carlos patches

aggregate.py

@@ -98,24 +98,28 @@ def build_file_items(base_dir: Path, files: list[str]) -> list[dict]:
         entry    : str   (original config entry string)
         content  : str   (file text, or error string)
         error    : bool
+        mtime    : float (last modification time, for skip-if-unchanged optimization)
     """
     items = []
     for entry in files:
         paths = resolve_paths(base_dir, entry)
         if not paths:
-            items.append({"path": None, "entry": entry, "content": f"ERROR: no files matched: {entry}", "error": True})
+            items.append({"path": None, "entry": entry, "content": f"ERROR: no files matched: {entry}", "error": True, "mtime": 0.0})
             continue
         for path in paths:
             try:
                 content = path.read_text(encoding="utf-8")
+                mtime = path.stat().st_mtime
                 error = False
             except FileNotFoundError:
                 content = f"ERROR: file not found: {path}"
+                mtime = 0.0
                 error = True
             except Exception as e:
                 content = f"ERROR: {e}"
+                mtime = 0.0
                 error = True
-            items.append({"path": path, "entry": entry, "content": content, "error": error})
+            items.append({"path": path, "entry": entry, "content": content, "error": error, "mtime": mtime})
     return items
 
 def build_summary_section(base_dir: Path, files: list[str]) -> str:
@@ -126,6 +130,40 @@ def build_summary_section(base_dir: Path, files: list[str]) -> str:
     items = build_file_items(base_dir, files)
     return summarize.build_summary_markdown(items)
 
+def _build_files_section_from_items(file_items: list[dict]) -> str:
+    """Build the files markdown section from pre-read file items (avoids double I/O)."""
+    sections = []
+    for item in file_items:
+        path = item.get("path")
+        entry = item.get("entry", "unknown")
+        content = item.get("content", "")
+        if path is None:
+            sections.append(f"### `{entry}`\n\n```text\n{content}\n```")
+            continue
+        suffix = path.suffix.lstrip(".") if hasattr(path, "suffix") else "text"
+        lang = suffix if suffix else "text"
+        original = entry if "*" not in entry else str(path)
+        sections.append(f"### `{original}`\n\n```{lang}\n{content}\n```")
+    return "\n\n---\n\n".join(sections)
+
+
+def build_markdown_from_items(file_items: list[dict], screenshot_base_dir: Path, screenshots: list[str], history: list[str], summary_only: bool = False) -> str:
+    """Build markdown from pre-read file items instead of re-reading from disk."""
+    parts = []
+    # STATIC PREFIX: Files and Screenshots must go first to maximize Cache Hits
+    if file_items:
+        if summary_only:
+            parts.append("## Files (Summary)\n\n" + summarize.build_summary_markdown(file_items))
+        else:
+            parts.append("## Files\n\n" + _build_files_section_from_items(file_items))
+    if screenshots:
+        parts.append("## Screenshots\n\n" + build_screenshots_section(screenshot_base_dir, screenshots))
+    # DYNAMIC SUFFIX: History changes every turn, must go last
+    if history:
+        parts.append("## Discussion History\n\n" + build_discussion_section(history))
+    return "\n\n---\n\n".join(parts)
+
+
 def build_markdown(base_dir: Path, files: list[str], screenshot_base_dir: Path, screenshots: list[str], history: list[str], summary_only: bool = False) -> str:
     parts = []
     # STATIC PREFIX: Files and Screenshots must go first to maximize Cache Hits
@@ -141,7 +179,7 @@ def build_markdown(base_dir: Path, files: list[str], screenshot_base_dir: Path,
         parts.append("## Discussion History\n\n" + build_discussion_section(history))
     return "\n\n---\n\n".join(parts)
 
-def run(config: dict) -> tuple[str, Path]:
+def run(config: dict) -> tuple[str, Path, list[dict]]:
     namespace = config.get("project", {}).get("name")
     if not namespace:
         namespace = config.get("output", {}).get("namespace", "project")
@@ -155,11 +193,11 @@ def run(config: dict) -> tuple[str, Path]:
     output_dir.mkdir(parents=True, exist_ok=True)
     increment = find_next_increment(output_dir, namespace)
     output_file = output_dir / f"{namespace}_{increment:03d}.md"
-    # Provide full files to trigger Gemini's 32k cache threshold and give the AI immediate context
+    # Build file items once, then construct markdown from them (avoids double I/O)
-    markdown = build_markdown(base_dir, files, screenshot_base_dir, screenshots, history,
-                              summary_only=False)
-    output_file.write_text(markdown, encoding="utf-8")
     file_items = build_file_items(base_dir, files)
+    markdown = build_markdown_from_items(file_items, screenshot_base_dir, screenshots, history,
+                                         summary_only=False)
+    output_file.write_text(markdown, encoding="utf-8")
     return markdown, output_file, file_items
 
 def main():

ai_client.py

@@ -13,6 +13,7 @@ during chat creation to avoid massive history bloat.
 # ai_client.py
 import tomllib
 import json
+import time
 import datetime
 from pathlib import Path
 import file_cache
@@ -34,6 +35,12 @@ def set_model_params(temp: float, max_tok: int, trunc_limit: int = 8000):
 _gemini_client = None
 _gemini_chat = None
 _gemini_cache = None
+_gemini_cache_md_hash: int | None = None
+_gemini_cache_created_at: float | None = None
+
+# Gemini cache TTL in seconds. Caches are created with this TTL and
+# proactively rebuilt at 90% of this value to avoid stale-reference errors.
+_GEMINI_CACHE_TTL = 3600
 
 _anthropic_client = None
 _anthropic_history: list[dict] = []
@@ -216,6 +223,7 @@ def cleanup():
 
 def reset_session():
     global _gemini_client, _gemini_chat, _gemini_cache
+    global _gemini_cache_md_hash, _gemini_cache_created_at
     global _anthropic_client, _anthropic_history
     global _CACHED_ANTHROPIC_TOOLS
     if _gemini_client and _gemini_cache:
@@ -226,6 +234,8 @@ def reset_session():
     _gemini_client = None
     _gemini_chat = None
     _gemini_cache = None
+    _gemini_cache_md_hash = None
+    _gemini_cache_created_at = None
     _anthropic_client = None
     _anthropic_history = []
     _CACHED_ANTHROPIC_TOOLS = None
@@ -383,12 +393,15 @@ def _run_script(script: str, base_dir: str) -> str:
 
 # ------------------------------------------------------------------ dynamic file context refresh
 
-def _reread_file_items(file_items: list[dict]) -> list[dict]:
+def _reread_file_items(file_items: list[dict]) -> tuple[list[dict], list[dict]]:
     """
-    Re-read every file in file_items from disk, returning a fresh list.
+    Re-read file_items from disk, but only files whose mtime has changed.
-    This is called after tool calls so the AI sees updated file contents.
+    Returns (all_items, changed_items) — all_items is the full refreshed list,
+    changed_items contains only the files that were actually modified since
+    the last read (used to build a minimal [FILES UPDATED] block).
     """
     refreshed = []
+    changed = []
     for item in file_items:
         path = item.get("path")
         if path is None:
@@ -397,11 +410,20 @@ def _reread_file_items(file_items: list[dict]) -> list[dict]:
         from pathlib import Path as _P
         p = _P(path) if not isinstance(path, _P) else path
         try:
+            current_mtime = p.stat().st_mtime
+            prev_mtime = item.get("mtime", 0.0)
+            if current_mtime == prev_mtime:
+                refreshed.append(item)  # unchanged — skip re-read
+                continue
             content = p.read_text(encoding="utf-8")
-            refreshed.append({**item, "content": content, "error": False})
+            new_item = {**item, "content": content, "error": False, "mtime": current_mtime}
+            refreshed.append(new_item)
+            changed.append(new_item)
         except Exception as e:
-            refreshed.append({**item, "content": f"ERROR re-reading {p}: {e}", "error": True})
+            err_item = {**item, "content": f"ERROR re-reading {p}: {e}", "error": True, "mtime": 0.0}
-    return refreshed
+            refreshed.append(err_item)
+            changed.append(err_item)
+    return refreshed, changed
 
 
 def _build_file_context_text(file_items: list[dict]) -> str:
@@ -466,25 +488,39 @@ def _get_gemini_history_list(chat):
     return []
 
 def _send_gemini(md_content: str, user_message: str, base_dir: str, file_items: list[dict] | None = None) -> str:
-    global _gemini_chat, _gemini_cache
+    global _gemini_chat, _gemini_cache, _gemini_cache_md_hash, _gemini_cache_created_at
     from google.genai import types
     try:
         _ensure_gemini_client(); mcp_client.configure(file_items or [], [base_dir])
         sys_instr = f"{_get_combined_system_prompt()}\n\n<context>\n{md_content}\n</context>"
         tools_decl = [_gemini_tool_declaration()]
-        
+
         # DYNAMIC CONTEXT: Check if files/context changed mid-session
         current_md_hash = hash(md_content)
         old_history = None
-        if _gemini_chat and getattr(_gemini_chat, "_last_md_hash", None) != current_md_hash:
+        if _gemini_chat and _gemini_cache_md_hash != current_md_hash:
             old_history = list(_get_gemini_history_list(_gemini_chat)) if _get_gemini_history_list(_gemini_chat) else []
             if _gemini_cache:
                 try: _gemini_client.caches.delete(name=_gemini_cache.name)
                 except: pass
             _gemini_chat = None
             _gemini_cache = None
+            _gemini_cache_created_at = None
             _append_comms("OUT", "request", {"message": "[CONTEXT CHANGED] Rebuilding cache and chat session..."})
 
+        # CACHE TTL: Proactively rebuild before the cache expires server-side.
+        # If we don't, send_message() will reference a deleted cache and fail.
+        if _gemini_chat and _gemini_cache and _gemini_cache_created_at:
+            elapsed = time.time() - _gemini_cache_created_at
+            if elapsed > _GEMINI_CACHE_TTL * 0.9:
+                old_history = list(_get_gemini_history_list(_gemini_chat)) if _get_gemini_history_list(_gemini_chat) else []
+                try: _gemini_client.caches.delete(name=_gemini_cache.name)
+                except: pass
+                _gemini_chat = None
+                _gemini_cache = None
+                _gemini_cache_created_at = None
+                _append_comms("OUT", "request", {"message": f"[CACHE TTL] Rebuilding cache (expired after {int(elapsed)}s)..."})
+
         if not _gemini_chat:
             chat_config = types.GenerateContentConfig(
                 system_instruction=sys_instr,
@@ -500,9 +536,10 @@ def _send_gemini(md_content: str, user_message: str, base_dir: str, file_items:
                     config=types.CreateCachedContentConfig(
                         system_instruction=sys_instr,
                         tools=tools_decl,
-                        ttl="3600s",
+                        ttl=f"{_GEMINI_CACHE_TTL}s",
                     )
                 )
+                _gemini_cache_created_at = time.time()
                 chat_config = types.GenerateContentConfig(
                     cached_content=_gemini_cache.name,
                     temperature=_temperature,
@@ -511,35 +548,38 @@ def _send_gemini(md_content: str, user_message: str, base_dir: str, file_items:
                 )
                 _append_comms("OUT", "request", {"message": f"[CACHE CREATED] {_gemini_cache.name}"})
             except Exception as e:
-                _gemini_cache = None  # Ensure clean state on failure
+                _gemini_cache = None
-                
+                _gemini_cache_created_at = None
+                _append_comms("OUT", "request", {"message": f"[CACHE FAILED] {type(e).__name__}: {e} — falling back to inline system_instruction"})
+
             kwargs = {"model": _model, "config": chat_config}
             if old_history:
                 kwargs["history"] = old_history
-            
+
             _gemini_chat = _gemini_client.chats.create(**kwargs)
-            _gemini_chat._last_md_hash = current_md_hash
+            _gemini_cache_md_hash = current_md_hash
         
         _append_comms("OUT", "request", {"message": f"[ctx {len(md_content)} + msg {len(user_message)}]"})
         payload, all_text = user_message, []
-        
-        for r_idx in range(MAX_TOOL_ROUNDS + 2):
-            # Strip stale file refreshes and truncate old tool outputs in Gemini history
-            if _gemini_chat and _get_gemini_history_list(_gemini_chat):
-                for msg in _get_gemini_history_list(_gemini_chat):
-                    if msg.role == "user" and hasattr(msg, "parts"):
-                        for p in msg.parts:
-                            if hasattr(p, "function_response") and p.function_response and hasattr(p.function_response, "response"):
-                                r = p.function_response.response
-                                if isinstance(r, dict) and "output" in r:
-                                    val = r["output"]
-                                    if isinstance(val, str):
-                                        if "[SYSTEM: FILES UPDATED]" in val:
-                                            val = val.split("[SYSTEM: FILES UPDATED]")[0].strip()
-                                        if _history_trunc_limit > 0 and len(val) > _history_trunc_limit:
-                                            val = val[:_history_trunc_limit] + "\n\n... [TRUNCATED BY SYSTEM TO SAVE TOKENS.]"
-                                        r["output"] = val
 
+        # Strip stale file refreshes and truncate old tool outputs ONCE before
+        # entering the tool loop (not per-round — history entries don't change).
+        if _gemini_chat and _get_gemini_history_list(_gemini_chat):
+            for msg in _get_gemini_history_list(_gemini_chat):
+                if msg.role == "user" and hasattr(msg, "parts"):
+                    for p in msg.parts:
+                        if hasattr(p, "function_response") and p.function_response and hasattr(p.function_response, "response"):
+                            r = p.function_response.response
+                            if isinstance(r, dict) and "output" in r:
+                                val = r["output"]
+                                if isinstance(val, str):
+                                    if "[SYSTEM: FILES UPDATED]" in val:
+                                        val = val.split("[SYSTEM: FILES UPDATED]")[0].strip()
+                                    if _history_trunc_limit > 0 and len(val) > _history_trunc_limit:
+                                        val = val[:_history_trunc_limit] + "\n\n... [TRUNCATED BY SYSTEM TO SAVE TOKENS.]"
+                                    r["output"] = val
+
+        for r_idx in range(MAX_TOOL_ROUNDS + 2):
             resp = _gemini_chat.send_message(payload)
             txt = "\n".join(p.text for c in resp.candidates if getattr(c, "content", None) for p in c.content.parts if hasattr(p, "text") and p.text)
             if txt: all_text.append(txt)
@@ -593,12 +633,12 @@ def _send_gemini(md_content: str, user_message: str, base_dir: str, file_items:
 
                 if i == len(calls) - 1:
                     if file_items:
-                        file_items = _reread_file_items(file_items)
+                        file_items, changed = _reread_file_items(file_items)
-                        ctx = _build_file_context_text(file_items)
+                        ctx = _build_file_context_text(changed)
                         if ctx:
                             out += f"\n\n[SYSTEM: FILES UPDATED]\n\n{ctx}"
                     if r_idx == MAX_TOOL_ROUNDS: out += "\n\n[SYSTEM: MAX ROUNDS. PROVIDE FINAL ANSWER.]"
-                
+
                 f_resps.append(types.Part.from_function_response(name=name, response={"output": out}))
                 log.append({"tool_use_id": name, "content": out})
             
@@ -630,7 +670,15 @@ _FILE_REFRESH_MARKER = "[FILES UPDATED"
 
 
 def _estimate_message_tokens(msg: dict) -> int:
-    """Rough token estimate for a single Anthropic message dict."""
+    """
+    Rough token estimate for a single Anthropic message dict.
+    Caches the result on the dict as '_est_tokens' so repeated calls
+    (e.g., from _trim_anthropic_history) don't re-scan unchanged messages.
+    Call _invalidate_token_estimate() when a message's content is modified.
+    """
+    cached = msg.get("_est_tokens")
+    if cached is not None:
+        return cached
     total_chars = 0
     content = msg.get("content", "")
     if isinstance(content, str):
@@ -648,7 +696,14 @@ def _estimate_message_tokens(msg: dict) -> int:
                     total_chars += len(_json.dumps(inp, ensure_ascii=False))
             elif isinstance(block, str):
                 total_chars += len(block)
-    return max(1, int(total_chars / _CHARS_PER_TOKEN))
+    est = max(1, int(total_chars / _CHARS_PER_TOKEN))
+    msg["_est_tokens"] = est
+    return est
+
+
+def _invalidate_token_estimate(msg: dict):
+    """Remove the cached token estimate so the next call recalculates."""
+    msg.pop("_est_tokens", None)
 
 
 def _estimate_prompt_tokens(system_blocks: list[dict], history: list[dict]) -> int:
@@ -660,7 +715,7 @@ def _estimate_prompt_tokens(system_blocks: list[dict], history: list[dict]) -> i
         total += max(1, int(len(text) / _CHARS_PER_TOKEN))
     # Tool definitions (rough fixed estimate — they're ~2k tokens for our set)
     total += 2500
-    # History messages
+    # History messages (uses cached estimates for unchanged messages)
     for msg in history:
         total += _estimate_message_tokens(msg)
     return total
@@ -695,6 +750,7 @@ def _strip_stale_file_refreshes(history: list[dict]):
             cleaned.append(block)
         if len(cleaned) < len(content):
             msg["content"] = cleaned
+            _invalidate_token_estimate(msg)
 
 
 def _trim_anthropic_history(system_blocks: list[dict], history: list[dict]):
@@ -786,6 +842,28 @@ def _strip_cache_controls(history: list[dict]):
                 if isinstance(block, dict):
                     block.pop("cache_control", None)
 
+def _add_history_cache_breakpoint(history: list[dict]):
+    """
+    Place cache_control:ephemeral on the last content block of the
+    second-to-last user message. This uses one of the 4 allowed Anthropic
+    cache breakpoints to cache the conversation prefix so the full history
+    isn't reprocessed on every request.
+    """
+    user_indices = [i for i, m in enumerate(history) if m.get("role") == "user"]
+    if len(user_indices) < 2:
+        return  # Only one user message (the current turn) — nothing stable to cache
+    target_idx = user_indices[-2]
+    content = history[target_idx].get("content")
+    if isinstance(content, list) and content:
+        last_block = content[-1]
+        if isinstance(last_block, dict):
+            last_block["cache_control"] = {"type": "ephemeral"}
+    elif isinstance(content, str):
+        history[target_idx]["content"] = [
+            {"type": "text", "text": content, "cache_control": {"type": "ephemeral"}}
+        ]
+
+
 def _repair_anthropic_history(history: list[dict]):
     """
     If history ends with an assistant message that contains tool_use blocks
@@ -823,23 +901,36 @@ def _send_anthropic(md_content: str, user_message: str, base_dir: str, file_item
         _ensure_anthropic_client()
         mcp_client.configure(file_items or [], [base_dir])
 
-        system_text = _get_combined_system_prompt() + f"\n\n<context>\n{md_content}\n</context>"
+        # Split system into two cache breakpoints:
-        system_blocks = _build_chunked_context_blocks(system_text)
+        # 1. Stable system prompt (never changes — always a cache hit)
+        # 2. Dynamic file context (invalidated only when files change)
+        stable_prompt = _get_combined_system_prompt()
+        stable_blocks = [{"type": "text", "text": stable_prompt, "cache_control": {"type": "ephemeral"}}]
+        context_text = f"\n\n<context>\n{md_content}\n</context>"
+        context_blocks = _build_chunked_context_blocks(context_text)
+        system_blocks = stable_blocks + context_blocks
 
         user_content = [{"type": "text", "text": user_message}]
 
         # COMPRESS HISTORY: Truncate massive tool outputs from previous turns
         for msg in _anthropic_history:
             if msg.get("role") == "user" and isinstance(msg.get("content"), list):
+                modified = False
                 for block in msg["content"]:
                     if isinstance(block, dict) and block.get("type") == "tool_result":
                         t_content = block.get("content", "")
                         if _history_trunc_limit > 0 and isinstance(t_content, str) and len(t_content) > _history_trunc_limit:
                             block["content"] = t_content[:_history_trunc_limit] + "\n\n... [TRUNCATED BY SYSTEM TO SAVE TOKENS. Original output was too large.]"
+                            modified = True
+                if modified:
+                    _invalidate_token_estimate(msg)
 
         _strip_cache_controls(_anthropic_history)
         _repair_anthropic_history(_anthropic_history)
         _anthropic_history.append({"role": "user", "content": user_content})
+        # Use the 4th cache breakpoint to cache the conversation history prefix.
+        # This is placed on the second-to-last user message (the last stable one).
+        _add_history_cache_breakpoint(_anthropic_history)
 
         n_chunks = len(system_blocks)
         _append_comms("OUT", "request", {
@@ -953,10 +1044,10 @@ def _send_anthropic(md_content: str, user_message: str, base_dir: str, file_item
                         "content":     output,
                     })
 
-            # Refresh file context after tool calls and inject into tool result message
+            # Refresh file context after tool calls — only inject CHANGED files
             if file_items:
-                file_items = _reread_file_items(file_items)
+                file_items, changed = _reread_file_items(file_items)
-                refreshed_ctx = _build_file_context_text(file_items)
+                refreshed_ctx = _build_file_context_text(changed)
                 if refreshed_ctx:
                     tool_results.append({
                         "type": "text",