feat(backend): global notices

Foxnouns.Backend/Controllers/MetaController.cs

@@ -13,20 +13,23 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 using System.Text.RegularExpressions;
+using Foxnouns.Backend.Database.Models;
 using Foxnouns.Backend.Dto;
+using Foxnouns.Backend.Services.Caching;
 using Foxnouns.Backend.Utils;
 using Microsoft.AspNetCore.Mvc;
 
 namespace Foxnouns.Backend.Controllers;
 
 [Route("/api/v2/meta")]
-public partial class MetaController(Config config) : ApiControllerBase
+public partial class MetaController(Config config, NoticeCacheService noticeCache)
+    : ApiControllerBase
 {
     private const string Repository = "https://codeberg.org/pronounscc/pronouns.cc";
 
     [HttpGet]
     [ProducesResponseType<MetaResponse>(StatusCodes.Status200OK)]
-    public IActionResult GetMeta() =>
+    public async Task<IActionResult> GetMeta(CancellationToken ct = default) =>
         Ok(
             new MetaResponse(
                 Repository,
@@ -45,10 +48,14 @@ public partial class MetaController(Config config) : ApiControllerBase
                     ValidationUtils.MaxCustomPreferences,
                     AuthUtils.MaxAuthMethodsPerType,
                     FlagsController.MaxFlagCount
-                )
+                ),
+                Notice: NoticeResponse(await noticeCache.GetAsync(ct))
             )
         );
 
+    private static MetaNoticeResponse? NoticeResponse(Notice? notice) =>
+        notice == null ? null : new MetaNoticeResponse(notice.Id, notice.Message);
+
     [HttpGet("page/{page}")]
     public async Task<IActionResult> GetStaticPageAsync(string page, CancellationToken ct = default)
     {
@@ -71,7 +78,7 @@ public partial class MetaController(Config config) : ApiControllerBase
 
     [HttpGet("/api/v2/coffee")]
     public IActionResult BrewCoffee() =>
-        Problem("Sorry, I'm a teapot!", statusCode: StatusCodes.Status418ImATeapot);
+        StatusCode(StatusCodes.Status418ImATeapot, "Sorry, I'm a teapot!");
 
     [GeneratedRegex(@"^[a-z\-_]+$")]
     private static partial Regex PageRegex();

Foxnouns.Backend/Controllers/Moderation/NoticesController.cs

@@ -0,0 +1,77 @@
+using Foxnouns.Backend.Database;
+using Foxnouns.Backend.Database.Models;
+using Foxnouns.Backend.Dto;
+using Foxnouns.Backend.Middleware;
+using Foxnouns.Backend.Services;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+using NodaTime;
+
+namespace Foxnouns.Backend.Controllers.Moderation;
+
+[Route("/api/v2/notices")]
+[Authorize("user.moderation")]
+[Limit(RequireModerator = true)]
+public class NoticesController(
+    DatabaseContext db,
+    UserRendererService userRenderer,
+    ISnowflakeGenerator snowflakeGenerator,
+    IClock clock
+) : ApiControllerBase
+{
+    [HttpGet]
+    public async Task<IActionResult> GetNoticesAsync(CancellationToken ct = default)
+    {
+        List<Notice> notices = await db
+            .Notices.Include(n => n.Author)
+            .OrderByDescending(n => n.Id)
+            .ToListAsync(ct);
+        return Ok(notices.Select(RenderNotice));
+    }
+
+    [HttpPost]
+    public async Task<IActionResult> CreateNoticeAsync(CreateNoticeRequest req)
+    {
+        Instant now = clock.GetCurrentInstant();
+        if (req.StartTime < now)
+        {
+            throw new ApiError.BadRequest(
+                "Start time cannot be in the past",
+                "start_time",
+                req.StartTime
+            );
+        }
+
+        if (req.EndTime < now)
+        {
+            throw new ApiError.BadRequest(
+                "End time cannot be in the past",
+                "end_time",
+                req.EndTime
+            );
+        }
+
+        var notice = new Notice
+        {
+            Id = snowflakeGenerator.GenerateSnowflake(),
+            Message = req.Message,
+            StartTime = req.StartTime ?? clock.GetCurrentInstant(),
+            EndTime = req.EndTime,
+            Author = CurrentUser!,
+        };
+
+        db.Add(notice);
+        await db.SaveChangesAsync();
+
+        return Ok(RenderNotice(notice));
+    }
+
+    private NoticeResponse RenderNotice(Notice notice) =>
+        new(
+            notice.Id,
+            notice.Message,
+            notice.StartTime,
+            notice.EndTime,
+            userRenderer.RenderPartialUser(notice.Author)
+        );
+}

Foxnouns.Backend/Controllers/UsersController.cs

@@ -281,6 +281,8 @@ public class UsersController(
 
         if (req.HasProperty(nameof(req.DarkMode)))
             user.Settings.DarkMode = req.DarkMode;
+        if (req.HasProperty(nameof(req.LastReadNotice)))
+            user.Settings.LastReadNotice = req.LastReadNotice;
 
         user.LastActive = clock.GetCurrentInstant();
         db.Update(user);

Foxnouns.Backend/Database/DatabaseContext.cs

@@ -73,6 +73,7 @@ public class DatabaseContext(DbContextOptions options) : DbContext(options)
     public DbSet<Report> Reports { get; init; } = null!;
     public DbSet<AuditLogEntry> AuditLog { get; init; } = null!;
     public DbSet<Notification> Notifications { get; init; } = null!;
+    public DbSet<Notice> Notices { get; init; } = null!;
 
     protected override void ConfigureConventions(ModelConfigurationBuilder configurationBuilder)
     {

Foxnouns.Backend/Database/Migrations/20250329131053_AddNotices.Designer.cs

@@ -0,0 +1,915 @@
+// <auto-generated />
+using System.Collections.Generic;
+using Foxnouns.Backend.Database;
+using Foxnouns.Backend.Database.Models;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Infrastructure;
+using Microsoft.EntityFrameworkCore.Migrations;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using NodaTime;
+using Npgsql.EntityFrameworkCore.PostgreSQL.Metadata;
+
+#nullable disable
+
+namespace Foxnouns.Backend.Database.Migrations
+{
+    [DbContext(typeof(DatabaseContext))]
+    [Migration("20250329131053_AddNotices")]
+    partial class AddNotices
+    {
+        /// <inheritdoc />
+        protected override void BuildTargetModel(ModelBuilder modelBuilder)
+        {
+#pragma warning disable 612, 618
+            modelBuilder
+                .HasAnnotation("ProductVersion", "9.0.2")
+                .HasAnnotation("Relational:MaxIdentifierLength", 63);
+
+            NpgsqlModelBuilderExtensions.HasPostgresExtension(modelBuilder, "hstore");
+            NpgsqlModelBuilderExtensions.UseIdentityByDefaultColumns(modelBuilder);
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Application", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    b.Property<string>("ClientId")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("client_id");
+
+                    b.Property<string>("ClientSecret")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("client_secret");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("name");
+
+                    b.PrimitiveCollection<string[]>("RedirectUris")
+                        .IsRequired()
+                        .HasColumnType("text[]")
+                        .HasColumnName("redirect_uris");
+
+                    b.PrimitiveCollection<string[]>("Scopes")
+                        .IsRequired()
+                        .HasColumnType("text[]")
+                        .HasColumnName("scopes");
+
+                    b.HasKey("Id")
+                        .HasName("pk_applications");
+
+                    b.ToTable("applications", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.AuditLogEntry", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    b.PrimitiveCollection<string[]>("ClearedFields")
+                        .HasColumnType("text[]")
+                        .HasColumnName("cleared_fields");
+
+                    b.Property<long>("ModeratorId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("moderator_id");
+
+                    b.Property<string>("ModeratorUsername")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("moderator_username");
+
+                    b.Property<string>("Reason")
+                        .HasColumnType("text")
+                        .HasColumnName("reason");
+
+                    b.Property<long?>("ReportId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("report_id");
+
+                    b.Property<long?>("TargetMemberId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("target_member_id");
+
+                    b.Property<string>("TargetMemberName")
+                        .HasColumnType("text")
+                        .HasColumnName("target_member_name");
+
+                    b.Property<long?>("TargetUserId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("target_user_id");
+
+                    b.Property<string>("TargetUsername")
+                        .HasColumnType("text")
+                        .HasColumnName("target_username");
+
+                    b.Property<int>("Type")
+                        .HasColumnType("integer")
+                        .HasColumnName("type");
+
+                    b.HasKey("Id")
+                        .HasName("pk_audit_log");
+
+                    b.HasIndex("ReportId")
+                        .IsUnique()
+                        .HasDatabaseName("ix_audit_log_report_id");
+
+                    b.ToTable("audit_log", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.AuthMethod", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    b.Property<int>("AuthType")
+                        .HasColumnType("integer")
+                        .HasColumnName("auth_type");
+
+                    b.Property<long?>("FediverseApplicationId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("fediverse_application_id");
+
+                    b.Property<string>("RemoteId")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("remote_id");
+
+                    b.Property<string>("RemoteUsername")
+                        .HasColumnType("text")
+                        .HasColumnName("remote_username");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("user_id");
+
+                    b.HasKey("Id")
+                        .HasName("pk_auth_methods");
+
+                    b.HasIndex("FediverseApplicationId")
+                        .HasDatabaseName("ix_auth_methods_fediverse_application_id");
+
+                    b.HasIndex("UserId")
+                        .HasDatabaseName("ix_auth_methods_user_id");
+
+                    b.HasIndex("AuthType", "RemoteId")
+                        .IsUnique()
+                        .HasDatabaseName("ix_auth_methods_auth_type_remote_id")
+                        .HasFilter("fediverse_application_id IS NULL");
+
+                    b.HasIndex("AuthType", "RemoteId", "FediverseApplicationId")
+                        .IsUnique()
+                        .HasDatabaseName("ix_auth_methods_auth_type_remote_id_fediverse_application_id")
+                        .HasFilter("fediverse_application_id IS NOT NULL");
+
+                    b.ToTable("auth_methods", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.DataExport", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Filename")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("filename");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("user_id");
+
+                    b.HasKey("Id")
+                        .HasName("pk_data_exports");
+
+                    b.HasIndex("Filename")
+                        .IsUnique()
+                        .HasDatabaseName("ix_data_exports_filename");
+
+                    b.HasIndex("UserId")
+                        .HasDatabaseName("ix_data_exports_user_id");
+
+                    b.ToTable("data_exports", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.FediverseApplication", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    b.Property<string>("ClientId")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("client_id");
+
+                    b.Property<string>("ClientSecret")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("client_secret");
+
+                    b.Property<string>("Domain")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("domain");
+
+                    b.Property<bool>("ForceRefresh")
+                        .HasColumnType("boolean")
+                        .HasColumnName("force_refresh");
+
+                    b.Property<int>("InstanceType")
+                        .HasColumnType("integer")
+                        .HasColumnName("instance_type");
+
+                    b.HasKey("Id")
+                        .HasName("pk_fediverse_applications");
+
+                    b.ToTable("fediverse_applications", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Member", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Avatar")
+                        .HasColumnType("text")
+                        .HasColumnName("avatar");
+
+                    b.Property<string>("Bio")
+                        .HasColumnType("text")
+                        .HasColumnName("bio");
+
+                    b.Property<string>("DisplayName")
+                        .HasColumnType("text")
+                        .HasColumnName("display_name");
+
+                    b.Property<List<Field>>("Fields")
+                        .IsRequired()
+                        .HasColumnType("jsonb")
+                        .HasColumnName("fields");
+
+                    b.Property<string>("LegacyId")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("text")
+                        .HasColumnName("legacy_id")
+                        .HasDefaultValueSql("gen_random_uuid()");
+
+                    b.PrimitiveCollection<string[]>("Links")
+                        .IsRequired()
+                        .HasColumnType("text[]")
+                        .HasColumnName("links");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("name");
+
+                    b.Property<List<FieldEntry>>("Names")
+                        .IsRequired()
+                        .HasColumnType("jsonb")
+                        .HasColumnName("names");
+
+                    b.Property<List<Pronoun>>("Pronouns")
+                        .IsRequired()
+                        .HasColumnType("jsonb")
+                        .HasColumnName("pronouns");
+
+                    b.Property<string>("Sid")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("text")
+                        .HasColumnName("sid")
+                        .HasDefaultValueSql("find_free_member_sid()");
+
+                    b.Property<bool>("Unlisted")
+                        .HasColumnType("boolean")
+                        .HasColumnName("unlisted");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("user_id");
+
+                    b.HasKey("Id")
+                        .HasName("pk_members");
+
+                    b.HasIndex("LegacyId")
+                        .IsUnique()
+                        .HasDatabaseName("ix_members_legacy_id");
+
+                    b.HasIndex("Sid")
+                        .IsUnique()
+                        .HasDatabaseName("ix_members_sid");
+
+                    b.HasIndex("UserId", "Name")
+                        .IsUnique()
+                        .HasDatabaseName("ix_members_user_id_name");
+
+                    b.ToTable("members", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.MemberFlag", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<long>("MemberId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("member_id");
+
+                    b.Property<long>("PrideFlagId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("pride_flag_id");
+
+                    b.HasKey("Id")
+                        .HasName("pk_member_flags");
+
+                    b.HasIndex("MemberId")
+                        .HasDatabaseName("ix_member_flags_member_id");
+
+                    b.HasIndex("PrideFlagId")
+                        .HasDatabaseName("ix_member_flags_pride_flag_id");
+
+                    b.ToTable("member_flags", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Notice", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    b.Property<long>("AuthorId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("author_id");
+
+                    b.Property<Instant>("EndTime")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("end_time");
+
+                    b.Property<string>("Message")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("message");
+
+                    b.Property<Instant>("StartTime")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("start_time");
+
+                    b.HasKey("Id")
+                        .HasName("pk_notices");
+
+                    b.HasIndex("AuthorId")
+                        .HasDatabaseName("ix_notices_author_id");
+
+                    b.ToTable("notices", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Notification", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    b.Property<Instant?>("AcknowledgedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("acknowledged_at");
+
+                    b.Property<string>("LocalizationKey")
+                        .HasColumnType("text")
+                        .HasColumnName("localization_key");
+
+                    b.Property<Dictionary<string, string>>("LocalizationParams")
+                        .IsRequired()
+                        .HasColumnType("hstore")
+                        .HasColumnName("localization_params");
+
+                    b.Property<string>("Message")
+                        .HasColumnType("text")
+                        .HasColumnName("message");
+
+                    b.Property<long>("TargetId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("target_id");
+
+                    b.Property<int>("Type")
+                        .HasColumnType("integer")
+                        .HasColumnName("type");
+
+                    b.HasKey("Id")
+                        .HasName("pk_notifications");
+
+                    b.HasIndex("TargetId")
+                        .HasDatabaseName("ix_notifications_target_id");
+
+                    b.ToTable("notifications", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.PrideFlag", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Description")
+                        .HasColumnType("text")
+                        .HasColumnName("description");
+
+                    b.Property<string>("Hash")
+                        .HasColumnType("text")
+                        .HasColumnName("hash");
+
+                    b.Property<string>("LegacyId")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("text")
+                        .HasColumnName("legacy_id")
+                        .HasDefaultValueSql("gen_random_uuid()");
+
+                    b.Property<string>("Name")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("name");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("user_id");
+
+                    b.HasKey("Id")
+                        .HasName("pk_pride_flags");
+
+                    b.HasIndex("LegacyId")
+                        .IsUnique()
+                        .HasDatabaseName("ix_pride_flags_legacy_id");
+
+                    b.HasIndex("UserId")
+                        .HasDatabaseName("ix_pride_flags_user_id");
+
+                    b.ToTable("pride_flags", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Report", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Context")
+                        .HasColumnType("text")
+                        .HasColumnName("context");
+
+                    b.Property<int>("Reason")
+                        .HasColumnType("integer")
+                        .HasColumnName("reason");
+
+                    b.Property<long>("ReporterId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("reporter_id");
+
+                    b.Property<int>("Status")
+                        .HasColumnType("integer")
+                        .HasColumnName("status");
+
+                    b.Property<long?>("TargetMemberId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("target_member_id");
+
+                    b.Property<string>("TargetSnapshot")
+                        .HasColumnType("text")
+                        .HasColumnName("target_snapshot");
+
+                    b.Property<int>("TargetType")
+                        .HasColumnType("integer")
+                        .HasColumnName("target_type");
+
+                    b.Property<long>("TargetUserId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("target_user_id");
+
+                    b.HasKey("Id")
+                        .HasName("pk_reports");
+
+                    b.HasIndex("ReporterId")
+                        .HasDatabaseName("ix_reports_reporter_id");
+
+                    b.HasIndex("TargetMemberId")
+                        .HasDatabaseName("ix_reports_target_member_id");
+
+                    b.HasIndex("TargetUserId")
+                        .HasDatabaseName("ix_reports_target_user_id");
+
+                    b.ToTable("reports", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Token", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    b.Property<long>("ApplicationId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("application_id");
+
+                    b.Property<Instant>("ExpiresAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("expires_at");
+
+                    b.Property<byte[]>("Hash")
+                        .IsRequired()
+                        .HasColumnType("bytea")
+                        .HasColumnName("hash");
+
+                    b.Property<bool>("ManuallyExpired")
+                        .HasColumnType("boolean")
+                        .HasColumnName("manually_expired");
+
+                    b.PrimitiveCollection<string[]>("Scopes")
+                        .IsRequired()
+                        .HasColumnType("text[]")
+                        .HasColumnName("scopes");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("user_id");
+
+                    b.HasKey("Id")
+                        .HasName("pk_tokens");
+
+                    b.HasIndex("ApplicationId")
+                        .HasDatabaseName("ix_tokens_application_id");
+
+                    b.HasIndex("UserId")
+                        .HasDatabaseName("ix_tokens_user_id");
+
+                    b.ToTable("tokens", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.User", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    b.Property<string>("Avatar")
+                        .HasColumnType("text")
+                        .HasColumnName("avatar");
+
+                    b.Property<string>("Bio")
+                        .HasColumnType("text")
+                        .HasColumnName("bio");
+
+                    b.Property<Dictionary<Snowflake, User.CustomPreference>>("CustomPreferences")
+                        .IsRequired()
+                        .HasColumnType("jsonb")
+                        .HasColumnName("custom_preferences");
+
+                    b.Property<bool>("Deleted")
+                        .HasColumnType("boolean")
+                        .HasColumnName("deleted");
+
+                    b.Property<Instant?>("DeletedAt")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("deleted_at");
+
+                    b.Property<long?>("DeletedBy")
+                        .HasColumnType("bigint")
+                        .HasColumnName("deleted_by");
+
+                    b.Property<string>("DisplayName")
+                        .HasColumnType("text")
+                        .HasColumnName("display_name");
+
+                    b.Property<List<Field>>("Fields")
+                        .IsRequired()
+                        .HasColumnType("jsonb")
+                        .HasColumnName("fields");
+
+                    b.Property<Instant>("LastActive")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("last_active");
+
+                    b.Property<Instant>("LastSidReroll")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("last_sid_reroll");
+
+                    b.Property<string>("LegacyId")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("text")
+                        .HasColumnName("legacy_id")
+                        .HasDefaultValueSql("gen_random_uuid()");
+
+                    b.PrimitiveCollection<string[]>("Links")
+                        .IsRequired()
+                        .HasColumnType("text[]")
+                        .HasColumnName("links");
+
+                    b.Property<bool>("ListHidden")
+                        .HasColumnType("boolean")
+                        .HasColumnName("list_hidden");
+
+                    b.Property<string>("MemberTitle")
+                        .HasColumnType("text")
+                        .HasColumnName("member_title");
+
+                    b.Property<List<FieldEntry>>("Names")
+                        .IsRequired()
+                        .HasColumnType("jsonb")
+                        .HasColumnName("names");
+
+                    b.Property<string>("Password")
+                        .HasColumnType("text")
+                        .HasColumnName("password");
+
+                    b.Property<List<Pronoun>>("Pronouns")
+                        .IsRequired()
+                        .HasColumnType("jsonb")
+                        .HasColumnName("pronouns");
+
+                    b.Property<int>("Role")
+                        .HasColumnType("integer")
+                        .HasColumnName("role");
+
+                    b.Property<UserSettings>("Settings")
+                        .IsRequired()
+                        .HasColumnType("jsonb")
+                        .HasColumnName("settings");
+
+                    b.Property<string>("Sid")
+                        .IsRequired()
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("text")
+                        .HasColumnName("sid")
+                        .HasDefaultValueSql("find_free_user_sid()");
+
+                    b.Property<string>("Timezone")
+                        .HasColumnType("text")
+                        .HasColumnName("timezone");
+
+                    b.Property<string>("Username")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("username");
+
+                    b.HasKey("Id")
+                        .HasName("pk_users");
+
+                    b.HasIndex("LegacyId")
+                        .IsUnique()
+                        .HasDatabaseName("ix_users_legacy_id");
+
+                    b.HasIndex("Sid")
+                        .IsUnique()
+                        .HasDatabaseName("ix_users_sid");
+
+                    b.HasIndex("Username")
+                        .IsUnique()
+                        .HasDatabaseName("ix_users_username");
+
+                    b.ToTable("users", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.UserFlag", b =>
+                {
+                    b.Property<long>("Id")
+                        .ValueGeneratedOnAdd()
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    NpgsqlPropertyBuilderExtensions.UseIdentityByDefaultColumn(b.Property<long>("Id"));
+
+                    b.Property<long>("PrideFlagId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("pride_flag_id");
+
+                    b.Property<long>("UserId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("user_id");
+
+                    b.HasKey("Id")
+                        .HasName("pk_user_flags");
+
+                    b.HasIndex("PrideFlagId")
+                        .HasDatabaseName("ix_user_flags_pride_flag_id");
+
+                    b.HasIndex("UserId")
+                        .HasDatabaseName("ix_user_flags_user_id");
+
+                    b.ToTable("user_flags", (string)null);
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.AuditLogEntry", b =>
+                {
+                    b.HasOne("Foxnouns.Backend.Database.Models.Report", "Report")
+                        .WithOne("AuditLogEntry")
+                        .HasForeignKey("Foxnouns.Backend.Database.Models.AuditLogEntry", "ReportId")
+                        .OnDelete(DeleteBehavior.SetNull)
+                        .HasConstraintName("fk_audit_log_reports_report_id");
+
+                    b.Navigation("Report");
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.AuthMethod", b =>
+                {
+                    b.HasOne("Foxnouns.Backend.Database.Models.FediverseApplication", "FediverseApplication")
+                        .WithMany()
+                        .HasForeignKey("FediverseApplicationId")
+                        .HasConstraintName("fk_auth_methods_fediverse_applications_fediverse_application_id");
+
+                    b.HasOne("Foxnouns.Backend.Database.Models.User", "User")
+                        .WithMany("AuthMethods")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_auth_methods_users_user_id");
+
+                    b.Navigation("FediverseApplication");
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.DataExport", b =>
+                {
+                    b.HasOne("Foxnouns.Backend.Database.Models.User", "User")
+                        .WithMany("DataExports")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_data_exports_users_user_id");
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Member", b =>
+                {
+                    b.HasOne("Foxnouns.Backend.Database.Models.User", "User")
+                        .WithMany("Members")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_members_users_user_id");
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.MemberFlag", b =>
+                {
+                    b.HasOne("Foxnouns.Backend.Database.Models.Member", null)
+                        .WithMany("ProfileFlags")
+                        .HasForeignKey("MemberId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_member_flags_members_member_id");
+
+                    b.HasOne("Foxnouns.Backend.Database.Models.PrideFlag", "PrideFlag")
+                        .WithMany()
+                        .HasForeignKey("PrideFlagId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_member_flags_pride_flags_pride_flag_id");
+
+                    b.Navigation("PrideFlag");
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Notice", b =>
+                {
+                    b.HasOne("Foxnouns.Backend.Database.Models.User", "Author")
+                        .WithMany()
+                        .HasForeignKey("AuthorId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_notices_users_author_id");
+
+                    b.Navigation("Author");
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Notification", b =>
+                {
+                    b.HasOne("Foxnouns.Backend.Database.Models.User", "Target")
+                        .WithMany()
+                        .HasForeignKey("TargetId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_notifications_users_target_id");
+
+                    b.Navigation("Target");
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.PrideFlag", b =>
+                {
+                    b.HasOne("Foxnouns.Backend.Database.Models.User", null)
+                        .WithMany("Flags")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_pride_flags_users_user_id");
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Report", b =>
+                {
+                    b.HasOne("Foxnouns.Backend.Database.Models.User", "Reporter")
+                        .WithMany()
+                        .HasForeignKey("ReporterId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_reports_users_reporter_id");
+
+                    b.HasOne("Foxnouns.Backend.Database.Models.Member", "TargetMember")
+                        .WithMany()
+                        .HasForeignKey("TargetMemberId")
+                        .HasConstraintName("fk_reports_members_target_member_id");
+
+                    b.HasOne("Foxnouns.Backend.Database.Models.User", "TargetUser")
+                        .WithMany()
+                        .HasForeignKey("TargetUserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_reports_users_target_user_id");
+
+                    b.Navigation("Reporter");
+
+                    b.Navigation("TargetMember");
+
+                    b.Navigation("TargetUser");
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Token", b =>
+                {
+                    b.HasOne("Foxnouns.Backend.Database.Models.Application", "Application")
+                        .WithMany()
+                        .HasForeignKey("ApplicationId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_tokens_applications_application_id");
+
+                    b.HasOne("Foxnouns.Backend.Database.Models.User", "User")
+                        .WithMany()
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_tokens_users_user_id");
+
+                    b.Navigation("Application");
+
+                    b.Navigation("User");
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.UserFlag", b =>
+                {
+                    b.HasOne("Foxnouns.Backend.Database.Models.PrideFlag", "PrideFlag")
+                        .WithMany()
+                        .HasForeignKey("PrideFlagId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_user_flags_pride_flags_pride_flag_id");
+
+                    b.HasOne("Foxnouns.Backend.Database.Models.User", null)
+                        .WithMany("ProfileFlags")
+                        .HasForeignKey("UserId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_user_flags_users_user_id");
+
+                    b.Navigation("PrideFlag");
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Member", b =>
+                {
+                    b.Navigation("ProfileFlags");
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Report", b =>
+                {
+                    b.Navigation("AuditLogEntry");
+                });
+
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.User", b =>
+                {
+                    b.Navigation("AuthMethods");
+
+                    b.Navigation("DataExports");
+
+                    b.Navigation("Flags");
+
+                    b.Navigation("Members");
+
+                    b.Navigation("ProfileFlags");
+                });
+#pragma warning restore 612, 618
+        }
+    }
+}

Foxnouns.Backend/Database/Migrations/20250329131053_AddNotices.cs

@@ -0,0 +1,56 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+using NodaTime;
+
+#nullable disable
+
+namespace Foxnouns.Backend.Database.Migrations
+{
+    /// <inheritdoc />
+    public partial class AddNotices : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.CreateTable(
+                name: "notices",
+                columns: table => new
+                {
+                    id = table.Column<long>(type: "bigint", nullable: false),
+                    message = table.Column<string>(type: "text", nullable: false),
+                    start_time = table.Column<Instant>(
+                        type: "timestamp with time zone",
+                        nullable: false
+                    ),
+                    end_time = table.Column<Instant>(
+                        type: "timestamp with time zone",
+                        nullable: false
+                    ),
+                    author_id = table.Column<long>(type: "bigint", nullable: false),
+                },
+                constraints: table =>
+                {
+                    table.PrimaryKey("pk_notices", x => x.id);
+                    table.ForeignKey(
+                        name: "fk_notices_users_author_id",
+                        column: x => x.author_id,
+                        principalTable: "users",
+                        principalColumn: "id",
+                        onDelete: ReferentialAction.Cascade
+                    );
+                }
+            );
+
+            migrationBuilder.CreateIndex(
+                name: "ix_notices_author_id",
+                table: "notices",
+                column: "author_id"
+            );
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropTable(name: "notices");
+        }
+    }
+}

Foxnouns.Backend/Database/Migrations/DatabaseContextModelSnapshot.cs

@@ -343,6 +343,38 @@ namespace Foxnouns.Backend.Database.Migrations
                     b.ToTable("member_flags", (string)null);
                 });
 
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Notice", b =>
+                {
+                    b.Property<long>("Id")
+                        .HasColumnType("bigint")
+                        .HasColumnName("id");
+
+                    b.Property<long>("AuthorId")
+                        .HasColumnType("bigint")
+                        .HasColumnName("author_id");
+
+                    b.Property<Instant>("EndTime")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("end_time");
+
+                    b.Property<string>("Message")
+                        .IsRequired()
+                        .HasColumnType("text")
+                        .HasColumnName("message");
+
+                    b.Property<Instant>("StartTime")
+                        .HasColumnType("timestamp with time zone")
+                        .HasColumnName("start_time");
+
+                    b.HasKey("Id")
+                        .HasName("pk_notices");
+
+                    b.HasIndex("AuthorId")
+                        .HasDatabaseName("ix_notices_author_id");
+
+                    b.ToTable("notices", (string)null);
+                });
+
             modelBuilder.Entity("Foxnouns.Backend.Database.Models.Notification", b =>
                 {
                     b.Property<long>("Id")
@@ -750,6 +782,18 @@ namespace Foxnouns.Backend.Database.Migrations
                     b.Navigation("PrideFlag");
                 });
 
+            modelBuilder.Entity("Foxnouns.Backend.Database.Models.Notice", b =>
+                {
+                    b.HasOne("Foxnouns.Backend.Database.Models.User", "Author")
+                        .WithMany()
+                        .HasForeignKey("AuthorId")
+                        .OnDelete(DeleteBehavior.Cascade)
+                        .IsRequired()
+                        .HasConstraintName("fk_notices_users_author_id");
+
+                    b.Navigation("Author");
+                });
+
             modelBuilder.Entity("Foxnouns.Backend.Database.Models.Notification", b =>
                 {
                     b.HasOne("Foxnouns.Backend.Database.Models.User", "Target")

Foxnouns.Backend/Database/Models/Notice.cs

@@ -0,0 +1,13 @@
+using NodaTime;
+
+namespace Foxnouns.Backend.Database.Models;
+
+public class Notice : BaseModel
+{
+    public required string Message { get; set; }
+    public required Instant StartTime { get; set; }
+    public required Instant EndTime { get; set; }
+
+    public Snowflake AuthorId { get; init; }
+    public User Author { get; init; } = null!;
+}

Foxnouns.Backend/Database/Models/User.cs

@@ -95,4 +95,5 @@ public enum PreferenceSize
 public class UserSettings
 {
     public bool? DarkMode { get; set; }
+    public Snowflake? LastReadNotice { get; set; }
 }

Foxnouns.Backend/Dto/Meta.cs

@@ -14,6 +14,8 @@
 // along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
 // ReSharper disable NotAccessedPositionalProperty.Global
+using Foxnouns.Backend.Database;
+
 namespace Foxnouns.Backend.Dto;
 
 public record MetaResponse(
@@ -22,9 +24,12 @@ public record MetaResponse(
     string Hash,
     int Members,
     UserInfoResponse Users,
-    LimitsResponse Limits
+    LimitsResponse Limits,
+    MetaNoticeResponse? Notice
 );
 
+public record MetaNoticeResponse(Snowflake Id, string Message);
+
 public record UserInfoResponse(int Total, int ActiveMonth, int ActiveWeek, int ActiveDay);
 
 public record LimitsResponse(

Foxnouns.Backend/Dto/Moderation.cs

@@ -122,3 +122,13 @@ public record QueryUserResponse(
 );
 
 public record QuerySensitiveUserDataRequest(string Reason);
+
+public record NoticeResponse(
+    Snowflake Id,
+    string Message,
+    Instant StartTime,
+    Instant EndTime,
+    PartialUser Author
+);
+
+public record CreateNoticeRequest(string Message, Instant? StartTime, Instant EndTime);

Foxnouns.Backend/Dto/User.cs

@@ -80,6 +80,7 @@ public record PartialUser(
 public class UpdateUserSettingsRequest : PatchRequest
 {
     public bool? DarkMode { get; init; }
+    public Snowflake? LastReadNotice { get; init; }
 }
 
 public class CustomPreferenceUpdateRequest

Foxnouns.Backend/Extensions/WebApplicationExtensions.cs

@@ -15,10 +15,12 @@
 using Coravel;
 using Coravel.Queuing.Interfaces;
 using Foxnouns.Backend.Database;
+using Foxnouns.Backend.Database.Models;
 using Foxnouns.Backend.Jobs;
 using Foxnouns.Backend.Middleware;
 using Foxnouns.Backend.Services;
 using Foxnouns.Backend.Services.Auth;
+using Foxnouns.Backend.Services.Caching;
 using Foxnouns.Backend.Services.V1;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Http.Resilience;
@@ -162,6 +164,7 @@ public static class WebApplicationExtensions
                     .AddScoped<ObjectStorageService>()
                     .AddTransient<DataCleanupService>()
                     .AddTransient<ValidationService>()
+                    .AddSingleton<NoticeCacheService>()
                     // Background services
                     .AddHostedService<PeriodicTasksService>()
                     // Transient jobs

Foxnouns.Backend/Services/Auth/AuthService.cs

@@ -253,14 +253,14 @@ public class AuthService(
     {
         AssertValidAuthType(authType, app);
 
-        // This is already checked when
+        // This is already checked when generating an add account state, but we check it here too just in case.
         int currentCount = await db
             .AuthMethods.Where(m => m.UserId == userId && m.AuthType == authType)
             .CountAsync(ct);
         if (currentCount >= AuthUtils.MaxAuthMethodsPerType)
         {
             throw new ApiError.BadRequest(
-                "Too many linked accounts of this type, maximum of 3 per account."
+                $"Too many linked accounts of this type, maximum of {AuthUtils.MaxAuthMethodsPerType} per account."
             );
         }
 

Foxnouns.Backend/Services/Caching/NoticeCacheService.cs

@@ -0,0 +1,39 @@
+// Copyright (C) 2023-present sam/u1f320 (vulpine.solutions)
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published
+// by the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+using Foxnouns.Backend.Database;
+using Foxnouns.Backend.Database.Models;
+using Microsoft.EntityFrameworkCore;
+using NodaTime;
+
+namespace Foxnouns.Backend.Services.Caching;
+
+public class NoticeCacheService(IServiceProvider serviceProvider, IClock clock, ILogger logger)
+    : SingletonCacheService<Notice>(serviceProvider, clock, logger)
+{
+    public override Duration MaxAge { get; init; } = Duration.FromMinutes(5);
+
+    public override Func<
+        DatabaseContext,
+        CancellationToken,
+        Task<Notice?>
+    > FetchFunc { get; init; } =
+        async (db, ct) =>
+            await db
+                .Notices.Where(n =>
+                    n.StartTime < clock.GetCurrentInstant() && n.EndTime > clock.GetCurrentInstant()
+                )
+                .OrderByDescending(n => n.Id)
+                .FirstOrDefaultAsync(ct);
+}

Foxnouns.Backend/Services/Caching/SingletonCacheService.cs

@@ -0,0 +1,63 @@
+// Copyright (C) 2023-present sam/u1f320 (vulpine.solutions)
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published
+// by the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+using Foxnouns.Backend.Database;
+using NodaTime;
+
+namespace Foxnouns.Backend.Services.Caching;
+
+public abstract class SingletonCacheService<T>(
+    IServiceProvider serviceProvider,
+    IClock clock,
+    ILogger logger
+)
+    where T : class
+{
+    private T? _item;
+    private Instant _lastUpdated = Instant.MinValue;
+    private readonly SemaphoreSlim _semaphore = new(1, 1);
+    private readonly ILogger _logger = logger.ForContext<SingletonCacheService<T>>();
+
+    public virtual Duration MaxAge { get; init; } = Duration.FromMinutes(5);
+
+    public virtual Func<DatabaseContext, CancellationToken, Task<T?>> FetchFunc { get; init; } =
+        (_, __) => Task.FromResult<T?>(null);
+
+    public async Task<T?> GetAsync(CancellationToken ct = default)
+    {
+        await _semaphore.WaitAsync(ct);
+        try
+        {
+            if (_lastUpdated > clock.GetCurrentInstant() - MaxAge)
+            {
+                return _item;
+            }
+
+            _logger.Debug("Cached item of type {Type} is expired, fetching it.", typeof(T));
+
+            await using AsyncServiceScope scope = serviceProvider.CreateAsyncScope();
+            await using DatabaseContext db =
+                scope.ServiceProvider.GetRequiredService<DatabaseContext>();
+
+            T? item = await FetchFunc(db, ct);
+            _item = item;
+            _lastUpdated = clock.GetCurrentInstant();
+            return item;
+        }
+        finally
+        {
+            _semaphore.Release();
+        }
+    }
+}