Posting Inline PR Review Comments to GitHub

This skill documents how to post inline review comments to GitHub Pull Requests using the GitHub CLI (gh) and GitHub API. Inline comments appear directly on specific lines of code in the PR diff, making it easier for PR authors to identify and address issues.

When to Use This Skill

Use this skill when you need to:

• Post inline review comments on specific lines of a PR
• Automate code review feedback with targeted comments
• Submit batch review comments via the GitHub API

Prerequisites

1. GitHub CLI installed: Check with gh --version

   • If not installed on Linux:

     curl -fsSL https://cli.github.com/packages/githubcli-archive-keyring.gpg | sudo dd of=/usr/share/keyrings/githubcli-archive-keyring.gpg
     sudo chmod go+r /usr/share/keyrings/githubcli-archive-keyring.gpg
     echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/githubcli-archive-keyring.gpg] https://cli.github.com/packages stable main" | sudo tee /etc/apt/sources.list.d/github-cli.list > /dev/null
     sudo apt update && sudo apt install gh -y
     

2. GitHub CLI authenticated: Check with gh auth status

   • If not authenticated: gh auth login -h github.com -p https --web
   • Follow the device code flow to complete authentication

Method: Using GitHub API with JSON Payload

Step 1: Get the PR's Head Commit SHA

COMMIT_SHA=$(gh api repos/{OWNER}/{REPO}/pulls/{PR_NUMBER} --jq '.head.sha')
echo "Commit SHA: $COMMIT_SHA"

Step 2: Create the Review JSON Payload

Create a JSON file with the review comments. Each comment needs:

• path: The file path relative to repository root
• line: The line number in the new version of the file (right side of diff)
• body: The comment content (supports Markdown)

cat > /tmp/review.json << 'EOF'
{
  "commit_id": "YOUR_COMMIT_SHA_HERE",
  "event": "COMMENT",
  "comments": [
    {
      "path": "src/path/to/file.py",
      "line": 40,
      "body": "🔴 **Critical:** Description of the issue.\n\n**Suggested fix:**\n```python\n# your code here\n```"
    },
    {
      "path": "src/path/to/another_file.py",
      "line": 21,
      "body": "🟡 **Minor:** Another issue description."
    }
  ]
}
EOF

Step 3: Post the Review

gh api repos/{OWNER}/{REPO}/pulls/{PR_NUMBER}/reviews --method POST --input /tmp/review.json

Important Notes

Line Numbers

• The line field refers to the line number in the new version of the file (right side of the diff)
• For deleted lines, use side: "LEFT" and the line number from the old version
• Make sure the line number exists in the diff, otherwise the API will reject the comment

Event Types

Comment Body Formatting

• Supports full GitHub Markdown
• Use \n for newlines in JSON
• Escape special characters properly
• Use emoji prefixes for severity: 🔴 Critical/High, 🟡 Medium/Minor, 🟢 Suggestion

Multi-line Comments

For commenting on a range of lines:

{
  "path": "src/file.py",
  "start_line": 10,
  "line": 15,
  "body": "This comment spans lines 10-15"
}

Troubleshooting

Alternative: Using gh pr review Command

For simpler reviews without inline comments:

gh pr review {PR_NUMBER} --repo {OWNER}/{REPO} --comment --body "Your review comment here"

This posts a general review comment but does not support inline comments on specific lines.

Repository-Specific Information

• Repository: microsoft/semantic-link-labs
• Common file paths:
  • src/sempy_labs/{module}/_items.py
  • src/sempy_labs/{module}/__init__.py
• Review comment conventions:
  • Use severity emojis: 🔴 Critical, 🟡 Medium, 🟢 Minor
  • Include "Suggested fix" with code blocks
  • Reference specific line numbers

Examples

See the examples/ folder for complete working scripts:

• post_pr1059_review.sh - Example script posting inline review comments to PR #1059