char-index-mcp

Instructions

Implementation Reference

• char_index_mcp/server.py:117-143 (handler)

  The handler function for the 'split_at_indices' tool. Decorated with @mcp.tool() for automatic registration in FastMCP. Takes text and list of indices, sorts/deduplicates/validates indices, and splits the text into parts at those positions, returning list of strings.

  @mcp.tool()
  def split_at_indices(
      text: Annotated[str, "Text to split"],
      indices: Annotated[list[int], "Split positions (auto-sorted & deduplicated)"]
  ) -> list[str]:
      """Split text at exact index positions. Indices auto-sorted and deduplicated."""
      if not indices:
          return [text]
      
      # Sort and remove duplicates
      sorted_indices = sorted(set(indices))
      
      # Validate
      for idx in sorted_indices:
          if idx < 0 or idx > len(text):
              raise ValueError(f"Index {idx} out of bounds [0, {len(text)}]")
      
      result = []
      start = 0
      
      for idx in sorted_indices:
          result.append(text[start:idx])
          start = idx
      
      result.append(text[start:])
      
      return result