`NexusOperationExecutionCount.getGroups()`.
+
+## Run Standalone Nexus Operations with Temporal Cloud {/* #run-standalone-nexus-operations-temporal-cloud */}
+
+The code samples referenced on this page build their client from a `ClientConfigProfile` loaded from a TOML profile, so
+the same code works against Temporal Cloud — just point the profile at your Cloud Namespace (or override the connection
+via `TEMPORAL_*` environment variables). No code changes are needed.
+
+For full details on connecting to Temporal Cloud, including Namespace creation, Nexus Endpoint setup, certificate
+generation, and authentication options, see
+[Make Nexus calls across Namespaces in Temporal Cloud](/develop/java/nexus/feature-guide#nexus-calls-across-namespaces-temporal-cloud)
+and [Connect to Temporal Cloud](/develop/java/client/temporal-client#connect-to-temporal-cloud).

sidebars.js

@@ -326,6 +326,7 @@ module.exports = {
               items: [
                 'develop/java/nexus/quickstart',
                 'develop/java/nexus/feature-guide',
+                'develop/java/nexus/standalone-operations',
               ],
             },
             {