Speed up artifact downloads

platform_web/api/client.test.ts

@@ -352,6 +352,19 @@ describe("PlatformApiClient AI providers", () => {
           }
         });
       }
+      if (url.endsWith("/api/v1/artifacts/artifact-1/content")) {
+        return new Response(new TextEncoder().encode("artifact full body").buffer, {
+          status: 200,
+          headers: {
+            "Content-Type": "application/octet-stream",
+            "Content-Length": "18",
+            "X-Artifact-Id": artifact.id,
+            "X-Artifact-Checksum": artifact.checksum,
+            "X-Artifact-Content-Checksum": "sha256:fullchecksum",
+            "X-Artifact-Storage": "platform-memory-transfer-session"
+          }
+        });
+      }
       if (url.endsWith("/api/v1/server-instances/workflows/create") && init?.method === "POST") {
         return jsonResponse({ accepted: true, action: "create", instance: { ...server, state: "installing" }, job: { ...job, capability: "process.install" } });
       }
@@ -611,6 +624,7 @@ describe("PlatformApiClient AI providers", () => {
     await expect(client.listArtifacts({ ownerKind: "job", ownerId: job.id, state: "available" })).resolves.toMatchObject({ count: 1, items: [{ id: artifact.id }] });
     await expect(client.openArtifactDownload(artifact.id)).resolves.toMatchObject({ downloadUrl: "/api/v1/artifacts/artifact-1/content", rangeSupported: true });
     await expect(client.readArtifactContent(artifact.id, 0, 8)).resolves.toMatchObject({ contentLength: 8, contentRange: "bytes 0-7/18", checksum: artifact.checksum });
+    await expect(client.downloadArtifactContent(artifact.id).then((response) => response.arrayBuffer())).resolves.toHaveProperty("byteLength", 18);
     await expect(client.createServerWorkflow({ id: "server-2", pluginId: plugin.id, name: "Server 2", idempotencyKey: "idem-create" })).resolves.toMatchObject({
       action: "create"
     });
@@ -659,7 +673,7 @@ describe("PlatformApiClient AI providers", () => {
       client.invokeAI({ requestId: "ai-1", serverInstanceId: server.id, purpose: "config.suggest", prompt: "Tune PVP safely", currentConfig: "server.name=Example Survival #1\n" })
     ).resolves.toMatchObject({ status: "ok", usage: { mocked: true }, configRecommendation: { diffSummary: "review required" } });
 
-    expect(fetchMock).toHaveBeenCalledTimes(45);
+    expect(fetchMock).toHaveBeenCalledTimes(46);
   });
 
   it("normalizes server file workspace null arrays from older platform responses", async () => {

platform_web/api/client.ts

@@ -298,6 +298,19 @@ export class PlatformApiClient {
     };
   }
 
+  async downloadArtifactContent(id: string): Promise<Response> {
+    const headers = new Headers();
+    const sessionToken = this.sessionTokenProvider();
+    if (sessionToken) {
+      headers.set("Authorization", `Bearer ${sessionToken}`);
+    }
+    const response = await fetch(`${this.baseUrl}/artifacts/${encodeURIComponent(id)}/content`, { headers, credentials: "same-origin" });
+    if (!response.ok) {
+      throw await responseError(response);
+    }
+    return response;
+  }
+
   async getJob(id: string): Promise<JobResponse> {
     return this.request<JobResponse>(`/jobs/${encodeURIComponent(id)}`);
   }

platform_web/api/contracts.md

@@ -29,7 +29,7 @@ Normal browser login uses the platform's HttpOnly SameSite cookie and `credentia
 - Game-specific pages use the scoped `plugin-data` collection API and declared plugin bridge machine actions; Platform does not expose game-specific projection or workflow clients.
 - `dispatchFileOperation` posts `FileOperationDispatchRequest` to `/file-operations/dispatch` using logical file keys and scoped refs rather than raw host paths; it remains the low-level compatibility dispatch for file work.
 - `getServerFileWorkspace`, `browseServerFiles`, `listServerFiles`, `refreshServerFiles`, `readServerFile`, `getServerFileReadSnapshot`, `writeServerFile`, `uploadServerFile`, and `prepareServerFileDownload` power the first-party server-detail file manager. The page renders a generic server-root entry and uses `browseServerFiles` as the live directory path for open, refresh, and search actions; compatibility `list`/`refresh` clients remain available for older flows. File reads use `files.read`, saves use `files.write`, and browser uploads stage server-instance artifacts before Run pulls input chunks on the dedicated file-transfer channel. Server detail may call only these server-file APIs plus the encapsulated download helper; it must not call raw artifact-transfer methods directly.
-- `listArtifacts`, `openArtifactDownload`, and `readArtifactContent` use platform artifact routes for available job/server artifacts. Browser reads are chunked through `/artifacts/{id}/content` and must render only safe filenames, checksums, progress, and platform storage behavior.
+- `listArtifacts`, `openArtifactDownload`, `downloadArtifactContent`, and `readArtifactContent` use platform artifact routes for available job/server artifacts. Browser downloads stream the full body through `/artifacts/{id}/content`; explicit range reads may still use bounded `offset`/`limit` chunks and must render only safe filenames, checksums, progress, and platform storage behavior.
 - `authorizePluginBridge` posts `PluginBridgeAuthorizeRequest` to `/plugin-bridge/authorize` for preflight decisions.
 - `executePluginBridge` posts `PluginBridgeExecuteRequest` to `/plugin-bridge/execute` from host-owned bridge dispatch utilities only. Plugin pages receive typed `PluginBridgeExecuteResponse` envelopes and never receive the platform API client, bearer token, raw provider key, run socket, host path, or storage credential.
 - `invokeAI` posts `AIInvocationRequest` to `/ai/invocations` for platform-mediated AI assistance. Responses carry redacted recommendations, usage metadata, optional reviewable config suggestions, and safe errors; they must not include provider base URLs, key refs, raw keys, or direct provider transport details.