Problem

When resuming tasks with native protocol, tool_use and tool_result blocks were being converted to text format:

Called read_file with files: [{"path":"config.json"}]

This confused the model, making it think that's how to call tools instead of using the proper OpenAI tool calling format.

Root Cause

The tool-to-text conversion logic added in v2.0 (commit 1d912bd) for XML protocol was running for all protocols. It should only run for XML protocol where tools are text-based, not for native protocol where tools use structured API calls.

Solution

Gate the conversion logic to only run for XML protocol (lines 1433-1465 in Task.ts). Native protocol now preserves tool_use/tool_result blocks, which convertToOpenAiMessages properly transforms to:

{
  "role": "assistant",
  "tool_calls": [{"id": "call_123", "type": "function", ...}]
},
{
  "role": "tool",
  "tool_call_id": "call_123",
  "content": "..."
}

This matches the OpenAI API format documented in tool_calling.md.

Testing

• Added 8 new tests verifying both protocols work correctly
• All 4,173 tests pass (319 test files)
• XML protocol behavior confirmed unchanged via regression tests

Backward Compatibility

Protocol is determined at resume time based on current settings. Old tasks with tool blocks are handled correctly:

• Resume with XML: blocks converted to text (unchanged behavior)
• Resume with native: blocks preserved and properly converted to OpenAI format