postdoc

Every engine gets a say, and the result says who said what.

postdoc is the process between hopper and the analysis engines. It claims artifacts from the corpus, asks each engine what it makes of one, and reports the answers together with the verdict they fold into. It replaces atomscan serve and atomscan worker.

It adds one thing neither had. When an artifact names a package, hopper can point at an earlier release of that package it already holds, and isomer judges the difference. A release that looks clean on its own can still have added something, and that is the shape most supply-chain compromises take.

postdoc grades nothing

Every severity in a result belongs to the engine that produced it.

Judge	Engine	Decides
cleave	cleave's traits, graded by scan's trait floor	whether severe traits corroborate each other across enough behaviour families
ml	the azoth model, read through scan	the tightest false-positive budget at which the artifact grades hostile
llm	scan's per-file interpreter	whether the code reads as benign, suspicious or hostile
diff	isomer, over this artifact and an earlier release	what this release introduced
diff_llm	isomer's per-diff interpreter	whether that change reads as an attack

postdoc owns two things: the order the engines are asked in, and keeping the worse of the two finished outcomes — scan's and isomer's. It holds no thresholds, no trait lists and no prompts. A verdict here can be traced to an engine and a build, and re-derived by running that engine again.

That constraint is the point. A coordinator that quietly re-weighed its inputs would be a sixth judge nobody could audit.

The result

One artifact produces one verdict and, beside it, one judge object per engine.

{
  "v": "1",
  "sha256": "…",
  "purl": "pkg:npm/left-pad@1.3.1",
  "verdict": {
    "severity": "hostile",
    "fires_at": 25,
    "reason": "postinstall fetches and executes a remote script",
    "findings": [{ "id": "…", "crit": 5, "desc": "…" }],
    "decided_by": ["ml", "diff"],
    "engines": { "postdoc": "0.1.0", "scan": "2.12.0", "…": "…" },
    "analyzed_at": "2026-09-15T12:00:00Z",
    "duration_ms": 4120
  },
  "cleave":   { "status": "ok", "severity": "benign",  "fires_at": null, "…": "…" },
  "ml":       { "status": "ok", "severity": "hostile", "fires_at": 25,   "…": "…" },
  "llm":      { "status": "ok", "severity": "hostile", "confidence": 0.95, "…": "…" },
  "diff":     { "status": "ok", "severity": "hostile", "fires_at": 25,   "…": "…" },
  "diff_llm": { "status": "skipped", "reason": "no_baseline" }
}

Every judge key is present in every result. An engine that was not asked says so and why; one that failed says that instead, with how long it ran before it did. A consumer writes one code path.

Each judge carries its own engine's native output under raw — the cleave report, the model's route scores, isomer's differential. The evidence sits with the opinion it supports rather than in a shared pile, so a judge object is readable on its own. raw is dropped unless the caller asks for it with full=1.

fires_at is the tightest false-positive budget, per 100 million benign files, at which the artifact grades hostile. Lower is worse; -1 means it fires at none. It is measured, and turning it into an allow or a block against a caller's own budget happens when a lookup is answered, never here.

Modes

postdoc worker --url https://hopper.example --name nuc

worker claims artifacts from hopper, judges them, and posts results back. It accepts the same arguments atomscan worker does, so hopper's supervised local worker is a binary-name change and nothing else.

serve implements Scan's existing /v1 HTTP API with the same routes, request forms, authentication, and response shapes. Beamline can keep referring to these as Scan servers during the mixed-fleet transition; point new and replacement hosts at postdoc serve without changing SCAN_URL consumers.

The worker and server implementations now live here. The server keeps Scan's existing /v1 contract during rollout; the worker keeps its existing hopper claim and result payload contract.

There is no one-shot CLI. atomscan and isomer are the tools for that.

Build

make build     # debug
make test      # the suite
make lint      # rustfmt --check, then clippy with warnings denied
make release

make install-precommit gates commits on both.

Design

docs/DESIGN.md is the plan of record: the judges, how the fold works, how a baseline is chosen, and the changes it needs in hopper, scan and isomer. docs/JSON.md is the field-by-field reference for the result object.

Licensed Apache-2.0.