Publish Data with SDK

# 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 (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.

npm install @zcatalyst/datastreams

Add the following dependency to your pom.xml:

<dependency>
    <groupId>com.zoho.catalyst</groupId>
    <artifactId>datastreams</artifactId>
    <version>LATEST</version>
</dependency>

pip install zcatalyst-sdk

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

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

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

import com.zc.component.datastream.ZCDatastream;

ZCDatastream datastream = ZCDatastream.getInstance();

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)<br>string or dict (Python)</td>
<td>The data to publish</td>
</tr>
</tbody>
</table>

**Publish text data:**

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

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

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).

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.

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 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>

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

Note: You must have a Data Streams channel created (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.

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

JavaScript

copy

         npm install @zcatalyst/datastreams

Java

Add the following dependency to your pom.xml:

copy

    com.zoho.catalyst
    datastreams
    LATEST

Python

copy

         pip install zcatalyst-sdk

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

JavaScript

copy

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

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

Java

copy

         import com.zc.component.datastream.ZCDatastream;

ZCDatastream datastream = ZCDatastream.getInstance();

Python

copy

         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.

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

Method Parameters:

Parameter	Type	Description
channelId	string	The unique Channel ID from the console
data	string (JavaScript/Java) string or dict (Python)	The data to publish

Publish text data:

JavaScript

copy

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

Java

copy

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

Python

copy

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

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

JavaScript

copy

         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

copy

         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

copy

         # 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.

Common Errors

Error	Cause	Solution
Invalid Channel ID	Wrong or non-existent channel	Verify Channel ID in console
Data must be a string	Passed object instead of string	Use JSON.stringify() (JavaScript/Java)
Unauthorized	Called from client-side	Move to server-side function
Channel not found	Channel deleted	Recreate channel or update Channel ID

Last Updated 2026-10-05 20:43:57 +0530 IST

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Create a Channel Key Concepts - Publishing Methods Advanced I/O Functions Java SDK JavaScript SDK Python SDK