pysince 0.2.0

Temporal context for LLM conversations — time awareness + stale-context detection

pysince

Temporal context for LLMs — time awareness + stale-context detection, zero AI calls.

pip install pysince
from since import Store, since_time

What it does

LLMs have no sense of time. Ask "what time is it?" and they guess. Ask "what did we talk about 3 hours ago?" and they can't. Context from 5 minutes ago looks the same as context from yesterday.

pysince (imported as since) wraps your LLM calls with a real clock, persistent timestamped memory, and TTL-based staleness detection.

Quick start

from since import Store, since_time
from openai import OpenAI

store = Store("~/.since/chat.db")
client = OpenAI()

@since_time(store=store, timezone="UTC+05:30")
def chat(messages):
    return client.chat.completions.create(model="gpt-4o", messages=messages)

# Every message is timestamped automatically
resp = chat(messages=[{"role": "user", "content": "hello"}])
print(resp.choices[0].message.content)

The prompt sent to the model looks like:

system: Every message has a UTC timestamp. The 'Now:' line below is the
        current time — use it for all time references. Never guess the time.

user: [Wed Jul 01, 02:36AM]  hello

system: Now: Wed Jul 01, 02:36 AM (night)
Session: just started · 1 message

Stale-file detection (for coding agents)

The real killer feature: agents that read files and act on outdated content.

from since.stale_files import stamp_file_read, check_and_invalidate

# Agent reads a file — stamp it
stamp_file_read("config.py", store, "session_1")

# File changes (git pull, manual edit, another tool)
# Next agent turn — stale warning fires automatically
if check_and_invalidate("config.py", store, "session_1"):
    # ⚠ Stale: "config.py" appears in the prompt tail
    # Agent sees the warning and re-reads
    stamp_file_read("config.py", store, "session_1")

The tail block shows:

⚠ Stale: "[FILE READ] config.py (mtime=...)" (read:config.py) — invalidated, 14m old

No daemon, no watcher, no polling — just mtime comparison at the next agent turn.

from since.stale_files import stamp_file_read, check_and_invalidate

How it works

Component	What it does
@since_time	Decorator that wraps any chat function, timestamps every message, adds the clock
with_time()	Formats history with absolute timestamps + tail block (Now, gaps, stale warnings)
Store	SQLite backend — persistent, thread-safe, WAL mode, zero deps
stamp_file_read()	Records a file read as an event with current mtime
check_and_invalidate()	Compares stored vs current mtime, invalidates if changed
timeparse	Natural language time parser — "3 days ago", "yesterday at 3pm"

TTL classes

Class	Decay	Use case
permanent	Never	User identity, project facts
slow	Session age	Normal conversation
event	store.invalidate(source_id)	File reads, tool outputs
ephemeral	5 minutes	"ok", "thanks", throwaway messages

Requirements

• Python 3.10+
• No dependencies (zero — no numpy, no pydantic, no LLM SDK)

Install

pip install pysince

Import as:

from since import Store, since_time
from since.stale_files import stamp_file_read, check_and_invalidate