Research: Prompt Engineer Remnants Removal

Research - Prompt Engineer Remnants Removal

Date: 2026-02-01 Owner: agent Phase: Research Git Commit: 35aa99e2

Goal

Identify all remnants of the "prompt engineer" feature that can be removed now that the codebase has returned to a simple prompt system. Exclude toolprompts from consideration.

Findings

Dead Code (Safe to Remove)

Over-Engineered Code (Consider Simplifying)

What IS Used (Do Not Remove)

• resolve_prompt() - Called from agent_config.py:225 to resolve {{CWD}}, {{OS}}, {{DATE}} placeholders
• Built-in placeholder providers (CWD, OS, DATE) - Used in system_prompt.md:124-127

Test File

Documentation

Recommended Removal Strategy

Option A: Minimal (Remove Dead Code Only)

1. Delete compose_prompt() function (lines 82-98)
2. Keep everything else as-is

Option B: Simplify (Flatten the Abstraction)

Replace the entire PromptingEngine class with a simple function:

"""Prompting engine for resolving {{placeholder}} syntax in prompts."""

import os
import platform
import re
from datetime import datetime

_PLACEHOLDER_PATTERN = re.compile(r"\{\{(.+?)\}\}")

_PROVIDERS = {
    "CWD": os.getcwd,
    "OS": platform.system,
    "DATE": lambda: datetime.now().isoformat(),
}

def resolve_prompt(template: str) -> str:
    """Resolve all placeholders in the template."""
    if not template:
        return template

    def replace_match(match: re.Match[str]) -> str:
        name = match.group(1).strip()
        provider = _PROVIDERS.get(name)
        return provider() if provider else match.group(0)

    return _PLACEHOLDER_PATTERN.sub(replace_match, template)

This removes:

• PromptingEngine class
• compose_prompt() function
• register() method
• Singleton pattern
• ~50 lines of code

Option C: Complete Removal (Inline Everything)

If placeholders are rarely changed, inline the resolution directly in agent_config.py:load_system_prompt():

def load_system_prompt(base_path: Path, model: str | None = None) -> str:
    prompt_file = base_path / "prompts" / "system_prompt.md"
    if not prompt_file.exists():
        raise FileNotFoundError(f"Required prompt file not found: {prompt_file}")

    content = prompt_file.read_text(encoding="utf-8")

    # Inline placeholder resolution
    replacements = {
        "{{CWD}}": os.getcwd(),
        "{{OS}}": platform.system(),
        "{{DATE}}": datetime.now().isoformat(),
    }
    for placeholder, value in replacements.items():
        content = content.replace(placeholder, value)

    return content

This would allow deleting the entire src/tunacode/core/prompting/ directory.

Files Affected by Each Option

Option A

• src/tunacode/core/prompting/prompting_engine.py - Remove lines 82-98

Option B

• src/tunacode/core/prompting/prompting_engine.py - Replace entirely
• tests/unit/core/test_prompting_engine.py - Update tests (remove class-based tests)

Option C

• src/tunacode/core/prompting/ - Delete entire directory
• src/tunacode/core/agents/agent_components/agent_config.py - Update import, inline logic
• tests/unit/core/test_prompting_engine.py - Delete file or move tests
• docs/codebase-map/modules/core-prompting.md - Delete file

Knowledge Gaps

• Confirm whether custom placeholder registration was ever planned for future use
• Verify no other files import from prompting_engine besides agent_config.py

References

• src/tunacode/core/prompting/prompting_engine.py
• src/tunacode/core/prompting/__init__.py
• tests/unit/core/test_prompting_engine.py
• docs/codebase-map/modules/core-prompting.md