# Add Review Comment

> Post a single inline review comment to a GitHub pull request. Use when you need to leave one comment on a specific line or line range of a PR via the GitHub API — supports single-line and multi-line anchors and one-click suggestion blocks.

- Skill: `bossjones/add-review-comment` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds@latest add bossjones/add-review-comment`
- Raw SKILL.md: https://api.skillmd.com/api/skills/bossjones/add-review-comment/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: bossjones (https://skillmd.com/u/bossjones)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/bossjones/add-review-comment

---


# Add Review Comment

Posts one inline review comment to a specific line in a GitHub pull request
using the GitHub REST API via the `gh` CLI.

This is a pure worker skill: one invocation posts exactly one comment. Give it
the anchor (`path`, `line`, optional range and `side`) and the comment `body`;
it resolves the head commit, posts the comment, and returns the new comment's
`html_url`. It does not decide *what* to review or batch multiple findings — a
caller (such as `pr-review`) drives that and calls this once per finding.

## When to Use

- You have a single finding and want to anchor a comment to the exact line.
- You need a multi-line comment spanning a range of changed lines.
- You want to attach a one-click `suggestion` block to a PR line.

For reviewing a whole PR and emitting a full set of comments, use the
[`pr-review`](../pr-review/SKILL.md) skill instead.

## Step 1: Locate the line to comment on

Invoke the [`fetch-diff`](../fetch-diff/SKILL.md) skill to fetch the PR diff with
line numbers, then identify the `path`, `line`, and `side` to anchor to:

- `side=RIGHT` — added or context lines (the post-merge file). The common case.
- `side=LEFT` — deleted lines (the pre-change file).

## Step 2: Post the comment

**Single-line comment** — the body must end with the
`🤖 Generated with Claude` footer on its own line:

```bash
gh api repos/<owner>/<repo>/pulls/<pr_number>/comments \
  -f body=<comment> \
  -f path=<file_path> \
  -F line=<line_number> \
  -f side=<side> \
  -f commit_id="$(gh pr view <pr_number> --repo <owner>/<repo> --json headRefOid -q .headRefOid)" \
  --jq '.html_url'
```

**Multi-line comment** — anchors a range from `start_line` to `line`:

```bash
gh api repos/<owner>/<repo>/pulls/<pr_number>/comments \
  -f body=<comment> \
  -f path=<file_path> \
  -F start_line=<first_line> \
  -f start_side=<side> \
  -F line=<last_line> \
  -f side=<side> \
  -f commit_id="$(gh pr view <pr_number> --repo <owner>/<repo> --json headRefOid -q .headRefOid)" \
  --jq '.html_url'
```

## Parameters

| Parameter | Meaning |
|-----------|---------|
| `path` | File path relative to the repo root; must have a hunk in the PR diff |
| `line` | Anchor line (for multi-line comments, the last line of the range) |
| `side` | `RIGHT` for added/modified lines, `LEFT` for deleted lines |
| `start_line` / `start_side` | First line of the range (multi-line comments only) |
| `commit_id` | Head commit SHA — resolved inline via `gh pr view` above |

## Best Practices

- Use suggestion blocks for simple fixes maintainers can apply in one click —
  fence with triple backticks and the word `suggestion`, and preserve the
  original indentation exactly:

  ````text
  ```suggestion
  <suggested code here>
  ```
  ````

- For a repeated issue, leave one representative comment rather than flagging
  every instance.
- For bugs, state the problem, why it matters, and a concrete fix.
- Always end the comment body with `🤖 Generated with Claude` on its own line.

## Output

A successful post returns the new comment's `html_url` (a permalink to the
inline comment) — that single URL is what the caller gets back and can surface
or log. A failed post returns a non-zero exit and an HTTP error from `gh api`
(typically 401 for auth or 422 for a bad line anchor); see the troubleshooting
reference for how to read each one.

## Reference Files

- `references/api-reference.md` — consult when constructing the request: the
  `gh api` endpoint, the full parameter table, single-line vs multi-line anchor
  rules, `side` selection, and `suggestion` block syntax.
- `references/troubleshooting.md` — consult when a post fails: auth errors and
  the line-anchor pitfalls behind 422 responses (line not in the diff, wrong
  `side`, stale `commit_id`, inverted `start_line`).

## Related skills

This skill is the "post one comment" worker in the PR-review family. A typical
flow chains them:

- [`fetch-diff`](../fetch-diff/SKILL.md) — fetch the PR diff with real file line
  numbers, so you know which `path`/`line`/`side` to anchor to.
- [`add-review-comment`](./SKILL.md) (this skill) — post a single inline comment
  to one of those lines.
- [`pr-review`](../pr-review/SKILL.md) — review a whole PR and drive this skill
  once per finding.
- [`fetch-unresolved-comments`](../fetch-unresolved-comments/SKILL.md) — read the
  open review threads on a PR, e.g. to follow up on comments left here.