---
title: "Publish Data to Channel Using SDK"
url: https://docs.catalyst.zoho.com/en/cloud-scale/help/data-streams/implementation/publish-data-sdk/
description: "Publish data to Data Streams channels from server-side Catalyst functions using Java, JavaScript, or Python SDK."
last_updated: 2026-10-05T15:13:57Z
service: Cloud Scale
type: general
related_links:
  - name: "Create a Channel"
    url: /en/cloud-scale/help/data-streams/implementation/create-channel/
  - name: "Key Concepts - Publishing Methods"
    url: /en/cloud-scale/help/data-streams/key-concepts/#publishing-methods
  - name: "Advanced I/O Functions"
    url: /en/serverless/help/functions/advanced-io/
  - name: "Java SDK"
    url: /en/sdk/java/v1/cloud-scale/data-streams/
  - name: "JavaScript SDK"
    url: /en/sdk/javascript/v1/cloudscale/data-streams/
  - name: "Python SDK"
    url: /en/sdk/python/v1/cloud-scale/data-streams/
---

# Publish Data with SDK

To publish data to a Data Streams channel using the Catalyst SDK:

> **Note:** You must have a [Data Streams channel created](https://docs.catalyst.zoho.com/en/cloud-scale/help/data-streams/implementation/create-channel/) (you'll need the Channel ID) and an Advanced I/O function for publishing. Publishing requires admin-level authentication. The `publishData()` method can only be called from a server-side Catalyst function, not from client/browser applications.

1. Navigate to your Advanced I/O function directory and install the SDK for your runtime.

**JavaScript**

```bash

npm install @zcatalyst/datastreams

```

**Java**

Add the following dependency to your `pom.xml`:

```xml

<!-- Refer to SDK documentation for the latest version -->
<dependency>
    <groupId>com.zoho.catalyst</groupId>
    <artifactId>datastreams</artifactId>
    <version>LATEST</version>
</dependency>

```

**Python**

```bash

pip install zcatalyst-sdk

```

2. Initialize the SDK in your function code. The SDK automatically resolves project credentials from the execution environment.

**JavaScript**

```javascript

const { DataStreams } = require('@zcatalyst/datastreams');

module.exports = async (req, res) => {
    const datastreams = new DataStreams();
    // ... use datastreams methods
};

```

**Java**

```java

import com.zc.component.datastream.ZCDatastream;

ZCDatastream datastream = ZCDatastream.getInstance();

```

**Python**

```python

import zcatalyst_sdk

app = zcatalyst_sdk.initialize_app()
data_streams = app.datastreams()

```

> **Note:** Do not use `DataStreamsWebSocket` for publishing. That class is for subscribers only.

3. Use the `publishData()` method to send data to your channel.

**Method Parameters:**

<table class="content-table">
<thead>
<tr>
<th>Parameter</th>
<th>Type</th>
<th>Description</th>
</tr>
</thead>
<tbody>
<tr>
<td>`channelId`</td>
<td>string</td>
<td>The unique Channel ID from the console</td>
</tr>
<tr>
<td>`data`</td>
<td>string (JavaScript/Java)
string or dict (Python)</td>
<td>The data to publish</td>
</tr>
</tbody>
</table>

**Publish text data:**

**JavaScript**

```javascript

const result = await datastreams.publishData('YOUR_CHANNEL_ID', 'Hello, subscribers!');
console.log('Published successfully:', result);

```

**Java**

```java

Boolean result = datastream.publishData("YOUR_CHANNEL_ID", "Hello, subscribers!");
System.out.println("Published successfully: " + result);

```

**Python**

```python

result = data_streams.publish_data("YOUR_CHANNEL_ID", "Hello, subscribers!")
print("Published successfully:", result)

```

4. For structured data, stringify your JSON before publishing (JavaScript/Java) or pass a dictionary (Python).

**JavaScript**

```javascript

const payload = JSON.stringify({
    event: 'temperature_update',
    value: 23.5,
    unit: 'celsius',
    timestamp: Date.now()
});

const result = await datastreams.publishData('YOUR_CHANNEL_ID', payload);
console.log('Published successfully:', result);

```

> **Note:** Always use `JSON.stringify()`. Passing an object directly will throw a validation error.

**Java**

```java

String payload = new Gson().toJson(Map.of(
    "event", "temperature_update",
    "value", 23.5,
    "unit", "celsius",
    "timestamp", System.currentTimeMillis()
));

Boolean result = datastream.publishData("YOUR_CHANNEL_ID", payload);
System.out.println("Published successfully: " + result);

```

> **Note:** Use `Gson` or another JSON library to convert objects to strings.

**Python**

```python

# Python SDK accepts dictionaries directly
result = data_streams.publish_data("YOUR_CHANNEL_ID", {
    "event": "temperature_update",
    "value": 23.5,
    "unit": "celsius",
    "timestamp": time.time()
})
print("Published successfully:", result)

# Or pass a JSON string
import json
payload = json.dumps({"event": "order_placed", "order_id": 12345})
result = data_streams.publish_data("YOUR_CHANNEL_ID", payload)

```

> **Note:** Python SDK handles both dictionaries and JSON strings.

After publishing, data is sent to the Data Streams channel where it is distributed to all active subscribers in real-time. Publishing succeeds even if no subscribers are connected; data is retained for 48 hours.

### Common Errors

<table class="content-table">
<thead>
<tr>
<th>Error</th>
<th>Cause</th>
<th>Solution</th>
</tr>
</thead>
<tbody>
<tr>
<td>`Invalid Channel ID`</td>
<td>Wrong or non-existent channel</td>
<td>Verify Channel ID in console</td>
</tr>
<tr>
<td>`Data must be a string`</td>
<td>Passed object instead of string</td>
<td>Use `JSON.stringify()` (JavaScript/Java)</td>
</tr>
<tr>
<td>`Unauthorized`</td>
<td>Called from client-side</td>
<td>Move to server-side function</td>
</tr>
<tr>
<td>`Channel not found`</td>
<td>Channel deleted</td>
<td>Recreate channel or update Channel ID</td>
</tr>
</tbody>
</table>