linear_addIssueLabel

Instructions

Implementation Reference

• src/tools/handlers/issue-handlers.ts:117-133 (handler)

  The handler function that implements the core logic of the linear_addIssueLabel tool. It validates the input arguments using the type guard and delegates to the LinearService to add the label to the issue.

  /**
   * Handler for adding a label to an issue
   */
  export function handleAddIssueLabel(linearService: LinearService) {
    return async (args: unknown) => {
      try {
        if (!isAddIssueLabelArgs(args)) {
          throw new Error("Invalid arguments for addIssueLabel");
        }
        
        return await linearService.addIssueLabel(args.issueId, args.labelId);
      } catch (error) {
        logError("Error adding label to issue", error);
        throw error;
      }
    };
  }

• src/tools/definitions/issue-tools.ts:393-421 (schema)

  The schema definition (MCPToolDefinition) for the linear_addIssueLabel tool, specifying input parameters (issueId, labelId) and output structure.

  /**
   * Tool definition for adding a label to an issue
   */
  export const addIssueLabelToolDefinition: MCPToolDefinition = {
    name: "linear_addIssueLabel",
    description: "Add a label to an issue in Linear",
    input_schema: {
      type: "object",
      properties: {
        issueId: {
          type: "string",
          description: "ID or identifier of the issue to add the label to (e.g., ABC-123)",
        },
        labelId: {
          type: "string",
          description: "ID of the label to add to the issue",
        },
      },
      required: ["issueId", "labelId"],
    },
    output_schema: {
      type: "object",
      properties: {
        success: { type: "boolean" },
        issueId: { type: "string" },
        labelId: { type: "string" }
      }
    }
  };

• src/tools/handlers/index.ts:51-101 (registration)

  The registration of the linear_addIssueLabel handler within the registerToolHandlers function, which maps tool names to their handler functions for the MCP server.

  export function registerToolHandlers(linearService: LinearService) {
    return {
      // User tools
      linear_getViewer: handleGetViewer(linearService),
      linear_getOrganization: handleGetOrganization(linearService),
      linear_getUsers: handleGetUsers(linearService),
      linear_getLabels: handleGetLabels(linearService),
  
      // Team tools
      linear_getTeams: handleGetTeams(linearService),
      linear_getWorkflowStates: handleGetWorkflowStates(linearService),
  
      // Project tools
      linear_getProjects: handleGetProjects(linearService),
      linear_createProject: handleCreateProject(linearService),
      
      // Project Management tools
      linear_updateProject: handleUpdateProject(linearService),
      linear_addIssueToProject: handleAddIssueToProject(linearService),
      linear_getProjectIssues: handleGetProjectIssues(linearService),
      
      // Cycle Management tools
      linear_getCycles: handleGetCycles(linearService),
      linear_getActiveCycle: handleGetActiveCycle(linearService),
      linear_addIssueToCycle: handleAddIssueToCycle(linearService),
  
      // Issue tools
      linear_getIssues: handleGetIssues(linearService),
      linear_getIssueById: handleGetIssueById(linearService),
      linear_searchIssues: handleSearchIssues(linearService),
      linear_createIssue: handleCreateIssue(linearService),
      linear_updateIssue: handleUpdateIssue(linearService),
      linear_createComment: handleCreateComment(linearService),
      linear_addIssueLabel: handleAddIssueLabel(linearService),
      linear_removeIssueLabel: handleRemoveIssueLabel(linearService),
      
      // New Issue Management tools
      linear_assignIssue: handleAssignIssue(linearService),
      linear_subscribeToIssue: handleSubscribeToIssue(linearService),
      linear_convertIssueToSubtask: handleConvertIssueToSubtask(linearService),
      linear_createIssueRelation: handleCreateIssueRelation(linearService),
      linear_archiveIssue: handleArchiveIssue(linearService),
      linear_setIssuePriority: handleSetIssuePriority(linearService),
      linear_transferIssue: handleTransferIssue(linearService),
      linear_duplicateIssue: handleDuplicateIssue(linearService),
      linear_getIssueHistory: handleGetIssueHistory(linearService),
      
      // Comment Management tools
      linear_getComments: handleGetComments(linearService)
    };
  }

• src/tools/type-guards.ts:216-230 (helper)

  Type guard function used in the handler to validate the input arguments for the linear_addIssueLabel tool.

   * Type guard for linear_addIssueLabel tool arguments
   */
  export function isAddIssueLabelArgs(args: unknown): args is {
    issueId: string;
    labelId: string;
  } {
    return (
      typeof args === "object" &&
      args !== null &&
      "issueId" in args &&
      typeof (args as { issueId: string }).issueId === "string" &&
      "labelId" in args &&
      typeof (args as { labelId: string }).labelId === "string"
    );
  }