WASM API¶

Package: @eddiethedean/dtcs-wasm.

Maturity: experimental / optional publish (see release runbook NPM_TOKEN). Pin versions explicitly when consuming from npm. Package version tracks tools 0.13.x.

Install¶

npm install @eddiethedean/dtcs-wasm@0.13.0

For browsers or custom hosts you must load the .wasm bytes and call initSync before other APIs. The Node wrapper (node.md) does this for you.

Surface (intentionally small)¶

Export	Arguments	Returns / notes
`initSync({ module })`	WASM bytes (`Uint8Array` / `Buffer`)	must call before other APIs
`parseDocument(content, format)`	`Uint8Array`/`string`, `"yaml"`\|`"json"`	`{ contract, report }` (may be `Map`-like)
`validateContract(contract)`	plain COM object	`{ diagnostics }` — check severities; does not throw on invalid
`conformanceDeclare(profile?)`	optional profile id	capability declaration object
`specVersion()`	—	`"3.0.0"`

3.0 surface limits: parse / validate / conformanceDeclare only — no reference runtime, plan export, optimize/compile/run, or offline conformanceRun. Use the Rust CLI or Python package for Rich Portable Analytics execution and certification.

Map vs plain object¶

Hosts may deserialize objects as ES Map. Coerce with a recursive mapToPlain helper (see node.md) before reading fields as plain properties.

Node bootstrap (after `npm run build` in `bindings/wasm`)¶

import { readFileSync } from "node:fs";
import {
  initSync,
  parseDocument,
  validateContract,
  specVersion,
} from "./pkg/dtcs_wasm.js";

initSync({ module: readFileSync("./pkg/dtcs_wasm_bg.wasm") });
console.log(specVersion()); // "3.0.0"

const yaml = `dtcsVersion: "3.0.0"
id: "demo.minimal"
name: "Minimal"
version: "0.1.0"
metadata:
  description: "wasm smoke"
  classification: internal
  governance: { owner: "docs", steward: "docs" }
  provenance: { author: "docs", createdAt: "2026-01-01T00:00:00Z" }
inputs:
  - id: "in"
    schema:
      fields: [{ name: "v", type: "string", nullable: false }]
outputs:
  - id: "out"
    schema:
      fields: [{ name: "v", type: "string", nullable: false }]
lineage:
  mappings: [{ output: "out", inputs: ["in"] }]
`;
const parsed = parseDocument(new TextEncoder().encode(yaml), "yaml");

Parity vs CLI / Python¶

Capability	CLI / Python	WASM
Parse / validate	Yes	Yes
Analyze / plan / run / export-portable	Yes (Rust CLI / Python lib)	No
`conformance declare`	Yes	Yes
`conformance run`	Yes	No

Errors¶

Invalid contracts produce diagnostics in the returned report. Prefer checking diagnostic severity rather than expecting thrown exceptions. See error-taxonomy.md.

Build from source¶

cd bindings/wasm
rustup target add wasm32-unknown-unknown
cargo install wasm-pack   # once
npm run build             # or: npx wasm-pack build --target web --out-dir pkg
npm test

See the package README.