Claude Code Meetup · June 10, 2026 · Munich

Start with a loop.

Three months ago I closed a talk with that line. Tonight: what /loop actually is, how it differs from Codex /goal, and how to design one that doesn’t just spin.

bett.ag x.com/fbettag no2vdp.bett.ag 2342.gmbh

start-with-a-loop.bett.ag

Outline

What we will cover in the next 20 minutes

~4 min · Recap What happened after “start with a loop”

~6 min · The primitive /loop — four modes, one file that matters

~3 min · Compare /loop vs Codex /goal

~5 min · Design How to build a loop that actually improves

~10 min Q&A

One thesis: a goal is easy to describe. A loop is hard to design. Everything tonight either supports or refutes that.

Who I am · the short version

Franz Bettag Polyglot engineer since 2001

25 years of consulting for enterprise to Fortune 500. On-prem, cloud, AI, security, and development — paid projects in 30+ languages before AI came around.

On-Prem & Cloud, AI & Security Engineering for Enterprise to Fortune 500

Most notable for the German market kleinanzeigen.de

Sole IT Engineer next to the CEO. Re-developed the platform from 2014–2019 serving 30M+ monthly users, then exited to eBay.

Wall Street HFT block-trade optimization

Tasked to fix a critical performance bottleneck. Found a $2M+ accounting error while rewriting the system. Cut monthly job runtime from 2+ hours to 5 minutes.

Fashion @ Scale Nordstrom / HauteLook

Rebuilt flash-sale push notification infra for the largest fashion retailer in the US. 10M+ concurrent pushes, delivery cut from 2 days to under 10 minutes.

Family lore

If you recognize my last name, it’s probably because my grandfather invented the BobbyCar and was the founder of BIG Spielwaren.

Recap · Q1 2026 was a use case

3 months on HackerOne, to prove the pattern.

Jan–Mar 2026 only. I picked vulnerability research as a hard, noisy, adversarial domain — if the loop pattern held there, it would hold anywhere.

CVE Keycloak CVE‑2026‑1190

Critical fix 2x ClickHouse RBAC bypass

Subdomain takeover → SIP/VoIP Opera

Subdomain takeover 3x Amazon VDP, OANDA

Valid finding Ruby on Rails

HackerOne Germany VDP leaderboard Q1 2026

Recap · Q2 2026

Then I stopped. Bug bounty isn’t my job.

The pattern worked

Loop with validation gates beat ad-hoc prompting on the hardest domain I could find.

The point was the architecture

Separate personas, hard gates, feedback. The CVEs were artifacts of that, not the goal.

So I redeployed the loop

Same architecture, different domains: SaaS development, SEO, paid ads, infra automation.

That’s what tonight is about

Not security. The mechanism underneath — /loop as a Claude Code primitive.

A use case is something you stop doing once it’s proven. A pattern is something you keep using.

April 16, 2026 · My last slide

Don’t start with one giant prompt. Start with a loop.

I didn’t know this would become a thing.

Validation from the source

Boris Cherny, Claude Code lead engineer

“I only write loops.”

The primitive

`/loop` has four modes

Bundled skill, ships with Claude Code. Session-scoped, restored on --resume. Also invokable as /proactive per the docs.

Fires between turns, never mid-response. If Claude is busy, it waits for idle. No catch-up on missed fires.

Both the interval and the prompt are optional. What you supply determines which of four modes you get.

Mode 1 · Fixed interval

/loop 5m check the deploy — cron-scheduled, your prompt fires on every tick.

Mode 2 · Dynamic self-paced

/loop check whether CI passed — Claude picks the next interval each iteration. 1 min to 1 hour.

Mode 3 · Bare (maintenance)

/loop alone — runs the built-in maintenance prompt, or .claude/loop.md if you have one.

Mode 4 · Nested skill

/loop 30m /review-pr 1234 — re-run a saved skill on a schedule.

Practical patterns

Three loops you can run before this talk ends

Light · polling /loop 5m check if the deploy at port 3000 returns 200

Tell me when state changes. Stop reading the GitLab UI every two minutes.

Composed · loop × skill /loop 30m /review-pr 1234

A skill that knows how to review the PR. The loop just supplies the cadence. Skills compose; intervals don’t.

Dynamic · self-paced /loop check whether CI passed and address review comments

No interval. Claude decides: tight while CI is running, long when the PR goes quiet. Can also exit on its own when the work is “provably complete.”

Esc stops a waiting loop. The 7‑day expiry kills forgotten ones.

The underrated primitive

`.claude/loop.md` is where it gets interesting.

Bare /loop looks for .claude/loop.md (project) then ~/.claude/loop.md (user). First match wins.

Plain Markdown. Write it like a prompt. Up to 25 KB — longer gets truncated.

Edits take effect on the next iteration. You can refine the instructions while the loop is running.

And so can the agent. If iteration N edits loop.md, iteration N+1 reads the new version. That is the only honest “self-improvement” mechanism in the primitive.

; .claude/loop.md
Check the `release/next` PR.
If CI is red, pull the failing job log,
diagnose, and push a minimal fix.
If new review comments arrived,
address each one and resolve the thread.
If everything is green and quiet,
say so in one line.

The prompt arg is constant. The file is variable. That distinction is most of the design space.

Side by side

`/loop` vs Codex `/goal`

/loop — Claude Code

Start: /loop [interval] [prompt]. Both args optional.
Rhythm: a clock tick, a dynamic self-paced delay, or whatever your nested skill needs.
Stops: Esc while waiting, or Claude self-ends in dynamic mode.
You design: the interval, the prompt, the exit condition, and what each iteration leaves behind.

Best when the work is ongoing and you want it to keep getting better.

When I use it

Anything where others would reach for OpenClaw, Hermes Agent, or OpenFang. I design it, refine loop.md, and tune it until it’s an autonomous process most of the time.

/goal — Codex CLI

Start: /goal <objective> (up to 4,000 chars).
Rhythm: Codex keeps working toward the objective across the thread.
Manage: /goal to view, /goal pause / resume / clear to control.
You design: one sentence that names the destination.

Best when the work has a destination and you want it reached.

When I use it

One-off problems with a clear finish line. “/goal build me a Rust version of Age of Empires 2, called OpenRAge.”

The thesis

A goal is easy to declare.
A loop is hard to design.
A good loop pays you back forever.

Designing the loop

The prompt is the constant. The world is the variable.

Each iteration must leave an artifact

Memory entry, code change, edited loop.md, log line. If iteration N changes nothing, iteration N+1 runs against the same world.

The artifact must be readable next iteration

Write to CLAUDE.md, MEMORY.md, the repo, or loop.md itself — not chat scrollback.

Pair the loop with a gate

The loop fires; the gate (test, lint, HTTP probe, sub-agent review) decides whether the artifact survives. No gate = drift.

Prefer dynamic + Monitor over short intervals

If you can react to an event (a file change, a build log line), do that. Monitor streams output; you avoid polling tokens entirely.

When loops fail

Three ways a loop stops being useful

Thrash

Interval too short for the work. The next iteration starts before the last artifact is ready. You burn tokens on context that hasn’t changed.

Drift

No exit criteria. The loop keeps running after the task is done; you trust it to notice. It does not. The 7-day expiry is your safety net, not your design.

Ghost work

Each iteration looks useful in the transcript but writes nothing durable. The loop is busy. The world is the same as it was an hour ago.

If you can’t name the artifact each iteration leaves behind, you don’t have a loop — you have a polling script.

Limits

`/loop` is session-scoped. Know when to reach past it.

Session-scoped. Tasks fire only while Claude Code is running and idle. Closing the terminal stops them.

7-day expiry. Recurring tasks auto-delete after 7 days — one final fire, then gone.

50-task cap. Per session. Easier to hit than you think.

Restored on --resume. Unexpired tasks come back when you continue the session.

Disable globally: CLAUDE_CODE_DISABLE_CRON=1.

Needs machine on → Desktop scheduled tasks

Machine off, durable → Routines (Anthropic cloud)

CI-driven → GitHub Actions schedule trigger

Event-driven → Channels + Monitor

My current loops

Three loops running across my projects today

GitLab pipeline babysit

Dynamic /loop watches CI on active branches. If a job goes red, it reads the log, classifies the failure, and either fixes (lint/format) or pings me (real bug). Tight cadence while CI runs, hour-long sleeps when the queue is empty.

`/seo-run` — the SEO operating loop

Pulls Search Console + DataForSEO + Grok trends, writes a backlog to .codex/seo-run/, implements one round of evidence-backed changes, commits, pushes, verifies CI/deploy. Each iteration leaves a snapshot artifact the next iteration reads.

`/ads-run` — cross-channel ads watchdog

Checks Meta + Google + X Ads delivery, spend, approvals, conversions. Writes a run report; never silently spends money. Drafts optimizations; I approve the irreversible step.

Take-home

Spend the design cost once.
Collect the maintenance value
forever.

Closing

Last time: start with a loop. This time: design one.

The prompt is the constant. The world is the variable. Pick the artifact each iteration leaves behind — and you have a loop, not a polling script.

https://bett.ag https://2342.gmbh no2vdp.bett.ag

Questions?