feat: agents open files in the side-panel Preview (amicode_open_preview) + 16 MB HTML cap (#2130)

packages/app-bundle/manifest.json

@@ -591,7 +591,7 @@
     "packages/ui/src/amicode/brain-ref.ts": "0f8e866933ec3d161973f5e62acdfd51b0320f3ad5be4c487685c469467901c4",
     "packages/ui/src/amicode/bridge.ts": "e7b93a15060a0cb1ab0be2b367f73e926d74b990a8af917a9966b451ee303b5b",
     "packages/ui/src/amicode/card.stories.tsx": "b1591abb4af426b0eb08588ea1585336a392d755b5d308cb31f17cb65acf5a3e",
-    "packages/ui/src/amicode/card.tsx": "1f462017d9113082bb2e802e3d812b25cf5ee9b1bd848559e0533de4d382517f",
+    "packages/ui/src/amicode/card.tsx": "c025b03d79630acf8a3754cc1b566dc3348f33c305bd62443a416ecb7c4a1a66",
     "packages/ui/src/amicode/connection-icon.tsx": "f0ffda2ebae57a2945a60cd278b5aa3986273b0cabe97ed46f417c037d167879",
     "packages/ui/src/amicode/connection-picker.tsx": "73293d1e159dab94a6d1600844fa1e47810ce0558bda6ba4e4209f7e368e3aff",
     "packages/ui/src/amicode/connections-paths.test.ts": "07c86e8e04700cdbd55bff8db342a8400d85114d76bc73fee8205e9162953f2a",
@@ -620,6 +620,9 @@
     "packages/ui/src/amicode/institution-lookup.ts": "3edf90b0778ea50b048975cc317a18a1aa82290cd4f5241cf9df74fd17866fe9",
     "packages/ui/src/amicode/onboarding-wizard.test.ts": "268df538ea99280c5297f9b1dc06a236da2fb82830c2d49a107feca3f610279f",
     "packages/ui/src/amicode/onboarding-wizard.tsx": "75db623f8f50fd875f1bde8942841fbb5167c77a34fe3c6dbfa80732841b53e8",
+    "packages/ui/src/amicode/preview-open-card.tsx": "f7acb9e25ef9d55c100fc977ad5435ba8f0afd07675ae9abd12d057e7712becc",
+    "packages/ui/src/amicode/preview-open.test.ts": "4f02dc2ceecdfb015a6ba6cfedccd8d0ce899cc417dadf6a94286303c22d9f0d",
+    "packages/ui/src/amicode/preview-open.ts": "69934ca6ed1af0e90e556a70abd9cf6c502a3b6825b7901fe08d7fb85bdfa07e",
     "packages/ui/src/amicode/problem.test.ts": "3b7d212cc5a11855c0606189c007f2bbc3957c6b2ee4e1642fc95242f3dd94bd",
     "packages/ui/src/amicode/problem.ts": "186c1615f387ce930f61b2a8bcc41a11c7d6979c3a398e04be9a3939a6931d5b",
     "packages/ui/src/amicode/project-type-icons.test.ts": "1db755e2818a5e97d018e7133ae329b9ce1ff63fc347a06bcac7b9f4d0784969",
@@ -800,11 +803,11 @@
     "packages/app/src/components/session/preview-draft-store.test.ts": "3985665fbbe2255dcc1ea683a4353c5d2e4c24e77e93e5981bb466698fe23c05",
     "packages/app/src/components/session/preview-draft-store.ts": "28355fc9be787f81ddc0f052f96d51c283ab9a917b309ae05a29c1c98ffba7a3",
     "packages/app/src/components/session/preview-draft-wiring.test.ts": "8d54de2788ab52e7ba02a90e606072602aa1de3411d2371148258e2a9d33b44a",
-    "packages/app/src/components/session/preview-file-helpers.test.ts": "e0c1ccb40b48990c0c5b87ea62a35de60b860cd760067c7f1327cbb1d36584b1",
-    "packages/app/src/components/session/preview-file-helpers.ts": "2244aaef25f7412df7b53a45a7d2f72380d45eb90caefa5e96c48d01e988eb4e",
+    "packages/app/src/components/session/preview-file-helpers.test.ts": "a1c180771a0279f82eead051266c1f3f2bcb1af7ff7b1914ae39862a0bebd601",
+    "packages/app/src/components/session/preview-file-helpers.ts": "8fcce56f9abce1be2a5868eba369bd3c3eb02c5cf49f548927cea8b82d0baed8",
     "packages/app/src/components/session/preview-file-target.test.ts": "d9a341349d8922b0369f3fdf911cce35d96344962ad442267e9078106d266db3",
     "packages/app/src/components/session/preview-file-target.ts": "11738d77fc1e86a4a968b65f3fb342f51792b6a2c2d57a08114197ff2e82a51b",
-    "packages/app/src/components/session/preview-file-view.tsx": "27153914e75d6e596fe56ebe6556653bc589c7f6c31fcdb24e37618814133268",
+    "packages/app/src/components/session/preview-file-view.tsx": "31779ea862550a5400aa9d1477e38de443f3c801326596cdfde7a01b01cfb020",
     "packages/app/src/components/session/preview-find-in-sidebar.test.ts": "68cdc2d9743b3c3a6a6c1fab6cbd362d27b4f7179cba973cba67d10f01b35970",
     "packages/app/src/components/session/preview-frontmatter-card.tsx": "00f439e3bf482673dfb06c0ce3464c0f51985093ed57b321cdebd38d452f2e5d",
     "packages/app/src/components/session/preview-frontmatter.test.ts": "93ec9f7f4c604d8ed8ee6009779c425bffecfca331a122a7a700b588a8ca3c0c",
@@ -1102,7 +1105,7 @@
     "packages/ui/src/v2/components/text-shimmer-v2.tsx"
   ],
   "exceptions": [],
-  "extracted_at": "2026-11-07T23:24:13.583Z",
+  "extracted_at": "2026-11-08T14:53:42.145Z",
   "per_package": {
     "packages/app": {
       "A": 312,
@@ -1145,13 +1148,13 @@
       "D": 0
     },
     "packages/ui": {
-      "A": 151,
+      "A": 154,
       "M": 66,
       "D": 0
     }
   },
   "counts": {
-    "overlay_total": 1080,
+    "overlay_total": 1083,
     "deletions": 7,
     "server_coupled": 0
   },
@@ -1768,6 +1771,9 @@
     "packages/ui/src/amicode/institution-lookup.ts": "A",
     "packages/ui/src/amicode/onboarding-wizard.test.ts": "A",
     "packages/ui/src/amicode/onboarding-wizard.tsx": "A",
+    "packages/ui/src/amicode/preview-open-card.tsx": "A",
+    "packages/ui/src/amicode/preview-open.test.ts": "A",
+    "packages/ui/src/amicode/preview-open.ts": "A",
     "packages/ui/src/amicode/problem.test.ts": "A",
     "packages/ui/src/amicode/problem.ts": "A",
     "packages/ui/src/amicode/project-type-icons.test.ts": "A",

packages/app-bundle/overlay/packages/app/src/components/session/preview-file-helpers.test.ts

@@ -1,5 +1,12 @@
 import { test, expect, describe } from "bun:test"
-import { toAbsolutePath, shouldApplyWatcherRead } from "./preview-file-helpers"
+import {
+  toAbsolutePath,
+  shouldApplyWatcherRead,
+  previewSizeLimit,
+  isPreviewRefreshFor,
+  MAX_HTML_PREVIEW_SIZE,
+  MAX_TEXT_PREVIEW_SIZE,
+} from "./preview-file-helpers"
 
 // #1414 (my review finding): saving a .tex opened by a workspace-RELATIVE path
 // posted `run-latex` with that relative path; the compile bridge's containment
@@ -66,3 +73,43 @@ describe("shouldApplyWatcherRead", () => {
     expect(shouldApplyWatcherRead({ ...base, hasUnsavedEdits: true })).toBe(false)
   })
 })
+
+// #2130: the HTML size cap and the agent tool's refresh request.
+describe("previewSizeLimit", () => {
+  test("HTML pages get the larger cap; everything else read as text keeps 1 MB", () => {
+    expect(previewSizeLimit("/r/transport-dashboard.html")).toBe(MAX_HTML_PREVIEW_SIZE)
+    expect(previewSizeLimit("page.HTM")).toBe(MAX_HTML_PREVIEW_SIZE)
+    expect(previewSizeLimit("/r/notes.md")).toBe(MAX_TEXT_PREVIEW_SIZE)
+    expect(previewSizeLimit("/r/data.json")).toBe(MAX_TEXT_PREVIEW_SIZE)
+    // a 1.73 MB dashboard with embedded plots now fits
+    expect(1_732_245).toBeLessThan(previewSizeLimit("/r/transport-dashboard.html"))
+  })
+})
+
+describe("isPreviewRefreshFor", () => {
+  const msg = (extra: Record<string, unknown> = {}) => ({
+    source: "amicode",
+    kind: "preview-file",
+    path: "/v/dash/index.html",
+    refresh: true,
+    sessionID: "ses_a",
+    ...extra,
+  })
+  test("a refresh for this file and this session", () => {
+    expect(isPreviewRefreshFor(msg(), "/v/dash/index.html", "ses_a")).toBe(true)
+  })
+  test("absolute message path matches a workspace-relative previewed path", () => {
+    expect(isPreviewRefreshFor(msg({ path: "/w/repo/docs/a.md" }), "docs/a.md", "ses_a")).toBe(true)
+  })
+  test("an unstamped message refreshes every view of the file", () => {
+    expect(isPreviewRefreshFor(msg({ sessionID: undefined }), "/v/dash/index.html", "ses_b")).toBe(true)
+  })
+  test("another session, another file, no refresh flag, or not a preview-file → no", () => {
+    expect(isPreviewRefreshFor(msg(), "/v/dash/index.html", "ses_b")).toBe(false)
+    expect(isPreviewRefreshFor(msg(), "/v/dash/other.html", "ses_a")).toBe(false)
+    expect(isPreviewRefreshFor(msg({ path: "/x/index.html" }), "/v/dash/index.html", "ses_a")).toBe(false)
+    expect(isPreviewRefreshFor(msg({ refresh: undefined }), "/v/dash/index.html", "ses_a")).toBe(false)
+    expect(isPreviewRefreshFor(msg({ kind: "open-file" }), "/v/dash/index.html", "ses_a")).toBe(false)
+    expect(isPreviewRefreshFor("preview-file", "/v/dash/index.html", "ses_a")).toBe(false)
+  })
+})

packages/app-bundle/overlay/packages/app/src/components/session/preview-file-helpers.ts

@@ -45,3 +45,41 @@ export function shouldApplyWatcherRead(args: {
     !args.hasUnsavedEdits
   )
 }
+
+/** The Preview's read cap for text-like files: bigger files show a placeholder. */
+export const MAX_TEXT_PREVIEW_SIZE = 1_000_000
+
+/** #2130: an HTML page's cap is larger — a campaign dashboard often carries its
+ *  plots as base64 data URIs, and the HTML renderer's own inlining budget
+ *  (preview-html.ts MAX_INLINE_CHARS) is already far above 1 MB. Mirrored by
+ *  the agent tool's size warning (extension opencode-plugin/preview_open.ts). */
+export const MAX_HTML_PREVIEW_SIZE = 16_000_000
+
+/** The size above which a text read shows "File too large to preview". */
+export function previewSizeLimit(path: string): number {
+  return /\.html?$/i.test(path) ? MAX_HTML_PREVIEW_SIZE : MAX_TEXT_PREVIEW_SIZE
+}
+
+/** Does a watcher/bridge path name the previewed file? The watcher reports
+ *  absolute paths; the previewed path may be workspace-relative. */
+export function previewPathMatches(other: string, filePath: string): boolean {
+  if (other === filePath) return true
+  return other.endsWith(`/${filePath}`) || filePath.endsWith(`/${other}`)
+}
+
+/**
+ * #2130: is this window message a request to RE-READ the file this view shows?
+ * The agent's open-in-Preview tool posts the ordinary `preview-file` open with
+ * `refresh: true`; when the file is already open the open itself is a no-op,
+ * so the view re-reads instead (files outside the project never reach the
+ * engine's watcher). Session targeting follows preview-file-target.ts: a
+ * stamped message is for its session only; an unstamped one is for everyone.
+ */
+export function isPreviewRefreshFor(data: unknown, filePath: string, sessionID: string | undefined): boolean {
+  if (!data || typeof data !== "object") return false
+  const msg = data as { source?: unknown; kind?: unknown; path?: unknown; sessionID?: unknown; refresh?: unknown }
+  if (msg.source !== "amicode" || msg.kind !== "preview-file" || msg.refresh !== true) return false
+  if (typeof msg.path !== "string" || msg.path === "") return false
+  if (msg.sessionID !== undefined && msg.sessionID !== sessionID) return false
+  return previewPathMatches(msg.path, filePath)
+}

packages/app-bundle/overlay/packages/app/src/components/session/preview-file-view.tsx

@@ -35,7 +35,12 @@ import type { PreviewViewState } from "@opencode-ai/session-ui/v2/preview-view-s
 import { PdfCanvasView } from "./pdf-canvas-view"
 import { createPdfFindController } from "./pdf-find-controller"
 import { PdfFindPill } from "./pdf-find-pill"
-import { toAbsolutePath, shouldApplyWatcherRead } from "./preview-file-helpers"
+import {
+  toAbsolutePath,
+  shouldApplyWatcherRead,
+  previewSizeLimit,
+  isPreviewRefreshFor,
+} from "./preview-file-helpers"
 import { validateHumanWritePath } from "./preview-human-write-gate"
 import { previewDrafts } from "./preview-draft-store"
 import {
@@ -86,8 +91,6 @@ type PdfPageNavigation = {
   navigate: (page: number) => boolean
 }
 
-const MAX_FILE_SIZE = 1_000_000
-
 // Wrapper padding: p-4 = 16px each side = 32px total
 const IMAGE_WRAPPER_PADDING = 32
 
@@ -224,10 +227,13 @@ export function PreviewFileView(props: {
 
   const category = () => getFileCategory(props.filePath)
 
+  // #2130: bumped to force a full re-load of the same path (a refresh request
+  // while the view shows a placeholder — too large, or a failed read).
+  const [reloadTick, setReloadTick] = createSignal(0)
   createEffect(
     on(
-      () => props.filePath,
-      (path) => {
+      () => [props.filePath, reloadTick()] as const,
+      ([path]) => {
         setLoading(true)
         setFileType(null)
         setBinaryData(null)
@@ -257,7 +263,7 @@ export function PreviewFileView(props: {
               return
             }
             const size = (content as any).length ?? content.content.length
-            if (size > MAX_FILE_SIZE) {
+            if (size > previewSizeLimit(path)) {
               setFileType("too-large")
               setFileContent("")
               return
@@ -286,6 +292,50 @@ export function PreviewFileView(props: {
   // #1414: reads are async — guard their completion so a read finishing after a
   // file switch, a newer read, or a fresh edit can't clobber the view.
   let watcherReadGen = 0
+  // Re-read the previewed file from disk (watcher change, or an explicit refresh
+  // request, #2130), tagging the read so a stale completion is discarded.
+  const rereadFromDisk = (filePath: string) => {
+    const capturedGeneration = ++watcherReadGen
+    sdk()
+      .client.file.read({ path: filePath })
+      .then((result) => {
+        if (
+          !shouldApplyWatcherRead({
+            capturedPath: filePath,
+            currentPath: props.filePath,
+            capturedGeneration,
+            latestGeneration: watcherReadGen,
+            hasUnsavedEdits: unsavedContent() !== null,
+          })
+        )
+          return
+        const content = result.data
+        if (!content) return
+        if (content.type !== "text") {
+          // Binary file (PDF, image) — update binary data
+          if ((content as any).encoding === "base64") {
+            setBinaryData({
+              base64: content.content,
+              mime: (content as any).mimeType ?? "application/octet-stream",
+            })
+          }
+        } else {
+          // Text file — update content
+          setFileContent(content.content)
+          // #1423: If a .tex/.ltx file was updated on disk (e.g. by the
+          // agent), trigger a LaTeX recompile so the PDF auto-refreshes.
+          if (/\.(tex|ltx)$/i.test(filePath)) {
+            try {
+              window.parent?.postMessage(
+                { source: "amicode", kind: "run-latex", file: toAbsolute(filePath) },
+                "*",
+              )
+            } catch {}
+          }
+        }
+      })
+      .catch(() => {})
+  }
   createEffect(() => {
     const filePath = props.filePath
     const unsub = sdk().event.listen((e) => {
@@ -299,51 +349,28 @@ export function PreviewFileView(props: {
       if (!changedPath.endsWith(filePath) && !filePath.endsWith(changedPath)) return
       // Skip if the user has unsaved edits — don't clobber their work
       if (unsavedContent() !== null) return
-      // Re-read the file, tagging this read so a stale completion is discarded.
-      const capturedGeneration = ++watcherReadGen
-      sdk()
-        .client.file.read({ path: filePath })
-        .then((result) => {
-          if (
-            !shouldApplyWatcherRead({
-              capturedPath: filePath,
-              currentPath: props.filePath,
-              capturedGeneration,
-              latestGeneration: watcherReadGen,
-              hasUnsavedEdits: unsavedContent() !== null,
-            })
-          )
-            return
-          const content = result.data
-          if (!content) return
-          if (content.type !== "text") {
-            // Binary file (PDF, image) — update binary data
-            if ((content as any).encoding === "base64") {
-              setBinaryData({
-                base64: content.content,
-                mime: (content as any).mimeType ?? "application/octet-stream",
-              })
-            }
-          } else {
-            // Text file — update content
-            setFileContent(content.content)
-            // #1423: If a .tex/.ltx file was updated on disk (e.g. by the
-            // agent), trigger a LaTeX recompile so the PDF auto-refreshes.
-            if (/\.(tex|ltx)$/i.test(filePath)) {
-              try {
-                window.parent?.postMessage(
-                  { source: "amicode", kind: "run-latex", file: toAbsolute(filePath) },
-                  "*",
-                )
-              } catch {}
-            }
-          }
-        })
-        .catch(() => {})
+      rereadFromDisk(filePath)
     })
     onCleanup(unsub)
   })
 
+  // #2130: the agent's open-in-Preview tool posts `preview-file` with
+  // `refresh: true`. Opening an already-open file changes nothing, so the view
+  // re-reads it here — the only way a file outside the project (a vault
+  // dashboard, a results folder) refreshes on demand. A placeholder view (too
+  // large, failed read) gets a full re-load instead; unsaved edits are kept.
+  onMount(() => {
+    const onRefresh = (event: MessageEvent) => {
+      if (!isPreviewRefreshFor(event.data, props.filePath, props.draftSession)) return
+      if (unsavedContent() !== null) return
+      const type = fileType()
+      if (type === "too-large" || type === "error") setReloadTick((n) => n + 1)
+      else rereadFromDisk(props.filePath)
+    }
+    window.addEventListener("message", onRefresh)
+    onCleanup(() => window.removeEventListener("message", onRefresh))
+  })
+
   // ─── PDF refresh after compile (#1254) ─────────────────────────────────
   // Re-read the file from disk and swap the base64 payload when the companion
   // PDF's producer (latexmk) reports "done" via run-latex-status.