Borrowing it
Nothing to install: this file belongs to jongwony/epistemic-protocols. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/jongwony/epistemic-protocols/main/.claude/skills/rederive/SKILL.mdgit clone --depth 1 https://github.com/jongwony/epistemic-protocolsWrote 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/jongwony/epistemic-protocols/rederive)<a href="https://agentmods.dev/skills/jongwony/epistemic-protocols/rederive"><img src="https://agentmods.dev/badge/skills/jongwony/epistemic-protocols/rederive/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/jongwony/epistemic-protocols/rederive"><img src="https://agentmods.dev/badge/skills/jongwony/epistemic-protocols/rederive.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 | $0.00109 | $0.04974 |
| Opus 5.5 | $0.00044 | $0.01990 |
| Sonnet 5.5 | $0.00022 | $0.00995 |
| Haiku 4.5 | $0.00011 | $0.00497 |
Grade A, and why
rederive 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 today.
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 — 72 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Re-derive a protocol contract
One skill per run, whose formal block is Lean or becomes Lean in the run: a core protocol in scripts/load-protocols.js CANONICAL_PROTOCOL_SET, or a utility skill in LEAN_CONTRACT_UTILITIES there, which a utility still carrying a text-DSL block enters in its run. Below, the protocol names that skill whichever kind it is. The object is the protocol itself — its SKILL.md on origin/main; an open PR whose branch carries the chart id, where one exists, is one more piece of material, never the anchor. Anchor chart: the protocol's own ROO-* chart, which for a utility may be one chart several skills' runs share; suite-wide ground: ROO-67.
What a re-derivation answers to. The target is the morphism that the AGENTS.md Northstar and the premise axiom Context and Utterance as First-Class Ground (premise/recognition-and-authority.md) admit, in the form lean/EpistemicProtocols/Ground.lean fixes: the fused context — turns bound to who sent them — and the person's utterance are the ground; the structure fixes only what the harness knows; everything else is the model's inference, declared as a documented judgment inside the types. The solution is derived from the gathered pre-understanding and taken at the fusion gate before the current contract is read; the pre-Lean DSL, the current block, any open PR and earlier decides are evidence read against that solution, never the target.
Steps
- Trigger — a contributor names the protocol. Resolve its chart; where the protocol's earlier chart is Done, open a new chart linked to it and to ROO-67 (ROO-67 decide 5e64392d). The order across protocols is the contributor's and session-local; nothing here fixes it.
- Gather the pre-understanding — afresh every run, since what it holds moves between runs:
- Ground: the Northstar, the premise axiom above,
Ground.lean, and the protocol's declared deficit and resolution type — its Type line and Definition only, not the formal block; the fusion gate may revise them. - Decide coordinates: both charts' decide comments, the protocol chart's Open questions and its related issues; a later decide that supersedes an earlier one says so (ROO-67 decide 78e615b4).
- Literature: delegate to a subagent — primary sources on the cognitive deficit this protocol takes and the resolution it yields; where a source's setting differs from the one the protocol runs in, the claim names that transfer. Every claim carries its verification strength and names the weakest link (
AGENTS.md§Settled Directions, Academic grounding). - Definition history: for each suite-level definition the protocol's contract leans on — the COMPOSITION operator, a GROUND term, a convention another surface states for it — the commit that introduced it and each later commit that narrowed or widened it, in the definition itself and at the places this contract uses it (
git log -Lon the definition,git blame,git log -Son its terms at each use site), read as the intent the current text carries forward. - Real use:
~/.claude/projects/*/*.jsonlsessions where the skill ran — typed by the contributor or invoked through its delivery path (exclude-private-tmp*); what the deficit looked like there, and where the run went wrong or right. Where the skill runs rarely by nature, its sessions leave little; the commit history of the artifact its deficit is resolved in — each time that deficit came up and was resolved, by this skill or another route — is the real use read instead.
- Ground: the Northstar, the premise axiom above,
- Derive the solution — the protocol's epistemic solution, from the gathered material, not from the current block: deficit → resolution, first stated as its solution sentence, one sentence of what the person can then say or recognize — the repair direction every later finding is read against; the coordinates only the person fills, the closure kinds, the domain boundary — what the transformation itself carries and what lies past its hand-off, which the contract names at its delegation point and does not prescribe (ROO-67 decide dad26302) —, and the conditions that hold only where a ground carries them — Northstar, premise, literature, the contributor's utterance, a decide, or observed use; any other morphism step is scaffolding, carried as guidance on a documented judgment (ROO-67 decide 0d3b1e3b). Each part names what grounds it. A shape carried from a sibling protocol's re-derivation is pre-understanding: each carried clause, constructor, or slot is tested against this protocol's deficit and governing surfaces before it enters the solution.
- Independent derivation:
/codex-plus:codexwith an English prompt carrying the locations of the gathered material, the literature findings as a file, and the question this step answers — never this session's solution; it may read beyond the list. Compare the two derivations part by part.
- Independent derivation:
- Fusion gate — present the derived solution beside the ground of each part, its domain boundary among them, where the independent derivation agrees and splits, the real-use reading, the contrary grounds and live alternatives with their consequences, and the limits of what was searched. Branches:
- the contributor takes it → write the solution decide on the protocol chart (
/unfold decide) and go to the reading step; - the contributor corrects or replaces part of it → fuse the utterance and derive again;
- the correction moves the pre-understanding (a source, a decide, a reading of use) → gather again where it moved, then derive;
- the contributor stops → the run ends; what was gathered and derived is recorded on the protocol chart;
- no utterance → nothing is taken as a decide; whether the run waits or goes on past the gate is judged from its context, and going on follows Without the contributor below.
- the contributor takes it → write the solution decide on the protocol chart (
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.
- today Changed 86e2727c8657
- yesterday Changed 53871238ecce
- 2d ago Changed f905538eb7c2
- 3d ago Changed df037a0bd21b
- 4d ago Changed · +1 lines 346fc0b37396
- 5d ago Changed 659e02e2d469
- 6d ago Changed · +15 tokens per session 650ec60e0403
- 7d ago Changed 2f2d8085889f
- 9d ago Changed ebd486cd58d2
- 10d ago First seen · 71 lines · 94 tokens per session scan A 46694f7473d2
rederive is a skill published in the GitHub repository jongwony/epistemic-protocols (173 stars, last pushed today), licensed MIT. It adds 109 tokens to every session and 4,974 once invoked, about $0.0004 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 2026-09-26.
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