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 skills/wallkop/opc-develop/retronpx skills add wallkop/opc-develop --skill retrogit clone --depth 1 https://github.com/wallkop/opc-developWhat 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 | $0.00040 | $0.00658 |
| Opus 5 | $0.00020 | $0.00329 |
| Sonnet 5 | $0.00008 | $0.00132 |
| Haiku 4.5 | $0.00004 | $0.00066 |
Grade A, and why
retro 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 — 55 lines — stays where its author put it; the contents beside it link to each section on GitHub.
retro
The loop that improves the loop. A historical problem becomes a cheap repeatable experiment; a rule becomes active only after that experiment proves it can kill the bad variant.
Load
${CLAUDE_PLUGIN_ROOT}/shared/core-contract.md${CLAUDE_PLUGIN_ROOT}/shared/formats/ledger-format.md${CLAUDE_PLUGIN_ROOT}/shared/formats/benchmark-case-format.md${CLAUDE_PLUGIN_ROOT}/shared/formats/report-style.md
Process
- Data-quality preflight: audit every active feature/error ledger and generated acceptance
receipt. Count eligible phase/gate/dispatch entries, cost coverage, unmapped sessions, invalid
gaps, command/provider capture, and benchmark linkage. Missing cost data creates or updates one
stable
observegap with its label cap; never duplicate it. - Collect: feature summaries, exact-match error pre-groups, semantic clusters, normalized Codex/Claude usage, benchmark reports, and crystallized rules. Label script findings separately from semantic judgment.
- Compute: measured/no-data cost by phase, time to first runnable core path, command and repeated-test counts, subtask/context modes, review/repair rounds, provider calls/cost, rework routing, user corrections, post-completion fixes, recurring clusters, open gaps, benchmark coverage, and false-green gates. Do not call missing capture “zero recurrence” or “efficient.”
- Executable case check: every P0/P1, irreversible-risk, false-green, or recurring incident links a project case, or a human-approved waiver. Profiles reproduce one problem at different cost. Prefer the cheapest stable profile and report when real calibration is stale.
- Crystallize: propose the lowest enforcement layer. Approval records
approved; building recordsimplemented; only a linked GREEN → RED → GREEN report promotesverified, thenactive-unmeasureduntil later observations exist. - Measure: after approval, count linked recurrences and rule fires. Zero with healthy capture
becomes
effective; recurrence becomesrecurringand proposes a lower layer; 8 weeks unfired or a model major-version change becomes a retirement candidate. - Human report: write
docs/opc/retro/<date>.jsonand.md, then render/lintdocs/opc/retro/<date>.html. Lead with conclusion, user impact, evidence, and decision. Only human-approved rule changes are written todocs/opc/rules.md.
What ships with it
1 file 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.
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 · 55 lines · 40 tokens per session scan A b7c0cd3d740e
retro is a skill published in the GitHub repository wallkop/opc-develop (11 stars, last pushed 1mo ago), licensed MIT. It adds 40 tokens to every session and 658 once invoked, about $0.0002 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.
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