Hello everyone!
Welcome back to another week of
Kaizen.
In this post, we explore the
Multi-Module Lookup (MML) field in the
Appointments module of Zoho CRM. You learn what an MML field is, how it works, and how to use it with
Zoho CRM APIs.
Table of Contents:
- What is a Multi-Module Lookup (MML) Field in Zoho CRM?
- Use Cases for MML
- How the "Appointment For" (MML) field in the "Appointments" module works?
- Creating a Record in the Appointments Module Using the Insert Records API
- Retrieving a Record from the Appointments Module Using the Get Records API
- Multi-module Lookup Using the COQL API
- Multi-module Lookup Using the Bulk Read API
- Frequently Asked Questions
What is a Multi-Module Lookup (MML) Field in Zoho CRM?
A Multi-Module Lookup (MML) field in Zoho CRM allows you to create a one-to-one relationship between a record in one module and a record from one of multiple other modules. Unlike a normal lookup field, which references a single module, an MML field can dynamically reference records from multiple modules.
Without the MML field, users must create multiple lookup fields for each module, which complicates the CRM layout and user experience.
Note:
- The multi-module lookup (multi_module_lookup) data type was introduced in Zoho CRM API version 3.
- Currently, the MML field is available as a system-defined field named Appointment For in the Appointments module.
- The Appointment For field supports lookups to both Contacts and custom modules.
- You cannot create a custom MML field in Zoho CRM.
Data Model Representation
MML's Data Model RepresentationUse Cases for MML
Zylker Healthcare is a multi-specialty hospital that uses Zoho CRM to maintain its appointment scheduling process.
In this setup, Zylker maintains two key modules:
- Contacts module - Stores records of physicians and surgeons, including attending physicians, specialists, and surgeons who diagnose and refer patients.
- Patients module - A custom module used to maintain records of all patients.
To improve the appointment booking process, Zylker uses the "Appointment For" Multi-Module Lookup (MML) field in the Appointments module. This field lets Zylker manage an appointment with either a Physician/Surgeon or a Patient, eliminating the need for multiple lookup fields.
How the "Appointment For" (MML) field in the "Appointments" module works?
- When creating an appointment, the user selects the "Appointment For" field.
- The field displays records based on the selected module, either the Contacts or Patients.
- The user selects the appropriate record (Contact or Patients) for the appointment.
- A related list is automatically created in the selected module (Contact or Patients) as the Open Activities / Closed Activities to display all appointments associated with that record.
Creating a Record in the Appointments module using the Insert Records API
Before creating a record in the Appointments module via the Insert Records API, make sure you know the API names of the system-defined mandatory fields. These fields are required to create an appointment successfully.
System-defined Mandatory Fields:
- Appointment_For (MML field)
- Service_Name
- Appointment_Start_Time
- Appointment_Name
- Member
- Location
The below image shows how these system-defined mandatory fields appear in the Appointments module UI:
System-defined mandatory keys in the Appointments Module in UI view.API calls you have to make before creating a record:
Before inserting a record into the Appointments module, it is important to know the API names of the fields and their parent modules.
Request URL : {api-domain}/crm/v8/settings/modules
Request Method : GET
Sample Response :
In the API response, search for the module with "module_name": "Appointments" and check the value of the "api_name" key to get the API name of the module. This is the name you will use in all related API calls.
ii. Use the
GET - Fields Metadata API and get fields metadata for the
Appointments module. Here, you can find the
API names of the mandatory fields along with other fields present in the Appointments module.
Below is the API call & response for the multi-module lookup field along with other mandatory fields.
Request URL : {api-domain}/crm/v8/settings/fields?module=Appointments__s
Request Method : GET
Sample Response :
Note: The above image highlights only the key properties of the Multi-Module Lookup (MML) field from the field metadata response. The complete API response contains additional properties not shown here.
In the response:
- The multi-module lookup field is identified by the key "data_type" with the value "multi_module_lookup".
- The associated modules supported by the MML field (e.g., Contacts, Patients) are listed under the "modules" key.
- Other mandatory fields like Service Name, Appointment Name, and Appointment Start Time can be identified by "system_mandatory": true.
The keys of the above multi_module_lookup JSON object are explained below:
"multi_module_lookup": { "display_label": "Appointments", // Display label of the module where the MML field is used "api_name": "Appointments__s", // API name of the Appointments module "modules": [ //List of modules associated with the Appointments module. { "api_name": "Contacts", //API name of the associated module "module_name": "Contacts", // Display Name of the module "id": "5725767000000002179" //Unique ID of the module }, { "api_name": "Patients", //API name of the associated custom module "module_name": "Patients", //Display label of the module "id": "5725767000006473007" //Unique module ID } } ] },
|
Note:
- You cannot add or remove modules from the Multi-Module Lookup (MML) field using APIs. These actions are only available through the Zoho CRM UI.
- Once a module is disassociated from the MML field, existing records associated with that module will remain in the Appointments module, and you will no longer be able to associate newly created records from the disassociated module using the MML field.
The remaining system-defined mandatory fields, along with their API names, are listed below.
System-defined Mandatory Field Names | System-defined Mandatory Field API Names |
Service Name | Service_Name |
Appointment Start Time | Appointment_Start_Time |
Appointment Name | Appointment_Name |
Member | Owner |
Location | Location
|
Note: The system-defined mandatory fields can be identified by "system_mandatory": true.
Search the system-defined mandatory field names and get their API names.
With the field API names, use the following request and sample input body to create a record in the Appointments module using the Insert Records API.
Request URL : {{api-domain}}/crm/v8/Appointments__s
Request Method : POST
Request Body :
{ "data": [ { "Appointment_Name": "General Consultation", "Owner": { "name": "Patricia Boyle", "id": "5725767000000411001", }, "Appointment_Start_Time": "2025-04-15T13:00:00-07:00", "Appointment_End_Time": "2025-04-15T13:30:00-07:00", "Appointment_For": { "module": { "api_name": "Contacts", "id": "5725767000000002179" }, "name": "John Doe", "id": "5725767000005607020" }, "Service_Name": { "name": "General Check-up", "id": "5725767000006387029" }, "Location": "Business Address" } ] }
|
Sample Response:
{ "data": [ { "code": "SUCCESS", "details": { "Modified_Time": "2025-05-06T20:33:42-07:00", "Modified_By": { "name": "Patricia Boyle", "id": "5725767000000411001" }, "Created_Time": "2025-05-06T20:33:42-07:00", "id": "5725767000006390001", //Unique ID if the newly created record. Please note that this record ID will be used in the following API get and update operations. "Created_By": { "name": "Patricia Boyle", "id": "5725767000000411001" } }, "message": "record added", "status": "success" } ] }
|
Note:
Only Contacts and custom modules are supported in the Multi-Module Lookup field. If you try to associate a new record with a module that has been removed from the MML field or an unsupported module in the MML field, the following error will be thrown.
Retrieving a Record from the Appointments Module Using the Get Records API
Request URL : {{api-domain}}/crm/v8/Appointments__s/5725767000006390001
Request Method: GET
Request Response:
{ "data": [ { "Owner": { "name": "Patricia Boyle", "id": "5725767000000411001", }, "$currency_symbol": "$", "Address": null, "Appointment_Start_Time": "2025-04-15T13:00:00-07:00", "Cancellation_Reason": null, "$field_states": null, "Appointment_For": { "module": { "api_name": "Contacts", "id": "5725767000000002179" }, "name": "John Doe", "id": "5725767000005607020" }, "Rescheduled_To": null, "$sharing_permission": "full_access", "Reschedule_Reason": null, "Additional_Information": null, "Last_Activity_Time": null, "Cancelled_Time": null, "Cancellation_Note": null, "Modified_By": { "name": "Patricia Boyle", "id": "5725767000000411001", }, "Reschedule_Count": 0, "Rescheduled_By": null, "id": "5725767000006390001", "Rescheduled_Time": null, "Remind_At": null, "Appointment_End_Time": "2025-04-15T13:30:00-07:00", "Status": "Overdue", "Modified_Time": "2025-05-06T20:04:38-07:00", "Service_Name": { "name": "General Check-up", "id": "5725767000006387029" }, "Created_Time": "2025-05-06T20:04:38-07:00", "testing": null, "Rescheduled_From": null, "Cancelled_By": null, "$editable": true, "Appointment_Name": "General Consultation", "Duration": 30, "Record_Status__s": "Available", "Created_By": { "name": "Patricia Boyle", "id": "5725767000000411001", }, "Tag": [], "Location": "Business Address", "Reschedule_Note": null } ] }
|
Request URL : {{api-domain}}/crm/v8/Appointments__s/5725767000006390001
Request Method: PUT
Request Body:
{ "data": [ { "Appointment_Start_Time": "2025-04-16T14:00:00-07:00", //Updating the Appointment_Start_Time "Appointment_End_Time": "2025-04-16T14:30:00-07:00", //Updating the Appointment_End_Time "Appointment_For": { "module": { "api_name": "Employees", //Updating a different module "id": "5725767000002161028" }, "name": "Patrica", //A record from the Employees module "id": "5725767000006272001" //unique ID of the record } } ] }
|
Multi-module Lookup Using the COQL API
Querying Inner Fields of Linked Modules within the MML Field
With the COQL API, you can query inner fields of linked modules within a Multi-Module Lookup (MML) field. This provides deeper insights into related fields data in a module. This query support is available from
Zoho CRM API Version 7.
Sample Query:
{ "select_query": "select 'Appointment_For->Contacts.Lead_Source' from Appointments__s where id is not null" }
|
The above query retrieves the
Lead Source field from the
Contacts module within the
Appointment_For MML field.
Sample Response:

Querying Multi-Module Lookup Module Name
Querying the module name associated with each record in a Multi-Module Lookup (MML) field. This query support is available from
Zoho CRM API Version 7.
Sample Query:
{ "select_query": "select Appointment_For.module.api_name, Appointment_For from Appointments__s where id is not null" }
|
The
Appointment_For.module.api_name returns the module name (e.g., Contacts or Accounts) for each record linked in the
Appointment_For MML field.
Sample Response:
Multi-module Lookup Using the Bulk Read API
Bulk Read API allows you to fetch a large set of data i.e., you can fetch a maximum of 2,00,000 records in a single API call.
Specify the API name of the Appointments module in the module JSON object when making API calls. Refer to the following section for an example.
Request Method : POST
Request Body :
{ "callback": { "method": "post" }, "query": { "module": { "api_name": "Appointments__s" //API name of the Appointments module }, "file_type": "csv" } }
|
Note: The Appointment_For field cannot be used in the criteria.
As the API is an asynchronous API, the response will not be available instantly; the bulk read job is scheduled, and the status can be checked. Once the job is completed, you will be notified in the callback URL. The records are available in a downloadable CSV file or ICS file (for events). See the
Bulk Read API document to know how to view the status of the scheduled job and download the file, along with more sample requests and responses.
Sample Exported Response
Frequently Asked Questions
1. Which modules are currently supported in the MML field?
Only Contacts and custom modules can be associated with an MML field.
2. What error is thrown if I try to associate a record with a removed or unsupported module in the MML field?
If you try to associate a record with a removed or unsupported module in an MML field, the system will throw an "INVALID_DATA" error.
3. Is the MML field available for all modules?
No, as of
Zoho CRM API Version 8, the MML field is available only as a system-defined field in the
Appointments module.
4. How do I get the list of modules associated with an MML field?
You can use the
GET - Fields Metadata API for the
Appointments module and look for the field with
"data_type" : "multi_module_lookup" and check its
"modules" JSON array.
5. Can I add or remove modules from a Multi-Module Lookup (MML) field via API?
Adding or removing modules in an MML field is not supported via API. These actions can only be done through the Zoho CRM UI.
6. What happens if I remove a module from an MML field?
If a module is removed from the MML through Zoho CRM UI, it can no longer be associated with new records, but existing records linked to that module will remain unaffected.
7. Is MML field supported in the Bulk Write API?
As of
Zoho CRM API Version 8, the MML field is available only in the Appointments module as a system-defined field. The Appointments module is not supported in the Bulk Write API.
8. Is MML field supported in the Search API?
The MML field is not currently supported in the Search API.
We trust that this post meets your needs and is helpful. Let us know your thoughts in the comment section or reach out to us at
support@zohocrm.com
Stay tuned for more insights in our upcoming Kaizen posts!
Cheers!!!
Related Readings:
Recent Topics
Why is the ability Customize Calls module so limited?
Why can't I add additional sections? why can't I add other field types than the very limited subset that zoho allows? Why can I only add fields to the outbound/inbound call sections and not to the Call Information section?
Zoho Desk - Upsert Ticket
Hi Desk Team, It is common to request more information from end-users. Using forms is a great way to ensure all the required information is collected. It would be great if there were an "upsert" option on the Zoho Form -> Zoho Desk integration which would
CRM gets location smart with the all new Map View: visualize records, locate records within any radius, and more
Hello all, We've introduced a new way to work with location data in Zoho CRM: the Map View. Instead of scrolling through endless lists, your records now appear as pins on a map. Built on top of the all-new address field and powered by Mappls (MapMyIndia),
Enhance Appointment Buffers in Zoho Bookings
There was previously a long-standing feature request related to enhancing the way appointment buffers work in Zoho Bookings, but it looks like the original post has been deleted. I am therefore adding a new request that Zoho Bookings adjust how appointment
Subscriptions for service call
So we install products and we want to offer a service contract for the customers yearly service calls to be billed monthly. So ideally at some point we want to email them a quote for their needs. WE will choice it our end based on the equipment. It would
Connection to other user
Zoho Cliq handles sharing of Custom OAuth Connections that require individual user logins.
How to invite friends on other social media platforms to one of my group chats in arattai?
Hello, I have formed chat groups in arattai. I want to invite my friends on other social media platforms like WhatsApp/ FB to one of my groups. Different friends would be invited to different groups. How to share an invite link of one of my groups to
Cliq does not sync messages after Sleep on Mac
I'm using the mac app of Cliq. When I open my mac after it was in sleep mode, Cliq does not sync the messages that I received. I always have to reload using cmd + R, which is not what I want when using a chat application.
Creator Offline
We had online access setup and working on our iphones. We have just set it up on an 'Android Tablet' and it is not downloading all the images? We use it to show customers our catalogue. Any ideas. Offline components all setup on both devices
Optimum CRM setup for new B2B business
Can some advise the most common way to setup Zoho CRM to handle sales for a B2B company? Specifically in how to handle inbound/outbound emails. I have spent hours researching online and can't seem to find an accepted approach, or even a tutorial. I have
Facing Issues with Sites Mobile font sizes
my page renediaz.com is facing issues mobile view, when i try to lower font sizes in home page, instead of changing the size, it changes the line space
Does the Customer “Company Name” field appear anywhere in the Zoho Books UI outside of PDFs?
Hi everyone, I’m trying to understand how the Company Name field is actually used in Zoho Books. There is a Company Name field on the customer record, but when viewing transactions like a Sales Order in the normal UI (non-PDF view), that field doesn’t
Set expiration date on document and send reminder
We have many company documents( for example business registration), work VISA documents. It will be nice if we can set a expiry date and set reminders ( for example 90 days, 60 days, 30 days etc.,) Does Zoho workdrive provide that option?
Analytics : How to share to an external client ?
We have a use case where a client wants a portal so that several of his users can view dashboards that we have created for them in Zoho Analytics. They are not part of our company or Zoho One account. The clients want the ability to have user specific,
Automatically Update Form Attachment Service with Newly added Fields
Hi, When I have a Form Setup and connected to a 3rd Party Service such as OneDrive for Form Attachments, when I later add a new Upload Field I have to remove and redo the entire 3rd Party Setup from scratch. This needs to be improved, such as when new
Zoho Sheet for Desktop
Does Zoho plans to develop a Desktop version of Sheet that installs on the computer like was done with Writer?
Payroll and BAS ( Australian tax report format )
Hello , I am evaluating Zoho Books and I find the interface very intuitive and straight forward. My company is currently using Quickbooks Premier the Australian version. Before we can consider moving the service we would need to have the following addressed : 1.Payroll 2.BAS ( business activity statement ) for tax purposes 3.Some form of local backup and possible export of data to a widely accepted format. Regards Codrin Mitin
Zoho Desk API - Send Reply to CUSTOMERPORTAL
Hello! I'll try to send a reply to Customer Portal, But the response is 500 (INTERNAL_SERVER_ERROR in service response). {"Error":"{\"errorCode\":\"INTERNAL_SERVER_ERROR\",\"message\":\"An internal server error occurred while performing this operation.\"}"}
Python - code studio
Hi, I see the code studio is "coming soon". We have some files that will require some more complex transformation, is this feature far off? It appears to have been released in Zoho Analytics already
Dheeraj Sudan and Meenu Hinduja-How do I customize Zoho apps to suit my needs?
Hi Everyone, I'm Meenu Hinduja and my husband Dheeraj Sudan, run a business. I’m looking to tweak a few things to fit my needs, and I’d love to hear what customizations others have done. Any tips or examples would be super helpful! Regards Dheeraj Sudan
From Zoho CRM to Paper : Design & Print Data Directly using Canvas Print View
Hello Everyone, We are excited to announce a new addition to your Canvas in Zoho CRM - Print View. Canvas print view helps you transform your custom CRM layouts into print-ready documents, so you can bring your digital data to the physical world with
Zoho Books Payroll
How am I supposed to do payroll and pay my employees with Zoho Books? I think it's pretty strange that an accounting software doesn't have the ability to perform one of the most common functions in business; paying your employees. Am I missing something,
Layout Rules Don't Apply To Blueprints
Hi Zoho the conditional layout rules for fields and making fields required don't work well with with Blueprints if those same fields are called DURING a Blueprint. Example. I have field A that is used in layout rule. If value of field A is "1" it is supposed to show and make required field B. If the value to field A is "2" it is supposed to show and make required field C. Now I have a Blueprint that says when last stage moves to "Closed," during the transition, the agent must fill out field A. Now
validation rules doesn't work in Blueprint when it is validated using function?
I have tried to create a validation rule in the deal module. it works if I try to create a deal manually or if I try to update the empty field inside a deal. but when I try to update the field via the blueprint mandatory field, it seems the validation
Sort Legend & stacked bar chart by value
I'd love to see an option added to sort the legend of graphs by the value that is being represented. This way the items with the largest value in the graph are displayed top down in the legend. For example, let's say I have a large sales team and I create
Is It Possible to Convert a Custom Module to a Quote?
I recently created a custom module in our CRM environment for RFQs so that our sales team can submit quote requests directly in Zoho rather than by email/phone. This allows for a cleaner overall process, minimizing potential errors and potentially encouraging
All new Address Field in Zoho CRM: maintain structured and accurate address inputs
The address field will be available exclusively for IN DC users. We'll keep you updated on the DC-specific rollout soon. It's currently available for all new sign-ups and for existing Zoho CRM orgs which are in the Professional edition. Latest update
How can Data Enrichment be automatically triggered when a new Lead is created in Zoho CRM?
Hi, I have a pipeline where a Lead is created automatically through the Zoho API and I've been trying to look for a way to automatically apply Data Enrichment on this created lead. 1) I did not find any way to do this through the Zoho API; it seems like
Client Side Scripts for Meetings Module
Will zoho please add client side scripting support to the meetings module? Our workflow requires most meeting details have a specific format to work with other software we have. So we rely on a custom function to auto fill certain things. We currently
Proposal: Actionable API Error Messages to Reduce Support Ticket Volume
I've encountered a long-standing frustration with how Zoho Creator's API communicates errors to developers, and I'm hoping the Zoho team can address this in a future update. This issue has persisted for over 9 years based on community discussions, and
Zoho CRM - Option to create Follow-Up Task
When completing a Zoho CRM Task, it would be very helpful if there was an option to "Complete and Create Follow-Up Task" in the pop-up which appears. It could clone the task you are closing and then show it on the screen in edit mode, all the user would
Dynamic Field Folders in OneDrive
Hi, With the 2 options today we have either a Dynamic Parent Folder and lots of attachments all in that one folder with only the ability to set the file name (Which is also not incremented so if I upload 5 photos to one field they are all named the same
Drag 'n' Drop Fields to a Sub-Form and "Move Field To" Option
Hi, I would like to be able to move fields from the Main Page to a Sub-Form or from a Sub-Form to either the Main Page or another Sub-Form. Today if you change the design you have to delete and recreate every field, not just move them. Would be nice to
File Conversion from PDF to JPG/PNG
Hi, I have a question did anyone every tried using custom function to convert a PDF file to JPG/PNG format? Any possibility by using the custom function to achieve this within zoho apps. I do know there are many third parties API provide this with
Allocating inventory to specific SO's
Is there a way that allocate inventory to a specific sales order? For example, let's say we have 90 items in stock. Customer 1 orders 100 items. This allocates all 90 items to their order, and they have a back order for the remaining 10 items which could
Cliq iOS can't see shared screen
Hello, I had this morning a video call with a colleague. She is using Cliq Desktop MacOS and wanted to share her screen with me. I'm on iPad. I noticed, while she shared her screen, I could only see her video, but not the shared screen... Does Cliq iOS is able to display shared screen, or is it somewhere else to be found ? Regards
Pull cells from one sheet onto another
Hello all! I have created an ingredients database where i have pricing and information and i want to pull from that database into a recipe calculator. I want it to pull based on what ingredient I choose. The ingredients database has an idea and i want
Closing the Loop: Why Lookup Asymmetry is Harming Data Integrity in Creator
TL;DR: Lookup fields allow users to add new related records inline via the "+" icon, but there's no equivalent ability to edit an existing related record without navigating away and losing form context. Adding a native "Edit" icon—with automatic User
Add the ability to Hide Pages in Page Rules
Hi, We have Field Rules to show and hide fields and we have page Rules, but we can't hide a page in Page Rules so it isn't completed before the previous page (And then have the Deny Rules to prevent submitting without both pages completed), we can only
Enable Free External Collaboration on Notecards in Zoho Notebook
Hi Zoho Notebook Team, I would like to suggest a feature enhancement regarding external collaboration in Zoho Notebook. Currently, we can share notes with external users, and they are able to view the content without any issue. However, when these external
Next Page