---
title: Use Access to Write to a Topic
slug: litmusedge/how-to-guides/flows-guides/use-access-to-write-to-a-topic
description: You can use an Access Publish node to write to a topic through the local message broker by using flows.
docTags: 
createdAt: 2023-06-06T18:17:33.000Z
---

You can use an **Access Publish **node to write to a topic through the local message broker by using flows. This guide uses the string message `Hi` to write to a topic.

#  Before you Begin

- Make sure you create an Access API account. See [Create an Access Account](docId\:ooFSO7dy11ARKZRYOxbOY) and [Manage API Accounts](docId:3frW37LYQLZRKaGGyROUb) for more information.
- Make sure you have created a flow to read from a topic. See [Use Access to Read from a Topic](docId:8SArcE33MDz1GYdbbyWDV) for more information.

**To write a topic using Access:**

1. In Litmus Edge, navigate to the **Flows Manager **and create a new flow. 
   See [Create a Flow](docId\:wh4ZihWF0PwMRYRbAZbco) to learn more. 
2. Drag the **Access Publish** and **Inject **nodes to the canvas and wire them together.
   ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/p8bDz90FNYOVUg5DqZMs0_image.png" size="70" width="707" height="148" position="center" caption="Access Publish node" showCaption="true"}
3. In Litmus Edge, navigate to **System **> **Tokens.**
4. Click the **Action menu **for the API account you created previously and select **Edit topics**.
   ![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/soVRVtUnE8YwNehhosaCr_image.png "System Tokens page")
5. From the *Edit topics* dialog box, do the following:
   - Enter `test-topic` in the **Write Topics** field, and click **Add Write Topic**.
     The topic name appears below the *Topic Name* field.
     Make sure that there are no spaces in the topic name.
   - Enter the same topic name(`test-topic`) in the **Read Topics** field, and click **Add Read Topic**.
     The topic name appears below the *Topic Name* field.
     Make sure that there are no spaces in the topic name.
   - Click **Update**.
     ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/Tly-ldZWH1MpXmvcNmSZU_image.png" size="70" width="613" height="297" position="center" caption="Edit topics dialog box" showCaption="true"}
6. Return to the **Flows **browser tab and double-click the **Access Publish **node. The *Edit Access Publish** **node* dialog box appears.
   - **Topic Name**: Paste the topic name `test-topic` you added in the Access **Topic Name **field.
   - Click the **Edit **icon next to the *Access* field.
     ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/rdajdjQFSdQw3uyOnGBNl_image.png" size="70" width="452" height="272" position="center" caption="Edit Access Publish node dialog box" showCaption="true"}
7. Return to the **System **>** Tokens **browser tab and do the following:
   - Click the **Action menu **for the API account you created previously and select **View API Key.**
   - Click the **Copy **icon next to the *API Key*.
     ![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/LAq65EwxGzLPNXkXUcmWC_image.png "Access accounts table")
8. Return to the *Edit Access Connect node* dialog box in the **Flows **browser tab and do the following:
   - **API Key: **Paste the API key you copied.
   - Click **Add **or **Update**.
     ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/PiOh8zafHdCFB2yOF9_8E_image.png" size="70" width="456" height="247" position="center" caption="Edit Access Connect node dialog box" showCaption="true"}
9. Click **Done.**
   ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/tHCI3fhRQV6J7XAOzBWMu_image.png" size="70" width="450" height="298" position="center" caption="Edit access-publish node dialog box" showCaption="true"}
10. Double-click the **Inject **node.
    The *Edit inject node* dialog box appears.
    - **msg.payload:** Select the **String **option from the drop-down list and enter `Hi` message in the **Payload **field.
    - **msg.topic:** Enter the name of the write topic (`test-topic`) you added in the *Access Write Topic* field.
    - **Repeat:** Select **interval **from the drop-down list.
    - **every:** Enter a value for how often to add a message.
    - Click **Done.**
      ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/0E8SUxV8GJKU1I1mbyixJ_image.png" size="70" width="777" height="885" position="center" caption="Edit inject node dialog box " showCaption="true"}
11. Drag an **Access Subscribe** node to the canvas and wire it to the **Debug **node.
    ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/HDePtjxGW2TzFk0UKG4bH_image.png" size="70" width="745" height="228" position="center" caption="Completed flows canvas" showCaption="true"}
12. Double-click the **Access Subscribe **node. 
    The *Edit access-subscribe node *dialog box appears.
    - **Topic Name: **Enter the name of the write topic you added in the *Access Write Topic* field.
    - **Access:** From the drop-down list, select the **Access Connect** you defined in the *Access-Publish* node.
    - Click **Done.**
      ::Image[]{src="https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/SqDQXeFYD0wwDlQVOrl09_image.png" size="70" width="452" height="293" position="center" caption="Edit access-subscribe node dialog box" showCaption="true"}
13. Click **Deploy**.
14. Expand the message window beneath the flow and click the **Debug **icon.
    ![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/wI_bbReMPplhSo_AuY11c_image.png "Flows canvas debug section")
15. Click the **Debug **node button to view the output in the *Debug message* window.
    ![](https://api.archbee.com/api/optimize/SSUUxKZUk9bFTEPNn_6Zo/9yiJJK7_PErFLTaXIK94f_image.png "View the flow output")