Generate NCPDP messages

The @cosyte/synth/ncpdp subpath builds both NCPDP standards through @cosyte/ncpdp's own emit surface, so every message is spec-clean by construction and round-trips through the parser with zero warnings. @cosyte/ncpdp is an optional peer dependency, needed only for this subpath.

NCPDP is two structurally unrelated standards under one brand, and the surface covers both:

• SCRIPT (XML ePrescribing) - generateNewRx (built through the validated buildNewRx builder), generateRxRenewalRequest, and generateRxChangeRequest (built as @cosyte/ncpdp's public typed ScriptMessage model, then serialized by serializeScript - the same typed-model→serializer path the X12 surface uses, never a hand-written byte).
• Telecom (vD.0 pharmacy claims) - generateB1 (billing), generateB2 (reversal), and generateB3 (rebill), built through buildTelecomRequest + serializeTelecom.

A NewRx, spec-clean by construction

The round-trip harness proves spec-cleanliness by @cosyte/ncpdp's own judgment - a spec-clean message re-parses with zero warnings and re-serializes byte-identically:

import { generateNewRx, scriptRoundTrip } from "@cosyte/synth/ncpdp";

// Same seed → byte-identical SCRIPT XML, on any machine, any run.
const result = scriptRoundTrip(generateNewRx({ seed: 12345 }));
result.warnings; // => []
result.byteStable; // => true
result.specClean; // => true

A Telecom claim

import { generateB1, telecomRoundTrip } from "@cosyte/synth/ncpdp";

const result = telecomRoundTrip(generateB1({ seed: 777 }));
result.specClean; // => true

A reproducible corpus

ncpdpCorpus builds a self-describing, deterministic corpus - one of each shipped transaction by default:

import { ncpdpCorpus } from "@cosyte/synth/ncpdp";

const corpus = ncpdpCorpus({ seed: 42 });
corpus.artifacts.map((a) => a.kind); // => ["NewRx", "RxRenewalRequest", "RxChangeRequest", "B1", "B2", "B3"]
corpus.artifacts.every((a) => a.warnings.length === 0); // => true

Synthetic-by-construction - patient and prescriber

NCPDP carries patient identity (name, DOB) and prescriber identity - including the DEA number, an identity locus the other formats do not have. Every value has a construction-level guarantee:

• Prescriber NPI - a 10-digit NPI with a deliberately-invalid Luhn check digit, so it can never be a NPPES-issued provider (safe.npi, isSyntheticNpi).
• Prescriber DEA - a XX+7-digit DEA number with a deliberately-invalid checksum. A real DEA number's 7th digit satisfies the published (d1+d3+d5) + 2·(d2+d4+d6) checksum, so a synth DEA can never be a validly-issued registration (safe.dea, isSyntheticDea).
• Patient / cardholder / member ids - scoped to a synthetic assigning authority (MBR-prefixed; there is no reserved id range, so the namespace is the guarantee).
• Names - the shipped clearly-fake pool; phone - the reserved 555-01xx block; DOBs / dates (including SCRIPT SentTime) - the seeded generator (never wall-clock); drug content - a small license-clean example pool with invented 00000-labeler NDCs (no NCPDP-copyrighted text is bundled).

import { isSyntheticNpi, isSyntheticDea, createRng } from "@cosyte/synth";
import { ncpdpPrescriber } from "@cosyte/synth/ncpdp";

const dr = ncpdpPrescriber(createRng(1));
isSyntheticNpi(dr.npi); // => true
isSyntheticDea(dr.dea); // => true

The repository's phi-scan gate runs NCPDP-aware structured detection over every generated corpus: a Luhn-valid <NPI> / DB or a checksum-valid <DEANumber> is a hard failure - it could denote a real provider.

Deferred

• SCRIPT coverage tracks the parser's builder surface: the renewal/change responses and other lifecycle transactions land as @cosyte/ncpdp grows its builders. synth never hand-writes bytes around a missing builder.
• Vendor-quirk mode (deliberately off-spec fixtures) is deferred for NCPDP.