Step One: One File, One Prompt, One Model

"""step1_chat.py: one identity file, one conversation log, one model.

A toy, single-device, single-brain, no memory engine. Stdlib only.
Run:  python3 step1_chat.py "your message"   (one turn per run)
"""
import hashlib, json, sys, time, uuid
from datetime import datetime
from pathlib import Path

DATA = Path("chat-data")
IDENTITY = DATA / "identity.md"           # who she is: read on EVERY turn
LOG = DATA / "default.jsonl"              # the conversation: append-only


def call_model(system, messages):
    """STUB: replace the body with one call to the model API you already have.
    e.g. Anthropic's SDK: client.messages.create(model=MODEL, max_tokens=1024,
    system=system, messages=messages).content[0].text
    The fake below lets the whole script run offline."""
    last = messages[-1]["content"].splitlines()[-1]
    return f"(fake model) I was handed {len(messages)} messages. You said: {last!r}"


def append(record):
    """Write one line and flush it to disk. Nothing is shown before this."""
    with LOG.open("a", encoding="utf-8") as f:
        f.write(json.dumps(record, ensure_ascii=False) + "\n")
        f.flush()


def load():
    if not LOG.exists():
        return []
    return [json.loads(line) for line in LOG.read_text(encoding="utf-8").splitlines() if line]


def turn(text):
    DATA.mkdir(exist_ok=True)
    if not IDENTITY.exists():
        IDENTITY.write_text("You are Pip, a warm, precise assistant.\n", encoding="utf-8")
    system = IDENTITY.read_text(encoding="utf-8")   # byte-stable unless YOU edit the file
    append({"id": uuid.uuid4().hex, "role": "user", "content": text, "at": time.time()})

    history = load()                                 # full replay, every turn
    messages = [{"role": r["role"], "content": r["content"]} for r in history]
    clock = datetime.now().astimezone().strftime("[Current time: %Y-%m-%d %H:%M %Z]")
    messages[-1] = {"role": "user", "content": f"{clock}\n{text}"}  # sent, never stored

    reply = call_model(system, messages)
    append({"id": uuid.uuid4().hex, "role": "assistant", "content": reply, "at": time.time()})
    print(f"system sha256 {hashlib.sha256(system.encode()).hexdigest()[:12]}"
          f" | replayed {len(messages)} messages, {sum(len(m['content']) for m in messages)} chars")
    print(reply)                                     # display comes AFTER the write


if __name__ == "__main__":
    turn(" ".join(sys.argv[1:]) or "hello")

$ python3 step1_chat.py "hello, who are you?"
system sha256 c9dc1328358e | replayed 1 messages, 56 chars
(fake model) I was handed 1 messages. You said: 'hello, who are you?'
$ python3 step1_chat.py "remember that my tea is green"
system sha256 c9dc1328358e | replayed 3 messages, 154 chars
(fake model) I was handed 3 messages. You said: 'remember that my tea is green'
$ python3 step1_chat.py "what tea do I drink?"
system sha256 c9dc1328358e | replayed 5 messages, 253 chars
(fake model) I was handed 5 messages. You said: 'what tea do I drink?'
$ wc -l < chat-data/default.jsonl
6
$ grep -c "Current time" chat-data/default.jsonl
0
$ echo "Answer in one sentence." >> chat-data/identity.md
$ python3 step1_chat.py "and now?"
system sha256 85a9d6c0b5e7 | replayed 7 messages, 331 chars
(fake model) I was handed 7 messages. You said: 'and now?'