GitLab MCP Server

Instructions

Implementation Reference

• src/handlers/repository-handlers.ts:168-183 (handler)

  The main handler function that implements the logic for updating a GitLab merge request's title and/or description by making a PUT request to the GitLab API.

  export const updateMergeRequest: ToolHandler = async (params, context) => {
    const { project_id, merge_request_iid, title, description } = params.arguments || {};
    if (!project_id || !merge_request_iid) {
      throw new McpError(ErrorCode.InvalidParams, 'project_id and merge_request_iid are required');
    }
    
    if (!title && !description) {
      throw new McpError(ErrorCode.InvalidParams, 'At least one of title or description is required');
    }
    
    const response = await context.axiosInstance.put(
      `/projects/${encodeURIComponent(String(project_id))}/merge_requests/${merge_request_iid}`,
      { title, description }
    );
    return formatResponse(response.data);
  };

• src/utils/tools-data.ts:172-197 (schema)

  The tool schema definition specifying the input parameters, descriptions, and requirements for the gitlab_update_merge_request tool.

  {
    name: 'gitlab_update_merge_request',
    description: 'Update a merge request title and description',
    inputSchema: {
      type: 'object',
      properties: {
        project_id: {
          type: 'string',
          description: 'The ID or URL-encoded path of the project'
        },
        merge_request_iid: {
          type: 'number',
          description: 'The internal ID of the merge request'
        },
        title: {
          type: 'string',
          description: 'The title of the merge request'
        },
        description: {
          type: 'string',
          description: 'The description of the merge request'
        }
      },
      required: ['project_id', 'merge_request_iid']
    }
  },

• src/utils/tool-registry.ts:32-32 (registration)

  The registration entry in the tool registry that maps the tool name 'gitlab_update_merge_request' to its handler function repoHandlers.updateMergeRequest.

  gitlab_update_merge_request: repoHandlers.updateMergeRequest,