gitlab-mcp-server

Instructions

Implementation Reference

• src/index.ts:144-148 (registration)

  Registration of the 'create_merge_request' tool in the ALL_TOOLS array, including name, description, input schema, and read-only flag.

  {
    name: "create_merge_request",
    description: "Create a new merge request in a GitLab project",
    inputSchema: createJsonSchema(CreateMergeRequestSchema),
    readOnly: false

• src/index.ts:408-412 (handler)

  MCP tool handler in the switch statement: parses arguments with CreateMergeRequestSchema, extracts project_id and options, calls gitlabApi.createMergeRequest, and returns JSON response.

  case "create_merge_request": {
    const args = CreateMergeRequestSchema.parse(request.params.arguments);
    const { project_id, ...options } = args;
    const mergeRequest = await gitlabApi.createMergeRequest(project_id, options);
    return { content: [{ type: "text", text: JSON.stringify(mergeRequest, null, 2) }] };

• src/schemas.ts:426-428 (schema)

  CreateMergeRequestSchema definition, which merges project_id with CreateMergeRequestOptionsSchema for input validation.

  export const CreateMergeRequestSchema = z.object({
    project_id: z.string()
  }).merge(CreateMergeRequestOptionsSchema);

• src/schemas.ts:382-389 (schema)

  CreateMergeRequestOptionsSchema defining input fields: title, description, source_branch, target_branch, allow_collaboration, draft.

  export const CreateMergeRequestOptionsSchema = z.object({
    title: z.string(),
    description: z.string().optional(),
    source_branch: z.string(),
    target_branch: z.string(),
    allow_collaboration: z.boolean().optional(),
    draft: z.boolean().optional()
  });

• src/gitlab-api.ts:728-780 (handler)

  Core implementation of createMergeRequest in GitLabApi class: makes POST request to GitLab API to create merge request and parses response.

  async createMergeRequest(
    projectId: string,
    options: z.infer<typeof CreateMergeRequestOptionsSchema>
  ): Promise<GitLabMergeRequest> {
    const response = await fetch(
      `${this.apiUrl}/projects/${encodeURIComponent(projectId)}/merge_requests`,
      {
        method: "POST",
        headers: {
          "Authorization": `Bearer ${this.token}`,
          "Content-Type": "application/json"
        },
        body: JSON.stringify({
          title: options.title,
          description: options.description,
          source_branch: options.source_branch,
          target_branch: options.target_branch,
          allow_collaboration: options.allow_collaboration,
          draft: options.draft
        })
      }
    );
  
    if (!response.ok) {
      throw new McpError(
        ErrorCode.InternalError,
        `GitLab API error: ${response.statusText}`
      );
    }
  
    const responseData = await response.json() as Record<string, any>;
  
    return {
      id: responseData.id,
      iid: responseData.iid,
      project_id: responseData.project_id,
      title: responseData.title,
      description: responseData.description || null,
      state: responseData.state,
      merged: responseData.merged,
      author: responseData.author,
      assignees: responseData.assignees || [],
      source_branch: responseData.source_branch,
      target_branch: responseData.target_branch,
      diff_refs: responseData.diff_refs || null,
      web_url: responseData.web_url,
      created_at: responseData.created_at,
      updated_at: responseData.updated_at,
      merged_at: responseData.merged_at,
      closed_at: responseData.closed_at,
      merge_commit_sha: responseData.merge_commit_sha
    };
  }