Internal module guide. This module is now part of @astrology/western; use the public package README for application setup.

rulebooks module

Western rulebook admission: manifest validation, content-hash integrity and typed technique lookup. Public imports use the package root. See the package specification and task W-13.

Run pnpm --filter @astrology/western build, check, and test. This package imports no technique, engine or provider implementation, so admission never loads a formula or an ephemeris.

Admission

createWesternRulebookRegistry(bundles) validates every manifest, then verifies that the supplied technique resources are exactly those the manifest declares:

• the same technique set, with no missing, duplicate or undeclared entry;
• the declared version and variant;
• a payload whose canonical SHA-256 equals the declared hash.

Any mismatch fails with RULEBOOK_INTEGRITY before a handle is served. Admitted handles store a frozen copy, and identity.hash hashes the manifest, so it covers every technique hash. A duplicate id@version is refused.

Lookup

resolveWesternRulebook(registry, reference) needs the exact id and version and fails with UNKNOWN_RULEBOOK; there is no nearby-version fallback.

assertRulebookCompatible(handle, profile) requires both that the profile names this rulebook and that the manifest lists the profile id@version; otherwise PROFILE_INCOMPATIBLE.

getWesternTechniqueRules<T>(handle, technique, validate) passes the stored payload through the owning technique’s validator and returns AdmittedRules<T>. A missing technique is UNKNOWN_RULEBOOK, and the validator’s own failure (for example INVALID_RULES) is preserved. The payload is never cast to a schema it does not satisfy.

hashTechniqueRules(payload) and verifyRulebookTechniques(manifest, techniques) are exported so a host can write and check its own manifest with the same canonical hash.

Consumer example

import {
  createWesternRulebookRegistry,
  getWesternTechniqueRules,
  resolveWesternRulebook,
} from './rulebooks/index.js';

const registry = createWesternRulebookRegistry([{ manifest, techniques: bundles }]);
const handle = resolveWesternRulebook(registry, profile.rulebook);
const natal = getWesternTechniqueRules(handle, 'natal', validateNatalRules);

Not implemented here

Technique payload schemas, table contents, profile resolution, feature registration and evaluation.