> ## Documentation Index
> Fetch the complete documentation index at: https://docs.streamnative.io/llms.txt
> Use this file to discover all available pages before exploring further.
# Connect to your cluster using the Pulsar Python client
This example describes how to connect to a cluster using a Python client, and use the Python producer and consumer to produce and consume messages to and from a topic. The Python client supports connecting to a StreamNative cluster using either [OAuth2](#use-oauth2) or [API Keys](#use-apikeys) authentication.
This document assumes that you have created a StreamNative cluster and a service account, and have granted the service account `produce` and `consume` permissions to the namespace for the target topic.
## Prerequisites
Install both Python 3.0 or higher versions and the Pulsar Python client.
You can use the following command to install the Pulsar Python client:
```shell theme={null}
python -m pip install pulsar-client
```
## Connect to your cluster using API keys
To connect a StreamNative cluster using [API keys](/cloud/security/authentication/service-accounts/use-api-keys/api-keys-overview), follow these steps.
### Step 1: Get the broker service URL of your cluster
To get the service URL(s) of a StreamNative cluster, follow these steps.
1. Navigate to the **Cluster Dashboard** page by [switching to the cluster workspace](/cloud/get-started/cloud-console#switch-a-cluster).
2. On the **Cluster Dashboard** page, click **Details** tab.
3. You will see the available service URLs in the **Access Points** area.
4. You can click **Copy** at the end of the row of the service URL that you want to use.
### Step 2: Create an API key of your service account
Before using an API key, verify that the service account is authorized to access the resources, such as tenants, namespaces, and topics.
You can follow the instructions to [create an API key](/cloud/security/authentication/service-accounts/use-api-keys/api-keys-overview#using-api-keys-to-connect-to-your-cluster) for the service account you choose to use.
### Step 3: Connect to your cluster
For a complete example of how to connect to a cluster using the Pulsar Python client, see [Python client examples](https://github.com/streamnative/cloud-manager/tree/master/ui/src/data/code/clients/python).
#### Create a Python consumer to consume messages
You can create and configure a Python consumer to consume messages using Token authentication as follows. For more information about the placeholders in the code sample, see [parameters for Token authentication](/cloud/build/pulsar-clients/cloud-connect-python#parameters-for-token-authentication).
```python theme={null}
import pulsar
client = pulsar.Client("${brokerServiceURL}", authentication=pulsar.AuthenticationToken("${apikey}"))
consumer = client.subscribe("persistent://${tenant}/${namespace}/${topic}", "${subscription}",initial_position=pulsar.InitialPosition.Earliest)
for i in range(10):
msg = consumer.receive()
try:
print("Received message '{}' id='{}'".format(msg.data().decode('utf-8'), msg.message_id()))
consumer.acknowledge(msg)
except Exception:
consumer.negative_acknowledge(msg)
client.close()
```
#### Create a Python producer to produce messages
You can create and configure a Python producer to produce messages using Token authentication as follows. For more information about the placeholders in the code sample, see [parameters for Token authentication](/cloud/build/pulsar-clients/cloud-connect-python#parameters-for-token-authentication).
```python theme={null}
import pulsar
client = pulsar.Client("${brokerServiceURL}",
authentication=pulsar.AuthenticationToken("${apikey}"))
producer = client.create_producer("persistent://${tenant}/${namespace}/${topic}")
for i in range(10):
producer.send(('Hello-%d' % i).encode('utf-8'))
client.close()
```
#### Parameters for Token authentication
* `${brokerServiceURL}`: the broker service URL of your StreamNative cluster.
* `${apikey}`: an API key of your service account.
* `${tenant}/${namespace}/${topic}`: the full name of the topic for message production & consumption. It is a combination of the tenant name, the namespace name and the topic name.
* `${subscription}`: the name of the subscription that will determine how messages are delivered.
## Connect to your cluster using OAuth2 authentication
To connect a StreamNative cluster using OAuth2 authentication, follow these steps.
### Step 1: Get the broker service URL of your cluster
To get the service URL(s) of a StreamNative cluster, follow these steps.
1. Navigate to the **Cluster Dashboard** page by [switching to the cluster workspace](/cloud/get-started/cloud-console#switch-a-cluster).
2. On the **Cluster Dashboard** page, click **Details** tab.
3. You will see the available service URLs in the **Access Points** area.
4. You can click **Copy** at the end of the row of the service URL that you want to use.
### Step 2: Get the OAuth2 credential file of your service account
To get an OAuth2 credential file of a service account through the StreamNative Console, follow these steps.
1. On the left navigation pane, click **Service Accounts**.
2. In the row of the service account you want to use, in the **Key File** column, click the **Download** icon to download the OAuth2 credential file to your local directory.
The OAuth2 credential file should be something like this:
```json theme={null}
{
"type": "SN_SERVICE_ACCOUNT",
"client_id": "CLIENT_ID",
"client_secret": "CLIENT_SECRET",
"client_email": "test@auth.streamnative.cloud",
"issuer_url": "https://auth.streamnative.cloud"
}
```
### Step 3: Connect to your cluster
For a complete example of how to connect to a cluster through the Pulsar Python client, see [Python client examples](https://github.com/streamnative/cloud-manager/tree/master/ui/src/data/code/clients/python).
#### Create a Python consumer to consume messages
You can create and configure a Python consumer to consume messages using the OAuth2 credential file as follows. For more information about the placeholders in the code sample, see [parameters for OAuth2 authentication](/cloud/build/pulsar-clients/cloud-connect-python#parameters-for-oauth2-authentication).
```python theme={null}
import pulsar
params = '''
{
"issuer_url": "https://auth.streamnative.cloud/",
"private_key": "/YOUR-KEY-FILE-PATH", // Absolute path of your downloaded key file. Dont forget to remove this comment on the code
"audience": "urn:sn:pulsar:${orgName}:${instanceName}"
}
'''
client = pulsar.Client("${brokerServiceURL}", authentication=pulsar.AuthenticationOauth2(params))
consumer = client.subscribe("persistent://${tenant}/${namespace}/${topic}", "${subscription}",initial_position=pulsar.InitialPosition.Earliest)
for i in range(10):
msg = consumer.receive()
try:
print("Received message '{}' id='{}'".format(msg.data().decode('utf-8'), msg.message_id()))
consumer.acknowledge(msg)
except Exception:
consumer.negative_acknowledge(msg)
client.close()
```
#### Create a Python producer to produce messages
You can create and configure a Python producer to produce messages using the OAuth2 credential file as follows. For more information about the placeholders in the code sample, see [parameters for OAuth2 authentication](/cloud/build/pulsar-clients/cloud-connect-python#parameters-for-oauth2-authentication).
```python theme={null}
import pulsar
params = '''
{
"issuer_url": "https://auth.streamnative.cloud/",
"private_key": "/YOUR-KEY-FILE-PATH", // Absolute path of your downloaded key file
"audience": "urn:sn:pulsar:${orgName}:${instanceName}"
}
'''
client = pulsar.Client("${brokerServiceURL}", authentication=pulsar.AuthenticationOauth2(params))
producer = client.create_producer("persistent://${tenant}/${namespace}/${topic}")
for i in range(10):
producer.send(('Hello-%d' % i).encode('utf-8'))
client.close()
```
#### Parameters for OAuth2 authentication
* `private_key`: your downloaded OAuth2 credential. This parameter supports the following two pattern formats:
* `file:///path/to/file`: the path to your downloaded OAuth2 credential file.
* `data:application/json;base64,`: the credential file content encoded into Base64 format.
* `audience`: the [Uniform Resource Name (URN)](/cloud/references/glossary#urn), which is a combination of the `urn:sn:pulsar`, your organization name, and your Pulsar instance name.
* `${orgName}`: the name of your [organization](/cloud/references/glossary#organization).
* `${instanceName}`: the name of your [instance](/cloud/references/glossary#instance).
* `${brokerServiceURL}`: the broker service URL of your StreamNative cluster.
* `${tenant}/${namespace}/${topic}`: the full name of the topic for message production & consumption. It is a combination of the tenant name, the namespace name and the topic name.
* `${subscription}`: the name of the subscription that will determine how messages are delivered.