DevLens MCP

Instructions

Implementation Reference

• src/devlens/tools/advanced.py:16-65 (handler)

  The implementation of compare_sources function.

  async def compare_sources(topic: str, sources: list[str]) -> str:
      """Compare information across multiple sources.
  
      Args:
          topic: Topic being compared.
          sources: List of URLs to compare.
  
      Returns:
          Comparison report showing differences and similarities.
  
      Example:
          >>> report = await compare_sources(
          ...     "Python async",
          ...     ["https://realpython.com/async", "https://docs.python.org/3/library/asyncio.html"]
          ... )
      """
      if len(sources) < 2:
          return "Error: Need at least 2 sources to compare"
  
      if len(sources) > 5:
          sources = sources[:5]  # Limit to 5 sources
  
      # Fetch all sources in parallel
      async def fetch_with_title(url: str) -> tuple[str, str, str | None]:
          """Fetch source and return (url, title, content)."""
          try:
              doc = await _scraper.fetch(url, retry=1)
              return (url, doc.title, doc.content)
          except Exception:
              return (url, "Failed", None)
  
      results = await asyncio.gather(*[fetch_with_title(url) for url in sources])
  
      # Build comparison report
      report_lines = [
          f"# Source Comparison: {topic}\n",
          "## Sources\n",
      ]
  
      for i, (url, title, _) in enumerate(results, 1):
          status = "✓" if results[i - 1][2] else "✗"
          report_lines.append(f"{i}. {status} [{title}]({url})")
  
      report_lines.append("\n## Content Analysis\n")
  
      # Extract key terms from each source
      import re
  
      all_words: list[list[str]] = []
      for _, _, content in results:

• src/devlens/server.py:115-127 (registration)

  The MCP tool wrapper tool_compare_sources which calls compare_sources.

  async def tool_compare_sources(topic: str, sources: list[str]) -> str:
      """Compare information across multiple sources.
  
      Analyzes differences and similarities between sources.
  
      Args:
          topic: Topic being compared.
          sources: List of URLs (2-5) to compare.
  
      Returns:
          Comparison report with common topics and differences.
      """
      return await compare_sources(topic, sources)