الذاكرة والسياق

def approx_tokens(text: str) -> int:
    return len(text) // 4 + 1            # rough rule: ~4 characters per token

def trim_history(messages: list[dict], budget: int = 300) -> list[dict]:
    """Keep the first message (the task) + as many recent messages as fit the budget."""
    first, rest = messages[0], messages[1:]
    kept, used = [], approx_tokens(str(first["content"]))
    for msg in reversed(rest):                         # newest first
        cost = approx_tokens(str(msg["content"]))
        if used + cost > budget:
            break
        kept.insert(0, msg)
        used += cost
    dropped = len(rest) - len(kept)
    note = {"role": "user", "content": f"[{dropped} earlier messages were removed to save space]"}
    return [first, note] + kept if dropped else [first] + kept

history = [{"role": "user", "content": "Help me track my 3 orders and fix the address."}]
for i in range(12):
    history.append({"role": "assistant", "content": f"Checking step {i}... " + "details " * 20})
    history.append({"role": "user", "content": f"result of step {i}"})

trimmed = trim_history(history)
print("before:", len(history), "messages,", sum(approx_tokens(str(m['content'])) for m in history), "tokens")
print("after: ", len(trimmed), "messages,", sum(approx_tokens(str(m['content'])) for m in trimmed), "tokens")
print(trimmed[1]["content"])

import json
from datetime import date
from pathlib import Path

MEMORY_FILE = Path("customer_memory.json")
MEMORY_FILE.write_text("{}", encoding="utf-8")      # fresh start for this demo

def save_note(customer_id: str, note: str) -> str:
    """Save a short, useful fact about a customer for future conversations."""
    data = json.loads(MEMORY_FILE.read_text(encoding="utf-8"))
    data.setdefault(customer_id, []).append({"date": date(2026, 9, 22).isoformat(), "note": note})
    MEMORY_FILE.write_text(json.dumps(data, ensure_ascii=False, indent=1), encoding="utf-8")
    return "saved"

def recall_notes(customer_id: str) -> str:
    """Get saved notes about a customer. Use at the start of a conversation."""
    data = json.loads(MEMORY_FILE.read_text(encoding="utf-8"))
    notes = data.get(customer_id, [])
    return "\n".join(f"{n['date']}: {n['note']}" for n in notes) or "No notes yet."

# conversation 1
save_note("C-77", "Prefers delivery after 6 PM (works mornings).")
save_note("C-77", "Order 1031 arrived damaged; replacement sent.")

# conversation 2 (days later): the agent starts by recalling
print(recall_notes("C-77"))
print(recall_notes("C-99"))