diff --git a/Documentation/ABI/JSON.md b/Documentation/ABI/JSON.md
index f313ddc00..e4ff24a4b 100644
--- a/Documentation/ABI/JSON.md
+++ b/Documentation/ABI/JSON.md
@@ -188,19 +188,24 @@ sufficient information to display the event in a human-readable format.
   "kind": <event-kind>,
   "instant": <instant>, ; when the event occurred
   ["issue": <issue>,] ; the recorded issue (if "kind" is "issueRecorded")
+  ["attachment": <attachment>,] ; the attachment (if kind is "valueAttached")
   "messages": <array:message>,
   ["testID": <test-id>,]
 }
 
 <event-kind> ::= "runStarted" | "testStarted" | "testCaseStarted" |
   "issueRecorded" | "testCaseEnded" | "testEnded" | "testSkipped" |
-  "runEnded" ; additional event kinds may be added in the future
+  "runEnded" | "valueAttached"; additional event kinds may be added in the future
 
 <issue> ::= {
   "isKnown": <bool>, ; is this a known issue or not?
   ["sourceLocation": <source-location>,] ; where the issue occurred, if known
 }
 
+<attachment> ::= {
+  "path": <string>, ; the absolute path to the attachment on disk
+}
+
 <message> ::= {
   "symbol": <message-symbol>,
   "text": <string>, ; the human-readable text of this message
diff --git a/Sources/Overlays/_Testing_CoreGraphics/Attachments/Attachment+AttachableAsCGImage.swift b/Sources/Overlays/_Testing_CoreGraphics/Attachments/Attachment+AttachableAsCGImage.swift
index ca520e0c0..ed1e6a2ee 100644
--- a/Sources/Overlays/_Testing_CoreGraphics/Attachments/Attachment+AttachableAsCGImage.swift
+++ b/Sources/Overlays/_Testing_CoreGraphics/Attachments/Attachment+AttachableAsCGImage.swift
@@ -42,9 +42,9 @@ extension Attachment {
     contentType: (any Sendable)?,
     encodingQuality: Float,
     sourceLocation: SourceLocation
-  ) where AttachableValue == _AttachableImageContainer<T> {
-    let imageContainer = _AttachableImageContainer(image: attachableValue, encodingQuality: encodingQuality, contentType: contentType)
-    self.init(imageContainer, named: preferredName, sourceLocation: sourceLocation)
+  ) where AttachableValue == _AttachableImageWrapper<T> {
+    let imageWrapper = _AttachableImageWrapper(image: attachableValue, encodingQuality: encodingQuality, contentType: contentType)
+    self.init(imageWrapper, named: preferredName, sourceLocation: sourceLocation)
   }
 
   /// Initialize an instance of this type that encloses the given image.
@@ -79,7 +79,7 @@ extension Attachment {
     as contentType: UTType?,
     encodingQuality: Float = 1.0,
     sourceLocation: SourceLocation = #_sourceLocation
-  ) where AttachableValue == _AttachableImageContainer<T> {
+  ) where AttachableValue == _AttachableImageWrapper<T> {
     self.init(attachableValue: attachableValue, named: preferredName, contentType: contentType, encodingQuality: encodingQuality, sourceLocation: sourceLocation)
   }
 
@@ -109,7 +109,7 @@ extension Attachment {
     named preferredName: String? = nil,
     encodingQuality: Float = 1.0,
     sourceLocation: SourceLocation = #_sourceLocation
-  ) where AttachableValue == _AttachableImageContainer<T> {
+  ) where AttachableValue == _AttachableImageWrapper<T> {
     self.init(attachableValue: attachableValue, named: preferredName, contentType: nil, encodingQuality: encodingQuality, sourceLocation: sourceLocation)
   }
 }
diff --git a/Sources/Overlays/_Testing_CoreGraphics/Attachments/_AttachableImageContainer.swift b/Sources/Overlays/_Testing_CoreGraphics/Attachments/_AttachableImageWrapper.swift
similarity index 96%
rename from Sources/Overlays/_Testing_CoreGraphics/Attachments/_AttachableImageContainer.swift
rename to Sources/Overlays/_Testing_CoreGraphics/Attachments/_AttachableImageWrapper.swift
index 90d1c0c70..7aa1fd139 100644
--- a/Sources/Overlays/_Testing_CoreGraphics/Attachments/_AttachableImageContainer.swift
+++ b/Sources/Overlays/_Testing_CoreGraphics/Attachments/_AttachableImageWrapper.swift
@@ -9,7 +9,7 @@
 //
 
 #if SWT_TARGET_OS_APPLE && canImport(CoreGraphics)
-@_spi(Experimental) public import Testing
+public import Testing
 private import CoreGraphics
 
 private import ImageIO
@@ -48,7 +48,7 @@ import UniformTypeIdentifiers
 ///
 /// - [`CGImage`](https://developer.apple.com/documentation/coregraphics/cgimage)
 @_spi(Experimental)
-public struct _AttachableImageContainer<Image>: Sendable where Image: AttachableAsCGImage {
+public struct _AttachableImageWrapper<Image>: Sendable where Image: AttachableAsCGImage {
   /// The underlying image.
   ///
   /// `CGImage` and `UIImage` are sendable, but `NSImage` is not. `NSImage`
@@ -127,8 +127,8 @@ public struct _AttachableImageContainer<Image>: Sendable where Image: Attachable
 
 // MARK: -
 
-extension _AttachableImageContainer: AttachableContainer {
-  public var attachableValue: Image {
+extension _AttachableImageWrapper: AttachableWrapper {
+  public var wrappedValue: Image {
     image
   }
 
diff --git a/Sources/Overlays/_Testing_Foundation/Attachments/Attachable+Encodable+NSSecureCoding.swift b/Sources/Overlays/_Testing_Foundation/Attachments/Attachable+Encodable+NSSecureCoding.swift
index cd26c24cc..46a1e11e6 100644
--- a/Sources/Overlays/_Testing_Foundation/Attachments/Attachable+Encodable+NSSecureCoding.swift
+++ b/Sources/Overlays/_Testing_Foundation/Attachments/Attachable+Encodable+NSSecureCoding.swift
@@ -9,7 +9,7 @@
 //
 
 #if canImport(Foundation)
-@_spi(Experimental) public import Testing
+public import Testing
 public import Foundation
 
 // This implementation is necessary to let the compiler disambiguate when a type
@@ -18,7 +18,9 @@ public import Foundation
 // (which explicitly document what happens when a type conforms to both
 // protocols.)
 
-@_spi(Experimental)
+/// @Metadata {
+///   @Available(Swift, introduced: 6.2)
+/// }
 extension Attachable where Self: Encodable & NSSecureCoding {
   @_documentation(visibility: private)
   public func withUnsafeBytes<R>(for attachment: borrowing Attachment<Self>, _ body: (UnsafeRawBufferPointer) throws -> R) throws -> R {
diff --git a/Sources/Overlays/_Testing_Foundation/Attachments/Attachable+Encodable.swift b/Sources/Overlays/_Testing_Foundation/Attachments/Attachable+Encodable.swift
index 812db0b70..683888801 100644
--- a/Sources/Overlays/_Testing_Foundation/Attachments/Attachable+Encodable.swift
+++ b/Sources/Overlays/_Testing_Foundation/Attachments/Attachable+Encodable.swift
@@ -9,7 +9,7 @@
 //
 
 #if canImport(Foundation)
-@_spi(Experimental) public import Testing
+public import Testing
 private import Foundation
 
 /// A common implementation of ``withUnsafeBytes(for:_:)`` that is used when a
@@ -53,7 +53,10 @@ func withUnsafeBytes<E, R>(encoding attachableValue: borrowing E, for attachment
 // Implement the protocol requirements generically for any encodable value by
 // encoding to JSON. This lets developers provide trivial conformance to the
 // protocol for types that already support Codable.
-@_spi(Experimental)
+
+/// @Metadata {
+///   @Available(Swift, introduced: 6.2)
+/// }
 extension Attachable where Self: Encodable {
   /// Encode this value into a buffer using either [`PropertyListEncoder`](https://developer.apple.com/documentation/foundation/propertylistencoder)
   /// or [`JSONEncoder`](https://developer.apple.com/documentation/foundation/jsonencoder),
@@ -86,6 +89,10 @@ extension Attachable where Self: Encodable {
   /// _and_ [`NSSecureCoding`](https://developer.apple.com/documentation/foundation/nssecurecoding),
   /// the default implementation of this function uses the value's conformance
   /// to `Encodable`.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   public func withUnsafeBytes<R>(for attachment: borrowing Attachment<Self>, _ body: (UnsafeRawBufferPointer) throws -> R) throws -> R {
     try _Testing_Foundation.withUnsafeBytes(encoding: self, for: attachment, body)
   }
diff --git a/Sources/Overlays/_Testing_Foundation/Attachments/Attachable+NSSecureCoding.swift b/Sources/Overlays/_Testing_Foundation/Attachments/Attachable+NSSecureCoding.swift
index c2cc28ea0..4acbf4960 100644
--- a/Sources/Overlays/_Testing_Foundation/Attachments/Attachable+NSSecureCoding.swift
+++ b/Sources/Overlays/_Testing_Foundation/Attachments/Attachable+NSSecureCoding.swift
@@ -9,13 +9,16 @@
 //
 
 #if canImport(Foundation)
-@_spi(Experimental) public import Testing
+public import Testing
 public import Foundation
 
 // As with Encodable, implement the protocol requirements for
 // NSSecureCoding-conformant classes by default. The implementation uses
 // NSKeyedArchiver for encoding.
-@_spi(Experimental)
+
+/// @Metadata {
+///   @Available(Swift, introduced: 6.2)
+/// }
 extension Attachable where Self: NSSecureCoding {
   /// Encode this object using [`NSKeyedArchiver`](https://developer.apple.com/documentation/foundation/nskeyedarchiver)
   /// into a buffer, then call a function and pass that buffer to it.
@@ -46,6 +49,10 @@ extension Attachable where Self: NSSecureCoding {
   /// _and_ [`NSSecureCoding`](https://developer.apple.com/documentation/foundation/nssecurecoding),
   /// the default implementation of this function uses the value's conformance
   /// to `Encodable`.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   public func withUnsafeBytes<R>(for attachment: borrowing Attachment<Self>, _ body: (UnsafeRawBufferPointer) throws -> R) throws -> R {
     let format = try EncodingFormat(for: attachment)
 
diff --git a/Sources/Overlays/_Testing_Foundation/Attachments/Attachment+URL.swift b/Sources/Overlays/_Testing_Foundation/Attachments/Attachment+URL.swift
index dbf7e2688..83c3909be 100644
--- a/Sources/Overlays/_Testing_Foundation/Attachments/Attachment+URL.swift
+++ b/Sources/Overlays/_Testing_Foundation/Attachments/Attachment+URL.swift
@@ -9,7 +9,7 @@
 //
 
 #if canImport(Foundation)
-@_spi(Experimental) public import Testing
+public import Testing
 public import Foundation
 
 #if !SWT_NO_PROCESS_SPAWNING && os(Windows)
@@ -32,8 +32,7 @@ extension URL {
   }
 }
 
-@_spi(Experimental)
-extension Attachment where AttachableValue == _AttachableURLContainer {
+extension Attachment where AttachableValue == _AttachableURLWrapper {
 #if SWT_TARGET_OS_APPLE
   /// An operation queue to use for asynchronously reading data from disk.
   private static let _operationQueue = OperationQueue()
@@ -51,6 +50,10 @@ extension Attachment where AttachableValue == _AttachableURLContainer {
   ///     attachment.
   ///
   /// - Throws: Any error that occurs attempting to read from `url`.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   public init(
     contentsOf url: URL,
     named preferredName: String? = nil,
@@ -91,8 +94,8 @@ extension Attachment where AttachableValue == _AttachableURLContainer {
     }
 #endif
 
-    let urlContainer = _AttachableURLContainer(url: url, data: data, isCompressedDirectory: isDirectory)
-    self.init(urlContainer, named: preferredName, sourceLocation: sourceLocation)
+    let urlWrapper = _AttachableURLWrapper(url: url, data: data, isCompressedDirectory: isDirectory)
+    self.init(urlWrapper, named: preferredName, sourceLocation: sourceLocation)
   }
 }
 
diff --git a/Sources/Overlays/_Testing_Foundation/Attachments/Data+Attachable.swift b/Sources/Overlays/_Testing_Foundation/Attachments/Data+Attachable.swift
index 38233cd3c..ce7b719a9 100644
--- a/Sources/Overlays/_Testing_Foundation/Attachments/Data+Attachable.swift
+++ b/Sources/Overlays/_Testing_Foundation/Attachments/Data+Attachable.swift
@@ -9,11 +9,16 @@
 //
 
 #if canImport(Foundation)
-@_spi(Experimental) public import Testing
+public import Testing
 public import Foundation
 
-@_spi(Experimental)
+/// @Metadata {
+///   @Available(Swift, introduced: 6.2)
+/// }
 extension Data: Attachable {
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   public func withUnsafeBytes<R>(for attachment: borrowing Attachment<Self>, _ body: (UnsafeRawBufferPointer) throws -> R) throws -> R {
     try withUnsafeBytes(body)
   }
diff --git a/Sources/Overlays/_Testing_Foundation/Attachments/EncodingFormat.swift b/Sources/Overlays/_Testing_Foundation/Attachments/EncodingFormat.swift
index bbbe934ab..49499a8c2 100644
--- a/Sources/Overlays/_Testing_Foundation/Attachments/EncodingFormat.swift
+++ b/Sources/Overlays/_Testing_Foundation/Attachments/EncodingFormat.swift
@@ -9,7 +9,7 @@
 //
 
 #if canImport(Foundation)
-@_spi(Experimental) import Testing
+import Testing
 import Foundation
 
 /// An enumeration describing the encoding formats we support for `Encodable`
diff --git a/Sources/Overlays/_Testing_Foundation/Attachments/_AttachableURLContainer.swift b/Sources/Overlays/_Testing_Foundation/Attachments/_AttachableURLWrapper.swift
similarity index 90%
rename from Sources/Overlays/_Testing_Foundation/Attachments/_AttachableURLContainer.swift
rename to Sources/Overlays/_Testing_Foundation/Attachments/_AttachableURLWrapper.swift
index c7a223a51..d6be53c80 100644
--- a/Sources/Overlays/_Testing_Foundation/Attachments/_AttachableURLContainer.swift
+++ b/Sources/Overlays/_Testing_Foundation/Attachments/_AttachableURLWrapper.swift
@@ -9,7 +9,7 @@
 //
 
 #if canImport(Foundation)
-@_spi(Experimental) public import Testing
+public import Testing
 public import Foundation
 
 /// A wrapper type representing file system objects and URLs that can be
@@ -17,8 +17,7 @@ public import Foundation
 ///
 /// You do not need to use this type directly. Instead, initialize an instance
 /// of ``Attachment`` using a file URL.
-@_spi(Experimental)
-public struct _AttachableURLContainer: Sendable {
+public struct _AttachableURLWrapper: Sendable {
   /// The underlying URL.
   var url: URL
 
@@ -31,8 +30,8 @@ public struct _AttachableURLContainer: Sendable {
 
 // MARK: -
 
-extension _AttachableURLContainer: AttachableContainer {
-  public var attachableValue: URL {
+extension _AttachableURLWrapper: AttachableWrapper {
+  public var wrappedValue: URL {
     url
   }
 
diff --git a/Sources/Overlays/_Testing_Foundation/CMakeLists.txt b/Sources/Overlays/_Testing_Foundation/CMakeLists.txt
index 54a340323..9343960ab 100644
--- a/Sources/Overlays/_Testing_Foundation/CMakeLists.txt
+++ b/Sources/Overlays/_Testing_Foundation/CMakeLists.txt
@@ -7,7 +7,7 @@
 # See http://swift.org/CONTRIBUTORS.txt for Swift project authors
 
 add_library(_Testing_Foundation
-  Attachments/_AttachableURLContainer.swift
+  Attachments/_AttachableURLWrapper.swift
   Attachments/EncodingFormat.swift
   Attachments/Attachment+URL.swift
   Attachments/Attachable+NSSecureCoding.swift
diff --git a/Sources/Testing/ABI/Encoded/ABI.EncodedEvent.swift b/Sources/Testing/ABI/Encoded/ABI.EncodedEvent.swift
index b8bafdde1..73e7db2ac 100644
--- a/Sources/Testing/ABI/Encoded/ABI.EncodedEvent.swift
+++ b/Sources/Testing/ABI/Encoded/ABI.EncodedEvent.swift
@@ -27,7 +27,7 @@ extension ABI {
       case testStarted
       case testCaseStarted
       case issueRecorded
-      case valueAttached = "_valueAttached"
+      case valueAttached
       case testCaseEnded
       case testEnded
       case testSkipped
@@ -50,9 +50,7 @@ extension ABI {
     ///
     /// The value of this property is `nil` unless the value of the
     /// ``kind-swift.property`` property is ``Kind-swift.enum/valueAttached``.
-    ///
-    /// - Warning: Attachments are not yet part of the JSON schema.
-    var _attachment: EncodedAttachment<V>?
+    var attachment: EncodedAttachment<V>?
 
     /// Human-readable messages associated with this event that can be presented
     /// to the user.
@@ -82,7 +80,7 @@ extension ABI {
         issue = EncodedIssue(encoding: recordedIssue, in: eventContext)
       case let .valueAttached(attachment):
         kind = .valueAttached
-        _attachment = EncodedAttachment(encoding: attachment, in: eventContext)
+        self.attachment = EncodedAttachment(encoding: attachment, in: eventContext)
       case .testCaseEnded:
         if eventContext.test?.isParameterized == false {
           return nil
diff --git a/Sources/Testing/Attachments/Attachable.swift b/Sources/Testing/Attachments/Attachable.swift
index 09a7e0b78..be466940b 100644
--- a/Sources/Testing/Attachments/Attachable.swift
+++ b/Sources/Testing/Attachments/Attachable.swift
@@ -24,9 +24,12 @@
 /// A type should conform to this protocol if it can be represented as a
 /// sequence of bytes that would be diagnostically useful if a test fails. If a
 /// type cannot conform directly to this protocol (such as a non-final class or
-/// a type declared in a third-party module), you can create a container type
-/// that conforms to ``AttachableContainer`` to act as a proxy.
-@_spi(Experimental)
+/// a type declared in a third-party module), you can create a wrapper type that
+/// conforms to ``AttachableWrapper`` to act as a proxy.
+///
+/// @Metadata {
+///   @Available(Swift, introduced: 6.2)
+/// }
 public protocol Attachable: ~Copyable {
   /// An estimate of the number of bytes of memory needed to store this value as
   /// an attachment.
@@ -42,6 +45,10 @@ public protocol Attachable: ~Copyable {
   ///
   /// - Complexity: O(1) unless `Self` conforms to `Collection`, in which case
   ///   up to O(_n_) where _n_ is the length of the collection.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   var estimatedAttachmentByteCount: Int? { get }
 
   /// Call a function and pass a buffer representing this instance to it.
@@ -64,6 +71,10 @@ public protocol Attachable: ~Copyable {
   /// the buffer to contain an image in PNG format, JPEG format, etc., but it
   /// would not be idiomatic for the buffer to contain a textual description of
   /// the image.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   borrowing func withUnsafeBytes<R>(for attachment: borrowing Attachment<Self>, _ body: (UnsafeRawBufferPointer) throws -> R) throws -> R
 
   /// Generate a preferred name for the given attachment.
@@ -80,6 +91,10 @@ public protocol Attachable: ~Copyable {
   /// when adding `attachment` to a test report or persisting it to storage. The
   /// default implementation of this function returns `suggestedName` without
   /// any changes.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   borrowing func preferredName(for attachment: borrowing Attachment<Self>, basedOn suggestedName: String) -> String
 }
 
@@ -119,28 +134,24 @@ extension Attachable where Self: StringProtocol {
 
 // Implement the protocol requirements for byte arrays and buffers so that
 // developers can attach raw data when needed.
-@_spi(Experimental)
 extension Array<UInt8>: Attachable {
   public func withUnsafeBytes<R>(for attachment: borrowing Attachment<Self>, _ body: (UnsafeRawBufferPointer) throws -> R) throws -> R {
     try withUnsafeBytes(body)
   }
 }
 
-@_spi(Experimental)
 extension ContiguousArray<UInt8>: Attachable {
   public func withUnsafeBytes<R>(for attachment: borrowing Attachment<Self>, _ body: (UnsafeRawBufferPointer) throws -> R) throws -> R {
     try withUnsafeBytes(body)
   }
 }
 
-@_spi(Experimental)
 extension ArraySlice<UInt8>: Attachable {
   public func withUnsafeBytes<R>(for attachment: borrowing Attachment<Self>, _ body: (UnsafeRawBufferPointer) throws -> R) throws -> R {
     try withUnsafeBytes(body)
   }
 }
 
-@_spi(Experimental)
 extension String: Attachable {
   public func withUnsafeBytes<R>(for attachment: borrowing Attachment<Self>, _ body: (UnsafeRawBufferPointer) throws -> R) throws -> R {
     var selfCopy = self
@@ -150,7 +161,6 @@ extension String: Attachable {
   }
 }
 
-@_spi(Experimental)
 extension Substring: Attachable {
   public func withUnsafeBytes<R>(for attachment: borrowing Attachment<Self>, _ body: (UnsafeRawBufferPointer) throws -> R) throws -> R {
     var selfCopy = self
diff --git a/Sources/Testing/Attachments/AttachableContainer.swift b/Sources/Testing/Attachments/AttachableWrapper.swift
similarity index 70%
rename from Sources/Testing/Attachments/AttachableContainer.swift
rename to Sources/Testing/Attachments/AttachableWrapper.swift
index e4d716e9c..81df52d4d 100644
--- a/Sources/Testing/Attachments/AttachableContainer.swift
+++ b/Sources/Testing/Attachments/AttachableWrapper.swift
@@ -21,11 +21,22 @@
 /// A type can conform to this protocol if it represents another type that
 /// cannot directly conform to ``Attachable``, such as a non-final class or a
 /// type declared in a third-party module.
-@_spi(Experimental)
-public protocol AttachableContainer<AttachableValue>: Attachable, ~Copyable {
-  /// The type of the attachable value represented by this type.
-  associatedtype AttachableValue
+///
+/// @Metadata {
+///   @Available(Swift, introduced: 6.2)
+/// }
+public protocol AttachableWrapper<Wrapped>: Attachable, ~Copyable {
+  /// The type of the underlying value represented by this type.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
+  associatedtype Wrapped
 
-  /// The attachable value represented by this instance.
-  var attachableValue: AttachableValue { get }
+  /// The underlying value represented by this instance.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
+  var wrappedValue: Wrapped { get }
 }
diff --git a/Sources/Testing/Attachments/Attachment.swift b/Sources/Testing/Attachments/Attachment.swift
index d7c1cddb7..c11ca7a50 100644
--- a/Sources/Testing/Attachments/Attachment.swift
+++ b/Sources/Testing/Attachments/Attachment.swift
@@ -18,7 +18,10 @@ private import _TestingInternals
 /// of some type that conforms to ``Attachable``. Initialize an instance of
 /// ``Attachment`` with that value and, optionally, a preferred filename to use
 /// when writing to disk.
-@_spi(Experimental)
+///
+/// @Metadata {
+///   @Available(Swift, introduced: 6.2)
+/// }
 public struct Attachment<AttachableValue>: ~Copyable where AttachableValue: Attachable & ~Copyable {
   /// Storage for ``attachableValue-7dyjv``.
   fileprivate var _attachableValue: AttachableValue
@@ -51,6 +54,10 @@ public struct Attachment<AttachableValue>: ~Copyable where AttachableValue: Atta
   /// testing library may substitute a different filename as needed. If the
   /// value of this property has not been explicitly set, the testing library
   /// will attempt to generate its own value.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   public var preferredName: String {
     let suggestedName = if let _preferredName, !_preferredName.isEmpty {
       _preferredName
@@ -90,6 +97,10 @@ extension Attachment where AttachableValue: ~Copyable {
   ///   - sourceLocation: The source location of the call to this initializer.
   ///     This value is used when recording issues associated with the
   ///     attachment.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   public init(_ attachableValue: consuming AttachableValue, named preferredName: String? = nil, sourceLocation: SourceLocation = #_sourceLocation) {
     self._attachableValue = attachableValue
     self._preferredName = preferredName
@@ -97,7 +108,7 @@ extension Attachment where AttachableValue: ~Copyable {
   }
 }
 
-@_spi(Experimental) @_spi(ForToolsIntegrationOnly)
+@_spi(ForToolsIntegrationOnly)
 extension Attachment where AttachableValue == AnyAttachable {
   /// Create a type-erased attachment from an instance of ``Attachment``.
   ///
@@ -105,7 +116,7 @@ extension Attachment where AttachableValue == AnyAttachable {
   ///   - attachment: The attachment to type-erase.
   fileprivate init(_ attachment: Attachment<some Attachable & Sendable & Copyable>) {
     self.init(
-      _attachableValue: AnyAttachable(attachableValue: attachment.attachableValue),
+      _attachableValue: AnyAttachable(wrappedValue: attachment.attachableValue),
       fileSystemPath: attachment.fileSystemPath,
       _preferredName: attachment._preferredName,
       sourceLocation: attachment.sourceLocation
@@ -114,7 +125,7 @@ extension Attachment where AttachableValue == AnyAttachable {
 }
 #endif
 
-/// A type-erased container type that represents any attachable value.
+/// A type-erased wrapper type that represents any attachable value.
 ///
 /// This type is not generally visible to developers. It is used when posting
 /// events of kind ``Event/Kind/valueAttached(_:)``. Test tools authors who use
@@ -125,54 +136,55 @@ extension Attachment where AttachableValue == AnyAttachable {
 //   Swift's type system requires that this type be at least as visible as
 //   `Event.Kind.valueAttached(_:)`, otherwise it would be declared private.
 // }
-@_spi(Experimental) @_spi(ForToolsIntegrationOnly)
-public struct AnyAttachable: AttachableContainer, Copyable, Sendable {
+@_spi(ForToolsIntegrationOnly)
+public struct AnyAttachable: AttachableWrapper, Copyable, Sendable {
 #if !SWT_NO_LAZY_ATTACHMENTS
-  public typealias AttachableValue = any Attachable & Sendable /* & Copyable rdar://137614425 */
+  public typealias Wrapped = any Attachable & Sendable /* & Copyable rdar://137614425 */
 #else
-  public typealias AttachableValue = [UInt8]
+  public typealias Wrapped = [UInt8]
 #endif
 
-  public var attachableValue: AttachableValue
+  public var wrappedValue: Wrapped
 
-  init(attachableValue: AttachableValue) {
-    self.attachableValue = attachableValue
+  init(wrappedValue: Wrapped) {
+    self.wrappedValue = wrappedValue
   }
 
   public var estimatedAttachmentByteCount: Int? {
-    attachableValue.estimatedAttachmentByteCount
+    wrappedValue.estimatedAttachmentByteCount
   }
 
   public func withUnsafeBytes<R>(for attachment: borrowing Attachment<Self>, _ body: (UnsafeRawBufferPointer) throws -> R) throws -> R {
-    func open<T>(_ attachableValue: T, for attachment: borrowing Attachment<Self>) throws -> R where T: Attachable & Sendable & Copyable {
+    func open<T>(_ wrappedValue: T, for attachment: borrowing Attachment<Self>) throws -> R where T: Attachable & Sendable & Copyable {
       let temporaryAttachment = Attachment<T>(
-        _attachableValue: attachableValue,
+        _attachableValue: wrappedValue,
         fileSystemPath: attachment.fileSystemPath,
         _preferredName: attachment._preferredName,
         sourceLocation: attachment.sourceLocation
       )
       return try temporaryAttachment.withUnsafeBytes(body)
     }
-    return try open(attachableValue, for: attachment)
+    return try open(wrappedValue, for: attachment)
   }
 
   public borrowing func preferredName(for attachment: borrowing Attachment<Self>, basedOn suggestedName: String) -> String {
-    func open<T>(_ attachableValue: T, for attachment: borrowing Attachment<Self>) -> String where T: Attachable & Sendable & Copyable {
+    func open<T>(_ wrappedValue: T, for attachment: borrowing Attachment<Self>) -> String where T: Attachable & Sendable & Copyable {
       let temporaryAttachment = Attachment<T>(
-        _attachableValue: attachableValue,
+        _attachableValue: wrappedValue,
         fileSystemPath: attachment.fileSystemPath,
         _preferredName: attachment._preferredName,
         sourceLocation: attachment.sourceLocation
       )
       return temporaryAttachment.preferredName
     }
-    return open(attachableValue, for: attachment)
+    return open(wrappedValue, for: attachment)
   }
 }
 
 // MARK: - Describing an attachment
 
 extension Attachment where AttachableValue: ~Copyable {
+  @_documentation(visibility: private)
   public var description: String {
     let typeInfo = TypeInfo(describing: AttachableValue.self)
     return #""\#(preferredName)": instance of '\#(typeInfo.unqualifiedName)'"#
@@ -180,6 +192,9 @@ extension Attachment where AttachableValue: ~Copyable {
 }
 
 extension Attachment: CustomStringConvertible {
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   public var description: String {
     #""\#(preferredName)": \#(String(describingForTest: attachableValue))"#
   }
@@ -187,9 +202,12 @@ extension Attachment: CustomStringConvertible {
 
 // MARK: - Getting an attachable value from an attachment
 
-@_spi(Experimental)
 extension Attachment where AttachableValue: ~Copyable {
   /// The value of this attachment.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   @_disfavoredOverload public var attachableValue: AttachableValue {
     _read {
       yield _attachableValue
@@ -197,21 +215,24 @@ extension Attachment where AttachableValue: ~Copyable {
   }
 }
 
-@_spi(Experimental)
-extension Attachment where AttachableValue: AttachableContainer & ~Copyable {
+extension Attachment where AttachableValue: AttachableWrapper & ~Copyable {
   /// The value of this attachment.
   ///
-  /// When the attachable value's type conforms to ``AttachableContainer``, the
-  /// value of this property equals the container's underlying attachable value.
+  /// When the attachable value's type conforms to ``AttachableWrapper``, the
+  /// value of this property equals the wrapper's underlying attachable value.
   /// To access the attachable value as an instance of `T` (where `T` conforms
-  /// to ``AttachableContainer``), specify the type explicitly:
+  /// to ``AttachableWrapper``), specify the type explicitly:
   ///
   /// ```swift
   /// let attachableValue = attachment.attachableValue as T
   /// ```
-  public var attachableValue: AttachableValue.AttachableValue {
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
+  public var attachableValue: AttachableValue.Wrapped {
     _read {
-      yield attachableValue.attachableValue
+      yield attachableValue.wrappedValue
     }
   }
 }
@@ -235,6 +256,10 @@ extension Attachment where AttachableValue: Sendable & Copyable {
   /// disk.
   ///
   /// An attachment can only be attached once.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   @_documentation(visibility: private)
   public static func record(_ attachment: consuming Self, sourceLocation: SourceLocation = #_sourceLocation) {
     var attachmentCopy = Attachment<AnyAttachable>(attachment)
@@ -263,6 +288,10 @@ extension Attachment where AttachableValue: Sendable & Copyable {
   /// attaches it to the current test.
   ///
   /// An attachment can only be attached once.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   @_documentation(visibility: private)
   public static func record(_ attachableValue: consuming AttachableValue, named preferredName: String? = nil, sourceLocation: SourceLocation = #_sourceLocation) {
     record(Self(attachableValue, named: preferredName, sourceLocation: sourceLocation), sourceLocation: sourceLocation)
@@ -286,12 +315,16 @@ extension Attachment where AttachableValue: ~Copyable {
   /// disk.
   ///
   /// An attachment can only be attached once.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   public static func record(_ attachment: consuming Self, sourceLocation: SourceLocation = #_sourceLocation) {
     do {
       let attachmentCopy = try attachment.withUnsafeBytes { buffer in
-        let attachableContainer = AnyAttachable(attachableValue: Array(buffer))
+        let attachableWrapper = AnyAttachable(wrappedValue: Array(buffer))
         return Attachment<AnyAttachable>(
-          _attachableValue: attachableContainer,
+          _attachableValue: attachableWrapper,
           fileSystemPath: attachment.fileSystemPath,
           _preferredName: attachment.preferredName, // invokes preferredName(for:basedOn:)
           sourceLocation: sourceLocation
@@ -325,6 +358,10 @@ extension Attachment where AttachableValue: ~Copyable {
   /// attaches it to the current test.
   ///
   /// An attachment can only be attached once.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   public static func record(_ attachableValue: consuming AttachableValue, named preferredName: String? = nil, sourceLocation: SourceLocation = #_sourceLocation) {
     record(Self(attachableValue, named: preferredName, sourceLocation: sourceLocation), sourceLocation: sourceLocation)
   }
@@ -349,6 +386,10 @@ extension Attachment where AttachableValue: ~Copyable {
   /// test report or to a file on disk. This function calls the
   /// ``Attachable/withUnsafeBytes(for:_:)`` function on this attachment's
   /// ``attachableValue-2tnj5`` property.
+  ///
+  /// @Metadata {
+  ///   @Available(Swift, introduced: 6.2)
+  /// }
   @inlinable public borrowing func withUnsafeBytes<R>(_ body: (UnsafeRawBufferPointer) throws -> R) throws -> R {
     try attachableValue.withUnsafeBytes(for: self, body)
   }
@@ -382,7 +423,7 @@ extension Attachment where AttachableValue: ~Copyable {
   /// This function is provided as a convenience to allow tools authors to write
   /// attachments to persistent storage the same way that Swift Package Manager
   /// does. You are not required to use this function.
-  @_spi(Experimental) @_spi(ForToolsIntegrationOnly)
+  @_spi(ForToolsIntegrationOnly)
   public borrowing func write(toFileInDirectoryAtPath directoryPath: String) throws -> String {
     try write(
       toFileInDirectoryAtPath: directoryPath,
diff --git a/Sources/Testing/CMakeLists.txt b/Sources/Testing/CMakeLists.txt
index 7e07636d5..81a0c550a 100644
--- a/Sources/Testing/CMakeLists.txt
+++ b/Sources/Testing/CMakeLists.txt
@@ -22,7 +22,7 @@ add_library(Testing
   ABI/Encoded/ABI.EncodedMessage.swift
   ABI/Encoded/ABI.EncodedTest.swift
   Attachments/Attachable.swift
-  Attachments/AttachableContainer.swift
+  Attachments/AttachableWrapper.swift
   Attachments/Attachment.swift
   Events/Clock.swift
   Events/Event.swift
diff --git a/Sources/Testing/Events/Event.swift b/Sources/Testing/Events/Event.swift
index b81f1c2c7..0be14ae88 100644
--- a/Sources/Testing/Events/Event.swift
+++ b/Sources/Testing/Events/Event.swift
@@ -102,7 +102,6 @@ public struct Event: Sendable {
     ///
     /// - Parameters:
     ///   - attachment: The attachment that was created.
-    @_spi(Experimental)
     indirect case valueAttached(_ attachment: Attachment<AnyAttachable>)
 
     /// A test ended.
diff --git a/Sources/Testing/Events/Recorder/Event.Symbol.swift b/Sources/Testing/Events/Recorder/Event.Symbol.swift
index 846fb2d4d..3354691fb 100644
--- a/Sources/Testing/Events/Recorder/Event.Symbol.swift
+++ b/Sources/Testing/Events/Recorder/Event.Symbol.swift
@@ -44,7 +44,6 @@ extension Event {
     case details
 
     /// The symbol to use when describing an instance of ``Attachment``.
-    @_spi(Experimental)
     case attachment
   }
 }
diff --git a/Sources/Testing/Issues/Issue.swift b/Sources/Testing/Issues/Issue.swift
index 5d7449b7b..d210ecec7 100644
--- a/Sources/Testing/Issues/Issue.swift
+++ b/Sources/Testing/Issues/Issue.swift
@@ -65,7 +65,6 @@ public struct Issue: Sendable {
     ///
     /// - Parameters:
     ///   - error: The error which was associated with this issue.
-    @_spi(Experimental)
     case valueAttachmentFailed(_ error: any Error)
 
     /// An issue occurred due to misuse of the testing library.
diff --git a/Sources/Testing/Running/Configuration.swift b/Sources/Testing/Running/Configuration.swift
index 30a2ce303..b8c48aa79 100644
--- a/Sources/Testing/Running/Configuration.swift
+++ b/Sources/Testing/Running/Configuration.swift
@@ -237,7 +237,6 @@ public struct Configuration: Sendable {
   /// The value of this property must refer to a directory on the local file
   /// system that already exists and which the current user can write to. If it
   /// is a relative path, it is resolved to an absolute path automatically.
-  @_spi(Experimental)
   public var attachmentsPath: String? {
     get {
       _attachmentsPath
diff --git a/Sources/Testing/Testing.docc/Attachments.md b/Sources/Testing/Testing.docc/Attachments.md
new file mode 100644
index 000000000..0da40c201
--- /dev/null
+++ b/Sources/Testing/Testing.docc/Attachments.md
@@ -0,0 +1,32 @@
+# Attachments
+
+<!--
+This source file is part of the Swift.org open source project
+
+Copyright (c) 2024–2025 Apple Inc. and the Swift project authors
+Licensed under Apache License v2.0 with Runtime Library Exception
+
+See https://swift.org/LICENSE.txt for license information
+See https://swift.org/CONTRIBUTORS.txt for Swift project authors
+-->
+
+Attach values to tests to help diagnose issues and gather feedback.
+
+## Overview
+
+Attach values such as strings and files to tests.  Implement the ``Attachable``
+protocol to create your own attachable types.
+
+## Topics
+
+### Attaching values to tests
+
+- ``Attachment``
+- ``Attachable``
+- ``AttachableWrapper``
+
+<!-- TODO: set up DocC content for overlays if possible
+### Attaching files to tests
+
+- ``/Foundation/URL/init(contentsOf:named:sourceLocation:)``
+-->
diff --git a/Sources/Testing/Testing.docc/Documentation.md b/Sources/Testing/Testing.docc/Documentation.md
index 901c0e3a6..cc4001889 100644
--- a/Sources/Testing/Testing.docc/Documentation.md
+++ b/Sources/Testing/Testing.docc/Documentation.md
@@ -69,3 +69,7 @@ their problems.
 ### Test customization
 
 - <doc:Traits>
+
+### Data collection
+
+- <doc:Attachments>
diff --git a/Sources/Testing/Testing.docc/MigratingFromXCTest.md b/Sources/Testing/Testing.docc/MigratingFromXCTest.md
index e3a9d961f..60744ba7a 100644
--- a/Sources/Testing/Testing.docc/MigratingFromXCTest.md
+++ b/Sources/Testing/Testing.docc/MigratingFromXCTest.md
@@ -742,6 +742,66 @@ suite serially:
 
 For more information, see <doc:Parallelization>.
 
+### Attach values
+
+In XCTest, you can create an instance of [`XCTAttachment`](https://developer.apple.com/documentation/xctest/xctattachment)
+representing arbitrary data, files, property lists, encodable objects, images,
+and other types of information that would be useful to have available if a test
+fails. Swift Testing has an ``Attachment`` type that serves much the same
+purpose.
+
+To attach a value from a test to the output of a test run, that value must
+conform to the ``Attachable`` protocol. The testing library provides default
+conformances for various standard library and Foundation types.
+
+If you want to attach a value of another type, and that type already conforms to
+[`Encodable`](https://developer.apple.com/documentation/swift/encodable) or to
+[`NSSecureCoding`](https://developer.apple.com/documentation/foundation/nssecurecoding),
+the testing library automatically provides a default implementation when you
+import Foundation:
+
+@Row {
+  @Column {
+    ```swift
+    // Before
+    import Foundation
+
+    class Tortilla: NSSecureCoding { /* ... */ }
+
+    func testTortillaIntegrity() async {
+      let tortilla = Tortilla(diameter: .large)
+      ...
+      let attachment = XCTAttachment(
+        archivableObject: tortilla
+      )
+      self.add(attachment)
+    }
+    ```
+  }
+  @Column {
+    ```swift
+    // After
+    import Foundation
+
+    struct Tortilla: Codable, Attachable { /* ... */ }
+
+    @Test func tortillaIntegrity() async {
+      let tortilla = Tortilla(diameter: .large)
+      ...
+      Attachment.record(tortilla)
+    }
+    ```
+  }
+}
+
+If you have a type that does not (or cannot) conform to `Encodable` or
+`NSSecureCoding`, or if you want fine-grained control over how it is serialized
+when attaching it to a test, you can provide your own implementation of
+``Attachable/withUnsafeBytes(for:_:)``.
+
+<!-- NOTE: not discussing attaching to activities here since there is not yet an
+equivalent interface in Swift Testing. -->
+
 ## See Also
 
 - <doc:DefiningTests>
diff --git a/Tests/TestingTests/AttachmentTests.swift b/Tests/TestingTests/AttachmentTests.swift
index 126633776..0281b4091 100644
--- a/Tests/TestingTests/AttachmentTests.swift
+++ b/Tests/TestingTests/AttachmentTests.swift
@@ -8,11 +8,11 @@
 // See https://swift.org/CONTRIBUTORS.txt for Swift project authors
 //
 
-@testable @_spi(Experimental) @_spi(ForToolsIntegrationOnly) import Testing
+@testable @_spi(ForToolsIntegrationOnly) import Testing
 private import _TestingInternals
 #if canImport(Foundation)
 import Foundation
-@_spi(Experimental) import _Testing_Foundation
+import _Testing_Foundation
 #endif
 #if canImport(CoreGraphics)
 import CoreGraphics