GitLab MCP Server

Instructions

Implementation Reference

• src/api/merge-requests.ts:38-64 (handler)

  The actual implementation of the 'createMergeRequest' function that interacts with the GitLab API.

  export async function createMergeRequest(projectId: string, options: CreateMergeRequestOptions): Promise<GitLabMergeRequest> {
    if (!projectId?.trim()) {
      throw new Error("Project ID is required");
    }
    if (!options?.title?.trim()) {
      throw new Error("Merge request title is required");
    }
    if (!options?.source_branch?.trim()) {
      throw new Error("Source branch is required");
    }
    if (!options?.target_branch?.trim()) {
      throw new Error("Target branch is required");
    }
  
    const endpoint = `/projects/${encodeProjectId(projectId)}/merge_requests`;
  
    const mergeRequest = await gitlabPost<GitLabMergeRequest>(endpoint, {
      title: options.title,
      description: options.description,
      source_branch: options.source_branch,
      target_branch: options.target_branch,
      allow_collaboration: options.allow_collaboration,
      draft: options.draft
    });
  
    return GitLabMergeRequestSchema.parse(mergeRequest);
  }

• src/schemas.ts:271-283 (schema)

  Input schema validation for the create_merge_request tool.

  export const CreateMergeRequestSchema = ProjectParamsSchema.extend({
    title: z.string().describe("Merge request title"),
    description: z.string().optional().describe("Merge request description"),
    source_branch: z.string().describe("Branch containing changes"),
    target_branch: z.string().describe("Branch to merge into"),
    draft: z.boolean().optional().describe("Create as draft merge request"),
    allow_collaboration: z.boolean().optional().describe("Allow commits from upstream members")
  });
  
  export const ForkRepositorySchema = ProjectParamsSchema.extend({
    namespace: z.string().optional().describe("Namespace to fork to (full path)")
  });

• src/server.ts:292-303 (registration)

  Tool handler registration for 'create_merge_request' in the server loop.

  case "create_merge_request": {
    const args = CreateMergeRequestSchema.parse(request.params.arguments);
    const { project_id, ...options } = args;
    const mergeRequest = await api.createMergeRequest(project_id, options);
    return { content: [{ type: "text", text: JSON.stringify(mergeRequest, null, 2) }] };
  }
  
  // Label tools
  case "list_labels": {
    const args = ListLabelsSchema.parse(request.params.arguments);
    const labels = await api.listLabels(args.project_id, args.page, args.per_page);
    return { content: [{ type: "text", text: JSON.stringify(labels, null, 2) }] };