{
  action: "list" | "get" | "diffs" | "compare",
  
  projectId: string,
  
  // For "list" action
  state?: "opened" | "closed" | "merged" | "all",
  scope?: "created_by_me" | "assigned_to_me" | "all",
  author_id?: number,
  assignee_id?: number,
  reviewer_id?: number,
  labels?: string,
  milestone?: string,
  search?: string,
  source_branch?: string,
  target_branch?: string,
  wip?: "yes" | "no",
  order_by?: "created_at" | "updated_at",
  sort?: "asc" | "desc",
  
  // For "get", "diffs"
  mergeRequestIid?: number,
  sourceBranch?: string,      // Alternative to IID
  
  // For "compare"
  from?: string,              // Base ref
  to?: string,                // Head ref
  straight?: boolean,
  
  // Pagination
  per_page?: number,
  page?: number
}

{
  action: "discussions" | "drafts" | "draft",
  
  projectId: string,
  mergeRequestIid: number,
  
  // For "draft" action
  draftNoteId?: number,
  
  // Pagination
  per_page?: number,
  page?: number
}

{
  action: "create" | "update" | "merge",
  
  projectId: string,
  
  // For "update" and "merge"
  mergeRequestIid?: number,
  sourceBranch?: string,      // Alternative to IID
  
  // For "create"
  source_branch?: string,
  target_branch?: string,
  
  // For "create" and "update"
  title?: string,
  description?: string,
  assignee_ids?: number[],
  reviewer_ids?: number[],
  labels?: string,
  milestone_id?: number,
  remove_source_branch?: boolean,
  squash?: boolean,
  draft?: boolean,
  
  // For "merge"
  merge_commit_message?: string,
  squash_commit_message?: string,
  should_remove_source_branch?: boolean,
  merge_when_pipeline_succeeds?: boolean,
  sha?: string
}

{
  action: "comment" | "thread" | "reply" | "update",
  
  projectId: string,
  mergeRequestIid: number,
  
  // For "comment" - simple comment
  body?: string,
  
  // For "thread" - start new discussion
  position?: {
    base_sha: string,
    start_sha: string,
    head_sha: string,
    position_type: "text" | "image",
    old_path?: string,
    new_path?: string,
    old_line?: number,
    new_line?: number
  },
  
  // For "reply"
  discussionId?: string,
  
  // For "update"
  noteId?: number
}

{
  action: "create" | "update" | "publish" | "publish_all" | "delete",
  
  projectId: string,
  mergeRequestIid: number,
  
  // For "update", "publish", "delete"
  draftNoteId?: number,
  
  // For "create" and "update"
  note?: string,
  position?: {
    base_sha: string,
    start_sha: string,
    head_sha: string,
    position_type: "text",
    old_path?: string,
    new_path?: string,
    old_line?: number,
    new_line?: number
  },
  
  // For "create"
  in_reply_to_discussion_id?: string,
  resolve_discussion?: boolean
}