diff --git a/CHANGELOG.md b/CHANGELOG.md
index 155743a..d86542d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,23 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [5.0.0] - 2026-02-20
+
+### Changed
+
+- **Breaking change:** All model types have been changed from `class`es to `record`s.
+- **Breaking change:** All property accessors on model types have changed from `{ get; set; }` to `{ get; init; }`.
+
+### Removed
+
+- **Breaking change:** `JsonApiLinksObject` has been removed.
+
+### Remarks
+
+This version refactors the entire model into immutable `record` types. While opinionated, I'm convinced this change is in the best interest of creating robust and resilient code.
+
+If you're not willing to part with mutable `class`es, this version is otherwise identical to version 4.0.0.
+
 ## [4.0.0] - 2026-02-16
 
 ### Changed
@@ -67,6 +84,7 @@ Additionally, this version aims to be more idiomatic by renaming class propertie
 
 Initial release.
 
+[5.0.0]: https://github.com/twcrews/jsonapi-client/compare/4.0.0...5.0.0
 [4.0.0]: https://github.com/twcrews/jsonapi-client/compare/3.0.0...4.0.0
 [3.0.0]: https://github.com/twcrews/jsonapi-client/compare/2.0.0...3.0.0
 [2.0.0]: https://github.com/twcrews/jsonapi-client/compare/1.0.0...2.0.0
diff --git a/Crews.Web.JsonApiClient.Tests/JsonApiDocumentTests.cs b/Crews.Web.JsonApiClient.Tests/JsonApiDocumentTests.cs
index 2cb501f..7aa4ec2 100644
--- a/Crews.Web.JsonApiClient.Tests/JsonApiDocumentTests.cs
+++ b/Crews.Web.JsonApiClient.Tests/JsonApiDocumentTests.cs
@@ -13,7 +13,7 @@ public JsonApiDocumentTests()
 	}
 
 	// Concrete implementation for testing abstract JsonApiDocument
-	private class TestJsonApiDocument : JsonApiDocument { }
+	private record TestJsonApiDocument : JsonApiDocument { }
 
 	#region HasCollectionResource Tests
 
@@ -475,15 +475,15 @@ public void DeserializeCollectionGenericStaticMethodReturnsValidDocumentForValid
 		Assert.True(doc.HasCollectionResource);
     }
 
-	public class MyModel
+	public record MyModel
 	{
-		public string? Name { get; set; }
-		public int Age { get; set; }
+		public string? Name { get; init; }
+		public int Age { get; init; }
 	}
 
-	public class MyModelResource : JsonApiResource<MyModel> { }
+	public record MyModelResource : JsonApiResource<MyModel> { }
 
-	public class MyModelDocument : JsonApiDocument<MyModelResource> { }
+	public record MyModelDocument : JsonApiDocument<MyModelResource> { }
 
     #endregion
 }
diff --git a/Crews.Web.JsonApiClient/Converters/JsonApiLinkConverter.cs b/Crews.Web.JsonApiClient/Converters/JsonApiLinkConverter.cs
index 2ab9077..cbb4ff4 100644
--- a/Crews.Web.JsonApiClient/Converters/JsonApiLinkConverter.cs
+++ b/Crews.Web.JsonApiClient/Converters/JsonApiLinkConverter.cs
@@ -22,12 +22,32 @@ internal class JsonApiLinkConverter : JsonConverter<JsonApiLink>
         // Case 2: Link is an object with properties
         if (reader.TokenType == JsonTokenType.StartObject)
         {
-            JsonApiLink link = new() { Href = new(string.Empty, UriKind.Relative) };
+            Uri? href = null;
+            string? rel = null;
+            JsonApiLink? describedBy = null;
+            string? title = null;
+            string? type = null;
+            string? hrefLang = null;
+            JsonObject? meta = null;
 
             while (reader.Read())
             {
                 if (reader.TokenType == JsonTokenType.EndObject)
-                    return link;
+                {
+                    if (href is null)
+                        throw new JsonException("Href is required for link objects.");
+
+                    return new JsonApiLink
+                    {
+                        Href = href,
+                        Rel = rel,
+                        DescribedBy = describedBy,
+                        Title = title,
+                        Type = type,
+                        HrefLang = hrefLang,
+                        Meta = meta
+                    };
+                }
 
                 if (reader.TokenType == JsonTokenType.PropertyName)
                 {
@@ -37,26 +57,26 @@ internal class JsonApiLinkConverter : JsonConverter<JsonApiLink>
                     switch (propertyName)
                     {
                         case "href":
-                            string href = reader.GetString() ?? throw new JsonException("Href cannot be null.");
-                            link.Href = new(href);
+                            string hrefString = reader.GetString() ?? throw new JsonException("Href cannot be null.");
+                            href = new(hrefString);
                             break;
                         case "rel":
-                            link.Rel = reader.GetString();
+                            rel = reader.GetString();
                             break;
                         case "describedby":
-                            link.DescribedBy = JsonSerializer.Deserialize<JsonApiLink>(ref reader, options);
+                            describedBy = JsonSerializer.Deserialize<JsonApiLink>(ref reader, options);
                             break;
                         case "title":
-                            link.Title = reader.GetString();
+                            title = reader.GetString();
                             break;
                         case "type":
-                            link.Type = reader.GetString();
+                            type = reader.GetString();
                             break;
                         case "hreflang":
-                            link.HrefLang = reader.GetString();
+                            hrefLang = reader.GetString();
                             break;
                         case "meta":
-                            link.Meta = JsonSerializer.Deserialize<JsonObject>(ref reader, options);
+                            meta = JsonSerializer.Deserialize<JsonObject>(ref reader, options);
                             break;
                         default:
                             // Skip unknown properties
diff --git a/Crews.Web.JsonApiClient/Crews.Web.JsonApiClient.csproj b/Crews.Web.JsonApiClient/Crews.Web.JsonApiClient.csproj
index fd7cc96..2ad8471 100644
--- a/Crews.Web.JsonApiClient/Crews.Web.JsonApiClient.csproj
+++ b/Crews.Web.JsonApiClient/Crews.Web.JsonApiClient.csproj
@@ -9,7 +9,7 @@
 
   <PropertyGroup>
     <PackageId>Crews.Web.JsonApiClient</PackageId>
-    <PackageVersion>4.0.0</PackageVersion>
+    <PackageVersion>5.0.0</PackageVersion>
     <Authors>Tommy Crews</Authors>
     <Description>
       A library containing serialization models and methods for the JSON:API specification.
diff --git a/Crews.Web.JsonApiClient/JsonApiDocument.cs b/Crews.Web.JsonApiClient/JsonApiDocument.cs
index 09d7e90..0615360 100644
--- a/Crews.Web.JsonApiClient/JsonApiDocument.cs
+++ b/Crews.Web.JsonApiClient/JsonApiDocument.cs
@@ -7,51 +7,51 @@ namespace Crews.Web.JsonApiClient;
 /// <summary>
 /// Represents a base class for JSON:API top-level objects as defined in section 7.1 of the JSON:API specification.
 /// </summary>
-public class JsonApiDocument
+public record JsonApiDocument
 {
     /// <summary>
     /// Gets or sets the <c>jsonapi</c> property of the document.
     /// </summary>
     [JsonPropertyName("jsonapi")]
-    public JsonApiInfo? JsonApi { get; set; }
+    public JsonApiInfo? JsonApi { get; init; }
 
     /// <summary>
     /// Gets or sets the primary data payload associated with the document.
     /// </summary>
     [JsonPropertyName("data")]
-    public JsonElement? Data { get; set; }
+    public JsonElement? Data { get; init; }
 
     /// <summary>
     /// Gets or sets the collection of errors associated with the document.
     /// </summary>
     [JsonPropertyName("errors")]
-    public IEnumerable<JsonApiError>? Errors { get; set; }
+    public IEnumerable<JsonApiError>? Errors { get; init; }
 
     /// <summary>
     /// Gets or sets the <c>links</c> property of the document.
     /// </summary>
     /// <seealso href="https://jsonapi.org/format/#document-links"/>
     [JsonPropertyName("links")]
-    public Dictionary<string, JsonApiLink>? Links { get; set; }
+    public Dictionary<string, JsonApiLink>? Links { get; init; }
 
     /// <summary>
     /// Gets or sets the <c>included</c> property of the document.
     /// </summary>
     [JsonPropertyName("included")]
-    public IEnumerable<JsonApiResource>? Included { get; set; }
+    public IEnumerable<JsonApiResource>? Included { get; init; }
 
     /// <summary>
     /// Gets or sets the <c>meta</c> property of the document.
     /// </summary>
     /// <seealso href="https://jsonapi.org/format/#document-meta"/>
     [JsonPropertyName("meta")]
-    public JsonObject? Meta { get; set; }
+    public JsonObject? Meta { get; init; }
 
     /// <summary>
     /// Gets or sets members defined by any applied JSON:API extensions.
     /// </summary>
     [JsonExtensionData]
-    public Dictionary<string, JsonElement>? Extensions { get; set; }
+    public Dictionary<string, JsonElement>? Extensions { get; init; }
 
     /// <summary>
     /// Gets a value indicating whether the <see cref="Data"/> property contains a resource collection object.
@@ -87,13 +87,13 @@ public class JsonApiDocument
 /// JSON:API specification.
 /// </summary>
 /// <typeparam name="T">The underlying resource type.</typeparam>
-public class JsonApiDocument<T> : JsonApiDocument where T : JsonApiResource
+public record JsonApiDocument<T> : JsonApiDocument where T : JsonApiResource
 {
     /// <summary>
     /// Gets or sets the primary data payload associated with the document.
     /// </summary>
     [JsonPropertyName("data")]
-    public new T? Data { get; set; }
+    public new T? Data { get; init; }
 
     /// <summary>
     /// Gets a value indicating whether the <see cref="Data"/> property contains a single resource object.
@@ -120,13 +120,13 @@ public class JsonApiDocument<T> : JsonApiDocument where T : JsonApiResource
 /// JSON:API specification.
 /// </summary>
 /// <typeparam name="T">The underlying resource type.</typeparam>
-public class JsonApiCollectionDocument<T> : JsonApiDocument where T : JsonApiResource
+public record JsonApiCollectionDocument<T> : JsonApiDocument where T : JsonApiResource
 {
     /// <summary>
     /// Gets or sets the primary data payload associated with the document.
     /// </summary>
     [JsonPropertyName("data")]
-    public new IEnumerable<T>? Data { get; set; }
+    public new IEnumerable<T>? Data { get; init; }
 
     /// <summary>
     /// Gets a value indicating whether the <see cref="Data"/> property contains a resource collection object.
diff --git a/Crews.Web.JsonApiClient/JsonApiError.cs b/Crews.Web.JsonApiClient/JsonApiError.cs
index df98666..8210c20 100644
--- a/Crews.Web.JsonApiClient/JsonApiError.cs
+++ b/Crews.Web.JsonApiClient/JsonApiError.cs
@@ -6,53 +6,53 @@ namespace Crews.Web.JsonApiClient;
 /// <summary>
 /// Represents an error in a document as defined in section 11.2 of the JSON:API specification.
 /// </summary>
-public class JsonApiError
+public record JsonApiError
 {
     /// <summary>
     /// Gets or sets the unique identifier for this particular occurrence of the problem.
     /// </summary>
     [JsonPropertyName("id")]
-    public string? Id { get; set; }
+    public string? Id { get; init; }
 
     /// <summary>
     /// Gets or sets the links that provide additional information about the error.
     /// </summary>
     [JsonPropertyName("links")]
-    public JsonApiErrorLinksObject? Links { get; set; }
+    public JsonApiErrorLinksObject? Links { get; init; }
 
     /// <summary>
     /// Gets or sets the HTTP status code associated with the error.
     /// </summary>
     [JsonPropertyName("status")]
-    public string? Status { get; set; }
+    public string? Status { get; init; }
 
     /// <summary>
     /// Gets or sets the application-specific error code associated with the error.
     /// </summary>
     [JsonPropertyName("code")]
-    public string? Code { get; set; }
+    public string? Code { get; init; }
 
     /// <summary>
     /// Gets or sets the title of the error.
     /// </summary>
     [JsonPropertyName("title")]
-    public string? Title { get; set; }
+    public string? Title { get; init; }
 
     /// <summary>
     /// Gets or sets the detailed description of the error.
     /// </summary>
     [JsonPropertyName("detail")]
-    public string? Detail { get; set; }
+    public string? Detail { get; init; }
 
     /// <summary>
     /// Gets or sets the source of the error.
     /// </summary>
     [JsonPropertyName("source")]
-    public JsonApiErrorSource? Source { get; set; }
+    public JsonApiErrorSource? Source { get; init; }
 
     /// <summary>
     /// Gets or sets the additional metadata associated with the object.
     /// </summary>
     [JsonPropertyName("meta")]
-    public JsonObject? Meta { get; set; }
+    public JsonObject? Meta { get; init; }
 }
diff --git a/Crews.Web.JsonApiClient/JsonApiErrorLinksObject.cs b/Crews.Web.JsonApiClient/JsonApiErrorLinksObject.cs
index 45ddbe4..26c0112 100644
--- a/Crews.Web.JsonApiClient/JsonApiErrorLinksObject.cs
+++ b/Crews.Web.JsonApiClient/JsonApiErrorLinksObject.cs
@@ -7,25 +7,25 @@ namespace Crews.Web.JsonApiClient;
 /// <summary>
 /// Represents a set of links that provide additional information about an error in a JSON:API document.
 /// </summary>
-public class JsonApiErrorLinksObject
+public record JsonApiErrorLinksObject
 {
     /// <summary>
     /// Gets or sets a link that provides additional information about the error.
     /// </summary>
     [JsonPropertyName("about")]
     [JsonConverter(typeof(JsonApiLinkConverter))]
-    public JsonApiLink? About { get; set; }
+    public JsonApiLink? About { get; init; }
 
     /// <summary>
     /// Gets or sets the link that specifies the type of the error.
     /// </summary>
     [JsonPropertyName("type")]
     [JsonConverter(typeof(JsonApiLinkConverter))]
-    public JsonApiLink? Type { get; set; }
+    public JsonApiLink? Type { get; init; }
 
     /// <summary>
     /// Gets or sets a collection of additional JSON properties that are not mapped to known members.
     /// </summary>
     [JsonExtensionData]
-    public Dictionary<string, JsonElement>? Extensions { get; set; }
+    public Dictionary<string, JsonElement>? Extensions { get; init; }
 }
diff --git a/Crews.Web.JsonApiClient/JsonApiErrorSource.cs b/Crews.Web.JsonApiClient/JsonApiErrorSource.cs
index f649f54..7ebf811 100644
--- a/Crews.Web.JsonApiClient/JsonApiErrorSource.cs
+++ b/Crews.Web.JsonApiClient/JsonApiErrorSource.cs
@@ -6,23 +6,23 @@ namespace Crews.Web.JsonApiClient;
 /// Represents the source of an error in a request, such as a specific field, parameter, or header that caused the
 /// error.
 /// </summary>
-public class JsonApiErrorSource
+public record JsonApiErrorSource
 {
     /// <summary>
     /// Gets or sets the JSON Pointer that identifies the location within a JSON document that caused the error.
     /// </summary>
     [JsonPropertyName("pointer")]
-    public string? Pointer { get; set; }
+    public string? Pointer { get; init; }
 
     /// <summary>
     /// Gets or sets the URI query parameter value that caused the error.
     /// </summary>
     [JsonPropertyName("parameter")]
-    public string? Parameter { get; set; }
+    public string? Parameter { get; init; }
 
     /// <summary>
     /// Gets or sets the name of a request header that caused the error.
     /// </summary>
     [JsonPropertyName("header")]
-    public string? Header { get; set; }
+    public string? Header { get; init; }
 }
diff --git a/Crews.Web.JsonApiClient/JsonApiInfo.cs b/Crews.Web.JsonApiClient/JsonApiInfo.cs
index ecd899e..23fb96a 100644
--- a/Crews.Web.JsonApiClient/JsonApiInfo.cs
+++ b/Crews.Web.JsonApiClient/JsonApiInfo.cs
@@ -6,29 +6,29 @@ namespace Crews.Web.JsonApiClient;
 /// <summary>
 /// Represents information about the JSON:API implementation as defined in section 7.7 of the JSON:API specification.
 /// </summary>
-public class JsonApiInfo
+public record JsonApiInfo
 {
     /// <summary>
     /// Gets or sets the JSON:API version for the document.
     /// </summary>
     [JsonPropertyName("version")]
-    public string? Version { get; set; }
+    public string? Version { get; init; }
 
     /// <summary>
     /// Gets or sets the collection of extension URIs associated with the document.
     /// </summary>
     [JsonPropertyName("ext")]
-    public IEnumerable<Uri>? Ext { get; set; }
+    public IEnumerable<Uri>? Ext { get; init; }
 
     /// <summary>
     /// Gets or sets the collection of profile URIs associated with the document.
     /// </summary>
     [JsonPropertyName("profile")]
-    public IEnumerable<Uri>? Profile { get; set; }
+    public IEnumerable<Uri>? Profile { get; init; }
 
     /// <summary>
     /// Gets or sets the collection of additional metadata associated with the object.
     /// </summary>
     [JsonPropertyName("meta")]
-    public JsonObject? Meta { get; set; }
+    public JsonObject? Meta { get; init; }
 }
diff --git a/Crews.Web.JsonApiClient/JsonApiLink.cs b/Crews.Web.JsonApiClient/JsonApiLink.cs
index 04b9207..110cab0 100644
--- a/Crews.Web.JsonApiClient/JsonApiLink.cs
+++ b/Crews.Web.JsonApiClient/JsonApiLink.cs
@@ -8,50 +8,50 @@ namespace Crews.Web.JsonApiClient;
 /// Represents a hypermedia link with associated metadata, as defined in section 7.6.1 of the JSON:API specification.
 /// </summary>
 [JsonConverter(typeof(JsonApiLinkConverter))]
-public class JsonApiLink
+public record JsonApiLink
 {
     /// <summary>
     /// Gets or sets the URL of the link.
     /// </summary>
     [JsonPropertyName("href")]
-    public required Uri Href { get; set; }
+    public required Uri Href { get; init; }
 
     /// <summary>
     /// Gets or sets the relation type for the link.
     /// </summary>
     [JsonPropertyName("rel")]
-    public string? Rel { get; set; }
+    public string? Rel { get; init; }
 
     /// <summary>
     /// Gets or sets a link to a resource that provides additional descriptive information about the current object.
     /// </summary>
     [JsonPropertyName("describedby")]
     [JsonConverter(typeof(JsonApiLinkConverter))]
-    public JsonApiLink? DescribedBy { get; set; }
+    public JsonApiLink? DescribedBy { get; init; }
 
     /// <summary>
     /// Gets or sets the title associated with the object.
     /// </summary>
     [JsonPropertyName("title")]
-    public string? Title { get; set; }
+    public string? Title { get; init; }
 
     /// <summary>
     /// Gets or sets the type of the object represented by this instance.
     /// </summary>
     [JsonPropertyName("type")]
-    public string? Type { get; set; }
+    public string? Type { get; init; }
 
     /// <summary>
     /// Gets or sets the language of the linked resource, as defined by the hreflang attribute in HTML or XML sitemaps.
     /// </summary>
     [JsonPropertyName("hreflang")]
-    public string? HrefLang { get; set; }
+    public string? HrefLang { get; init; }
 
     /// <summary>
     /// Gets or sets metadata about the link.
     /// </summary>
     [JsonPropertyName("meta")]
-    public JsonObject? Meta { get; set; }
+    public JsonObject? Meta { get; init; }
 
     /// <summary>
     /// Implicitly converts a string URL to a JsonApiLink instance.
diff --git a/Crews.Web.JsonApiClient/JsonApiRelationship.cs b/Crews.Web.JsonApiClient/JsonApiRelationship.cs
index ca1c26f..e6463c6 100644
--- a/Crews.Web.JsonApiClient/JsonApiRelationship.cs
+++ b/Crews.Web.JsonApiClient/JsonApiRelationship.cs
@@ -7,31 +7,31 @@ namespace Crews.Web.JsonApiClient;
 /// <summary>
 /// Represents a relationship object as defined in section 7.2.2.2 of the JSON:API specification.
 /// </summary>
-public class JsonApiRelationship
+public record JsonApiRelationship
 {
     /// <summary>
     /// Gets or sets the <c>links</c> property of the relationship object.
     /// </summary>
     [JsonPropertyName("links")]
-    public Dictionary<string, JsonApiLink>? Links { get; set; }
+    public Dictionary<string, JsonApiLink>? Links { get; init; }
 
     /// <summary>
     /// Gets or sets the data payload associated with the response or request.
     /// </summary>
     [JsonPropertyName("data")]
-    public JsonElement? Data { get; set; }
+    public JsonElement? Data { get; init; }
 
     /// <summary>
     /// Gets or sets additional metadata associated with the object.
     /// </summary>
     [JsonPropertyName("meta")]
-    public JsonObject? Meta { get; set; }
+    public JsonObject? Meta { get; init; }
 
     /// <summary>
     /// Gets or sets members defined by any applied JSON:API extensions.
     /// </summary>
     [JsonExtensionData]
-    public Dictionary<string, JsonElement>? Extensions { get; set; }
+    public Dictionary<string, JsonElement>? Extensions { get; init; }
 }
 
 /// <summary>
@@ -39,12 +39,12 @@ public class JsonApiRelationship
 /// JSON:API specification.
 /// </summary>
 /// <typeparam name="T">The type of the resource identifier object in the <see cref="Data"/> property.</typeparam>
-public class JsonApiRelationship<T> : JsonApiRelationship where T : JsonApiResourceIdentifier
+public record JsonApiRelationship<T> : JsonApiRelationship where T : JsonApiResourceIdentifier
 {
     /// <summary>
     /// Gets or sets the data payload associated with the response or request.
     /// </summary>
-    public new T? Data { get; set; }
+    public new T? Data { get; init; }
 }
 
 /// <summary>
@@ -54,10 +54,10 @@ public class JsonApiRelationship<T> : JsonApiRelationship where T : JsonApiResou
 /// <typeparam name="T">
 /// The type of the resource identifier collection object in the <see cref="Data"/> property.
 /// </typeparam>
-public class JsonApiCollectionRelationship<T> : JsonApiRelationship where T : IEnumerable<JsonApiResourceIdentifier>
+public record JsonApiCollectionRelationship<T> : JsonApiRelationship where T : IEnumerable<JsonApiResourceIdentifier>
 {
     /// <summary>
     /// Gets or sets the data payload associated with the response or request.
     /// </summary>
-    public new T? Data { get; set; }
+    public new T? Data { get; init; }
 }
\ No newline at end of file
diff --git a/Crews.Web.JsonApiClient/JsonApiResource.cs b/Crews.Web.JsonApiClient/JsonApiResource.cs
index 149ecd6..ae0e7b0 100644
--- a/Crews.Web.JsonApiClient/JsonApiResource.cs
+++ b/Crews.Web.JsonApiClient/JsonApiResource.cs
@@ -6,31 +6,31 @@ namespace Crews.Web.JsonApiClient;
 /// <summary>
 /// Represents a resource object as defined in section 7.2 of the JSON:API specification.
 /// </summary>
-public class JsonApiResource : JsonApiResourceIdentifier
+public record JsonApiResource : JsonApiResourceIdentifier
 {
     /// <summary>
     /// Gets or sets the collection of custom attributes associated with this object.
     /// </summary>
     [JsonPropertyName("attributes")]
-    public JsonObject? Attributes { get; set; }
+    public JsonObject? Attributes { get; init; }
 
     /// <summary>
     /// Gets or sets the collection of relationships associated with this object.
     /// </summary>
     [JsonPropertyName("relationships")]
-    public Dictionary<string, JsonApiRelationship>? Relationships { get; set; }
+    public Dictionary<string, JsonApiRelationship>? Relationships { get; init; }
 
     /// <summary>
     /// Gets or sets the <c>links</c> property of the resource object.
     /// </summary>
     [JsonPropertyName("links")]
-    public Dictionary<string, JsonApiLink>? Links { get; set; }
+    public Dictionary<string, JsonApiLink>? Links { get; init; }
 
     /// <summary>
     /// Gets or sets the custom metadata associated with this object.
     /// </summary>
     [JsonPropertyName("meta")]
-    public JsonObject? Meta { get; set; }
+    public JsonObject? Meta { get; init; }
 }
 
 /// <summary>
@@ -38,12 +38,12 @@ public class JsonApiResource : JsonApiResourceIdentifier
 /// specification.
 /// </summary>
 /// <typeparam name="T">The type of the <see cref="Attributes"/> property.</typeparam>
-public class JsonApiResource<T> : JsonApiResource
+public record JsonApiResource<T> : JsonApiResource
 {
     /// <summary>
     /// Gets or sets the collection of custom attributes associated with this object.
     /// </summary>
-    public new T? Attributes { get; set; }
+    public new T? Attributes { get; init; }
 }
 
 /// <summary>
@@ -51,11 +51,11 @@ public class JsonApiResource<T> : JsonApiResource
 /// </summary>
 /// <typeparam name="TAttributes">The type used to represent the attributes of the resource object.</typeparam>
 /// <typeparam name="TRelationships">The type used to represent the relationships associated with the resource object.</typeparam>
-public class JsonApiResource<TAttributes, TRelationships> : JsonApiResource<TAttributes>
+public record JsonApiResource<TAttributes, TRelationships> : JsonApiResource<TAttributes>
 {
     /// <summary>
     /// Gets or sets the collection of relationships associated with this object.
     /// </summary>
     [JsonPropertyName("relationships")]
-    public new TRelationships? Relationships { get; set; }
+    public new TRelationships? Relationships { get; init; }
 }
\ No newline at end of file
diff --git a/Crews.Web.JsonApiClient/JsonApiResourceIdentifier.cs b/Crews.Web.JsonApiClient/JsonApiResourceIdentifier.cs
index 80516eb..f3c2727 100644
--- a/Crews.Web.JsonApiClient/JsonApiResourceIdentifier.cs
+++ b/Crews.Web.JsonApiClient/JsonApiResourceIdentifier.cs
@@ -6,23 +6,23 @@ namespace Crews.Web.JsonApiClient;
 /// Represents a reference to a resource by its type and identifier, as defined in section 7.3 of the JSON:API
 /// specification.
 /// </summary>
-public class JsonApiResourceIdentifier
+public record JsonApiResourceIdentifier
 {
     /// <summary>
     /// Gets or sets the unique identifier for the object.
     /// </summary>
     [JsonPropertyName("id")]
-    public string? Id { get; set; }
+    public string? Id { get; init; }
 
     /// <summary>
     /// Gets or sets the local identifier associated with the object.
     /// </summary>
     [JsonPropertyName("lid")]
-    public string? LId { get; set; }
+    public string? LId { get; init; }
 
     /// <summary>
     /// Gets or sets the type identifier for the object represented by this instance.
     /// </summary>
     [JsonPropertyName("type")]
-    public required string Type { get; set; }
+    public required string Type { get; init; }
 }
diff --git a/README.md b/README.md
index db96792..6ad908a 100644
--- a/README.md
+++ b/README.md
@@ -16,9 +16,9 @@ dotnet add package Crews.Web.JsonApiClient
 // Step 1: Define your base model
 public class Article
 {
-    public string? Title { get; set; }
-    public string? Body { get; set; }
-    public DateTime? PublishedAt { get; set; }
+    public string? Title { get; init; }
+    public string? Body { get; init; }
+    public DateTime? PublishedAt { get; init; }
 }
 
 // Step 2: Define a strongly-typed resource class extending JsonApiResource<T>
@@ -109,22 +109,22 @@ public class UserResource : JsonApiResource<User, UserRelationships> { }
 public class User
 {
     [JsonPropertyName("name")]
-    public string? Name { get; set; }
+    public string? Name { get; init; }
 
     [JsonPropertyName("email")]
-    public string? Email { get; set; }
+    public string? Email { get; init; }
 
     [JsonPropertyName("createdAt")]
-    public DateTime? CreatedAt { get; set; }
+    public DateTime? CreatedAt { get; init; }
 }
 
 public class UserRelationships
 {
     [JsonPropertyName("posts")]
-    public JsonApiCollectionRelationship<List<JsonApiResourceIdentifier>>? Posts { get; set; }
+    public JsonApiCollectionRelationship<List<JsonApiResourceIdentifier>>? Posts { get; init; }
 
     [JsonPropertyName("profile")]
-    public JsonApiRelationship<JsonApiResourceIdentifier>? Profile { get; set; }
+    public JsonApiRelationship<JsonApiResourceIdentifier>? Profile { get; init; }
 }
 
 // Use the types