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
Integration with...
Dear Zoho Commerce team, Please could you consider the integration within Zoho Commerce / Inventory and Qapla'? (https://www.qapla.it/en/) This app is better than Aftership in many ways: - Aftership integration require PRO plan and price start from more
Zoho Sign - Zoho CRM extension upgrade
Hi everyone, We've updated Zoho Sign extension for Zoho CRM with significant internal changes. Impact on existing Zoho Sign extension users Users using the extension without customization If you are using the integration without implementing Zoho Sign's
Consultant-Only Booking Page
Zoho Bookings does not allow for Meeting Type OR Workspace-Wide booking pages to be turned off. This is detrimental to organizations that have territory-based or assigned accounts, because if prospects can go to these booking pages and either select the
Start Workflow from Deluge Script
I have developed a customized process from our CRM that leverages a deluge script to create a statement of work document. Once the document has been created via the merge and store function, I would like the ability to start a workdrive review & approve
Request for Auto PO - Min–Max based Automated Purchase Feature
Dear Zoho POS Team, I’m writing to request a feature enhancement that would significantly streamline inventory management for businesses using Zoho POS — particularly supermarkets, FMCG retail, and multi-store operations like ours. Feature Requested:
Masters in UK – Experiences, Universities, and Career Outcomes
This forum discussion is for students who are planning or considering a Masters in UK and want to gain practical insights beyond official university websites. The UK attracts international students due to its globally recognized universities, diverse
Export your notes from Notebook!
Dear users, The long awaited feature is now live. Yes, you can now export your notes from Notebook app in bulk. But the feature has just started with web app alone for now. You can try the export feature as mentioned below: Go to our web app, https://notebook.zoho.com Go to 'Settings' > 'Export' Now, select the format: You can select either ZNote or HTML Once done, you can use the same to import or can have this a local backup of your notes. Note: Export for other platforms are in development and
Prepopulating Fields
Hello, I have a form (Assets) with 2 lookup fields: Client (from Clients) Site (from Client Sites) I modified the code (highlighted in red below), so the Site dropdown shows the list of sites related to the Client. must have Client_Site ( type = picklist
Unable to sort as Descending order
Trying to change the sort order for a lookup field (checkboxes) from Ascending to Descending and keep getting an error in Deluge that the order must be Ascending Did anyone ran into this? Thanks Eyal
Export Invoices to XML file
Namaste! ZOHO suite of Apps is awesome and we as Partner, would like to use and implement the app´s from the Financial suite like ZOHO Invoice, but, in Portugal, we can only use certified Invoice Software and for this reason, we need to develop/customize on top of ZOHO Invoice to create an XML file with specific information and after this, go to the government and certified the software. As soon as we have for example, ZOHO CRM integrated with ZOHO Invoice up and running, our business opportunities
Can I change the format of the buttons in the email templates?
Hi all! We have been working hard trying to brand our email templates, and have some way to go yet. One of the things we can't seem to edit is the green ${Cases.CUSTOMER_PORTAL_BUTTON} button and the font of the View Ticket text. Is there any way of doing
issue with deluge script
i used chat gpt to build this script and I am getting 2 errors which I cannot figure out how to fix: void monthly_sales_order_generation() { try { // ---------------- CONFIG ------------------- analytics_url_1 = "https://analytics.zoho.com/api/<workspaceID>/report/<reportID1>/data";
Introducing LinkedIn Apply Connect for Zoho Recruit
Attract up to 3x more qualified candidates and hire more efficiently with LinkedIn Apply Connect. Let candidates fill-in job applications without any redirections, gain deeper insights with applicant highlights within Zoho Recruit, and keep candidates
Recruit paid support?
Hi all, Could anyone who has paid support package advise if it provides value for money with regards to support response times? Exploring the idea as unfortunately when we have faced issues with Recruit it has been a 7+ day timescale from reporting to
Introducing Dedicated Modules for Plans, Addons, and Coupons in Zoho Billing
We’ve enhanced the way you manage Plans, Addons, and Coupons in Zoho Billing. Previously, all three grouped together under Subscription Items. Now, each one has its own dedicated module, giving you a cleaner and more intuitive experience. This update
Ticket Status email
Good day, This was discussed in the past, but it would be helpful if we could have the system assign a custom response to a status. We have various statuses for tickets, e.g. "closed due to no response", or "Pending Status", it would be helpful for the
Customer ticket creation via Microsoft Teams
Hi all, I'm looking to see if someone could point me in the right direction. I'd love to make it so my customers/ end users can make tickets, see responses and respond within microsoft teams. As Admin and an Agent i've installed the zoho assist app within
Holidays
Hi; For defining Holidays, you need to add logic to handle the year as well as the month & day. We need to be able to enter Holidays for the next year. I need to add a holiday for January 2, 2017, but I can't until January 1st, which is a Sunday and we
Can I use a Standalone CRM Function as the Callback URL For Async Export Data API?
I am creating an export job using this API https://www.zoho.com/analytics/api/v2/bulk-api/export-data-async/create-export/view-id.html There is a "callbackUrl" key in the CONFIG object. I tried copying the URL for a standalone function in CRM which can
Future Orders - Due Date
Hi In my role, I can receive tickets where the work required is requested months in advance. Using a Future Orders option, which I believe was setup under the On Hold status type, hides the Due Date, in all views/ticket etc. Whilst I understand the reasoning
Introducing Withdrawal Reasons for Offers
We’re excited to introduce a new enhancement to the Offer module that brings more clarity and accountability to every withdrawn offer. The Withdrawal Reason update ensures that each withdrawal — manual or automatic — is backed by a clear explanation,
Zoho Creator customer portal users
Hi, I'm in a Zoho One subscription with our company. I'm running a project now that involves creating a Zoho Creater application and using the Zoho Creator Customer Portal. At most we need 25 customer portal users. In our Zoho One plan we only get 3
GPS tracking only or Check out facility
Dear Team, Zoho CRM is quite robust CRM but till date i was waiting for the feature of having GPS tracking of Sales employees which is a common demand by all customers for thier field sales executives. We cover them by saying that CRM provides Checkin
HTML Tags added to Reports with Notes
Recently Zoho added the ability to markup text within notes. That way, users can change font size, colors, etc. It's a great change. However, since the change, reports that include a column for "Note Content" are printing HTML tags within the report.
In App Auto Refresh/Update Features
Hi, I am trying to use Zoho Creator for Restaurant management. While using the android apps, I reliased the apps would not auto refresh if there is new entries i.e new kitchen order ticket (KOT) from other users. The apps does received notification but would not auto refresh, users required to refresh the apps manually in order to see the new KOT in the apps. I am wondering why this features is not implemented? Or is this feature being considered to be implemented in the future? With the
Appraisals on Employee Information Profile
Is it possible to show completed appraisals on each employee's "Employee Information" page? I would presume at the bottom - similar to the "Related Lists" concept in Zoho CRM. Obviously view access would be limited to employee and appropriate other roles
AI Interview Insights: Turn Recorded Interviews into Quick Transcripts & Summaries
Evaluating interviews shouldn’t require replaying long recordings or taking manual notes. With AI Interview Insights, you can now review complete transcripts and AI-generated summaries of your One-way (Recorded) interviews right inside Zoho Recruit. This
Kaizen #220: Actions API - Webhooks APIs - Part 2
Hello all!! Welcome back to the follow-up Kaizen post of Kaizen #219: Actions API - Webhooks APIs - Part 1. In the previous week, we covered how to configure a basic Webhook and how to include Headers, Body, and URL Parameters using both the POST Webhook
Standard Payment Term is not pulled from account to quotation
Hey Team There seems to be something off. I do have "Net 30" as my default payment term in Zoho Books for my customers. If, from the customer overview or quote section, I create a new Quotation, the payment terms field stays blank and doesn't get the
Canva Integration
Hello! As many marketing departments are streamlining their teams, many have begun utilizing Canva for all design mockups and approvals prior to its integration into Marketing automation software. While Zoho Social has this integration already accomplished,
Manage your invoices from Bigin's mobile app (iOS)
Hello everyone! We're happy to announce that users can now integrate Zoho Books with the latest version of Bigin's iOS app. Zoho Books can be integrated with Bigin only via the web application. Users can view the Zoho Books tab in the detail pages of
HubSpot CRM to Zoho Creator Integration
I'm trying to create an integration between HubSpot CRM and Zoho Creator with HubSpot being the push source (if a contact is created or updated in HubSpot, it pushes the information to Zoho Creator). I have two questions: 1- Is it best to use Zoho Flow
Systematic SPF alignment issues with Zoho subdomains
Analysis Period: August 19 - September 1, 2025 PROBLEM SUMMARY Multiple Zoho services are causing systematic SPF authentication failures in DMARC reports from major email providers (Google, Microsoft, Zoho). While emails are successfully delivered due
Accessibility controls and multilingual captcha authorization for Help Center users
Hello everyone, As part of our ongoing effort to improve user experience, we are excited about the accessibility controls and predefined accessibility personas added in the Help Center, similar to what is already available in Zoho Desk. Help Center users
Gain control over record sharing with portal users through our new enhancement: criteria-based data exposure
Dear Customers, We hope you're well! Portals is a self-service avenue through which your clients can access and manage their direct and related data in Zoho CRM. This empowers them to be more independent and enables them to experience a sense of transparency
Zoho Sign + Zoho CRM : la solution pour simplifier vos accords de vente
La conclusion d’un contrat de vente nécessite de nombreuses étapes : préparation de documents, validations successives et collecte des signatures. Les équipes commerciales passent souvent par plusieurs cycles de collaboration et de révision, tout en assurant
Zoho Desk Limitations
Good day, all, I would like to know whether others share my frustration with some of Zoho's limitations. Don't get me wrong, I like Desk (and I also have a subscription for Analytics), I have been with them for close to 10 years, and unfortunately, I
Item/service subtotal
Just discovered & really pleased that we can drag to re-order the line items in Sales orders & Invoices, a very nice feature which doesn't seem to be documented? It would be nice to be able to insert a subtotal as a line item to complete this great feature
Converting Sales Order to Purchase Order
Hi All, Firstly, this code works to convert a sales order(SO) to a purchase order (PO) via a button, however I am running into an issue when I convert the SO where the values from the line items are not pulled across from the SO to the PO. The ones in
how to Solve Conflict Invoices in Zoho POS
Hello Team, I am facing a repeated issue in Zoho POS while saving a sale that contains service-based items. My products are intentionally created as Service (Non-Inventory) items because I do not want to track stock for them. However, every time I try
Next Page