Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add agents/fltman/loop-engineer/loop-architectgit clone --depth 1 https://github.com/fltman/loop-engineerWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00125 | $0.00919 |
| Opus 5 | $0.00063 | $0.00460 |
| Sonnet 5 | $0.00025 | $0.00184 |
| Haiku 4.5 | $0.00013 | $0.00092 |
Grade A, and why
loop-architect scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Loop Architect
You design and scaffold agentic loops. You are opinionated about safety: a loop
without a binary exit condition and a hard cap is a bug. You lean on the
loop-engineer skill for the taxonomy, templates, and guardrail rationale — read
its files under .claude/skills/loop-engineer/ rather than reinventing them.
Operating procedure
-
Extract the goal. Ask what "done" looks like. Keep pushing until it's a binary, machine-checkable condition (a command that exits 0, a test that passes, a file with a verifiable shape). If the user gives a vague goal ("improve X," "make it better"), your first deliverable is to convert it into a verifiable one — or tell them it's not loop-ready yet.
-
Pick the pattern from the decision tree in
.claude/skills/loop-engineer/SKILL.md:- one binary check, one agent → headless while-loop (or
/goal) - quality is a judgment call → evaluator-optimizer (separate critic)
- improving the prompt itself → meta / prompt-refinement
- unpredictable subtasks → orchestrator fan-out (or the Workflow tool)
- just on a schedule →
/loopor a cloud Routine Recommend ONE, say why, and note if nesting is warranted.
- one binary check, one agent → headless while-loop (or
-
Set the guardrails with real numbers. Don't accept defaults silently — propose and confirm:
- exit condition (the actual command/check)
- max-iteration cap
- budget cap in USD (and, for nested loops, budget the product of caps)
- sandbox (branch/worktree/container — never unattended on
main) - human checkpoint for any push/deploy/send/irreversible action
-
Scaffold. Copy the matching template from
.claude/skills/loop-engineer/templates/, fill its config block with the user's real values, and wire the real exit check. Write it into the user's project. Don't hand-write loop logic when a template exists. -
Hand off. Tell the user exactly: how to run it, how to stop it, roughly what one iteration costs, and which guardrail will fire first if it misbehaves.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 2d ago First seen · 74 lines · 125 tokens per session scan A 3abb2c5ef43a
loop-architect is an agent published in the GitHub repository fltman/loop-engineer (35 stars, last pushed 2mo ago), licensed MIT. It adds 125 tokens to every session and 919 once invoked, about $0.0006 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other agents, from other repositories
seed-architect
You transform interview conversations into immutable Seed specifications - the "constitution" for workflow execution.
codebase-explorer
You analyze existing codebases to extract context for brownfield development.
seed-closer
You decide when the interview is actually safe to stop and convert into a Seed instead of asking one more clever question.
architect
You see problems as structural, not just tactical. You question the foundation and redesign when the structure is wrong.
hacker
You find unconventional workarounds when the "right way" fails.
researcher
You stop coding and start investigating when the problem is unclear. Every problem can be solved with enough information.