fix(messages): decode the metadata route's real {links} shape

InterlinedList.xcodeproj/project.pbxproj

@@ -66,7 +66,6 @@
 		61621697746E8CF1769E9C80 /* IdentityHealth.swift in Sources */ = {isa = PBXBuildFile; fileRef = 80D1D19E4DB2D914AD6551D7 /* IdentityHealth.swift */; };
 		64F5804ECC25725FD1E58E84 /* APIClientModerationTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6A569D8DB8DFD3CC59072FDB /* APIClientModerationTests.swift */; };
 		C0FFEE9102ABCDEF00000091 /* ComposeLinkDetectionTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C0FFEE9101ABCDEF00000091 /* ComposeLinkDetectionTests.swift */; };
-		C0FFEE9602ABCDEF00000096 /* LinkMetadataConversionTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C0FFEE9601ABCDEF00000096 /* LinkMetadataConversionTests.swift */; };
 		6749119D27FA93BE00D5A27F /* FeedTruncationTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 05A695D62B746B092CF51AFA /* FeedTruncationTests.swift */; };
 		6A89622E299B0D172D5B5556 /* GitHubModelTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = C337406C10876F331B1888E3 /* GitHubModelTests.swift */; };
 		6C10CC420377B0E8AE5C82DB /* GapModelsTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 93642F79C3049C4A2ECC8AFF /* GapModelsTests.swift */; };
@@ -274,7 +273,6 @@
 		03C47A3ECFD7F4D25F91E3BE /* ShareLinksSheet.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = ShareLinksSheet.swift; sourceTree = "<group>"; };
 		03D6C33FD59101503195F14F /* SharedDocumentView.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = SharedDocumentView.swift; sourceTree = "<group>"; };
 		C0FFEE9101ABCDEF00000091 /* ComposeLinkDetectionTests.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = ComposeLinkDetectionTests.swift; sourceTree = "<group>"; };
-		C0FFEE9601ABCDEF00000096 /* LinkMetadataConversionTests.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = LinkMetadataConversionTests.swift; sourceTree = "<group>"; };
 		05A695D62B746B092CF51AFA /* FeedTruncationTests.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = FeedTruncationTests.swift; sourceTree = "<group>"; };
 		06CAA8B0033D6DD27ED089CD /* ShareInvitesSheet.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = ShareInvitesSheet.swift; sourceTree = "<group>"; };
 		08D80C6D8E2B0C7A3AB7E0B2 /* DocumentLinkView.swift */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = sourcecode.swift; path = DocumentLinkView.swift; sourceTree = "<group>"; };
@@ -842,7 +840,6 @@
 				93642F79C3049C4A2ECC8AFF /* GapModelsTests.swift */,
 				F78B096C366108083D174366 /* MarkdownBlockTests.swift */,
 				C0FFEE9101ABCDEF00000091 /* ComposeLinkDetectionTests.swift */,
-				C0FFEE9601ABCDEF00000096 /* LinkMetadataConversionTests.swift */,
 				05A695D62B746B092CF51AFA /* FeedTruncationTests.swift */,
 				EE6BD1CB3C5C5C494971E0B4 /* DirectMessageModelTests.swift */,
 				A5C9FAA36F8413788E1776C7 /* LinkedInTargetModelTests.swift */,
@@ -1188,7 +1185,6 @@
 				09037C64E9D988371F29AD75 /* ComposeImageUploaderTests.swift in Sources */,
 				98CC00030F4340A4BD821FC4 /* MarkdownBlockTests.swift in Sources */,
 				C0FFEE9102ABCDEF00000091 /* ComposeLinkDetectionTests.swift in Sources */,
-				C0FFEE9602ABCDEF00000096 /* LinkMetadataConversionTests.swift in Sources */,
 				6749119D27FA93BE00D5A27F /* FeedTruncationTests.swift in Sources */,
 				362DEA03EA2CDD9E135B1411 /* APIClientDirectMessagesTests.swift in Sources */,
 				874DE298749DF285984F1182 /* DirectMessageModelTests.swift in Sources */,

InterlinedList/Models/Message.swift

@@ -32,51 +32,6 @@ struct LinkMetadata: Codable {
     let links: [LinkMetadataItem]
 }
 
-/// A single resolved link preview from POST /api/messages/:id/metadata.
-struct MessageLinkPreview: Codable, Identifiable {
-    let url: String
-    let title: String?
-    let description: String?
-    let image: String?
-
-    var id: String { url }
-}
-
-extension LinkMetadataItem {
-    /// Rebuilds the feed row's nested preview shape from the flat previews the
-    /// metadata refresh returns, so a just-published message can render its card
-    /// without waiting for the next feed fetch.
-    ///
-    /// `metadata` stays nil when a preview resolved to nothing renderable: the feed
-    /// card is drawn only for a non-nil `metadata` (`LinkPreviewBlock`), so an
-    /// all-nil content object would draw an empty box. The item itself is kept,
-    /// because its `url` is what the rest of the app reads off a link.
-    ///
-    /// `platform` and `fetchStatus` stay nil rather than being guessed: the flat
-    /// preview carries neither, and nothing renders off them.
-    init(preview: MessageLinkPreview) {
-        let title = Self.trimmedNonEmpty(preview.title)
-        let description = Self.trimmedNonEmpty(preview.description)
-        let thumbnail = Self.trimmedNonEmpty(preview.image)
-        let content: LinkMetadataItemContent? =
-            title == nil && description == nil && thumbnail == nil
-            ? nil
-            : LinkMetadataItemContent(thumbnail: thumbnail, title: title,
-                                      description: description, text: nil, type: nil)
-        self.init(url: preview.url, platform: nil, metadata: content, fetchStatus: nil)
-    }
-
-    static func from(previews: [MessageLinkPreview]) -> [LinkMetadataItem] {
-        previews.map(LinkMetadataItem.init(preview:))
-    }
-
-    private static func trimmedNonEmpty(_ value: String?) -> String? {
-        guard let trimmed = value?.trimmingCharacters(in: .whitespacesAndNewlines),
-              !trimmed.isEmpty else { return nil }
-        return trimmed
-    }
-}
-
 /// One destination a message was actually cross-posted to, echoed back on the
 /// Message after it publishes (server field: `crossPostUrls`). The shape differs
 /// per platform — Mastodon carries `statusId`/`instanceUrl`, Bluesky carries

InterlinedList/Services/APIClient.swift

@@ -420,20 +420,19 @@ final class APIClient {
 
     /// Fetch/refresh OpenGraph link-preview metadata for a message's links.
     ///
-    /// No caller yet, deliberately. The web fires this after publishing and after an
-    /// edit (`MessageInput.tsx:511`) so a new post's link previews populate without a
-    /// reload. Wiring it adds a request to the publish path, so it is tracked
-    /// separately rather than slipped into a hygiene sweep.
+    /// `app/api/messages/[id]/metadata/route.ts` answers `{ "links": [...] }` at the
+    /// top level from both exits (no links detected → `[]`; otherwise the fetched
+    /// items), and each entry is the same `LinkMetadataItem` the feed row carries —
+    /// both come out of `fetchMultipleLinkMetadata`, as `/api/link-metadata` does.
+    /// `links` is decoded as required on purpose: the previous wrapper mismatch
+    /// survived because a missing key degraded to an empty array in silence.
     @discardableResult
-    func refreshMessageMetadata(messageId: String) async throws -> [MessageLinkPreview] {
-        struct Response: Decodable {
-            struct Meta: Decodable { let links: [MessageLinkPreview]? }
-            let metadata: Meta?
-        }
+    func refreshMessageMetadata(messageId: String) async throws -> [LinkMetadataItem] {
+        struct Response: Decodable { let links: [LinkMetadataItem] }
         let encoded = messageId.addingPercentEncoding(withAllowedCharacters: .urlPathAllowed) ?? messageId
         struct Empty: Encodable {}
         let response: Response = try await postCamel("/api/messages/\(encoded)/metadata", body: Empty())
-        return response.metadata?.links ?? []
+        return response.links
     }
 
     func editMessage(id: String, content: String, publiclyVisible: Bool?) async throws -> Message {

InterlinedList/Views/ComposeView.swift

@@ -820,9 +820,9 @@ struct ComposeView: View {
     /// can't change server-side anyway. See issue #76.
     private func refreshLinkMetadata(for messageId: String) {
         Task { @MainActor in
-            guard let previews = try? await APIClient.shared.refreshMessageMetadata(messageId: messageId)
+            guard let links = try? await APIClient.shared.refreshMessageMetadata(messageId: messageId)
             else { return }
-            store.applyLinkMetadata(LinkMetadataItem.from(previews: previews), toMessageId: messageId)
+            store.applyLinkMetadata(links, toMessageId: messageId)
         }
     }
 }

InterlinedListTests/APIClientTests/APIClientGapPhasesTests.swift

@@ -272,12 +272,4 @@ final class APIClientGapPhasesTests: XCTestCase {
         XCTAssertEqual(result.crossPostResults.first?.platform, "bluesky")
         XCTAssertEqual(result.crossPostResults.first?.success, true)
     }
-
-    func test_refreshMessageMetadata_decodesLinks() async throws {
-        session.stub(json: #"{"message":"ok","metadata":{"links":[{"url":"https://x.com","title":"X","description":"d","image":"i"}]}}"#)
-        let links = try await sut.refreshMessageMetadata(messageId: "m1")
-        XCTAssertEqual(session.lastRequest?.httpMethod, "POST")
-        XCTAssertTrue(session.lastRequest?.url?.path.hasSuffix("/api/messages/m1/metadata") == true)
-        XCTAssertEqual(links.first?.title, "X")
-    }
 }

InterlinedListTests/APIClientTests/APIClientMessagesTests.swift

@@ -247,4 +247,128 @@ final class APIClientMessagesTests: XCTestCase {
             XCTAssertTrue(msg.lowercased().contains("own"))
         }
     }
+
+    // MARK: refreshMessageMetadata()
+
+    /// Every fixture below is transcribed from the route itself —
+    /// `app/api/messages/[id]/metadata/route.ts` (`serialize({ links: … })` at :86
+    /// and :105) — and from the entry shape its items are built with,
+    /// `lib/messages/metadata-fetcher.ts` (`fetchMultipleLinkMetadata`, which also
+    /// feeds `GET /api/link-metadata`). Do not re-derive them from the Swift type:
+    /// the bug this covers (#104) shipped green because the old fixture was written
+    /// to the decoder's assumption instead of to the wire.
+    private let metadataSuccessJSON = #"""
+    {"links":[{
+      "url":"https://example.com/post",
+      "platform":"other",
+      "metadata":{
+        "thumbnail":"https://example.com/og.png",
+        "title":"Example Post",
+        "description":"A description",
+        "type":"link",
+        "ogType":"article"
+      },
+      "fetchStatus":"success",
+      "fetchedAt":"2026-09-16T12:00:00.000Z"
+    }]}
+    """#
+
+    func test_refreshMessageMetadata_sendsPostToMetadataPath() async throws {
+        session.stub(json: metadataSuccessJSON)
+        _ = try await sut.refreshMessageMetadata(messageId: "m1")
+        XCTAssertEqual(session.lastRequest?.httpMethod, "POST")
+        XCTAssertEqual(session.lastRequest?.url?.path, "/api/messages/m1/metadata")
+        XCTAssertEqual(session.lastRequest?.value(forHTTPHeaderField: "Authorization"), "Bearer tok")
+    }
+
+    func test_refreshMessageMetadata_routeShape_decodesNonEmptyLinks() async throws {
+        session.stub(json: metadataSuccessJSON)
+        let links = try await sut.refreshMessageMetadata(messageId: "m1")
+        XCTAssertEqual(links.count, 1)
+        XCTAssertEqual(links.first?.url, "https://example.com/post")
+        XCTAssertEqual(links.first?.platform, "other")
+        XCTAssertEqual(links.first?.fetchStatus, "success")
+        XCTAssertEqual(links.first?.metadata?.title, "Example Post")
+        XCTAssertEqual(links.first?.metadata?.description, "A description")
+        XCTAssertEqual(links.first?.metadata?.thumbnail, "https://example.com/og.png")
+        XCTAssertEqual(links.first?.metadata?.type, "link")
+    }
+
+    /// The pre-#104 shape: a `metadata` wrapper the route has never sent. It must
+    /// now fail loudly rather than decode to an empty array, which is how the
+    /// mismatch stayed invisible.
+    func test_refreshMessageMetadata_legacyMetadataWrapper_throwsDecodingError() async throws {
+        session.stub(json: #"{"message":"ok","metadata":{"links":[{"url":"https://x.com","title":"X","description":"d","image":"i"}]}}"#)
+        do {
+            _ = try await sut.refreshMessageMetadata(messageId: "m1")
+            XCTFail("Expected a decoding failure for the wrapped shape")
+        } catch is DecodingError {
+            // expected
+        }
+    }
+
+    /// Route :84-89 — content with no detectable link short-circuits to `{links:[]}`.
+    func test_refreshMessageMetadata_noDetectedLinks_returnsEmpty() async throws {
+        session.stub(json: #"{"links":[]}"#)
+        let links = try await sut.refreshMessageMetadata(messageId: "m1")
+        XCTAssertTrue(links.isEmpty)
+    }
+
+    /// `fetchMultipleLinkMetadata` emits `{url, platform, fetchStatus:"failed"}` with
+    /// no `metadata` and no `fetchedAt` when a fetch throws or resolves to nothing —
+    /// and the route persists exactly that on the message, so the item is kept.
+    func test_refreshMessageMetadata_failedEntry_keepsUrlWithNilMetadata() async throws {
+        session.stub(json: #"{"links":[{"url":"https://dead.example","platform":"other","fetchStatus":"failed"}]}"#)
+        let links = try await sut.refreshMessageMetadata(messageId: "m1")
+        XCTAssertEqual(links.count, 1)
+        XCTAssertEqual(links.first?.url, "https://dead.example")
+        XCTAssertEqual(links.first?.fetchStatus, "failed")
+        XCTAssertNil(links.first?.metadata)
+    }
+
+    /// Instagram entries carry `caption`/`derivedList` for the composer's
+    /// paste-to-expand assist; the link card models neither, and neither may break
+    /// the decode of the fields it does model.
+    func test_refreshMessageMetadata_instagramExtras_decodeWithoutError() async throws {
+        session.stub(json: #"""
+        {"links":[{
+          "url":"https://www.instagram.com/p/abc123/",
+          "platform":"instagram",
+          "metadata":{"thumbnail":"https://cdn.example/ig.jpg","title":"On Instagram","description":"caption text","type":"image"},
+          "caption":"caption text - one - two",
+          "derivedList":{"markdown":"- one","ordered":false,"itemCount":2},
+          "fetchStatus":"success",
+          "fetchedAt":"2026-09-16T12:00:00.000Z"
+        }]}
+        """#)
+        let links = try await sut.refreshMessageMetadata(messageId: "m1")
+        XCTAssertEqual(links.first?.platform, "instagram")
+        XCTAssertEqual(links.first?.metadata?.type, "image")
+        XCTAssertEqual(links.first?.metadata?.thumbnail, "https://cdn.example/ig.jpg")
+    }
+
+    func test_refreshMessageMetadata_multipleLinks_preservesRouteOrder() async throws {
+        session.stub(json: #"""
+        {"links":[
+          {"url":"https://one.example","platform":"other","metadata":{"title":"One","type":"link"},"fetchStatus":"success"},
+          {"url":"https://two.example","platform":"other","metadata":{"title":"Two","type":"link"},"fetchStatus":"success"}
+        ]}
+        """#)
+        let links = try await sut.refreshMessageMetadata(messageId: "m1")
+        XCTAssertEqual(links.map(\.url), ["https://one.example", "https://two.example"])
+        XCTAssertEqual(links.map { $0.metadata?.title }, ["One", "Two"])
+    }
+
+    /// Route :65-67 — the POST is owner-only, so an unauthenticated refresh 401s.
+    /// It stays a bare `.status(401)`: the publish path swallows it rather than
+    /// treating it as a logout (CLAUDE.md).
+    func test_refreshMessageMetadata_401_throwsStatus401() async throws {
+        session.stub(data: Data(), statusCode: 401)
+        do {
+            _ = try await sut.refreshMessageMetadata(messageId: "m1")
+            XCTFail("Expected throw")
+        } catch APIError.status(let code) {
+            XCTAssertEqual(code, 401)
+        }
+    }
 }

InterlinedListTests/ModelTests/ComposeLinkDetectionTests.swift

@@ -52,7 +52,7 @@ final class ComposeLinkDetectionTests: XCTestCase {
         let session = MockURLSession()
         let sut = APIClient(session: session)
         sut.setBearerToken("tok")
-        session.stub(json: #"{"metadata":{"links":[]}}"#)
+        session.stub(json: #"{"links":[]}"#)
 
         await publishAndRefreshIfLinked("just a thought, no links at all", using: sut)
 
@@ -64,7 +64,7 @@ final class ComposeLinkDetectionTests: XCTestCase {
         let session = MockURLSession()
         let sut = APIClient(session: session)
         sut.setBearerToken("tok")
-        session.stub(json: #"{"metadata":{"links":[{"url":"https://example.com","title":"E","description":null,"image":null}]}}"#)
+        session.stub(json: #"{"links":[{"url":"https://example.com","platform":"other","metadata":{"title":"E","type":"link"},"fetchStatus":"success"}]}"#)
 
         await publishAndRefreshIfLinked("read this https://example.com", using: sut, messageId: "m42")