Reference · Snippet · python

Summarize chat history

Last updated Jul 17, 2026

pythonmemorychat

def compress_history(messages: list[dict], keep_last: int = 4) -> list[dict]:
    if len(messages) <= keep_last + 1:
        return messages
    system = messages[0] if messages[0]["role"] == "system" else None
    old = messages[1:-keep_last]
    recent = messages[-keep_last:]
    summary_prompt = {
        "role": "user",
        "content": "Summarize prior turns in ≤6 bullets. Keep names and decisions.",
    }
    summary = llm([summary_prompt] + old)  # swap for your client
    compressed = []
    if system:
        compressed.append(system)
    compressed.append({"role": "assistant", "content": summary})
    compressed.extend(recent)
    return compressed