Skip to main content
Get Started

Automating Weekly Reports with OfficeIMO.Excel and GitHub Actions

A real-world guide to building automated Excel reports in CI/CD using OfficeIMO.Excel and GitHub Actions, complete with YAML workflow and C# code.

Every Monday morning, your team lead asks for the same report: open issues by label, pull request merge times, and a trend chart. Instead of rebuilding it manually, you can have GitHub Actions generate the workbook on a schedule and publish it as an artifact or pass it on to the next delivery step.

Architecture

The workflow has three stages:

  1. Fetch data from the GitHub API using the gh CLI.
  2. Generate the Excel report with a small C# console app that uses OfficeIMO.Excel.
  3. Upload the artifact so it can be downloaded or forwarded.

The C# Report Generator

Create a console project:

dotnet new console -n WeeklyReport
cd WeeklyReport
dotnet add package OfficeIMO.Excel
dotnet add package System.Text.Json

The generator reads a JSON file produced by the workflow and writes an Excel workbook:

using System.Text.Json;
using OfficeIMO.Excel;

var issues = JsonSerializer.Deserialize<List<Issue>>(
    File.ReadAllText("issues.json"));

using var workbook = ExcelDocument.Create("WeeklyReport.xlsx");
var sheet = workbook.AddSheet("Open Issues");

// Header row
sheet.SetRow(0, new object[] { "Number", "Title", "Labels", "Created", "Age (days)" });

int row = 1;
foreach (var issue in issues!)
{
    var age = (DateTime.UtcNow - issue.CreatedAt).Days;
    sheet.SetRow(row++, new object[]
    {
        issue.Number,
        issue.Title,
        string.Join(", ", issue.Labels),
        issue.CreatedAt.ToString("yyyy-MM-dd"),
        age
    });
}

sheet.AutoFitColumns();
workbook.Save();
Console.WriteLine($"Report generated with {issues.Count} issues.");

record Issue(int Number, string Title, List<string> Labels, DateTime CreatedAt);

The GitHub Actions Workflow

name: Weekly Report
on:
  schedule:
    - cron: "0 7 * * 1"  # Every Monday at 07:00 UTC
  workflow_dispatch:       # Allow manual trigger

permissions:
  contents: read
  issues: read

jobs:
  generate:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Setup .NET
        uses: actions/setup-dotnet@v4
        with:
          dotnet-version: "8.0.x"

      - name: Fetch open issues
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          gh issue list \
            --repo ${{ github.repository }} \
            --state open \
            --limit 500 \
            --json number,title,labels,createdAt \
            > WeeklyReport/issues.json

      - name: Generate Excel report
        run: dotnet run --project WeeklyReport

      - name: Upload report artifact
        uses: actions/upload-artifact@v4
        with:
          name: weekly-report-${{ github.run_number }}
          path: WeeklyReport/WeeklyReport.xlsx
          retention-days: 30

After each run, the Excel file is available as a downloadable artifact on the workflow run page.

Sending the Report via Email

Add a step using a mail action:

      - name: Send report
        uses: dawidd6/action-send-mail@v3
        with:
          server_address: smtp.office365.com
          server_port: 587
          username: ${{ secrets.MAIL_USER }}
          password: ${{ secrets.MAIL_PASS }}
          subject: "Weekly Issue Report - ${{ github.run_number }}"
          to: [email protected]
          from: [email protected]
          body: "Attached is this week's open-issue report."
          attachments: WeeklyReport/WeeklyReport.xlsx

Extending the Report

Once the skeleton is working, you can add more sheets:

  • PR Merge Times : fetch gh pr list --state merged --json mergedAt,createdAt and compute duration.
  • Label Distribution : pivot issues by label into a summary table.
  • Trend Sheet : append a row to a persistent CSV in the repo and chart it over time.

Each sheet is just another call to workbook.AddSheet() with its own data.

Operational Note

Runner availability, retention limits, and billing depend on your GitHub plan and repository type. Check the current GitHub Actions pricing and usage docs for the exact limits that apply to your environment.

Automating repeatable reports like this can take manual dashboard work out of the loop. OfficeIMO.Excel and GitHub Actions make a straightforward starting point for that workflow.

Continue with