HL7

A modern, robust C# library for parsing, serializing, and working with HL7 v2.x messages. Built with .NET 9 and C# 13, this library provides strong typing, extensibility, and comprehensive error handling for healthcare data exchange scenarios.

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Note:
This library currently supports only single HL7 v2.x messages.
Batch and file-level segments (such as FHS, BHS, BTS, FTS) are not supported at this time.

Features

• HL7 Message Parsing & Serialization
  Parse HL7 messages into strongly-typed objects and serialize them back to HL7 format.

• Custom Encoding Support
  Handles standard and custom HL7 delimiters and escape sequences.

• Domain Models
  Includes models for HL7 segments (e.g., FT1 for Financial Transaction Information).

• Error Handling
  Custom exceptions (HL7Exception) for granular error reporting.

• Immutability & Modern C#
  Uses records and immutable data structures for safety and clarity.

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Getting Started

Requirements

• .NET 9 or later
• C# 13.0

Usage

Parse an HL7 Message

using HL7;

string hl7Text = "MSH|^~\\&|..."; // your HL7 message
var message = Message.Parse(hl7Text);

// Access segments and fields
var msh = message.Segments.FirstOrDefault(s => s.Name == "MSH");
string sendingApp = msh?.Fields[2].Value;

Serialize a Message

string serialized = message.SerializeMessage();

Converts HL7 to c# classes (e.g., FT1)

var isSuccess = HL7Message.TryCreate(message, out var hl7Message);
if (isSuccess) {
  var msh = hl7Message.MSH;
  var versionId = msh.VersionId;
 var FT1s = hl7Message.GetRecords<FT1>();
}

Encode/Decode HL7 Values

var encoding = new HL7Encoding('|', '^', '~', '\\', '&');
string encoded = encoding.Encode("A|B^C");
string decoded = encoding.Decode(encoded);

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Testing

Unit tests are provided in the HL7Test project.
Run with your preferred test runner (e.g., dotnet test).

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Extending

• Add new segment models by inheriting from HL7Data<T>.
• Customize encoding by creating new HL7Encoding instances.

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Contributing

Pull requests and issues are welcome!

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Acknowledgments

• HL7 and Health Level Seven are registered trademarks of Health Level Seven International.
• Started from Fork of Efferent.HL7.V2 but rewrote close to 100% of the code.