diff --git a/src/codegen/extensions/tools/link_annotation.py b/src/codegen/extensions/tools/link_annotation.py
new file mode 100644
index 000000000..45e75f134
--- /dev/null
+++ b/src/codegen/extensions/tools/link_annotation.py
@@ -0,0 +1,125 @@
+"""Tool for viewing PR contents and modified symbols."""
+
+import re
+from enum import StrEnum
+from typing import Callable
+
+from codegen import Codebase
+
+
+class MessageChannel(StrEnum):
+    LINEAR = "linear"
+    MARKDOWN = "markdown"
+    HTML = "html"
+    SLACK = "slack"
+
+
+def format_link_linear(name: str, url: str) -> str:
+    return f"[{name}]({url})"
+
+
+def format_link_markdown(name: str, url: str) -> str:
+    return f"[{name}]({url})"
+
+
+def format_link_html(name: str, url: str) -> str:
+    return f"<a href='{url}'>{name}</a>"
+
+
+def format_link_slack(name: str, url: str) -> str:
+    return f"<{url}|{name}>"
+
+
+LINK_FORMATS: dict[MessageChannel, Callable[[str, str], str]] = {
+    "linear": format_link_linear,
+    "markdown": format_link_markdown,
+    "html": format_link_html,
+    "slack": format_link_slack,
+}
+
+
+def clean_github_url(url: str) -> str:
+    """Clean a GitHub URL by removing access tokens and standardizing format."""
+    # Remove access token if present
+    url = re.sub(r"https://[^@]+@", "https://", url)
+
+    # Ensure it starts with standard github.com
+    if not url.startswith("https://github.com"):
+        url = "https://github.com" + url.split("github.com")[-1]
+
+    return url
+
+
+def format_link(name: str, url: str | None, format: MessageChannel = MessageChannel.SLACK) -> str:
+    # Clean the URL if it's a GitHub URL
+    if url is None:
+        url = ""
+    if "github.com" in url:
+        url = clean_github_url(url)
+    return LINK_FORMATS[format](name, url)
+
+
+def extract_code_snippets(message: str) -> list[str]:
+    """Find all text wrapped in single backticks, excluding content in code blocks.
+
+    Args:
+        message: The message to process
+
+    Returns:
+        List of strings found between single backticks, excluding those in code blocks
+    """
+    # First remove all code blocks (text between ```)
+    code_block_pattern = r"```[^`]*```"
+    message_without_blocks = re.sub(code_block_pattern, "", message)
+
+    # Then find all text wrapped in single backticks
+    matches = re.findall(r"`([^`]+)`", message_without_blocks)
+    return matches
+
+
+def is_likely_filepath(text: str) -> bool:
+    """Check if a string looks like a filepath."""
+    # Common file extensions we want to link
+    extensions = [".py", ".ts", ".tsx", ".jsx", ".js", ".json", ".mdx", ".md", ".yaml", ".yml", ".toml"]
+
+    # Check if it contains a slash (path separator)
+    if "/" in text:
+        return True
+
+    # Check if it ends with a common file extension
+    return any(text.endswith(ext) for ext in extensions)
+
+
+def add_links_to_message(message: str, codebase: Codebase, channel: MessageChannel = MessageChannel.SLACK) -> str:
+    """Add links to symbols and files in a message.
+
+    This function:
+    1. Links code snippets that match symbol names
+    2. Links anything that looks like a filepath
+
+    Args:
+        message: The message to process
+        codebase: The codebase to look up symbols and files in
+        channel: The message channel format to use
+
+    Returns:
+        The message with appropriate links added
+    """
+    snippets = extract_code_snippets(message)
+    for snippet in snippets:
+        # Filepaths
+        if is_likely_filepath(snippet):
+            file = codebase.get_file(snippet, optional=True)
+            if file:
+                link = format_link(snippet, file.github_url, channel)
+                message = message.replace(f"`{snippet}`", link)
+
+        # Symbols
+        else:
+            symbols = codebase.get_symbols(snippet)
+            # Only link if there's exactly one symbol
+            if len(symbols) == 1:
+                link = format_link(symbols[0].name, symbols[0].github_url, channel)
+                message = message.replace(f"`{snippet}`", link)
+
+    return message
diff --git a/src/codegen/sdk/core/file.py b/src/codegen/sdk/core/file.py
index 540800190..e857273f4 100644
--- a/src/codegen/sdk/core/file.py
+++ b/src/codegen/sdk/core/file.py
@@ -223,7 +223,11 @@ def owners(self) -> set[str]:
     @noapidoc
     def github_url(self) -> str | None:
         if self.ctx.base_url:
-            return self.ctx.base_url + "/" + self.file_path
+            if self.ctx.base_url.endswith(".git"):
+                print("HERE")
+                return self.ctx.base_url.replace(".git", "/blob/develop/") + self.file_path
+            else:
+                return self.ctx.base_url + "/" + self.file_path
 
     @property
     @reader
diff --git a/tests/unit/codegen/extensions/langchain/__init__.py b/tests/unit/codegen/extensions/langchain/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/tests/unit/codegen/extensions/langchain/test_agent.py b/tests/unit/codegen/extensions/langchain/test_agent.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/tests/unit/codegen/extensions/test_message_annotation.py b/tests/unit/codegen/extensions/test_message_annotation.py
new file mode 100644
index 000000000..0063c27e0
--- /dev/null
+++ b/tests/unit/codegen/extensions/test_message_annotation.py
@@ -0,0 +1,194 @@
+"""Tests for message annotation functionality."""
+
+import pytest
+
+from codegen.extensions.tools.link_annotation import (
+    MessageChannel,
+    add_links_to_message,
+    extract_code_snippets,
+    format_link,
+    is_likely_filepath,
+)
+from codegen.sdk.codebase.factory.get_session import get_codebase_session
+
+
+@pytest.fixture
+def codebase(tmpdir):
+    """Create a simple codebase for testing."""
+    # language=python
+    content = """
+def hello():
+    print("Hello, world!")
+
+class Greeter:
+    def greet(self):
+        hello()
+
+def hello_duplicate():
+    pass
+
+def hello_duplicate():
+    pass
+
+class Greeter_duplicate:
+    pass
+"""
+    # Create multiple files to test file linking
+    files = {
+        "src/main.py": content,
+        "src/utils/helpers.py": "# Helper functions",
+        "docs/README.md": "# Documentation",
+        "tsconfig.json": "{}",
+    }
+    with get_codebase_session(tmpdir=tmpdir, files=files) as codebase:
+        yield codebase
+
+
+def test_format_link_linear():
+    """Test linear link formatting."""
+    assert format_link("test", "http://example.com", MessageChannel.LINEAR) == "[test](http://example.com)"
+
+
+def test_format_link_markdown():
+    """Test markdown link formatting."""
+    assert format_link("test", "http://example.com", MessageChannel.MARKDOWN) == "[test](http://example.com)"
+
+
+def test_format_link_html():
+    """Test HTML link formatting."""
+    assert format_link("test", "http://example.com", MessageChannel.HTML) == "<a href='http://example.com'>test</a>"
+
+
+def test_format_link_slack():
+    """Test Slack link formatting."""
+    assert format_link("test", "http://example.com", MessageChannel.SLACK) == "<http://example.com|test>"
+
+
+def test_extract_code_snippets():
+    """Test extracting code snippets from messages."""
+    message = "Here is some `code` and `more code` and ```a code block``` and `final code`"
+    snippets = extract_code_snippets(message)
+    assert snippets == ["code", "more code", "final code"]
+
+
+def test_is_likely_filepath():
+    """Test filepath detection."""
+    # Should detect paths with slashes
+    assert is_likely_filepath("src/file.py")
+    assert is_likely_filepath("path/to/file")
+
+    # Should detect common extensions
+    assert is_likely_filepath("file.py")
+    assert is_likely_filepath("component.tsx")
+    assert is_likely_filepath("config.json")
+    assert is_likely_filepath("README.md")
+
+    # Should not detect regular words
+    assert not is_likely_filepath("hello")
+    assert not is_likely_filepath("Greeter")
+    assert not is_likely_filepath("function")
+
+
+def test_add_links_single_symbol(codebase):
+    """Test adding links for a single symbol."""
+    message = "Here is the `hello` function"
+    result = add_links_to_message(message, codebase, channel=MessageChannel.SLACK)
+    assert "|hello>" in result
+
+
+def test_add_links_class(codebase):
+    """Test adding links for a class."""
+    message = "The `Greeter` class"
+    result = add_links_to_message(message, codebase)
+    assert "Greeter" in result
+    assert result.count("<") == 1  # One link should be created
+
+
+def test_add_links_filepath(codebase):
+    """Test adding links for filepaths."""
+    message = "Check out `src/main.py` and `src/utils/helpers.py`"
+    result = add_links_to_message(message, codebase)
+    assert "|src/main.py>" in result
+    assert "|src/utils/helpers.py>" in result
+
+
+def test_add_links_filepath_with_extension(codebase):
+    """Test adding links for files with common extensions."""
+    message = "See `tsconfig.json` and `docs/README.md`"
+    result = add_links_to_message(message, codebase)
+    assert "|tsconfig.json>" in result
+    assert "|docs/README.md>" in result
+
+
+def test_nonexistent_filepath(codebase):
+    """Test handling of nonexistent filepaths."""
+    message = "This `src/nonexistent.py` should not be linked"
+    result = add_links_to_message(message, codebase)
+    assert result == message  # Message should remain unchanged
+
+
+def test_ignore_code_blocks(codebase):
+    """Test that code blocks are ignored."""
+    message = """Here's a code block:
+```python
+def hello():
+    print("Hello!")
+```
+And here's an inline `hello` reference."""
+
+    result = add_links_to_message(message, codebase)
+    # The inline reference should be linked
+    assert "<" in result
+    # But the code block should remain unchanged
+    assert "```python" in result
+    assert "def hello():" in result
+
+
+def test_nonexistent_symbol(codebase):
+    """Test handling of nonexistent symbols."""
+    message = "This `nonexistent_function` should not be linked"
+    result = add_links_to_message(message, codebase)
+    assert result == message  # Message should remain unchanged
+
+
+def test_duplicate_symbols(codebase):
+    """Test handling of duplicate symbols."""
+    message = "This `hello_duplicate` should not be linked"
+    result = add_links_to_message(message, codebase)
+    assert result == message  # Message should remain unchanged
+
+
+def test_mixed_content(codebase):
+    """Test message with mixed content types."""
+    message = """Here's a complex message:
+- Valid symbol: `hello`
+- Valid file: `src/main.py`
+- Invalid symbol: `nonexistent`
+- Invalid file: `src/nonexistent.py`
+- Code block:
+```python
+def hello():
+    pass
+```
+- Duplicate symbol: `hello_duplicate`
+- Another valid symbol: `Greeter`
+- Another valid file: `docs/README.md`
+"""
+    result = add_links_to_message(message, codebase)
+
+    # Valid symbols should be linked
+    assert "|hello>" in result
+    assert "|Greeter>" in result
+
+    # Valid files should be linked
+    assert "|src/main.py>" in result
+    assert "|docs/README.md>" in result
+
+    # Invalid symbols and files should remain as-is
+    assert "`nonexistent`" in result
+    assert "`src/nonexistent.py`" in result
+    assert "`hello_duplicate`" in result
+
+    # Code block should be preserved
+    assert "```python" in result
+    assert "def hello():" in result