how to get claude code to update PR comment instead of adding new ones

[pdeva]

So every time I push a commit to a PR, Claude Code github action adds a whole brand new pr comment to it instead of modifying the previous comment. Is there any way I can change this behavior so that it would modify the comment instead of adding a new one every time? Currently this results in tons of Claude Code pr comments where the old ones are just completely useless.

[jblemee]

use_sticky_comment does not work ? (Edit: I confirm it does not work for code review)

[nunodonato]

Sorry to kind of hijack the topic. I was also annoyed by this.
I do think it makes sense to make new comments, so I'm not so interested in the use_stick_comment solution. What I think would be interesting is to have Claude take into account its previous reviews, and just add relevant stuff to the new comments instead of repeating the entire review again as a whole.
Any way to achieve this?

[jblemee]

I'm interested. I was thinking about changing the prompt in claude-code-review.yml to tell it to. Did you try it ?

[nunodonato]

I didn't. I'm not so familiar with gh cli, so I'm not sure if Claude is able to actually read what it wrote before

[jblemee]

it can by default (if you followed the standard installation steps)

[service-paradis]

I'm using something like this in my workflow:

    # Find existing Claude review comment to update instead of creating new ones
    - name: Find existing Claude review
        uses: peter-evans/find-comment@v4
        id: find_claude_comment
        with:
          issue-number: ${{ github.event.pull_request.number }}
          body-includes: '<!-- claude-code-review -->'
          
    - name: Run Claude Code Review
        id: claude-review
        uses: anthropics/claude-code-action@v1
        ...
        prompt: |
            REPO: ${{ github.repository }}
            PR NUMBER: ${{ github.event.pull_request.number }}
            ...
            CRITICAL OUTPUT REQUIREMENTS:
            1. Return a JSON object with a "review" field containing your complete markdown review
            2. The review markdown must start with EXACTLY this line (including the HTML comment):
               <!-- claude-code-review -->
               ## PR Review
            3. The HTML comment is required for the workflow to identify and update this comment
            4. Example output format:
               {
                 "review": "<!-- claude-code-review -->\n## PR Review\n\n### Summary\n..."
               }
        claude_args: |
            --allowed-tools "Read,Bash(gh pr diff:*),Bash(gh pr view:*),Bash(gh issue view:*),Bash(gh search:*),Bash(gh issue list:*),Bash(gh pr list:*)"
            --json-schema '{"type":"object","properties":{"review":{"type":"string","description":"Complete markdown review starting with <!-- claude-code-review --> comment"}},"required":["review"]}'
          
    # Create or update the review comment (single comment that gets updated on each run)
      - name: Post or update Claude review
        uses: peter-evans/create-or-update-comment@v5
        with:
          comment-id: ${{ steps.find_claude_comment.outputs.comment-id }}
          issue-number: ${{ github.event.pull_request.number }}
          body: ${{ fromJSON(steps.claude-review.outputs.structured_output).review }}
          edit-mode: replace

[mahirhir]

the action has a built-in use_sticky_comment input for this. set it to true and it updates a single comment instead of creating new ones each run:

- uses: anthropics/claude-code-action@v1
  with:
    use_sticky_comment: true

caveat from the docs: use_sticky_comment only works with the default claude[bot] auth. with a custom github_token (PAT or different app) sticky comments won't update correctly, because the feature finds its own previous comment by the claude[bot] username. in that case the peter-evans/find-comment + create-or-update-comment (edit-mode: replace) pattern in this thread works.