How do I create a Custom module in Vtiger CRM?

Step 1: Accessing the Module Management Settings

1. Log in to the CRM.
2. Click the User Menu on the top right corner of the screen.
3. Click Settings. You will land on the Settings page.
4. Look for the Module Management section.
5. Click Module Builder. A Create New Module window opens.

Step 2: Specifying the details for the new module 

6. Enter or select the following information to add information for the new module:
   1. Module Label - Specify the module name. For example, Workforce
   2. Singular Module Label - Specify the module name in the singular form. For example, if the module name is Contacts, then Contact is its singular form. The singular form of Workforce is Workforce.
   3. Select App Category - Select the app under which you want to create the module. For instance, you can create Workforce under Projects.
   4. Record Identifier - Specify the label by which you want to identify the module’s records. For example, Workforce Records are identified by Workforce Name.
7. Click the Create button.

Step 3: Creating Blocks and Fields

8. Click the +Add Block button to create a new block. An Add Block window opens.
   1. Enter the Block Name.
   2. Select Add After from the drop-down. Choose the existing block, after which you want to add the new block. 
   3. Click Save.
9. Click the +Add Custom Field button in the newly created block.
   1. Select the Field type. For example, Phone for a phone number, Text for a name, etc.
   2. Enter the Label name. 
   3. Enter Min characters allowed.
   4. Enter Max characters allowed.
   5. Enter a default value for the field.
   6. Set the field properties:
      1. Mandatory Field - If enabled, entering a value for the field becomes mandatory.
      2. +Quick Create - The field becomes available under Quick Create if enabled. 
      3. Key Field View - If enabled, the field appears in the Key Fields section of a contact’s Summary View.
      4. Header View -If enabled, the field appears in the Header section of a contact’s Summary View.
      5. Mass Edit - If enabled, you can perform a mass edit action on the field.
10. Click Save. A success message will appear.
11. Click the Next button.

Step 4: Choose the Default Filter

12. Click on the space provided under Choose columns and order (Max 16).
13. Select fields from the list to add to the List View.
14. Click the Next button.

Step 5: Build a relationship between the custom module and other modules 

15. Click the +Add Relationship button (on the left, under the tabs).
16. Choose the module you want to create a relationship with from the Select related module drop-down.
    1. Considering the example above, you must choose Projects from the drop-down. Projects become the related module.
17. Pick a relationship type under Select relationship type.
18. Specify the names of the related and custom module field or tab that must appear in the module’s records. 
19. Click Save.