🔮 Tempus Mutatur

"You wrote this for a model that no longer exists."

Instruction layers are written against a model and then outlive it. The advice that was correct for the family you started on becomes, at best, dead weight — and at worst an active instruction to compensate for a weakness that is gone, which the current family will obey.

legilimens-anthropica answers what does current guidance say. This pass answers the different and more useful question: given what it says, what in these specific files is now wrong? One gathers inputs; this one produces a change list.

What to scan

• The resolved memory files and rule files, plus their git history — when were they written, and against what
• Skill and agent frontmatter, for pinned model identifiers
• Scripts, CI config and settings files, for model IDs and API parameters
• Any dated decision records the repo keeps
• legilimens-anthropica's digest from this session, when it ran

Establish the era from evidence, not assumption. A file's first commit date, a model ID named in it, a decision record's date, or a piece of advice that was current in a known window. Say which evidence you used. If the era cannot be established, this pass is ? — could not verify — the delta between an unknown era and today is not a finding, it is a guess.

Anti-patterns to find

1. Compensation for a fixed weakness. Text instructing the model to do what the current family does unprompted — thoroughness demands, self-verification prose, step-by-step relics, elaborate role-play framing. It was load-bearing once, which is why it reads as harmless now.
2. A dated model identifier that has aged out. A specific model ID in agent frontmatter, a script, a settings file, or CI. IDs are retired on a schedule; an alias is not. Distinguish a pin that is deliberate (reproducibility, a known-good evaluation) from one that is merely old.
3. Advice current guidance reverses. Not "no longer needed" but "now counterproductive" — the most valuable class, and the one nobody finds by re-reading their own file, because it still reads exactly as sensible as the day it was written.
4. Capability the layer does not use because it did not exist. Path-scoped rules, newer hook events, frontmatter fields, plugin mechanisms. The absence is invisible: nothing errors, the layer just does by hand what the harness would now do for it.
5. Era mismatch between files. One file written for the current family, another two generations back, both live and both obeyed. The older one usually wins in novel situations, because it was written when instructions had to be broader.
6. A version fact stated as a constant. A hardcoded cliff, cap, limit or version number that was measured once and typed. It ages silently and is quoted forever — the same defect obliviate-fossilium calls a typed fact.

Fix prescriptions

Bounds

• Prefer legilimens-anthropica's digest from this session over anything remembered. Guidance moves faster than any snapshot in this file, and training data is not a source.
• Scope: this repo's instruction layer and the config that pins models for it. Not application source, not dependency versions, not another plugin's files.
• Cap: at most 15 findings, aged model IDs and reversed advice first — those two classes act today; the rest are hygiene.
• Done when the layer has been read once against the established era. Not when the era feels fully mapped: there is always another guidance page.
• Offline, or where the delta cannot be sourced, report ? — could not verify per finding rather than reasoning from training data. Guessing a version delta is worse than declining one.
• Quote once, at read time; mark anything you cannot re-confirm UNVERIFIED rather than re-reading to check yourself.
• See skills/opus-pocus/references/casting-safety.md for the full rules.

Report format

Lead with the era finding: which family these files were written for, and the evidence that established it (commit dates, model IDs, decision records). Then per finding: file:line · class (1–6) · the quoted text · what changed · the prescription · the guidance source with its date. A prescription citing no source is a ?, not a finding.

SCANNED NOTHING if no instruction layer was found; ? — could not verify if one was found but its era could not be established, or if no current guidance was reachable.