Github GraphQL: Latest commits on a particular revision (branch or commit)

github-graphql-latest-branch-or-commit.graphql

{
  repository(owner: "microsoft", name: "vscode") {
    object(expression: "720b72ea268ed1a0001b4be2cac35dbbfd74e079") { 
      ... on Commit {
        id
        history(first: 5) {
          nodes {
            hash: oid
            message
            author {
              name
              date
              user {
                name
              }
            }
          }
        }
      }
    }
  }
}

Also works with a branch name:

{
  repository(owner: "microsoft", name: "vscode") {
    object(expression: "master") { 
      ... on Commit {
        id
        history(first: 5) {
          nodes {
            hash: oid
            message
            author {
              name
              date
              user {
                name
              }
            }
          }
        }
      }
    }
  }
}