> ## Documentation Index > Fetch the complete documentation index at: https://superthread.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Add related card > Creates a relationship between a specified card (`card_id`) and another card using a defined link type (`blocks`, `blocked_by`, `related`, or `duplicates`). This relationship helps visualize dependencies or connections between cards. A 200 response includes details of the linked card. ## OpenAPI ````yaml POST /{team_id}/cards/{card_id}/linked_cards openapi: 3.0.0 info: description: Superthread Public API Specification version: '0.1' title: Public API contact: email: engineering@superthread.com servers: - url: https://api.superthread.com/v1 security: - BearerAuth: [] tags: - name: AI description: >- [Service: AI]. Handles AI-powered functionalities, such as recommendations, predictions, and automation features. - name: Activity description: >- [Service: Activity] Manages all activities; creating notifications and digests - name: Auth description: >- [Service: Auth] Responsible for user authentication, authorization, and session management. - name: Boards description: >- [Service: Boards] Manages core collaboration features such as "boards", "cards", "lists", "sprints", "epics". - name: Comments description: >- [Service: Comments] Handles the creation, editing, and management of comments across various entities. - name: Favourites description: >- [Service: Favourites] Responsible for favouriting resources in the system for quick access. - name: Files description: >- [Service: Files] Manages file uploads, storage, and retrieval for user and project resources. - name: Importer description: >- [Service: Importer] Handles data import operations from external sources into the platform. - name: Integrations description: >- [Service: Integrations] Facilitates connectivity with external tools and services, enabling smooth integration with third-party platforms and APIs. - name: Pages description: >- [Service: Pages] Manages the creation and organization of both public and private pages, supporting structured content and navigation and collaboration. - name: Projects description: '[Service: Projects] Handles all project related tasks.' - name: Reports description: >- [Service: Reports] Generates and manages analytical reports and insights for users and projects. - name: Search description: >- [Service: Search] Provides search functionalities, including indexing and retrieval of platform data. - name: TimeTracking description: >- [Service: TimeTracking] Manages time entries, active timers, time categories, billing rates, and audit/lock for time-tracking workflows. - name: Views description: >- [Feature] Provides tools to create and customize views, enabling users to organize and visualize their data according to their preferences and workflows. - name: OAuth2 description: >- [Feature] Supports OAuth2 integration for seamless user authentication and authorization, ensuring secure access to external APIs and services. - name: Sprints description: >- [Feature] Facilitates sprint management within agile workflows, including planning, progress tracking, and reporting. - name: Cards description: >- [Feature] A Card is the core concept used in the system to describe an individual task or work item. They are used across Boards, Sprints, and Roadmaps. Cards include features like descriptions, checklists, comments, priorities, tags and more. - name: Checklists description: >- [Feature] A Checklist is a list of items that need to be completed. It is used to track progress on a card. - name: Lists description: >- [Feature] Represents a collection of tasks or items grouped within different contexts in the system. Lists (externally referenced as "statuses") are utilized across various entities such as boards, sprints, and roadmaps. - name: Notes description: >- [Feature] Enables users to create, edit, and organize notes, supporting rich text, attachments, transcriptions and AI enhancements. - name: Tags description: >- [Feature] Groups endpoints related to the creation, retrieval, updating, deletion, and merging of tags within teams (workspaces). - name: Agents description: >- [Feature] Manages agents and runs. Provides CRUD operations for agents, launching cloud agents, monitoring agent status, retrieving conversations, and sending follow-ups. paths: /{team_id}/cards/{card_id}/linked_cards: parameters: - $ref: '#/components/parameters/path_team_id' - $ref: '#/components/parameters/path_card_id' post: tags: - Boards - Cards summary: Link a card with another description: > Creates a relationship between a specified card (`card_id`) and another card using a defined link type (`blocks`, `blocked_by`, `related`, or `duplicates`). This relationship helps visualize dependencies or connections between cards. A 200 response includes details of the linked card. operationId: addLinkedCard requestBody: content: application/json: schema: $ref: '#/components/schemas/AddLinkedCardRequest' description: Create linked card request details required: true responses: '200': description: Linked card successfully created content: application/json: schema: $ref: '#/components/schemas/AddLinkedCardResponse' default: description: client error content: application/json: schema: type: object properties: error: $ref: '#/components/schemas/Error' components: parameters: path_team_id: in: path name: team_id description: >- Team ID is an alphanumerical string that identifies a Team. This is externally referred to as a "Workspace". required: true schema: type: string path_card_id: in: path name: card_id description: Card ID is a numerical string that identifies a card. required: true schema: type: string schemas: AddLinkedCardRequest: type: object required: - card_id - linked_card_type properties: card_id: type: string example: '41' description: ID of the card which was linked with current card linked_card_type: $ref: '#/components/schemas/LinkedCardType' AddLinkedCardResponse: type: object properties: linked_card: $ref: '#/components/schemas/LinkedCard' Error: type: object properties: id: type: string example: err5f744ab code: type: integer format: int32 example: 403 sec: $ref: '#/components/schemas/SuperthreadErrorCode' message: type: string example: You do not have access to this resource description: A user-friendly error message date: $ref: '#/components/schemas/STime' LinkedCardType: type: string enum: - blocks - blocked_by - related - duplicates example: blocks LinkedCard: type: object properties: title: type: string example: Create illustration for upcoming holidays card_id: type: string example: '42' x-go-custom-tag: diff:"card_id,identifier" user_id: type: string example: '42' project_id: type: string example: '3' board_id: type: string example: '15' board_title: type: string example: Ideas list_id: type: string example: list 1 list_title: type: string example: list 1 status: $ref: '#/components/schemas/CardStatus' archived: $ref: '#/components/schemas/Archived' linked_card_type: $ref: '#/components/schemas/LinkedCardType' icon: $ref: '#/components/schemas/Image' SuperthreadErrorCode: type: string description: | Superthread Error Code (`SEC`): A structured error code. Format: `SEC:{ServiceID}-{InternalErrorCode}`. - `SEC`: Prefix for all structured error codes. - `ServiceID`: First 3 characters identify the service, '000' is reserved for generic errors. - `InternalErrorCode`: the next (last) 5 characters define the specific error. pattern: ^SEC:\d{3}-\d{5}$ example: SEC:000-00014 STime: type: integer format: int64 example: 1608742037016 description: unix timestamp in seconds x-go-type: type: STime import: package: github.com/superthread-com/common/pkg/types hints: noValidation: true kind: primitive CardStatus: type: string enum: - committed - started - completed - cancelled example: started Archived: type: object properties: user_id: type: string example: uDsu0j19 time_archived: $ref: '#/components/schemas/STime' Image: type: object required: - type - src properties: type: type: string enum: - image - icon - emoji nullable: false id: type: string description: Unique identifier for the image (optional). src: type: string example: >- data:image/png;base64, iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg== description: >- Depending on the type this can be a URL, base64 image data, emoji unicode or an icon name nullable: false blurhash: type: string example: LEHV6nWB2yk8pyoJadR*.7kCMdnj x-go-custom-tag: dynamodbav:",omitempty" color: type: string example: black x-go-custom-tag: dynamodbav:",omitempty" emoji: type: string example: thumbsup description: Emoji string ID x-go-custom-tag: dynamodbav:",omitempty" securitySchemes: BearerAuth: type: http scheme: bearer ````