docs/admin-api-functions.md

---
id: admin-api-functions
title: Manage Functions
sidebar_label: "Functions"
description: Learn how to manage functions using Pulsar CLI and admin APIs.
---

````mdx-code-block
import Tabs from '@theme/Tabs';
import TabItem from '@theme/TabItem';
````

:::tip

This page only shows **some frequently used operations**. For the latest and complete information, see the **reference docs** below.

:::

Category|Method|If you want to manage functions...
|---|---|---
[Pulsar CLI](reference-cli-tools.md) |[pulsar-admin](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/), which lists all commands, flags, descriptions, and more.| See the `functions` command
[Pulsar admin APIs](admin-api-overview.md)| {@inject: rest:REST API:/}, which lists all parameters, responses, samples, and more.|See the `/admin/v3/functions` endpoint
[Pulsar admin APIs](admin-api-overview.md)|[Java admin API](/api/admin/), which lists all classes, methods, descriptions, and more.|See the `functions` method of the `PulsarAdmin` object


You can perform the following operations on [functions](functions-overview.md/#what-are-pulsar-functions).
## Create a function

You can create a Pulsar function in cluster mode (deploy it on a Pulsar cluster) using Admin CLI, REST API or Java Admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`create`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=create) subcommand.

**Example**

```shell
pulsar-admin functions create \
    --tenant public \
    --namespace default \
    --name (the name of Pulsar Functions) \
    --inputs test-input-topic \
    --output persistent://public/default/test-output-topic \
    --classname org.apache.pulsar.functions.api.examples.ExclamationFunction \
    --jar /examples/api-examples.jar
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName|operation/registerFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
FunctionConfig functionConfig = new FunctionConfig();
functionConfig.setTenant(tenant);
functionConfig.setNamespace(namespace);
functionConfig.setName(functionName);
functionConfig.setRuntime(FunctionConfig.Runtime.JAVA);
functionConfig.setParallelism(1);
functionConfig.setClassName("org.apache.pulsar.functions.api.examples.ExclamationFunction");
functionConfig.setProcessingGuarantees(FunctionConfig.ProcessingGuarantees.ATLEAST_ONCE);
functionConfig.setTopicsPattern(sourceTopicPattern);
functionConfig.setSubName(subscriptionName);
functionConfig.setAutoAck(true);
functionConfig.setOutput(sinkTopic);
admin.functions().createFunction(functionConfig, fileName);
```

</TabItem>

</Tabs>
````

## Update a function

You can update a Pulsar function that has been deployed to a Pulsar cluster using Admin CLI, REST API or Java Admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`update`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=update) subcommand.

**Example**

```shell
pulsar-admin functions update \
    --tenant public \
    --namespace default \
    --name (the name of Pulsar Functions) \
    --output persistent://public/default/update-output-topic \
    # other options
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|PUT|/admin/v3/functions/:tenant/:namespace/:functionName|operation/updateFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
FunctionConfig functionConfig = new FunctionConfig();
functionConfig.setTenant(tenant);
functionConfig.setNamespace(namespace);
functionConfig.setName(functionName);
functionConfig.setRuntime(FunctionConfig.Runtime.JAVA);
functionConfig.setParallelism(1);
functionConfig.setClassName("org.apache.pulsar.functions.api.examples.ExclamationFunction");
UpdateOptions updateOptions = new UpdateOptions();
updateOptions.setUpdateAuthData(updateAuthData);
admin.functions().updateFunction(functionConfig, userCodeFile, updateOptions);
```

</TabItem>

</Tabs>
````

## Start a function

You can [start an instance of a function](#start-an-instance-of-a-function) or [start all instances of a function](#start-all-instances-of-a-function).
### Start an instance of a function

You can start a stopped function instance with `instance-id` using Admin CLI, REST API or Java Admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`start`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=start) subcommand.

```shell
pulsar-admin functions start \
    --tenant public \
    --namespace default \
    --name (the name of Pulsar Functions) \
    --instance-id 1
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/:instanceId/start|operation/startFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().startFunction(tenant, namespace, functionName, Integer.parseInt(instanceId));
```

</TabItem>

</Tabs>
````

### Start all instances of a function

You can start all stopped function instances using Admin CLI, REST API or Java Admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`start`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=start) subcommand.

**Example**

```shell
pulsar-admin functions start \
    --tenant public \
    --namespace default \
    --name (the name of Pulsar Functions) \
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/start|operation/startFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().startFunction(tenant, namespace, functionName);
```

</TabItem>

</Tabs>
````

## Stop a function

You can [stop an instance of a function](#stop-an-instance-of-a-function) or [stop all instances of a function](#stop-all-instances-of-a-function).

### Stop an instance of a function

You can stop a function instance with `instance-id` using Admin CLI, REST API or Java Admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`stop`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=stop) subcommand.

**Example**

```shell
pulsar-admin functions stop \
	--tenant public \
	--namespace default \
	--name (the name of Pulsar Functions) \
	--instance-id 1
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/:instanceId/stop|operation/stopFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().stopFunction(tenant, namespace, functionName, Integer.parseInt(instanceId));
```

</TabItem>

</Tabs>
````

### Stop all instances of a function

You can stop all function instances using Admin CLI, REST API or Java Admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`stop`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=stop) subcommand.

**Example**

```shell
pulsar-admin functions stop \
	--tenant public \
	--namespace default \
	--name (the name of Pulsar Functions)
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/stop|operation/stopFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().stopFunction(tenant, namespace, functionName);
```

</TabItem>

</Tabs>
````

## Restart a function

You can [restart an instance of a function](#restart-an-instance-of-a-function) or [restart all instances of a function](#restart-all-instances-of-a-function).

### Restart an instance of a function

Restart a function instance with `instance-id` using Admin CLI, REST API or Java Admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`restart`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=restart) subcommand.

**Example**

```shell
pulsar-admin functions restart \
	--tenant public \
	--namespace default \
	--name (the name of Pulsar Functions) \
	--instance-id 1
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/:instanceId/restart|operation/restartFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().restartFunction(tenant, namespace, functionName, Integer.parseInt(instanceId));
```

</TabItem>

</Tabs>
````

### Restart all instances of a function

You can restart all function instances using Admin CLI, REST API or Java admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`restart`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=restart) subcommand.

**Example**

```shell
pulsar-admin functions restart \
	--tenant public \
	--namespace default \
	--name (the name of Pulsar Functions)
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/restart|operation/restartFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().restartFunction(tenant, namespace, functionName);
```

</TabItem>

</Tabs>
````

## List all functions

You can list all Pulsar functions running under a specific tenant and namespace using Admin CLI, REST API or Java Admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`list`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=list) subcommand.

**Example**

```shell
pulsar-admin functions list \
	--tenant public \
	--namespace default
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace|operation/listFunctions?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().getFunctions(tenant, namespace);
```

</TabItem>

</Tabs>
````

## Delete a function

You can delete a Pulsar function that is running on a Pulsar cluster using Admin CLI, REST API or Java Admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`delete`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=delete) subcommand.

**Example**

```shell
pulsar-admin functions delete \
	--tenant public \
	--namespace default \
	--name (the name of Pulsar Functions)
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|DELETE|/admin/v3/functions/:tenant/:namespace/:functionName|operation/deregisterFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().deleteFunction(tenant, namespace, functionName);
```

</TabItem>

</Tabs>
````

## Get info about a function

You can get information about a Pulsar function currently running in cluster mode using Admin CLI, REST API or Java Admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`get`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=get) subcommand.

**Example**

```shell
pulsar-admin functions get \
	--tenant public \
	--namespace default \
	--name (the name of Pulsar Functions)
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace/:functionName|operation/getFunctionInfo?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().getFunction(tenant, namespace, functionName);
```

</TabItem>

</Tabs>
````

## Get status of a function

You can [get the status of an instance of a function](#get-status-of-an-instance-of-a-function) or [get the status of all instances of a function](#get-status-of-all-instances-of-a-function).

### Get status of an instance of a function

You can get the current status of a Pulsar function instance with `instance-id` using Admin CLI, REST API or Java Admin API.
````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`status`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=status) subcommand.

**Example**

```shell
pulsar-admin functions status \
	--tenant public \
	--namespace default \
	--name (the name of Pulsar Functions) \
	--instance-id 1
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace/:functionName/:instanceId/status|operation/getFunctionInstanceStatus?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().getFunctionStatus(tenant, namespace, functionName, Integer.parseInt(instanceId));
```

</TabItem>

</Tabs>
````

### Get status of all instances of a function

You can get the current status of a Pulsar function instance using Admin CLI, REST API or Java Admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`status`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=status) subcommand.

**Example**

```shell
pulsar-admin functions status \
	--tenant public \
	--namespace default \
	--name (the name of Pulsar Functions)
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace/:functionName/status|operation/getFunctionStatus?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().getFunctionStatus(tenant, namespace, functionName);
```

</TabItem>

</Tabs>
````

## Get stats of a function

You can [get stats of an instance of a function](#get-stats-of-an-instance-of-a-function) or [get stats of all instances of a function](#get-stats-of-all-instances-of-a-function).
### Get stats of an instance of a function

You can get the current stats of a Pulsar Function instance with `instance-id` using Admin CLI, REST API or Java admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`stats`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=stats) subcommand.

**Example**

```shell
pulsar-admin functions stats \
	--tenant public \
	--namespace default \
	--name (the name of Pulsar Functions) \
	--instance-id 1
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace/:functionName/:instanceId/stats|operation/getFunctionInstanceStats?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().getFunctionStats(tenant, namespace, functionName, Integer.parseInt(instanceId));
```

</TabItem>

</Tabs>
````

### Get stats of all instances of a function

You can get the current stats of a Pulsar function using Admin CLI, REST API or Java admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`stats`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=stats) subcommand.

**Example**

```shell
pulsar-admin functions stats \
	--tenant public \
	--namespace default \
	--name (the name of Pulsar Functions)
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace/:functionName/stats|operation/getFunctionStats?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().getFunctionStats(tenant, namespace, functionName);
```

</TabItem>

</Tabs>
````

## Trigger a function

You can trigger a specified Pulsar function with a supplied value using Admin CLI, REST API or Java admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`trigger`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=trigger) subcommand.

**Example**

```shell
pulsar-admin functions trigger \
	--tenant public \
	--namespace default \
	--name (the name of Pulsar Functions) \
	--topic (the name of input topic) \
	--trigger-value \"hello pulsar\"
	# or --trigger-file (the path of trigger file)
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/trigger|operation/triggerFunction?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().triggerFunction(tenant, namespace, functionName, topic, triggerValue, triggerFile);
```

</TabItem>

</Tabs>
````



## Put state associated with a function

You can put the state associated with a Pulsar function using Admin CLI, REST API or Java admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`putstate`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=putstate) subcommand.

**Example**

```shell
pulsar-admin functions putstate \
	--tenant public \
	--namespace default \
	--name (the name of Pulsar Functions) \
	--state "{\"key\":\"pulsar\", \"stringValue\":\"hello pulsar\"}"
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|POST|/admin/v3/functions/:tenant/:namespace/:functionName/state/:key|operation/putFunctionState?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
TypeReference<FunctionState> typeRef = new TypeReference<FunctionState>() {};
FunctionState stateRepr = ObjectMapperFactory.getThreadLocal().readValue(state, typeRef);
admin.functions().putFunctionState(tenant, namespace, functionName, stateRepr);
```

</TabItem>

</Tabs>
````

## Fetch state associated with a function

You can fetch the current state associated with a Pulsar function using Admin CLI, REST API or Java admin API.

````mdx-code-block
<Tabs groupId="api-choice"
  defaultValue="Admin CLI"
  values={[{"label":"Admin CLI","value":"Admin CLI"},{"label":"REST API","value":"REST API"},{"label":"Java","value":"Java"}]}>
<TabItem value="Admin CLI">

Use the [`querystate`](pathname:///reference/#/@pulsar:version_reference@/pulsar-admin/functions?id=querystate) subcommand.

**Example**

```shell
pulsar-admin functions querystate \
	--tenant public \
	--namespace default \
	--name (the name of Pulsar Functions) \
	--key (the key of state)
```

</TabItem>
<TabItem value="REST API">

{@inject: endpoint|GET|/admin/v3/functions/:tenant/:namespace/:functionName/state/:key|operation/getFunctionState?version=@pulsar:version_number@}

</TabItem>
<TabItem value="Java">

```java
admin.functions().getFunctionState(tenant, namespace, functionName, key);
```

</TabItem>

</Tabs>
````