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 skills add Beichen-H/Loopower --skill prompt-to-loop-engineeringgit clone --depth 1 https://github.com/Beichen-H/LoopowerWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/beichen-h/loopower/prompt-to-loop-engineering)<a href="https://agentmods.dev/skills/beichen-h/loopower/prompt-to-loop-engineering"><img src="https://agentmods.dev/badge/skills/beichen-h/loopower/prompt-to-loop-engineering/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/beichen-h/loopower/prompt-to-loop-engineering"><img src="https://agentmods.dev/badge/skills/beichen-h/loopower/prompt-to-loop-engineering.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What 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 5.1 | $0.00040 | $0.09989 |
| Opus 5.5 | $0.00016 | $0.03996 |
| Sonnet 5.5 | $0.00008 | $0.01998 |
| Haiku 4.5 | $0.00004 | $0.00999 |
Grade A, and why
prompt-to-loop-engineering 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 2mo 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 — 658 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Prompt to Loop Engineering
Skill version: 3.1.0
Normative contract: Loop Engineering KB v4.0.2
Self-design graph: loop_spec.json
Mandatory execution protocol
For every invocation, the agent:
- MUST read
loop_spec.jsonbefore designing the result. - MUST preserve the raw request and run
scripts/normalize_design_request.pyto materialize a separate effectiveLoop_design_request. Missing capability booleans arefalse; missing tools are unavailable. - MUST use the effective request—not the raw request—to generate exactly one
loop_design_resultand save it as JSON. - MUST run
scripts/validate_design_result.pywith the result, raw request, effective request, and normalization report before returning the result. - MUST NOT emit
spec_readywhen validation fails. Correct and revalidate the design, or return a non-executable disposition with the validation errors preserved. - MUST NOT execute the user task, invoke a generated node or tool, advance a generated edge, or report runtime success during design validation.
- MUST NOT create or require an independent Runtime Engine. Codex is the host executor when the user explicitly asks to use or continue a generated scaffold.
Example validation command:
python scripts/validate_design_result.py path/to/loop_design_result.json \
--request path/to/effective_request.json \
--raw-request path/to/raw_request.json \
--normalization-report path/to/request_normalization_report.json
Example normalization command:
python scripts/normalize_design_request.py path/to/raw_request.json \
--output path/to/effective_request.json \
--report path/to/request_normalization_report.json
This Skill contains no Runtime Engine and must never scaffold one. Runtime capabilities are constraints supplied by the caller so generated LoopSpec and Agent Config Scaffold files match the real Codex session and project permissions.
v2.0.0 — Release-Hardened Contract Alignment
What ships with it
60 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- agents/openai.yaml 544 B
- examples/agent_loop.json 16 KB
- examples/codex-loop/.status 22 B
- examples/codex-loop/agent_manifest.json 6.1 KB
- examples/codex-loop/evidence/activation/feature-engineer.json 504 B
- examples/codex-loop/evidence/activation/requirements-analyst.json 511 B
- examples/codex-loop/evidence/activation/security-auditor.json 497 B
- examples/codex-loop/evidence/activation/test-verifier.json 493 B
- examples/codex-loop/evidence/completion/feature-engineer.json 317 B
- examples/codex-loop/evidence/completion/requirements-analyst.json 320 B
- examples/codex-loop/evidence/completion/security-auditor.json 310 B
- examples/codex-loop/evidence/completion/terminal-export.json 301 B
- examples/codex-loop/evidence/completion/test-verifier.json 309 B
- examples/codex-loop/evidence/handoff/handoff-01.json 376 B
- examples/codex-loop/evidence/handoff/handoff-02.json 365 B
- examples/codex-loop/evidence/handoff/handoff-03.json 358 B
- examples/codex-loop/evidence/handoff/handoff-04.json 341 B
- examples/codex-loop/evidence/preflight/go-preflight.json 939 B
- examples/codex-loop/evidence/progress/iteration_1.json 745 B
- examples/codex-loop/evidence/progress/iteration_2.json 746 B
- examples/codex-loop/guardrails.json 1.2 KB
- examples/codex-loop/loop_spec.json 10 KB
- examples/codex-loop/subagents/feature-engineer.md 737 B
- examples/codex-loop/subagents/requirements-analyst.md 674 B
- examples/codex-loop/subagents/security-auditor.md 666 B
- examples/codex-loop/subagents/test-verifier.md 678 B
- examples/needs_input.json 2.2 KB
- examples/one_shot.json 2.5 KB
- examples/requests/agent_loop.json 1.2 KB
- examples/requests/needs_input.json 1004 B
- examples/requests/one_shot.json 978 B
- examples/requests/unsupported.json 979 B
- examples/requests/workflow.json 984 B
- examples/unsupported.json 2.1 KB
- examples/workflow.json 8.4 KB
- loop_spec.json 23 KB
- schemas/agent_manifest.schema.json 8.5 KB
- schemas/go_capability_preflight.schema.json 1.7 KB
- schemas/guardrails.schema.json 2.2 KB
- schemas/loop_design_request.schema.json 3.5 KB
- schemas/loop_design_result.schema.json 7.6 KB
- schemas/loop_spec.schema.json 18 KB
- schemas/normalization_report.schema.json 1.1 KB
- schemas/progress_evidence.schema.json 1.6 KB
- schemas/replan_proposal.schema.json 1.2 KB
- scripts/governance_contracts.py 14 KB runs code
- scripts/normalize_design_request.py 7.3 KB runs code
- scripts/test_dag_execution_evidence.py 11 KB runs code
- scripts/test_loop_progress_evidence.py 8.9 KB runs code
- scripts/test_normalize_design_request.py 4.1 KB runs code
- scripts/test_replan_proposal.py 3.7 KB runs code
- scripts/test_scaffold_validation.py 19 KB runs code
- scripts/test_skill_surface.py 40 KB runs code
- scripts/test_spec_loading.py 5.8 KB runs code
- scripts/test_validate_design_result.py 37 KB runs code
- scripts/validate_codex_loop_scaffold.py 21 KB runs code
- scripts/validate_dag_execution_evidence.py 15 KB runs code
- scripts/validate_design_result.py 63 KB runs code
- scripts/validate_loop_progress_evidence.py 9.9 KB runs code
- scripts/validate_replan_proposal.py 3.3 KB runs code
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.
- 2mo ago First seen · 658 lines · 40 tokens per session scan A 3bae212af418
prompt-to-loop-engineering is a skill published in the GitHub repository Beichen-H/Loopower (2 stars, last pushed 3mo ago), licensed MIT. It adds 40 tokens to every session and 9,989 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-31.
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