Business API Design Specification - Create Messagethread

A Business API is a set of logical actions centered around a main data object. These actions can range from simple CRUD operations to complex workflows that implement intricate business logic.

While the term “API” traditionally refers to an interface that allows software systems to interact, in Mindbricks a Business API represents a broader concept. It encapsulates a business workflow around a data object, going beyond basic CRUD operations to include rich, internally coordinated actions that can be fully designed and customized.

This document provides an in-depth explanation of the architectural design of the createMessageThread Business API. It is intended to guide backend architects and developers in maintaining the current design. Additionally, frontend developers and frontend AI agents can use this document to understand how to properly consume this API on the client side.

Main Data Object and CRUD Operation

The createMessageThread Business API is designed to handle a create operation on the MessageThread data object. This operation is performed under the specified conditions and may include additional, coordinated actions as part of the workflow.

API Description

Create a new message thread (private or group). Can optionally link to a film project. Enforces participants count and role access.

API Frontend Description By The Backend Architect

For users to start a new conversation (private or group chat) with one or more participants (including themselves); optionally link the thread to a project, set subject (required for group/flagged threads only), subject can be empty for 1-to-1; lastMessageAt auto-set to creation time.

API Options

API Controllers

A Mindbricks Business API can be accessed through multiple interfaces, including REST, gRPC, WebSocket, Kafka, or Cron. The controllers listed below map the business workflow to a specific interface, enabling consistent interaction regardless of the communication channel.

REST Controller

The createMessageThread Business API includes a REST controller that can be triggered via the following route:

/v1/messagethreads

By sending a request to this route using the service API address, you can execute this Business API. Parameters can be provided in multiple HTTP locations, including the URL path, URL query, request body, and request headers. Detailed information about these parameters is provided in the Parameters section.

MCP Tool

REST controllers also expose the Business API as a tool in the MCP, making it accessible to AI agents. This createMessageThread Business API will be registered as a tool on the MCP server within the service binding.

API Parameters

The createMessageThread Business API has 8 parameters that must be sent from the controller. Note that all parameters, except session and Redis parameters, should be provided by the client.

Business API parameters can be:

Regular Parameters

Name Type Required Default Location Data Path
messageThreadId ID No - body messageThreadId
Description: This id paremeter is used to create the data object with a given specific id. Leave null for automatic id.
participantIds ID Yes - body participantIds
Description: IDs of all participants in the thread (must be 2+ for group, exactly 2 for 1-1)
subject String No - body subject
Description: Optional subject for the thread, required for group or flagged; for 1-on-1 may be null/empty.
relatedProjectId ID No - body relatedProjectId
Description: (Optional) The project this thread is about.
isGroup Boolean Yes - body isGroup
Description: True if thread is a group chat, false if private 1-to-1 message.
createdBy ID Yes - session userId
Description: User who created the thread.
lastMessageAt Date Yes - body lastMessageAt
Description: Timestamp of the last message in this thread (used for sorting).
threadStatus Enum Yes - body threadStatus
Description: Status of the thread: active, archived, flagged.

Parameter Transformations

Some parameters are post-processed using transform scripts after being read from the request but before validation or workflow execution. Only parameters with a transform script are listed below.

No parameters are transformed in this API.

AUTH Configuration

The authentication and authorization configuration defines the core access rules for the createMessageThread Business API. These checks are applied after parameter validation and before executing the main business logic.

While these settings cover the most common scenarios, more fine-grained or conditional access control—such as permissions based on object context, nested memberships, or custom workflows—should be implemented using explicit actions like PermissionCheckAction, MembershipCheckAction, or ObjectPermissionCheckAction.

Login Requirement

This API requires login (loginRequired = true). Requests from non-logged-in users will return a 401 Unauthorized error. Login is necessary but not sufficient, as additional role, permission, or other authorization checks may still apply.

Ownership Checks

Role and Permission Settings

Data Clause

Defines custom field-value assignments used to modify or augment the default payload for create and update operations. These settings override values derived from the session or parameters if explicitly provided.", Note that a default data clause is always prepared by Mindbricks using data property settings, however any property in the data clause can be override by Data Clause Settings.

Custom Data Clause Override No custom data clause override configured

Actual Data Clause

The business api will use the following data clause. Note that any calculated value will be added to the data clause in the api manager.

{
  id: this.messageThreadId,
  participantIds: this.participantIds,
  subject: this.subject,
  relatedProjectId: this.relatedProjectId,
  isGroup: this.isGroup,
  createdBy: this.createdBy,
  lastMessageAt: this.lastMessageAt,
  threadStatus: this.threadStatus,
  isActive: true,
  _archivedAt: null,
}

Business Logic Workflow

[1] Step : startBusinessApi

Manager initializes context, populates session and request objects, prepares internal structures for parameter handling and workflow execution.

You can use the following settings to change some behavior of this step. apiOptions, restSettings, grpcSettings, kafkaSettings, sseSettings, cronSettings

[2] Step : readParameters

Manager reads input parameters, normalizes missing values, applies default type casting, and stores them in the API context.

You can use the following settings to change some behavior of this step. customParameters, redisParameters

[3] Action : validateParticipantsCount

Action Type: FunctionCallAction

Validates participants: if isGroup - minimum 2; else exactly 2.

class Api {
  async validateParticipantsCount() {
    try {
      return runMScript(
        () => LIB.validateParticipantsCount(this.participantIds, this.isGroup),
        {
          path: "services[2].businessLogic[0].actions.functionCallActions[0].callScript",
        },
      );
    } catch (err) {
      console.error(
        "Error in FunctionCallAction validateParticipantsCount:",
        err,
      );
      throw err;
    }
  }
}

[4] Step : transposeParameters

Manager transforms parameters, computes derived values, flattens or remaps arrays/objects, and adjusts formats for downstream processing.

[5] Step : checkParameters

Manager executes built-in validations: required field checks, type enforcement, and basic business rules. Prevents operation if validation fails.

[6] Action : enforceParticipantRules

Action Type: ValidationAction

Thread must have at least two unique participants. For private, exactly two.

class Api {
  async enforceParticipantRules() {
    const isValid = runMScript(() => this.isParticipantsValid === true, {
      path: "services[2].businessLogic[0].actions.validationActions[0].validationScript",
    });

    if (!isValid) {
      throw new BadRequestError(
        "Invalid participant count: must be at least 2 for group or exactly 2 for private.",
      );
    }
    return isValid;
  }
}

[7] Step : checkBasicAuth

Manager performs authentication and authorization checks: verifies session, user roles, permissions, and tenant restrictions.

You can use the following settings to change some behavior of this step. authOptions

[8] Step : buildDataClause

Manager constructs the final data object for creation, fills auto-generated fields (IDs, timestamps, owner fields), and ensures schema consistency.

You can use the following settings to change some behavior of this step. dataClause

[9] Action : setInitialLastMessageAt

Action Type: AddToContextAction

Sets lastMessageAt to now.

class Api {
  async setInitialLastMessageAt() {
    try {
      this["lastMessageAt"] = runMScript(() => new Date(), {
        path: "services[2].businessLogic[0].actions.addToContextActions[0].context[0].contextValue",
      });

      return true;
    } catch (error) {
      console.error("AddToContextAction error:", error);
      throw error;
    }
  }
}

[10] Step : mainCreateOperation

Manager executes the database insert operation, updates indexes/caches, and triggers internal post-processing like linked default records.

[11] Step : buildOutput

Manager shapes the response: masks sensitive fields, resolves linked references, and formats output according to API contract.

[12] Step : sendResponse

Manager sends the response to the client and finalizes internal tasks like flushing logs or updating session state.

[13] Step : raiseApiEvent

Manager triggers API-level events (Kafka, WebSocket, async workflows) as the final internal step.

Rest Usage

Rest Client Parameters

Client parameters are the api parameters that are visible to client and will be populated by the client. Note that some api parameters are not visible to client because they are populated by internal system, session, calculation or joint sources.

The createMessageThread api has got 6 regular client parameters

Parameter Type Required Population
participantIds ID true request.body?.[“participantIds”]
subject String false request.body?.[“subject”]
relatedProjectId ID false request.body?.[“relatedProjectId”]
isGroup Boolean true request.body?.[“isGroup”]
lastMessageAt Date true request.body?.[“lastMessageAt”]
threadStatus Enum true request.body?.[“threadStatus”]

REST Request

To access the api you can use the REST controller with the path POST /v1/messagethreads

  axios({
    method: 'POST',
    url: '/v1/messagethreads',
    data: {
            participantIds:"ID",  
            subject:"String",  
            relatedProjectId:"ID",  
            isGroup:"Boolean",  
            lastMessageAt:"Date",  
            threadStatus:"Enum",  
    
    },
    params: {
    
        }
  });

REST Response

The API response is encapsulated within a JSON envelope. Successful operations return an HTTP status code of 200 for get, list, update, or delete requests, and 201 for create requests. Each successful response includes a "status": "OK" property. For error handling, refer to the “Error Response” section.

Following JSON represents the most comprehensive form of the messageThread object in the respones. However, some properties may be omitted based on the object’s internal logic.

{
	"status": "OK",
	"statusCode": "201",
	"elapsedMs": 126,
	"ssoTime": 120,
	"source": "db",
	"cacheKey": "hexCode",
	"userId": "ID",
	"sessionId": "ID",
	"requestId": "ID",
	"dataName": "messageThread",
	"method": "POST",
	"action": "create",
	"appVersion": "Version",
	"rowCount": 1,
	"messageThread": {
		"id": "ID",
		"participantIds": "ID",
		"subject": "String",
		"relatedProjectId": "ID",
		"isGroup": "Boolean",
		"createdBy": "ID",
		"lastMessageAt": "Date",
		"threadStatus": "Enum",
		"threadStatus_idx": "Integer",
		"isActive": true,
		"recordVersion": "Integer",
		"createdAt": "Date",
		"updatedAt": "Date",
		"_owner": "ID",
		"lastMessage": [
			{
				"senderId": "ID",
				"content": "Text",
				"sentAt": "Date",
				"moderationStatus": "Enum",
				"moderationStatus_idx": "Integer"
			},
			{},
			{}
		],
		"relatedProject": {
			"title": "String",
			"projectType": "Enum",
			"projectType_idx": "Integer",
			"ownerUserId": "ID",
			"isPublic": "Boolean",
			"approvalStatus": "Enum",
			"approvalStatus_idx": "Integer"
		}
	}
}