Lesson 8 · 20 min
Time to put the pieces together in a real loop, small on purpose: a word-counting function, six tests frozen with a hash, and a level 3 /goal condition with a turn cap. Small enough to finish in minutes; complete enough to have all five pieces. At the end, the map of the track and your plan with dates.
Start the lesson
Goal: run your first loop with /goal on a small project, with frozen tests, a level 3 criterion, and a turn cap, and leave with the track plan.
Four deliverables that become your first loop. Tap an exercise to see its "done when".
goal, state, action, verification, stop
3 exercises
A loop that stops on the test or on the cap.
View the lessonfiles and git
3 exercises
A disposable cycle that resumes without redoing work.
View the lesson0–4 scale
3 exercises
A level 3 criterion that runs and locks the shortcut.
View the lessonturns, time, memory, stagnation, cost
3 exercises
A loop that stops on its own when it gets stuck.
View the lessonThe skeleton: the five pieces in a bash loop, with two exit doors and a different exit code for each.
Memory outside the model: a list with passes, progress, and one commit per verified item.
The verification that can't be gamed: a command, a minimum count, and a frozen file.
The safety door: each cap catches one way the loop might never end, and the human gate catches what can't be done without you.
Pieces, state, criterion and caps are what you use next. The rest of the lessons (harness, engines, LOOP-R) say where each piece lives and which course goes deeper.
The exercises from lessons 2, 3 and 4 go into the plan below.
One folder, one test file frozen by hash, and not a single line of the function. The agent writes the function.
mkdir -p ~/ensaio-loop/conta/tests && cd ~/ensaio-loop/conta && git init -q # paste the test file from the next block into tests/test_conta.py, then: sha256sum tests/test_conta.py > tests.sha256 git add -A && git commit -qm "testes congelados" python3 -m pytest -q -p no:cacheprovider tests/ | tail -1 # still fails: conta.py does not exist
from conta import conta_palavras
def test_vazio():
assert conta_palavras("") == 0
def test_uma():
assert conta_palavras("loop") == 1
def test_espacos_repetidos():
assert conta_palavras(" o loop para ") == 3
def test_quebra_de_linha_e_tab():
assert conta_palavras("objetivo\nestado\tação") == 3
def test_pontuacao_nao_e_palavra():
assert conta_palavras("pronto , quando - passa") == 3
def test_acentos():
assert conta_palavras("verificação e parada") == 3/goal python3 -m pytest -q -p no:cacheprovider tests/ prints 6 passed, sha256sum -c tests.sha256 prints OK and git diff --exit-code -- tests/ exits with code 0, with all three outputs printed in the conversation, or stop after 8 turns
cd ~/ensaio-loop/conta python3 -m pytest -q -p no:cacheprovider tests/ | tail -1 sha256sum -c tests.sha256 git diff --exit-code -- tests/; echo "rc=$?"
#!/usr/bin/env bash
# Your own loop: at most 3 cycles of codex exec; the three commands decide when to stop.
set -u
cd ~/ensaio-loop/conta
passes() {
python3 -m pytest -q -p no:cacheprovider tests/ 2>&1 | tail -1 | grep -q '^6 passed' &&
sha256sum -c --quiet tests.sha256 &&
git diff --quiet -- tests/
}
for ciclo in 1 2 3; do
if passes; then echo "PRONTO no ciclo $((ciclo - 1))"; exit 0; fi
echo "ciclo $ciclo: codex exec"
timeout 15m codex exec --sandbox workspace-write \
"Crie conta.py com conta_palavras(texto) que faça os testes de tests/ passarem. Não altere nada em tests/."
done
if passes; then echo "PRONTO no ciclo 3"; exit 0; fi
echo "PARADO: teto de 3 ciclos"; exit 2With the same condition, in headless mode (claude -p "/goal …"), the agent wrote conta.py and finished by printing:
- python3 -m pytest -q -p no:cacheprovider tests/ → 6 passed in 0.01s - sha256sum -c tests.sha256 → tests/test_conta.py: OK - git diff --exit-code -- tests/ → saiu com código 0
Its function and yours may be different; what has to match are the three outputs.
$ echo "def test_x(): pass" > tests/test_conta.py $ sha256sum -c tests.sha256 tests/test_conta.py: FAILED sha256sum: WARNING: 1 computed checksum did NOT match $ echo $? 1
Swapping the test for an empty one would make pytest pass, but the hash and the git diff flag it. That's the difference between level 2 and level 3.
On your machine. Exercise 2 uses little of your quota.
Create the folder, the test file, the hash and the first commit. Run pytest before the function exists.
Done when: sha256sum -c tests.sha256 → tests/test_conta.py: OK, git log --oneline | wc -l → 1, and pytest still fails (the function doesn't exist).
Open Claude Code in the folder and paste the /goal condition. Let it run without interfering; if Claude asks permission to run pytest, approve it.
Done when: The goal status shows the condition met, and the three check commands, run by you, give 6 passed, tests/test_conta.py: OK and rc=0.
Delete conta.py and run the same request through codex exec with a write sandbox, using the loop-codex.sh from the block above: at most 3 cycles, stopping when the three commands pass.
Done when: Your loop ends before the 3rd cycle, and the same three commands give 6 passed, OK and rc=0; git diff --stat -- tests/ comes out empty.
Pick the start date and how much time you have per week. The plan lists the exercises from the eight lessons in order.
Question 1 of 4
Why does the /goal condition ask for "all three outputs printed in the conversation"?competency
Question 2 of 4
What does the hash in tests.sha256 add to "6 passed"?
Question 3 of 4
The /goal finished with the condition met. What's the next step?competency
Question 4 of 4
After this course, what's next in the suggested order of the track?
Choose one answer. The explanation appears after you try.