Add attachment list API

extra/admin-api/Models/Spacebar.Models.Api/CreateAttachmentRequest.cs

@@ -1,4 +1,5 @@
 using System.Text.Json.Serialization;
+using Spacebar.Models.Generic;
 
 namespace Spacebar.Models.Api;
 
@@ -38,4 +39,20 @@ public class CreateAttachmentResponse {
         [JsonPropertyName("original_content_type")]
         public string? OriginalContentType { get; set; }
     }
+}
+
+public class AttachmentListResponse {
+    [JsonPropertyName("total")]
+    public int Total { get; set; }
+
+    [JsonPropertyName("items")]
+    public List<Entry> Items { get; set; }
+
+    public class Entry {
+        [JsonPropertyName("attachment")]
+        public MessageAttachment Attachment { get; set; }
+
+        [JsonPropertyName("message_reference")]
+        public MessageReference MessageReference { get; set; }
+    }
 }

extra/admin-api/Models/Spacebar.Models.Api/Spacebar.Models.Api.csproj

@@ -6,4 +6,9 @@
         <Nullable>enable</Nullable>
     </PropertyGroup>
 
+    <ItemGroup>
+        <ProjectReference Include="..\Spacebar.Models.Generic\Spacebar.Models.Generic.csproj" Condition="'$(ContinuousIntegrationBuild)'!='true'"/>
+        <PackageReference Include="Spacebar.Models.Generic" Version="*-preview*" Condition="'$(ContinuousIntegrationBuild)'=='true'"/>
+    </ItemGroup>
+
 </Project>

extra/admin-api/Tests/Spacebar.Tests/Tests/ChannelTests.cs

@@ -1,5 +1,8 @@
-using System.Net.Http.Json;
+using System.Net.Http.Headers;
+using System.Net.Http.Json;
+using System.Text.Json;
 using System.Text.Json.Nodes;
+using Spacebar.Models.Api;
 using Spacebar.Models.Generic;
 using Spacebar.Sdk.Core;
 using Spacebar.Tests.Abstractions;
@@ -84,4 +87,72 @@ public class ChannelTests(ITestOutputHelper testOutputHelper, TestFixture fixtur
 
         await Assert.HttpSuccess(await Client.ApiHttpClient.DeleteAsync($"channels/{c.Id}", TestContext.Current.CancellationToken));
     }
+    
+    [Fact]
+    public async Task GetAttachmentList() {
+        var channel = await Client!.GetGuild(Guild.Id).CreateChannelAsync(new() {
+            Name = "test",
+            Type = 0 // TODO: this should be the default
+        });
+
+        Assert.Equal("test", channel.Name);
+        
+        var createAttResp = await Assert.HttpSuccess(await Client.ApiHttpClient.PostAsJsonAsync($"channels/{channel.Id}/attachments", new CreateAttachmentRequest() {
+            Files = [
+                new() {
+                    Id = 0,
+                    FileName = "hellorld.txt",
+                    FileSize = "Hellorld!".Length
+                }
+            ]
+        }, cancellationToken: TestContext.Current.CancellationToken));
+        var createAttRespContent = await createAttResp.Content.ReadFromJsonAsync<JsonObject>(cancellationToken: TestContext.Current.CancellationToken);
+        // testOutputHelper.WriteLine(createAttRespContent?.ToString());
+
+        var createAtt = createAttRespContent.Deserialize<CreateAttachmentResponse>();
+        foreach (var attFile in createAtt.Attachments)
+            await Assert.HttpSuccess(await Client.ApiHttpClient.PutAsync(attFile.UploadUrl, new ByteArrayContent("Hellorld!"u8.ToArray()) {
+                Headers = {
+                    ContentType = new MediaTypeHeaderValue("text/plain")
+                }
+            }, TestContext.Current.CancellationToken));
+
+        var content = new JsonObject() {
+            { "content", "meow" }, {
+                "attachments", new JsonArray() {
+                    new JsonObject() {
+                        { "id", createAtt.Attachments[0].Id.ToString() },
+                        { "filename", "hellorld.txt" },
+                        { "uploaded_filename", createAtt.Attachments[0].UploadFileName },
+                        { "original_content_type", "text/plain" },
+                    }
+                }
+            }
+        };
+        var res = await Assert.HttpSuccess(await Client.ApiHttpClient.PostAsJsonAsync($"channels/{channel.Id}/messages", content,
+            cancellationToken: TestContext.Current.CancellationToken));
+        var json = (await res.Content.ReadFromJsonAsync<JsonObject>(cancellationToken: TestContext.Current.CancellationToken));
+        // testOutputHelper.WriteLine(json.ToJson(indent: true));
+        var msg = json.Deserialize<Message>();
+        Assert.Equal("meow", msg.Content);
+        Assert.Single(msg.Attachments);
+
+        var attListResp = await Assert.HttpSuccess(await Client.ApiHttpClient.GetAsync($"/_spacebar/api/v1/channels/{channel.Id}/attachments", TestContext.Current.CancellationToken));
+        var attListJson = await attListResp.Content.ReadFromJsonAsync<JsonObject>(cancellationToken: TestContext.Current.CancellationToken);
+        var attList = attListJson.Deserialize<AttachmentListResponse>()!;
+        Assert.Equal(1, attList.Total);
+        Assert.All(attList.Items, e => {
+            Assert.Equal(channel.Id, e.MessageReference.ChannelId);
+            Assert.Equal(msg.Id, e.MessageReference.MessageId);
+            Assert.Equal(Guild.Id, e.MessageReference.GuildId);
+
+            Assert.StringNotNullOrWhitespace(e.Attachment.ContentType);
+            Assert.StringNotNullOrWhitespace(e.Attachment.Filename);
+            Assert.StringNotNullOrWhitespace(e.Attachment.ProxyUrl);
+            Assert.StringNotNullOrWhitespace(e.Attachment.Url);
+            Assert.NotEqual(0, e.Attachment.Size);
+            Assert.Null(e.Attachment.Width);
+            Assert.Null(e.Attachment.Height);
+        });
+    }
 }

src/api/routes_toplevel/_spacebar/api/v1/channels/#channel_id/attachments.ts

@@ -0,0 +1,97 @@
+/*
+	Spacebar: A FOSS re-implementation and extension of the Discord.com backend.
+	Copyright (C) 2023 Spacebar and Spacebar Contributors
+
+	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/>.
+*/
+
+import { Request, Response, Router } from "express";
+import { HTTPError } from "lambert-server/HTTPError";
+import { FindOptionsOrderValue, LessThan, MoreThan } from "typeorm";
+import { route } from "@spacebar/api/middlewares";
+import { Attachment, Channel, Message } from "@spacebar/database";
+import { FieldErrors, getPermission } from "@spacebar/util";
+import { AttachmentListResponse } from "@spacebar/schemas/api/spacebar/AttachmentListResponse";
+
+const router: Router = Router({ mergeParams: true });
+
+router.get(
+    "/",
+    route({
+        responses: {
+            200: {
+                body: "AttachmentListResponse",
+            },
+            403: {
+                body: "APIErrorResponse",
+            },
+            422: {
+                body: "APIErrorResponse",
+            },
+        },
+    }),
+    async (req: Request, res: Response) => {
+        const { channel_id } = req.params as { [key: string]: string };
+        const channel = await Channel.findOneOrFail({
+            where: { id: channel_id },
+        });
+        const { sort_order, limit } = req.query;
+
+        const parsedLimit = Number(limit) || 50;
+        if (parsedLimit < 1 || parsedLimit > 100) throw new HTTPError("limit must be between 1 and 100", 422);
+
+        if (sort_order) {
+            if (typeof sort_order != "string" || ["desc", "asc"].indexOf(sort_order) == -1)
+                throw FieldErrors({
+                    sort_order: {
+                        message: "Value must be one of ('desc', 'asc').",
+                        code: "BASE_TYPE_CHOICES",
+                    },
+                }); // todo this is wrong
+        }
+
+        const permissions = await getPermission(req.user_id, channel.guild_id, channel_id as string | undefined);
+        permissions.hasThrow("VIEW_CHANNEL");
+        if (!permissions.has("READ_MESSAGE_HISTORY")) return res.json({ items: [], total: 0 } satisfies AttachmentListResponse);
+
+        const attCount = Attachment.count({ where: { channel_id: req.params.channel_id as string } });
+        const atts = await Attachment.find({
+            where: {
+                channel_id: req.params.channel_id as string,
+                id: (sort_order == "asc" ? MoreThan : LessThan)((req.params.after as string) ?? "0"),
+            },
+            order: {
+                id: sort_order as FindOptionsOrderValue,
+            },
+            take: parsedLimit,
+        });
+
+        return res.json({
+            items: atts.map((x) => ({
+                attachment: x.signUrls({
+                    userAgent: req.headers["user-agent"],
+                    ip: req.ip,
+                }),
+                message_reference: {
+                    message_id: x.message_id,
+                    channel_id: x.channel_id,
+                    guild_id: channel.guild_id,
+                },
+            })),
+            total: await attCount,
+        } satisfies AttachmentListResponse);
+    },
+);
+
+export default router;

src/schemas/api/messages/Message.ts

@@ -234,10 +234,13 @@ export enum PotionType {
     CONFETTI = 0,
 }
 
-export interface MessageReference {
+export interface MessageReferenceIds {
     message_id?: string;
     channel_id?: string;
     guild_id?: string;
+}
+
+export interface MessageReference extends MessageReferenceIds {
     fail_if_not_exists?: boolean;
     type?: MessageReferenceType;
 }

src/schemas/api/spacebar/AttachmentListResponse.ts

@@ -0,0 +1,28 @@
+/*
+	Spacebar: A FOSS re-implementation and extension of the Discord.com backend.
+	Copyright (C) 2026 Spacebar and Spacebar Contributors
+
+	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/>.
+*/
+
+import { PublicAttachment } from "@spacebar/schemas/api/messages/Attachments";
+import { MessageReferenceIds } from "@spacebar/schemas";
+
+export interface AttachmentListResponse {
+    items: {
+        attachment: PublicAttachment;
+        message_reference: MessageReferenceIds;
+    }[];
+    total: number;
+}