Build, parse, and master X12 with precision — the Node.js way.

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Why node‑x12‑edi?

• Bi‑directional mapping Seamlessly parse EDI → JSON with mapSegments(mapLogic) and generate JSON → EDI using toX12(json, mapLogic).
• Rock‑solid structure Map using FieldMap and LoopMap to define how your JSON schema connects to segments and loops, offering clarity and reusability.
• JSON-first mapping Define mapLogic as plain JSON objects with _type keys — perfect for serverless environments, configuration files, and database storage.
• Performance optimized Compiles mapping logic into fast blueprints — lightning-fast serialization, even for large payloads.
• Pure JS, zero dependencies Works anywhere Node.js goes — server, CLI, AWS Lambda, CI pipelines.

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Quick Start

npm install node‑x12‑edi

import Transaction from "node‑x12‑edi";
import { FieldMap, LoopMap } from "node‑x12‑edi";

// 1. Define your mapping logic (class-based)
const mapLogic = {
  header: {
    date: new FieldMap({ segmentIdentifier: "GS", valuePosition: 4 }),
    receiptNumber: new FieldMap({ segmentIdentifier: "W17", valuePosition: 2 }),
  },
  detail: {
    items: new LoopMap({
      position: 0,
      values: {
        itemCode: new FieldMap({ segmentIdentifier: "W07", valuePosition: 4 }),
        lotCode: new FieldMap({ segmentIdentifier: "W07", valuePosition: 7 }),
        weight: new FieldMap({ segmentIdentifier: "W20", valuePosition: 3 }),
      },
    }),
  },
};

// 1. Alternative: Define mapping logic as plain JSON (great for serverless!)
const jsonMapLogic = {
  header: {
    date: { _type: "FieldMap", segmentIdentifier: "GS", valuePosition: 4 },
    receiptNumber: {
      _type: "FieldMap",
      segmentIdentifier: "W17",
      valuePosition: 2,
    },
  },
  detail: {
    items: {
      _type: "LoopMap",
      position: 0,
      values: {
        itemCode: {
          _type: "FieldMap",
          segmentIdentifier: "W07",
          valuePosition: 4,
        },
        lotCode: {
          _type: "FieldMap",
          segmentIdentifier: "W07",
          valuePosition: 7,
        },
        weight: {
          _type: "FieldMap",
          segmentIdentifier: "W20",
          valuePosition: 3,
        },
      },
    },
  },
};

// 2. Parse EDI to JSON (works with either mapLogic format)
const transaction = new Transaction();
transaction.generateSegments(ediString);
transaction.runLoops(); // necessary to build loop contexts
const json = transaction.mapSegments(jsonMapLogic); // auto-revives JSON to classes
console.log("Parsed JSON:", json);

// 3. Generate EDI back from JSON
const edi = transaction.toX12(json, jsonMapLogic);
console.log("Regenerated EDI:", edi);

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Features

Feature	Description
Flexible mapping	Use FieldMap and LoopMap to easily map between hierarchical JSON and flat EDI formats.
JSON mapLogic	Define mapping logic as plain JSON with _type keys — perfect for config files and serverless environments.
Two-way conversion	Fully supports EDI → JSON and JSON → EDI conversion using the same mapping structure.
Loop support	Automatically handles repeating segments via LoopMap and RepeatingSegmentMap.
High performance	Pre-compiles mapping logic to minimize per-conversion overhead.
Clear API	Intuitive class methods — generateSegments, mapSegments, toX12.

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Next Steps & Pro Tips

• Create reusable mapLogic: Define a library of mappings per transaction type (e.g. 944, 850, 810) for reuse.
• Serverless-friendly: Store JSON mapLogic in databases, config files, or environment variables — no class instantiation needed.
• Add formats: Implement validation, segment padding, or normalized date formatting.
• Test coverage: Use real-world EDI samples and round-trip your JSON mappings.
• CLI wrapper: Create a lightweight CLI tool like edi2json or json2edi leveraging this library.

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Contributing & Credits

• Bug reports, feature ideas, and sample files are welcome!
• Please open issues and submit pull requests via GitHub.