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Version: v0.0.4

@cosyte/synth

Generate deterministic, seedable synthetic healthcare fixtures - spec-clean HL7 v2, FHIR R4 / US Core, C-CDA, X12, NCPDP and ASTM - without hand-writing a byte of the wire format, and without any chance the "patient" you just generated is a real person.

@cosyte/synth is a consumer of the cosyte parsers, not a parser. It builds each artifact through the parser's own builder/serializer (so the output is spec-clean by construction) and draws every identifier, name, date, phone, and address from a guaranteed-non-colliding synthetic source (SSA never-issued SSNs, NANP 555-01xx phones, example.* domains, TEST-NET IPs, a synthetic assigning authority for MRNs, and a shipped clearly-fake name pool). It is a format/conformance generator, not a clinical simulator - it does not model disease progression (that is Synthea).

Status: pre-alpha (0.0.x), not yet published to npm.

Install​

npm install @cosyte/synth @cosyte/hl7

@cosyte/hl7 is an optional peer dependency - install it only if you use the @cosyte/synth/hl7 subpath. The package core (PRNG + safe providers) has zero third-party runtime dependencies.

Generate a spec-clean message​

import { generateAdt, roundTrip } from "@cosyte/synth/hl7";

// Same seed → byte-identical message, on any machine, any run.
const message = generateAdt({ seed: 12345, trigger: "A01" });

// It round-trips through @cosyte/hl7 with zero warnings - spec-clean by construction.
roundTrip(message).specClean; // => true

Every value in that message is provably synthetic: the SSN is never-issued (900–999 area), the phone is in the reserved 555-01xx block, the name is from a clearly-fake pool, and the MRN lives under a synthetic assigning authority.

Next​

  • Quickstart - the core primitives and the HL7 corpus.
  • Core Concepts - synthetic-by-construction, determinism, the round-trip gate.