---
title: "Post Message"
slug: "post-message"
updated: 2025-08-01T16:19:47Z
published: 2025-08-01T16:19:47Z
canonical: "documentation.decisions.com/post-message"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://documentation.decisions.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Post Message

| Step Details |
| --- |
| **Introduced in Version** | 3.0.0 |
| **Last Modified in Version** | 8.0.0 |
| **Location** | Integration > Message Queues |

The Post Message Step sends a message to the selected queue defined on the SETTINGS for the step. The Queue Name can be selected from the drop-down menu, or provided as part of a Message Queue Handler Flow. The message will be sent as a list of encoded bytes.

### Prerequisites

This Step requires Users to install the [About Messaging](https://documentation.decisions.com/docs/about-messaging#message-queues-and-decisions) Module before it will be available in the toolbox.

In V9 a dependency must be established before the steps will be available in the toolbox.

---

## Properties

#### Settings

| Property | Description | Data Type |
| --- | --- | --- |
| Queue Name | Name of queue to post message. | String |
| Get Queue from Flow | If enabled, the queue will be pulled from a connected queue in the flow. This option requires the flow to be created as a message queue handler. | Boolean |

#### Inputs

| Property | Description | Data Type |
| --- | --- | --- |
| Always Override Id | If enabled, this will override the given Id always. | Boolean |
| Message Body | The main part of the message to be posted. | List of Byte |
| Override Message Id | Message Id that overrides the original Id. | String |

#### Outputs

| Property | Description | Data Type |
| --- | --- | --- |
| Done |  |  |
|  | Message Id | Outputs the Id of the posted message. | String |

![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2025-07-31_11h40_59.png)

---

## Example Inputs and Outputs

| Always Override Id (Even if Null or Empty) | Message Body | Override Message Id | Output |
| --- | --- | --- | --- |
| False | YWJjDQpkZWYNCmdoaSAgIA0Kamts | False | Message Id: 08dadf96-196b-42aa-c360-f149cc047f0d |
| False | YWJjDQpkZWYNCmdoaSAgIA0Kamts | ABC123 | Message Id: ABC123 |
| True | YWJjDQpkZWYNCmdoaSAgIA0Kamts | NULL | Message Id: NULL |

---

## Common Errors

#### Missing Queue Selection

If a message queue is not selected under the SETTINGS category for the step, the step will throw an error. Ensure that a queue has been selected before running the step.

#### Exception Message:

```cpp
Exception Stack Trace: DecisionsFramework.Design.Flow.ErrorRunningFlowStep: Error running step Post Message 1[PostMessage] in flow [Testing]: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object.   at DecisionsFramework.Data.Messaging.MessageServerEndpoint.GetQueueByName(String queueName)   at DecisionsFramework.Data.Messaging.MessagingService.GetQueueByName(String queueName)   at DecisionsFramework.Data.Messaging.BaseMessagingStep.GetQueue(StepStartData stepData)   at DecisionsFramework.Data.Messaging.PostMessage.Run(StepStartData data)   at DecisionsFramework.Design.Flow.FlowStep.RunStepInternal(String flowTrackingID, String stepTrackingID, KeyValuePairDataStructure[] stepRunDataValues, AbstractFlowTrackingData trackingData)   at DecisionsFramework.Design.Flow.FlowStep.Start(String flowTrackingID, String stepTrackingID, FlowStateData data, AbstractFlowTrackingData trackingData, RunningStepData currentStepData)
   --- End of inner exception stack trace ---
```

---

Related Information

Forum Posts:

[Get Message from Message Queue](https://support.decisions.com/forum/topic309-get-message-from-message-queue.aspx)