char-index-mcp

Instructions

Implementation Reference

• char_index_mcp/server.py:91-110 (handler)

  The handler function for the 'find_all_substring_indices' tool. It is decorated with @mcp.tool() for registration and implements the logic to find all starting indices of the substring in the text, including overlaps, using a loop with str.find.

  @mcp.tool()
  def find_all_substring_indices(
      text: Annotated[str, "Text to search in"],
      substring: Annotated[str, "Substring to find"]
  ) -> list[int]:
      """Find all starting indices where a substring appears (includes overlaps)."""
      if not substring:
          raise ValueError("substring cannot be empty")
      
      indices = []
      start = 0
      
      while True:
          index = text.find(substring, start)
          if index == -1:
              break
          indices.append(index)
          start = index + 1
      
      return indices