Hona · Sep 17, 2026 · Sep 17, 2026
@@ -4,64 +4,6 @@ import { createBlobReference } from "@/runtime/persistence/drafts"
 import { uuid } from "@/runtime/persistence/uuid"
 import type { ComposerAttachment, ComposerPrompt } from "../types"
 
-const accepted = [
-  "image/png",
-  "image/jpeg",
-  "image/gif",
-  "image/webp",
-  "application/pdf",
-  "text/*",
-  "application/json",
-  "application/ld+json",
-  "application/toml",
-  "application/x-toml",
-  "application/x-yaml",
-  "application/xml",
-  "application/yaml",
-  ".c",
-  ".cc",
-  ".cjs",
-  ".conf",
-  ".cpp",
-  ".css",
-  ".csv",
-  ".cts",
-  ".env",
-  ".go",
-  ".gql",
-  ".graphql",
-  ".h",
-  ".hh",
-  ".hpp",
-  ".htm",
-  ".html",
-  ".ini",
-  ".java",
-  ".js",
-  ".json",
-  ".jsx",
-  ".log",
-  ".md",
-  ".mdx",
-  ".mjs",
-  ".mts",
-  ".py",
-  ".rb",
-  ".rs",
-  ".sass",
-  ".scss",
-  ".sh",
-  ".sql",
-  ".toml",
-  ".ts",
-  ".tsx",
-  ".txt",
-  ".xml",
-  ".yaml",
-  ".yml",
-  ".zsh",
-]
-
 type PromptTarget = {
   current: () => ComposerPrompt
   cursor: () => number | undefined
@@ -75,7 +17,6 @@ export type ComposerAttachmentConfig = {
   ) => Promise<void>
   directory: () => string
   isDialogActive: () => boolean
-  warn: () => void
   duplicate: () => void
   onError: (error: unknown) => void
   readClipboardImage?: () => Promise<File | null>
@@ -102,13 +43,9 @@ export function createComposerAttachments(
     if (!editor) return
     return { prompt, cursor: prompt.cursor() ?? cursorPosition(editor) }
   }
-  const add = async (file: File, toast = true, target = capture(), clipboard = false) => {
+  const add = async (file: File, target = capture(), clipboard = false) => {
     if (!target) return false
     const mime = await attachmentMime(file)
-    if (!mime) {
-      if (toast) input.warn()
-      return false
-    }
     const blob = input.store ? await input.store(file) : await createBlobReference(file)
     const sourcePath = input.getPathForFile?.(file) || undefined
     // Native clipboard images arrive with a fresh timestamped filename on every paste, so identical
@@ -138,13 +75,11 @@ export function createComposerAttachments(
     target.prompt.set([...target.prompt.current(), attachment], target.cursor)
     return true
   }
-  const addAttachments = async (files: File[], toast = true, target = capture()) => {
-    const found = await files.reduce(async (result, file) => {
+  const addAttachments = async (files: File[], target = capture()) => {
+    return files.reduce(async (result, file) => {
       const previous = await result
-      return (await add(file, false, target)) || previous
+      return (await add(file, target)) || previous
     }, Promise.resolve(false))
-    if (!found && files.length > 0 && toast) input.warn()
-    return found
   }
   const handlePaste = async (event: ClipboardEvent) => {
     const clipboardData = event.clipboardData
@@ -159,13 +94,13 @@ export function createComposerAttachments(
       return file ? [file] : []
     })
     if (files.length > 0) {
-      await addAttachments(files, true, target)
+      await addAttachments(files, target)
       return
     }
     const plainText = clipboardData.getData("text/plain") ?? ""
     if (input.readClipboardImage && !plainText) {
       const file = await input.readClipboardImage()
-      if (file && (await add(file, true, target, true))) return
+      if (file && (await add(file, target, true))) return
     }
     if (!plainText) return
     const text = plainText.includes("\r") ? plainText.replace(/\r\n?/g, "\n") : plainText
@@ -223,9 +158,7 @@ export function createComposerAttachments(
         fallback()
         return
       }
-      void input
-        .picker({ defaultPath: input.directory(), multiple: true, accept: accepted }, (file) => add(file))
-        .catch(input.onError)
+      void input.picker({ defaultPath: input.directory(), multiple: true }, (file) => add(file)).catch(input.onError)
     },
   }
 }
@@ -249,6 +182,8 @@ const textMimes = new Set([
   "application/yaml",
 ])
 
+// Text-like files normalize to text/plain so the server inlines their content; every other
+// file keeps a binary type and is delivered to the model by path or as native media.
 async function attachmentMime(file: File) {
   const type = file.type.split(";", 1)[0]?.trim().toLowerCase() ?? ""
   if (imageMimes.has(type) || type === "application/pdf") return type
@@ -259,10 +194,11 @@ async function attachmentMime(file: File) {
   if (type.startsWith("text/") || textMimes.has(type) || type.endsWith("+json") || type.endsWith("+xml")) {
     return "text/plain"
   }
+  const binary = type || "application/octet-stream"
   const bytes = new Uint8Array(await file.slice(0, 4096).arrayBuffer())
-  if (bytes.some((byte) => byte === 0)) return
+  if (bytes.some((byte) => byte === 0)) return binary
   const control = bytes.filter((byte) => byte < 9 || (byte > 13 && byte < 32)).length
-  if (bytes.length > 0 && control / bytes.length > 0.3) return
+  if (bytes.length > 0 && control / bytes.length > 0.3) return binary
   return "text/plain"
 }
 

@@ -0,0 +1,70 @@
+import type { Accessor } from "solid-js"
+import { blobBytes, blobDataUrl } from "@/runtime/persistence/drafts"
+import { useServer } from "@/runtime/server/current"
+import { useServerSDK } from "@/runtime/server/client"
+import { useWorkspaceLocation } from "@/workspaces/location"
+import type { ComposerControls } from "../adapter"
+import type { ImageAttachmentPart } from "../state"
+
+// Where a prompt is headed: the model that reads it and the server that runs its tools.
+export type AttachmentDestination = {
+  /** Input modalities the selected model reads natively. */
+  input: { image: boolean; pdf: boolean }
+  /** The server shares the client's filesystem, so an attachment's source path resolves as-is. */
+  local: boolean
+  /** Copies a file into the server's temporary directory and returns its absolute path there. */
+  upload: (file: { name: string; data: Uint8Array }) => Promise<string>
+}
+
+export type DeliveredAttachment =
+  | { type: "inline"; attachment: ImageAttachmentPart; dataUrl: string }
+  | { type: "path"; attachment: ImageAttachmentPart; path: string }
+
+// An attachment travels inline when the model reads its bytes natively. Anything else reaches
+// the model as a path on the server, which its tools can open, instead of being rejected.
+export function deliverAttachments(attachments: ImageAttachmentPart[], destination: AttachmentDestination) {
+  return Promise.all(attachments.map((attachment) => deliver(attachment, destination)))
+}
+
+async function deliver(
+  attachment: ImageAttachmentPart,
+  destination: AttachmentDestination,
+): Promise<DeliveredAttachment> {
+  if (native(attachment.mime, destination.input)) {
+    return { type: "inline", attachment, dataUrl: await blobDataUrl(attachment.blob, attachment.mime) }
+  }
+  if (destination.local && attachment.sourcePath) return { type: "path", attachment, path: attachment.sourcePath }
+  const path = await destination.upload({ name: attachment.filename, data: await blobBytes(attachment.blob) })
+  return { type: "path", attachment, path }
+}
+
+const imageMimes = new Set(["image/png", "image/jpeg", "image/gif", "image/webp"])
+
+// Mirrors the attachment kinds the server forwards to the model as message content.
+function native(mime: string, input: AttachmentDestination["input"]) {
+  if (mime === "text/plain") return true
+  if (imageMimes.has(mime)) return input.image
+  if (mime === "application/pdf") return input.pdf
+  return false
+}
+
+export function useAttachmentDestination(controls: Accessor<ComposerControls>) {
+  const server = useServer()
+  const sdk = useServerSDK()
+  const location = useWorkspaceLocation()
+  return (): AttachmentDestination => ({
+    input: controls().model.selection.current()?.capabilities.input ?? { image: false, pdf: false },
+    local: server.isLocal,
+    upload: async (file) => {
+      const info = await sdk.api.server.info()
+      // One directory per upload keeps the original filename without collisions; the server
+      // normalizes the separators and returns the resolved path.
+      const written = await sdk.api.file.write({
+        location: { directory: location().directory },
+        path: `${info.paths.tmp}/uploads/${crypto.randomUUID()}/${file.name}`,
+        payload: file.data,
+      })
+      return written.data.path
+    },
+  })
+}
@@ -8,6 +8,13 @@ export type PromptComment = {
   origin?: "review" | "file"
 }
 
+/** An attachment the model receives as a path on the server rather than inline bytes. */
+export type PromptAttachmentReference = {
+  name: string
+  mime: string
+  path: string
+}
+
 function selection(selection: unknown) {
   if (!selection || typeof selection !== "object") return undefined
   const startLine = Number((selection as FileSelection).startLine)
@@ -58,8 +65,17 @@ export function readPromptPresentation(value: unknown) {
   const displayText = (value as { displayText?: unknown }).displayText
   const comments = (value as { comments?: unknown }).comments
   if (typeof displayText !== "string" || !Array.isArray(comments)) return
+  const attachments = (value as { attachments?: unknown }).attachments
   return {
     displayText,
+    attachments: (Array.isArray(attachments) ? attachments : []).flatMap((item): PromptAttachmentReference[] => {
+      if (!item || typeof item !== "object") return []
+      const name = (item as { name?: unknown }).name
+      const mime = (item as { mime?: unknown }).mime
+      const path = (item as { path?: unknown }).path
+      if (typeof name !== "string" || typeof mime !== "string" || typeof path !== "string") return []
+      return [{ name, mime, path }]
+    }),
     comments: comments.flatMap((item): PromptComment[] => {
       if (!item || typeof item !== "object") return []
       const path = (item as { path?: unknown }).path
@@ -80,6 +96,10 @@ export function readPromptPresentation(value: unknown) {
   }
 }
 
+export function formatAttachmentReference(input: PromptAttachmentReference) {
+  return `Attached file: \`${input.path}\``
+}
+
 export function formatCommentNote(input: { path: string; selection?: FileSelection; comment: string }) {
   const start = input.selection ? Math.min(input.selection.startLine, input.selection.endLine) : undefined
   const end = input.selection ? Math.max(input.selection.startLine, input.selection.endLine) : undefined

@@ -167,7 +167,7 @@ function ComposerStory(props: {
             ? buildPromptRequest({
                 prompt: draft.prompt,
                 context: draft.context.items,
-                images: [],
+                attachments: [],
                 text: value,
                 sessionDirectory: "C:/repo",
               })

@@ -102,7 +102,6 @@ export function ComposerEditor(props: ComposerEditorProps) {
         ref={props.controller.setFileInput}
         type="file"
         multiple
-        accept="image/png,image/jpeg,image/gif,image/webp,application/pdf,text/*,application/json,application/ld+json,application/toml,application/x-toml,application/x-yaml,application/xml,application/yaml,.c,.cc,.cjs,.conf,.cpp,.css,.csv,.cts,.env,.go,.gql,.graphql,.h,.hh,.hpp,.htm,.html,.ini,.java,.js,.json,.jsx,.log,.md,.mdx,.mjs,.mts,.py,.rb,.rs,.sass,.scss,.sh,.sql,.toml,.ts,.tsx,.txt,.xml,.yaml,.yml,.zsh"
         class="hidden"
         onChange={(event) => {
           const list = event.currentTarget.files

@@ -22,6 +22,7 @@ import type { PromptHistoryComment } from "./history/entry"
 import { createComposerHistory } from "./history/store"
 import { composerPlaceholder } from "./placeholder"
 import { createComposerSubmit } from "./submit"
+import { useAttachmentDestination } from "./attachments/deliver"
 
 export type ComposerModel = ComposerEditorModel & {
   readonly model: ComposerControls["model"]
@@ -265,6 +266,7 @@ export function createComposerModel(adapter: ComposerAdapter, options?: { queue?
     resetHistory: () => controller.resetHistory(),
     setMode: (next) => controller.dispatch({ type: next === "shell" ? "mode.shell" : "mode.normal" }),
     closePopover: () => controller.dispatch({ type: "popover.close" }),
+    destination: useAttachmentDestination(adapter.controls),
     delivery: (alternate) => {
       const queue = options?.queue
       if (!queue) return "steer"
@@ -339,11 +341,6 @@ export function createComposerModel(adapter: ComposerAdapter, options?: { queue?
       picker: platform.openAttachmentPickerDialog,
       directory: () => sdk().directory,
       isDialogActive: () => !!dialog.active,
-      warn: () =>
-        showToast({
-          title: language.t("prompt.toast.pasteUnsupported.title"),
-          description: language.t("prompt.toast.pasteUnsupported.description"),
-        }),
       duplicate: () => showToast({ title: language.t("prompt.toast.attachmentDuplicate.title") }),
       onError: (error) =>
         showToast({