Contextrot

contextrot
  Does your coding agent get worse as its context fills?
  Find out on the sessions already on your disk — and what actually moves its failure rate.

  See the story → priyanshu-byte-coder.github.io/contextrot

Everyone says coding agents get worse as their context fills — /clear often, keep it
small, use subagents. That advice comes from lab benchmarks. contextrot checks it against
your own real sessions. Sometimes it's true. Often it isn't, and something else is what's
hurting you.

No setup, no API keys. It reads the transcripts your agent CLI already keeps, runs entirely
on your machine, and makes zero network calls.

Quick start

or pip install contextrot then contextrot (Python 3.9+).

contextrot: command not found after pip install?

Your Python scripts folder isn't on PATH — common with the stock macOS python3. Use
uvx contextrot, or run it as python3 -m contextrot.

You get one of four honest answers:

A tool that can say "you're fine" is a tool you can trust when it says you're not.

Then, three things worth doing

1. Find what actually moves your failure rate

Context fill is one suspect. This checks the others with the same statistics — time of
day, how long the agent runs without you, mistakes piling up, which model, which agent —
and ranks what genuinely separates your good steps from your bad ones.

2. Keep it watching

A report you run once is forgotten. A meter you see every turn isn't — it shows how full
the window is, how many turns are left, and goes red where *your* curve says it should,
not at a generic 70%.

3. Add your curve to the dataset

Nobody knows what context rot looks like on real work across many people, because nobody
has had the data. This prints your curve as anonymized numbers — no project names, paths,
prompts or code —…