github-sandbox-file-downloader

# GitHub Sandbox File Downloader > Skill by [ara.so](https://ara.so) — Daily 2026 Skills collection. A GitHub Actions-based tool that lets you download files into your repository simply by writing a specially formatted commit message — no CLI, no tokens, no secrets required. --- ## What It Does `github-sandbox` listens for commit messages containing `download:` or `download-zip:` commands. When detected, a GitHub Actions workflow runs and: - **`download:`** — Fetches each URL and saves files individually to `downloads/` using their original filenames. - **`download-zip:`** — Fetches all URLs and bundles them into a single timestamped `.zip` archive in `downloads/`. --- ## Setup ### 1. Fork the Repository Fork [maanimis/github-sandbox](https://github.com/maanimis/github-sandbox) into your GitHub account. ### 2. Enable Read/Write Workflow Permissions 1. Go to your forked repo on GitHub 2. Navigate to **Settings → Actions → General** 3. Scroll to **Workflow permissions** 4. Select **Read and write permissions** 5. Click **Save** No API keys, tokens, or secrets are needed. --- ## Usage Trigger downloads by committing to your repo with a specially formatted commit message. ### Via GitHub Web UI 1. Open any file (e.g., `README.md`) in your repo 2. Click the **pencil icon** (✏️) to edit 3. Make any minor change (a space, blank line, etc.) 4. In the **Commit changes** box, type your download command 5. Select **Commit directly to the `main` branch** 6. Click **Commit changes** ### Via Git CLI ```bash # Download individual files git commit --allow-empty -m "download: https://example.com/file.zip" # Download multiple files git commit --allow-empty -m "download: https://example.com/a.zip https://example.com/b.pdf" # Download and bundle into a ZIP archive git commit --allow-empty -m "download-zip: https://example.com/a.zip https://example.com/b.pdf" git push origin main ``` --- ## Command Reference ### `download:` — Save Files Individually ``` download: URL1 URL2 URL3 ``` **Examples:** ```bash # Single file git commit --allow-empty -m "download: https://example.com/dataset.csv" # Multiple files git commit --allow-empty -m "download: https://example.com/model.bin https://example.com/config.json https://example.com/vocab.txt" ``` **Output:** Files saved individually to `downloads/` with original filenames: ``` downloads/ dataset.csv model.bin config.json vocab.txt ``` --- ### `download-zip:` — Bundle Into ZIP Archive ``` download-zip: URL1 URL2 URL3 ``` **Examples:** ```bash # Single file zipped git commit --allow-empty -m "download-zip: https://example.com/report.pdf" # Multiple files bundled git commit --allow-empty -m "download-zip: https://example.com/a.zip https://example.com/b.pdf https://example.com/c.csv" ``` **Output:** A single timestamped archive in `downloads/`: ``` downloads/ archive_20260423_153012.zip ``` --- ## Command Summary Table | Command | URLs | Output | |---|---|---| | `download: URL` | Single | `downloads/filename.ext` | | `download: URL1 URL2` | Multiple | `downloads/file1.ext`, `downloads/file2.ext` | | `download-zip: URL` | Single | `downloads/archive_YYYYMMDD_HHMMSS.zip` | | `download-zip: URL1 URL2` | Multiple | `downloads/archive_YYYYMMDD_HHMMSS.zip` (all bundled) | --- ## How the Workflow Works The GitHub Actions workflow (`.github/workflows/download.yml`) operates as follows: ```yaml # Conceptual workflow structure on: push: branches: [main] jobs: download: runs-on: ubuntu-latest steps: - name: Check commit message for download command # Parses commit message for "download:" or "download-zip:" # Extracts URLs from the message # Downloads files using curl/wget # Commits results to downloads/ with [skip ci] to prevent loops ``` Key design details: - The workflow uses `[skip ci]` in its own commit message to avoid infinite trigger loops. - If no `download:` or `download-zip:` command is found, the workflow exits without doing anything. - All output files are committed back to the `downloads/` directory automatically. --- ## Checking Download Results 1. Click the **Actions** tab in your repository 2. Click the latest workflow run to monitor progress and view logs 3. After completion, go to the **Code** tab and open `downloads/` to find your files --- ## Common Patterns ### Downloading a Dataset ```bash git commit --allow-empty -m "download: https://raw.githubusercontent.com/datasets/covid-19/main/data/worldwide-aggregated.csv" git push origin main ``` ### Downloading Multiple Assets and Archiving ```bash git commit --allow-empty -m "download-zip: https://example.com/weights.bin https://example.com/tokenizer.json https://example.com/config.yaml" git push origin main ``` ### Downloading a Public GitHub Release Asset ```bash git commit --allow-empty -m "download: https://github.com/owner/repo/releases/download/v1.0.0/binary-linux-amd64.tar.gz" git push origin main ``` --- ## Troubleshooting ### Workflow doesn't trigger - Confirm **Read and write permissions** are enabled under **Settings → Actions → General → Workflow permissions**. - Make sure you committed directly to the `main` branch (not a PR or other branch, unless the workflow is configured otherwise). - Check the **Actions** tab for any failed or skipped runs. ### Files not appearing in `downloads/` - Verify the URLs are publicly accessible — no authentication, login, or VPN required. - Check workflow logs in the **Actions** tab for HTTP errors (403, 404, etc.). - Ensure URLs don't redirect to a login page. ### Workflow runs in an infinite loop - This shouldn't happen — the workflow appends `[skip ci]` to its own commit messages. - If you've modified the workflow file, verify the `[skip ci]` tag is still present in the auto-commit step. ### Multiple URLs not downloading - Ensure URLs are separated by **spaces only** (no commas). - Avoid special characters in the commit message that might break shell parsing. ```bash # ✅ Correct git commit --allow-empty -m "download: https://example.com/a.zip https://example.com/b.zip" # ❌ Incorrect (comma separator) git commit --allow-empty -m "download: https://example.com/a.zip, https://example.com/b.zip" ``` ### Commit message not recognized - The command prefix must be exactly `download:` or `download-zip:` (lowercase, with colon, followed by a space). - The command must appear in the **commit message subject line** (first line), not the body. ```bash # ✅ Correct git commit --allow-empty -m "download: https://example.com/file.zip" # ❌ Won't trigger (wrong prefix) git commit --allow-empty -m "Download: https://example.com/file.zip" ``` --- ## Notes & Limitations - **Public URLs only** — downloads require no authentication. - **GitHub Actions limits apply** — workflow execution time, storage, and API rate limits are subject to your GitHub plan. - **Branch** — by default, the workflow triggers on pushes to `main`. Check `.github/workflows/` if your default branch differs. - **File size** — very large files may hit GitHub repository size limits (typically 100MB per file, 1GB total soft limit).