fix: add get_pr_review_comments tool to fetch PR review comments with auth (#1043)

* feat: add get_pr_review_comments tool for authenticated GitHub API access

The agent was asking users to paste PR review comments because it had no
tool to fetch them with auth. This adds get_pr_review_comments, which uses
the GitHub App installation token to fetch all three comment types (thread
comments, inline review comments, review submissions) from private repos.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* u

* u

---------

Co-authored-by: Forge Agent <agent@forge.ai>
Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>
Co-authored-by: Palash Shah <palash@langchain.dev>
Co-authored-by: Palash Shah <35114859+Palashio@users.noreply.github.com>
Co-authored-by: open-swe[bot] <open-swe@users.noreply.github.com>

agent/prompt.py

@@ -153,7 +153,10 @@ Format messages using Slack's mrkdwn format, NOT standard Markdown.
     To mention/tag a user, use `<@USER_ID>` (e.g. `<@U06KD8BFY95>`). You can find user IDs in the conversation context next to display names (e.g. `@Name(U06KD8BFY95)`).
 
 #### `github_comment`
-Posts a comment to a GitHub issue or pull request. Provide the `issue_number` explicitly. Use this when the task was triggered from GitHub — to reply with updates, answers, or a summary after completing work."""
+Posts a comment to a GitHub issue or pull request. Provide the `issue_number` explicitly. Use this when the task was triggered from GitHub — to reply with updates, answers, or a summary after completing work.
+
+#### `get_pr_review_comments`
+Fetches all review comments on a GitHub pull request (thread comments, inline review comments, and review submissions), sorted chronologically. Requires `pr_number`. Optionally accepts `repo_owner` and `repo_name` if different from the configured repo. Use this whenever you need to read PR feedback — do NOT ask users to paste comments."""
 
 
 TOOL_BEST_PRACTICES_SECTION = """---

agent/server.py

@@ -40,6 +40,7 @@ from .tools import (
     fetch_url,
     get_branch_name,
     get_pr_review,
+    get_pr_review_comments,
     github_comment,
     http_request,
     linear_comment,
@@ -306,6 +307,7 @@ async def get_agent(config: RunnableConfig) -> Pregel:
             slack_read_thread_messages,
             slack_thread_reply,
             github_comment,
+            get_pr_review_comments,
             list_pr_reviews,
             get_pr_review,
             create_pr_review,

agent/tools/__init__.py

@@ -1,6 +1,7 @@
 from .commit_and_open_pr import commit_and_open_pr
 from .fetch_url import fetch_url
 from .get_branch_name import get_branch_name
+from .get_pr_review_comments import get_pr_review_comments
 from .github_comment import github_comment
 from .github_review import (
     create_pr_review,
@@ -31,6 +32,7 @@ __all__ = [
     "fetch_url",
     "get_branch_name",
     "get_pr_review",
+    "get_pr_review_comments",
     "github_comment",
     "http_request",
     "linear_comment",

agent/tools/get_pr_review_comments.py

@@ -0,0 +1,96 @@
+import asyncio
+from typing import Any
+
+from langgraph.config import get_config
+
+from ..utils.github_app import get_github_app_installation_token
+from ..utils.github_comments import _fetch_paginated
+
+
+def get_pr_review_comments(
+    pr_number: int,
+    repo_owner: str | None = None,
+    repo_name: str | None = None,
+) -> dict[str, Any]:
+    """Fetch all review comments for a GitHub pull request.
+
+    Returns thread comments, inline review comments, and review submissions
+    sorted chronologically.
+    """
+    config = get_config()
+    configurable = config.get("configurable", {})
+    repo_config = configurable.get("repo", {})
+
+    owner = repo_owner or repo_config.get("owner", "")
+    repo = repo_name or repo_config.get("name", "")
+
+    if not owner or not repo:
+        return {
+            "success": False,
+            "error": "No repo config found — provide repo_owner/repo_name or set repo in config",
+        }
+
+    token = asyncio.run(get_github_app_installation_token())
+    if not token:
+        return {"success": False, "error": "Failed to get GitHub App installation token"}
+
+    headers = {
+        "Authorization": f"Bearer {token}",
+        "Accept": "application/vnd.github+json",
+        "X-GitHub-Api-Version": "2022-11-28",
+    }
+
+    base = f"https://api.github.com/repos/{owner}/{repo}"
+
+    async def _fetch_all() -> list[dict[str, Any]]:
+        import httpx
+
+        async with httpx.AsyncClient() as http_client:
+            pr_comments, review_comments, reviews = await asyncio.gather(
+                _fetch_paginated(http_client, f"{base}/issues/{pr_number}/comments", headers),
+                _fetch_paginated(http_client, f"{base}/pulls/{pr_number}/comments", headers),
+                _fetch_paginated(http_client, f"{base}/pulls/{pr_number}/reviews", headers),
+            )
+        all_comments: list[dict[str, Any]] = []
+
+        for c in pr_comments:
+            all_comments.append(
+                {
+                    "body": c.get("body", ""),
+                    "author": c.get("user", {}).get("login", "unknown"),
+                    "created_at": c.get("created_at", ""),
+                    "type": "pr_comment",
+                    "comment_id": c.get("id"),
+                }
+            )
+        for c in review_comments:
+            all_comments.append(
+                {
+                    "body": c.get("body", ""),
+                    "author": c.get("user", {}).get("login", "unknown"),
+                    "created_at": c.get("created_at", ""),
+                    "type": "review_comment",
+                    "comment_id": c.get("id"),
+                    "path": c.get("path", ""),
+                    "line": c.get("line") or c.get("original_line"),
+                }
+            )
+        for r in reviews:
+            body = r.get("body", "")
+            if not body:
+                continue
+            all_comments.append(
+                {
+                    "body": body,
+                    "author": r.get("user", {}).get("login", "unknown"),
+                    "created_at": r.get("submitted_at", ""),
+                    "type": "review",
+                    "comment_id": r.get("id"),
+                }
+            )
+
+        all_comments.sort(key=lambda c: c.get("created_at", ""))
+        return all_comments
+
+    comments = asyncio.run(_fetch_all())
+    return {"success": True, "pr_number": pr_number, "total": len(comments), "comments": comments}

tests/test_get_pr_review_comments.py

@@ -0,0 +1,289 @@
+"""Tests for get_pr_review_comments tool."""
+
+from __future__ import annotations
+
+from typing import Any
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from agent.tools.get_pr_review_comments import get_pr_review_comments
+
+
+@pytest.fixture()
+def repo_config() -> dict[str, str]:
+    return {"owner": "langchain-ai", "name": "open-swe"}
+
+
+@pytest.fixture()
+def mock_langgraph_config(repo_config: dict[str, str]) -> MagicMock:
+    config = MagicMock()
+    config.get.return_value = {"repo": repo_config}
+    return config
+
+
+def _make_pr_comment(
+    body: str = "LGTM",
+    login: str = "reviewer",
+    created_at: str = "2026-03-01T10:00:00Z",
+    comment_id: int = 1,
+) -> dict[str, Any]:
+    return {
+        "body": body,
+        "user": {"login": login},
+        "created_at": created_at,
+        "id": comment_id,
+    }
+
+
+def _make_review_comment(
+    body: str = "Nit: rename this",
+    login: str = "reviewer",
+    created_at: str = "2026-03-01T11:00:00Z",
+    comment_id: int = 2,
+    path: str = "src/foo.py",
+    line: int = 42,
+) -> dict[str, Any]:
+    return {
+        "body": body,
+        "user": {"login": login},
+        "created_at": created_at,
+        "id": comment_id,
+        "path": path,
+        "line": line,
+    }
+
+
+def _make_review(
+    body: str = "Looks good, minor nit",
+    login: str = "reviewer",
+    submitted_at: str = "2026-03-01T12:00:00Z",
+    review_id: int = 3,
+) -> dict[str, Any]:
+    return {
+        "body": body,
+        "user": {"login": login},
+        "submitted_at": submitted_at,
+        "id": review_id,
+    }
+
+
+class TestGetPrReviewComments:
+    """Tests for the get_pr_review_comments tool."""
+
+    def test_returns_formatted_comments_from_all_three_sources(
+        self, mock_langgraph_config: MagicMock, repo_config: dict[str, str]
+    ) -> None:
+        pr_comments = [_make_pr_comment(body="Thread comment", comment_id=10)]
+        review_comments = [_make_review_comment(body="Inline comment", comment_id=20)]
+        reviews = [_make_review(body="Review body", review_id=30)]
+
+        with (
+            patch(
+                "agent.tools.get_pr_review_comments.get_config", return_value=mock_langgraph_config
+            ),
+            patch(
+                "agent.tools.get_pr_review_comments.get_github_app_installation_token",
+                new_callable=AsyncMock,
+                return_value="ghs_token123",
+            ),
+            patch(
+                "agent.tools.get_pr_review_comments._fetch_paginated",
+                new_callable=AsyncMock,
+                side_effect=[pr_comments, review_comments, reviews],
+            ),
+        ):
+            result = get_pr_review_comments(pr_number=42)
+
+        assert result["success"] is True
+        assert "comments" in result
+        assert len(result["comments"]) == 3
+        bodies = [c["body"] for c in result["comments"]]
+        assert "Thread comment" in bodies
+        assert "Inline comment" in bodies
+        assert "Review body" in bodies
+
+    def test_inline_review_comments_include_path_and_line(
+        self, mock_langgraph_config: MagicMock
+    ) -> None:
+        review_comments = [_make_review_comment(path="agent/tools/foo.py", line=17)]
+
+        with (
+            patch(
+                "agent.tools.get_pr_review_comments.get_config", return_value=mock_langgraph_config
+            ),
+            patch(
+                "agent.tools.get_pr_review_comments.get_github_app_installation_token",
+                new_callable=AsyncMock,
+                return_value="ghs_token123",
+            ),
+            patch(
+                "agent.tools.get_pr_review_comments._fetch_paginated",
+                new_callable=AsyncMock,
+                side_effect=[[], review_comments, []],
+            ),
+        ):
+            result = get_pr_review_comments(pr_number=42)
+
+        assert result["success"] is True
+        assert len(result["comments"]) == 1
+        comment = result["comments"][0]
+        assert comment["path"] == "agent/tools/foo.py"
+        assert comment["line"] == 17
+        assert comment["type"] == "review_comment"
+
+    def test_uses_repo_config_from_get_config_when_no_owner_name_provided(
+        self, mock_langgraph_config: MagicMock
+    ) -> None:
+        with (
+            patch(
+                "agent.tools.get_pr_review_comments.get_config", return_value=mock_langgraph_config
+            ) as mock_cfg,
+            patch(
+                "agent.tools.get_pr_review_comments.get_github_app_installation_token",
+                new_callable=AsyncMock,
+                return_value="ghs_token123",
+            ),
+            patch(
+                "agent.tools.get_pr_review_comments._fetch_paginated",
+                new_callable=AsyncMock,
+                side_effect=[[], [], []],
+            ) as mock_fetch,
+        ):
+            get_pr_review_comments(pr_number=5)
+
+        mock_cfg.assert_called_once()
+        # Verify the URLs passed to _fetch_paginated use the configured owner/repo
+        called_urls = [call.args[1] for call in mock_fetch.call_args_list]
+        assert all("langchain-ai/open-swe" in url for url in called_urls)
+
+    def test_accepts_explicit_repo_owner_and_name(self) -> None:
+        config = MagicMock()
+        config.get.return_value = {"repo": {"owner": "other-org", "name": "other-repo"}}
+
+        with (
+            patch("agent.tools.get_pr_review_comments.get_config", return_value=config),
+            patch(
+                "agent.tools.get_pr_review_comments.get_github_app_installation_token",
+                new_callable=AsyncMock,
+                return_value="ghs_token123",
+            ),
+            patch(
+                "agent.tools.get_pr_review_comments._fetch_paginated",
+                new_callable=AsyncMock,
+                side_effect=[[], [], []],
+            ) as mock_fetch,
+        ):
+            result = get_pr_review_comments(
+                pr_number=7, repo_owner="explicit-org", repo_name="explicit-repo"
+            )
+
+        assert result["success"] is True
+        called_urls = [call.args[1] for call in mock_fetch.call_args_list]
+        assert all("explicit-org/explicit-repo" in url for url in called_urls)
+
+    def test_handles_auth_failure_gracefully(self, mock_langgraph_config: MagicMock) -> None:
+        with (
+            patch(
+                "agent.tools.get_pr_review_comments.get_config", return_value=mock_langgraph_config
+            ),
+            patch(
+                "agent.tools.get_pr_review_comments.get_github_app_installation_token",
+                new_callable=AsyncMock,
+                return_value=None,
+            ),
+        ):
+            result = get_pr_review_comments(pr_number=42)
+
+        assert result["success"] is False
+        assert "token" in result["error"].lower()
+
+    def test_handles_missing_repo_config(self) -> None:
+        config = MagicMock()
+        config.get.return_value = {}  # no "repo" key
+
+        with patch("agent.tools.get_pr_review_comments.get_config", return_value=config):
+            result = get_pr_review_comments(pr_number=42)
+
+        assert result["success"] is False
+        assert "repo" in result["error"].lower()
+
+    def test_skips_reviews_with_empty_body(self, mock_langgraph_config: MagicMock) -> None:
+        reviews = [
+            _make_review(body="", review_id=1),
+            _make_review(body="Approved", review_id=2),
+        ]
+
+        with (
+            patch(
+                "agent.tools.get_pr_review_comments.get_config", return_value=mock_langgraph_config
+            ),
+            patch(
+                "agent.tools.get_pr_review_comments.get_github_app_installation_token",
+                new_callable=AsyncMock,
+                return_value="ghs_token123",
+            ),
+            patch(
+                "agent.tools.get_pr_review_comments._fetch_paginated",
+                new_callable=AsyncMock,
+                side_effect=[[], [], reviews],
+            ),
+        ):
+            result = get_pr_review_comments(pr_number=42)
+
+        assert result["success"] is True
+        assert len(result["comments"]) == 1
+        assert result["comments"][0]["body"] == "Approved"
+
+    def test_comments_sorted_chronologically(self, mock_langgraph_config: MagicMock) -> None:
+        pr_comments = [
+            _make_pr_comment(body="Third", created_at="2026-03-01T13:00:00Z", comment_id=3)
+        ]
+        review_comments = [
+            _make_review_comment(body="First", created_at="2026-03-01T10:00:00Z", comment_id=1)
+        ]
+        reviews = [_make_review(body="Second", submitted_at="2026-03-01T12:00:00Z", review_id=2)]
+
+        with (
+            patch(
+                "agent.tools.get_pr_review_comments.get_config", return_value=mock_langgraph_config
+            ),
+            patch(
+                "agent.tools.get_pr_review_comments.get_github_app_installation_token",
+                new_callable=AsyncMock,
+                return_value="ghs_token123",
+            ),
+            patch(
+                "agent.tools.get_pr_review_comments._fetch_paginated",
+                new_callable=AsyncMock,
+                side_effect=[pr_comments, review_comments, reviews],
+            ),
+        ):
+            result = get_pr_review_comments(pr_number=42)
+
+        assert result["success"] is True
+        bodies = [c["body"] for c in result["comments"]]
+        assert bodies == ["First", "Second", "Third"]
+
+    def test_returns_total_count(self, mock_langgraph_config: MagicMock) -> None:
+        pr_comments = [_make_pr_comment(comment_id=1), _make_pr_comment(comment_id=2)]
+
+        with (
+            patch(
+                "agent.tools.get_pr_review_comments.get_config", return_value=mock_langgraph_config
+            ),
+            patch(
+                "agent.tools.get_pr_review_comments.get_github_app_installation_token",
+                new_callable=AsyncMock,
+                return_value="ghs_token123",
+            ),
+            patch(
+                "agent.tools.get_pr_review_comments._fetch_paginated",
+                new_callable=AsyncMock,
+                side_effect=[pr_comments, [], []],
+            ),
+        ):
+            result = get_pr_review_comments(pr_number=42)
+
+        assert result["success"] is True
+        assert result["total"] == 2