linear_addIssueLabel

Add a label to a Linear issue using its ID and label ID to organize and categorize project tasks.

Instructions

Add a label to an issue in Linear

Input Schema

TableJSON Schema

Name	Required	Description	Default
`issueId`	Yes	ID or identifier of the issue to add the label to (e.g., ABC-123)
`labelId`	Yes	ID of the label to add to the issue

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"
  );
}

Linear MCP Server