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
Is it possible to customize ZC Themes?
I understand you can choose a layout and customize Brand Color, App Header, Menu, and Sub-Menu components, but can you override some of the default theme settings with CSS or a config file? For example, - Table highlight color - Listview auto filter highlight
Is it possible to create Custom function-based Lookup field in Zoho CRM
Is it possible to create a custom function-based lookup field in Zoho CRM? If so, how? Use case: Need to fetch users from Zoho Projects into a dropdown field in Zoho CRM.
@mention in comments no notification
Hi, hope someone can help. When we @mention someone in the comments in Zoho Creator, how is that user notifed as we don't get anything on email or in the app notifications.
Add "Running Balance" column to Account Transaction Reports
Hello, Currently Zoho Account Transaction Reports give you the opening balance, then lists the transactions, then provides the closing balance. It would be great if you could add a column on the far right that shows the "Running Balance" on the account after each transaction. There are many times when analyzing or tie-ing out transactions that this would be very helpful. I currently have to frequently run a tape on my adding machine to get balance totals after a specific transaction on the list.
error : Object code : 6500
b3 = map(); b3.put("name", "Test Project Name"); updateprojects2 = invokeurl [ url :"https://projectsapi.zoho.eu/restapi/portal/era0130/projects/169495000000928007/" type :PUT parameters: b3 connection:"in2" ]; info b3 ; info updateprojects2; ------------
I got unknown charge from Zoho
Good day, I need help disputing a charge I don't know from, zoho. I have ZohoMail and ZeptoMail. I purchase credits for ZeptoMail, and for ZohoMail I am not subcribed.
Function 56: Automatically enable the option for customers to pay via bank account
Hello everyone and welcome back to our series! One of the key features of Zoho Books is its integration with multiple payment gateways, allowing you to receive online payments for your invoices. This ensures faster payments, automates payment tracking
Attach Files to Your Notecards and share them on the go!
Hey everyone! We’re excited to share a feature many of you have been asking for — you can now attach files directly to your text notecards and share with ease! 🙌 This update was built with your feedback in mind, especially for those who wanted a simple
How to searchByCriteria records that are under approval?
I need to search for both approved and pending approval records Is that possible with this method? Or I need to a different method? var priceReqID = $Page.record_id; log(priceReqID); var records = ZDK.Apps.CRM.Price_List_Item.searchByCriteria("Price_Request:equals:"
How to add Simple Analytics to Zoho Pages?
I have a website with Zoho Pages, how do I add Simple Analytics on it? They seem to have code they need to be embedded https://docs.simpleanalytics.com/script
Cant seem to delete an email account
Hello, I have researching for 4 days how to delete an email account and I am absolutely without a clue. The email account I am trying to delete is support<AT>fyshoes<dot>com. It's the first email account I made and it (is???) was associated with the super user (me). I have since changed it to adming<AT>fychoes<dot>com and I see the support email in my list but I just cant seem to get rid of it. Ultimately I want to associate that email account with another user that I want to add. This is really
Import data into Multi-Select lookup field from CSV/Excel
How to import data into a multi-select lookup field from the CSV/Excel Sheet? Let's say I have an Accounts multi-select lookup field in the Deals module and I want to import the Deals with Accounts field. Steps:- 1. Create/edit a multi-select lookup field
Script that deletes a record?
We're using WP Plugin "Integration for WooCommerce and Zoho Pro", and have created a couple of Feeds to send data to Zoho. We are trying to create Contact records, but only based upon condition. Tried to make it with small Deluge function and Workflow,
A formula that capitalises the first letter of each word
Hi all, is there a zoho formula that can capitalise the first letter of each word in a string? INITCAP only capitalises the first letter of the first word.
Quotes in Commerce?
In Zoho Ecommerce, I need to be able to generate quotes, negotiate with customers, and then generate invoices. Currently, I plan to integrate Zoho CRM to generate quotes. After negotiation and confirmation, I will push the details to Zoho Ecommerce to
Zoho Commerce - Mobile Application
Does Zoho Commerce have a mobile application for customers to place an order?
Register user through Phone Number by Generating OTP
In zoho commerce , I am developing website on online food store Inilialy the user get verification code to their email for registering there account for login. But I need to login using phone number by generating OTP automatically rather than verification
Custom Buttons for Mass Actions
Hello everyone, We’ve just made Custom Buttons in Zoho Recruit even more powerful! You can now create Bulk Action Buttons that let you perform actions on multiple records at once, directly from the List View. What’s new? Until now, custom buttons were
Zoho Vault Passwords
Is there a way to consume Zoho Vault Manager passwords using the API? Thanks in advance.
Is the ChatGPT Assistant integration capable of recognizing WhatsApp voice messages?
I was wondering: if a visitor sends me a voice message on WhatsApp, would the assistant be able to transcribe it and reply to them?
Zoho Creator to Zoho CRM Images
Right now, I am trying to setup a Notes form within Zoho Creator. This Notes will note the Note section under Accounts > Selected Account. Right now, I use Zoho Flow to push the notes and it works just fine, with text only. Images do not get sent (there
【Zoho CRM】レポート機能のアップデート
ユーザーの皆さま、こんにちは。コミュニティチームの藤澤です。 今回は「Zoho CRM アップデート情報」の中から、レポート機能のアップデートをご紹介します。 目次 1. レポートのエクスポート時のレコードIDの表示について 2. 通貨項目の表示について 3. レポートの削除の監査ログへの反映について 1. レポートのエクスポート時のレコードIDの表示について これまで、レポートをエクスポートするとファイルにレコードIDが必ず含まれていました。レコードIDが識別子として役立つ場合もありますが、実際には多くの企業で参照されることはありません。
Translation in zoho bookings
We cant translate zoho booking emails. The general text we can change. But what about text like: ""Here a link to join the meeting online:"" and "Add to Zoho Calendar" and "Add to Google Calendar"? No professional business have mixed languages. Its looking
Is there any way to bill one client in different currencies on different invoices?
I have some customers who have their currency set as USD and most of their billing is done in USD. However, from time to time I have a need to bill them in my base currency GBP for some specific invoices, but there seems to be no way of doing this that I can see. The only workaround that I can see is to create two client records for the same client, one for USD billing and one for GBP billing, but this is not an ideal situation. Is it likely that the (hopefully!) soon to arrive multi-currency support
API name for all fields in Zoho Project (Standard or custom)
Hi! I struggle to find easily all API name of all field in Zoho Project to build my API rest with other services. We can find them very fast in CRM but not in PRoject. Could you share a function to get the list of all API Name of any field of an App
Disappearing Mouse cursor in Zoho Mail / Windows 11 (Chrome + Edge)
I'm seeing an issue when writing mails with the light theme with the mouse cursor being white and the document area also being white - making it nearly impossible to see the mouse cursor. I see the problem on Windows 11 under Chrome and Edge. (Yet to
Zoho Assist not rendering NinjaTrader chart properly
Hi everyone. Just installed and testing Zoho Assist. I want to display my laptop' screen (Windows 11) on a monitor connected to my Mac mini. The laptop is running a stock trading program called NinjaTrader. Basically, when running, this program displays
Link(s) between Notes
Hello Everyone, It would be great if links could be created between notes. Let's say we have 5 Notes A, B, C , D, E. I would like to be able to link Note A to Note B but not in other way, so no link appears in Note B linking to Note A. An so on, linking
Feature Request: Assign Documents to Already Entered Bills, Expenses, Invoices, etc.
Hi Zoho Team, We are regular users of the Documents module in Zoho Books and appreciate its ability to keep financial records well-organized. However, we’ve noticed a limitation: There is no way to attach a document from the "Documents > Files" section
I don't see any WITHDRAWL transaction at all
Hi I manually imported my bank statement to Zoho books today and I am a complete newbie. I have been reading the knowledgebase but unable to fix this. I only see "Uncategorized 91 DEPOSIT transactions". I don't see any WITHDRAWL transaction at all. Also,
Shared inbox unable to see replies
Hi we are a small company me and someone else, we have a shared inbox for our sale@ and contact@ however we have this issue where by if i reply to an email or the other person reply to the email, it does not show it to them and therefore we end up replying
404 error at checkout
Our customers are getting a 404 error at checkout. Anyone else with the same problem?
FONT Sizing in Notebook
Hi Kishore - What is the status of adding font sizing to the application? I have several things that I have pasted directly into Notebook and the fonts are HUGE! I would like the ability to highlight them and reduce the font to a legible size. Nothing
Can managers Upload documents to their direct rapports?
Admin employees have the ability to upload documents to employees' files; however, managers do not have add/manage button - is it possible for managers to upload their direct reports' documents, such as absence documents or 121 documents. Is there something
Leave balance display for next year
Is there a way to not have a rollover or not limit the leave balance depending on the date. For example an employee has 10 days leave balance and wants to apply for January leave in December. They cant because the rollover doesnt show the leave balance
Please add an “Auto-Apply Unused Credits” toggle
Hello — please add a simple org-level option to automatically apply unused credits (credit notes, excess payments, retainers) to new invoices and/or bills. An ON/OFF toggle with choices “invoices”, “bills”, or “both” would save lots of manual work for
Zoho Books not working/loading
Hi! I haven't been able to access/load Zoho Books for the past hours. I get a time out (and it is not due to my internet connection). Could you please check this asap? Thank you!
Custom Fields with Data Types for Expense and Payments Received in Zoho Books
Hi all, We are glad to present to you, the option to create Custom Fields for the Expense and Payments received modules in Zoho Books. This also comes with an icing on top of it - Yes, the custom fields can now be created with different data types. Types like Text, Number, Decimal, Amount, Auto Number and Check Box are supported as of now. Rush to the gear icon at the top right corner, select 'More Settings', choose 'Preferences' in the left pane. Click the Expense/Payment preferences where you can
Zoho Cliq - Incident alert (Server outage - IN DC) | August 28
We've received server down alerts and are currently investigating the issue (IN DC) to find the root cause. Our team is actively working to restore normal operations at the earliest. Status: Under investigation Start time: 09:44:21 AM IST Affected location:
Claude + MCP Server + Zoho CRM Integration – AI-Powered Sales Automation
Hello Zoho Community 👋 I’m excited to share a recent integration we’ve worked on at OfficehubTech: ✅ Claude + MCP Server + Zoho CRM This integration connects Zoho CRM with Claude AI through our custom MCP Server, enabling intelligent AI-driven responses
Next Page