Judgment Pack MCP server

judgment-pack

Status: pre-1.0

Tagged binaries are official only when they appear on this repository's GitHub Releases page

with checksums.txt. Development checkouts may temporarily embed unreleased JPS snapshots, but

the release workflow rejects them.

judgment-pack is the vendor-neutral reference runtime for the Judgment Pack Specification (JPS). It is a reference implementation, not the only valid one: the normative specification, schemas, and conformance corpus are owned by the separate judgment-pack-spec repository, and an independent implementation is judged against the complete normative requirements of the conformance class it claims — not against this runtime. Results from the corpus published for the exact version it names are required evidence for such a claim and are not exhaustive evidence of it (§3.4.1).

The runtime validates documents. It does not fetch a source, authorize an action, or establish truth, organizational authority, safety, or operational fitness. It bundles two specification versions, 0.1.0-draft and 0.2.0-draft, and validates a document against the exact version that document declares; 0.1.0-draft defines carrier, structural, and semantic document conformance only, and 0.2.0-draft changes no part of the document format.

One shared evaluator applies the specification's §§7–8 resolution model per ADR-0007, and eight surfaces reach it: jpack experimental evaluate and evaluate-corpus, the project walk jpack packs test, the graph verbs jpack experimental graph evaluate and graph test, and the experimentalevaluate, experimentaltestpacks and experimentaltestgraphs MCP tools. The experimental namespace is a stability** statement: such a surface may change or be removed without compatibility promise. It is not a statement about conformance. That evaluator implements the evaluator conformance class Core 0.2.0-draft adds — the §8.2 input preflight, the §8.3 portable disposition with its RFC 8785 byte agreement, the §8.4 error classes and their fixed precedence, and the §10 limits — per ADR-0010 and ADR-0011. Only a pack declaring specVersion 0.2.0-draft is evaluated: §11 makes the declared value exact and requires an unedited 0.1.0-draft pack to be re-declared — one edit, the specVersion string, and nothing else in the document — before an implementation claiming this draft evaluates it, so any other version is refused as pack-not-conformant in the preflight phase.

This runtime's conformance claim is stated, in full and only, in CONFORMANCE.md. JPS §3.4.1 fixes the entire form such a claim may take — the class, one exact specVersion, the corpus version, the results obtained, and in the claim's own words that every row of that corpus version passed — so this README states no part of it and neither does any other surface: a partial restatement would be the partial claim §3.4.1 forbids. Read that file for the claim, its version scope, its evidence, and everything it does not assert, which includes anything at all about a pack, its facts, or the wisdom of acting on a disposition (§3.5). jpack experimental evaluate-corpus runs the bundled evaluation corpus and reports its rows — the evidence §3.4.1 requires of a claim of this class, and explicitly not exhaustive evidence of one; see CONFORMANCE.md.

Shortened. The full README is on GitHub.