gitlab_get_merge_request_details

Retrieve comprehensive details and file changes from a GitLab merge request to review code modifications and track development progress.

Instructions

Fetches detailed information about a GitLab Merge Request, including file diffs.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`mrUrl`	Yes	The URL of the GitLab Merge Request.

Implementation Reference

src/index.ts:69-82 (registration)

Tool registration and input schema definition for gitlab_get_merge_request_details

{
  name: 'gitlab_get_merge_request_details',
  description:
    'Fetches detailed information about a GitLab Merge Request, including file diffs.',
  inputSchema: {
    type: 'object',
    properties: {
      mrUrl: {
        type: 'string',
        description: 'The URL of the GitLab Merge Request.',
      },
    },
    required: ['mrUrl'],
  },

src/index.ts:1214-1229 (handler)

MCP server handler that dispatches the tool call to GitLabService.getMergeRequestDetailsFromUrl

case 'gitlab_get_merge_request_details': {
  if (!gitlabService) {
    throw new Error('GitLab service is not initialized.');
  }
  const { mrUrl } = args as { mrUrl: string };
  const result =
    await gitlabService.getMergeRequestDetailsFromUrl(mrUrl);
  return {
    content: [
      {
        type: 'text',
        text: JSON.stringify(result, null, 2),
      },
    ],
  };
}

src/gitlab.service.ts:154-204 (handler)

Core handler function that fetches MR details from GitLab API, processes changes, parses diffs, and returns structured GitLabMRDetails

async getMergeRequestDetails(
  projectPath: string,
  mrIid: number,
): Promise<GitLabMRDetails> {
  const encodedProjectPath = encodeURIComponent(projectPath);
  const baseUrl = `projects/${encodedProjectPath}/merge_requests/${mrIid}`;

  const mrDetails = await this.callGitLabApi<any>(baseUrl);
  const mrChanges = await this.callGitLabApi<any>(
    `projects/${encodedProjectPath}/merge_requests/${mrIid}/changes`,
  );

  // Map file diffs
  const fileDiffs = mrChanges.changes.map((change: any) => ({
    old_path: change.old_path,
    new_path: change.new_path,
    new_file: change.new_file,
    deleted_file: change.deleted_file,
    renamed_file: change.renamed_file,
    diff: change.diff,
  }));

  const parsedDiffs = fileDiffs.map((diff: any) => ({
    filePath: diff.new_path,
    oldPath: diff.old_path,
    isNew: diff.new_file,
    isDeleted: diff.deleted_file,
    isRenamed: diff.renamed_file,
    hunks: this.parseDiff(diff.diff),
  }));

  return {
    projectPath: mrDetails.path_with_namespace,
    mrIid: mrDetails.iid.toString(),
    projectId: mrDetails.project_id,
    title: mrDetails.title,
    authorName: mrDetails.author.name,
    webUrl: mrDetails.web_url,
    sourceBranch: mrDetails.source_branch,
    targetBranch: mrDetails.target_branch,
    base_sha: mrDetails.diff_refs.base_sha,
    start_sha: mrDetails.diff_refs.start_sha,
    head_sha: mrDetails.diff_refs.head_sha,
    fileDiffs: fileDiffs,
    diffForPrompt: fileDiffs.map((diff: any) => diff.diff).join('\n'),
    parsedDiffs: parsedDiffs,
    fileContents: new Map(), // fileContents will be populated by a separate tool
    discussions: [], // Discussions will be fetched by a separate tool
    existingFeedback: [], // Existing feedback will be derived from discussions
  };
}

src/gitlab.service.ts:207-210 (handler)

Convenience handler that parses MR URL and delegates to getMergeRequestDetails (directly called by MCP handler)

async getMergeRequestDetailsFromUrl(mrUrl: string): Promise<GitLabMRDetails> {
  const { projectPath, mrIid } = this.parseMrUrl(mrUrl, this.config.url);
  return this.getMergeRequestDetails(projectPath, mrIid);
}

src/gitlab.service.ts:120-150 (helper)

Helper function to parse GitLab MR URL into projectPath and mrIid

private parseMrUrl(
  mrUrl: string,
  gitlabBaseUrl: string,
): { projectPath: string; mrIid: number } {
  try {
    const url = new URL(mrUrl);
    const baseUrl = new URL(gitlabBaseUrl);

    // Ensure the URL is from the same GitLab instance
    if (url.origin !== baseUrl.origin) {
      throw new Error(
        `MR URL is not from the configured GitLab instance: ${gitlabBaseUrl}`,
      );
    }

    // Parse the path: /{namespace}/{project}/-/merge_requests/{iid}
    const pathMatch = url.pathname.match(/^\/(.+)\/-\/merge_requests\/(\d+)/);
    if (!pathMatch) {
      throw new Error(`Invalid GitLab MR URL format: ${mrUrl}`);
    }

    const projectPath = pathMatch[1];
    const mrIid = parseInt(pathMatch[2], 10);

    return { projectPath, mrIid };
  } catch (error) {
    throw new Error(
      `Failed to parse GitLab MR URL: ${error instanceof Error ? error.message : String(error)}`,
    );
  }
}

src/gitlab.ts:96-119 (schema)

Type definition for the output schema (GitLabMRDetails interface)

export interface GitLabMRDetails {
  projectPath: string;
  mrIid: string;
  projectId: number;
  title: string;
  authorName: string;
  webUrl: string;
  sourceBranch: string;
  targetBranch: string;
  base_sha: string;
  start_sha: string;
  head_sha: string;
  fileDiffs: FileDiff[];
  diffForPrompt: string;
  parsedDiffs: ParsedFileDiff[];
  fileContents: Map<string, { oldContent?: string[]; newContent?: string[] }>;
  discussions: GitLabDiscussion[];
  existingFeedback: ReviewFeedback[];
  approvals?: {
    approved_by: Array<{ user: { name: string; username: string } }>;
    approvals_left: number;
    approvals_required: number;
  };
}

mcp-gitlab-jira