feat: add PDF attachment support using unpdf, extend attachment handling and runtime to process and extract text from PDFs

studio/frontend/bun.lock

@@ -51,6 +51,7 @@
         "tailwindcss": "^4.1.17",
         "tw-animate-css": "^1.4.0",
         "tw-shimmer": "^0.4.4",
+        "unpdf": "^1.4.0",
         "zustand": "^5.0.10",
       },
       "devDependencies": {
@@ -1809,6 +1810,8 @@
 
     "universalify": ["universalify@2.0.1", "", {}, "sha512-gptHNQghINnc/vTGIk0SOFGFNXw7JVrlRUtConJRlvaw6DuX0wO5Jeko9sWrMBhh+PsYAZ7oXAiOnf/UKogyiw=="],
 
+    "unpdf": ["unpdf@1.4.0", "", { "peerDependencies": { "@napi-rs/canvas": "^0.1.69" }, "optionalPeers": ["@napi-rs/canvas"] }, "sha512-TahIk0xdH/4jh/MxfclzU79g40OyxtP00VnEUZdEkJoYtXAHWLiir6t3FC6z3vDqQTzc2ZHcla6uEiVTNjejuA=="],
+
     "unpipe": ["unpipe@1.0.0", "", {}, "sha512-pjy2bYhSsufwWlKwPc+l3cN7+wuJlK6uz0YdJEOlQDbl6jo/YlPi4mb8agUkVC8BF7V8NuzeyPNqRksA3hztKQ=="],
 
     "until-async": ["until-async@3.0.2", "", {}, "sha512-IiSk4HlzAMqTUseHHe3VhIGyuFmN90zMTpD3Z3y8jeQbzLIq500MVM7Jq2vUAnTKAFPJrqwkzr6PoTcPhGcOiw=="],

studio/frontend/package.json

@@ -59,6 +59,7 @@
     "tailwindcss": "^4.1.17",
     "tw-animate-css": "^1.4.0",
     "tw-shimmer": "^0.4.4",
+    "unpdf": "^1.4.0",
     "zustand": "^5.0.10"
   },
   "devDependencies": {

studio/frontend/src/features/chat/adapter.ts

@@ -6,13 +6,21 @@ type RunMessages = Parameters<ChatModelAdapter["run"]>[0]["messages"];
 
 function makeBody(messages: RunMessages): string {
   return JSON.stringify({
-    messages: messages.map((m) => ({
-      role: m.role,
-      content: m.content
+    messages: messages.map((m) => {
+      const textParts = m.content
         .filter((c) => c.type === "text")
-        .map((c) => c.text)
-        .join(""),
-    })),
+        .map((c) => c.text);
+
+      if ("attachments" in m && m.attachments?.length) {
+        for (const att of m.attachments) {
+          for (const part of att.content ?? []) {
+            if (part.type === "text") textParts.push(part.text);
+          }
+        }
+      }
+
+      return { role: m.role, content: textParts.join("\n") };
+    }),
   });
 }
 

studio/frontend/src/features/chat/runtime-provider.tsx

@@ -1,8 +1,11 @@
 import {
+  type AttachmentAdapter,
   AssistantRuntimeProvider,
+  type CompleteAttachment,
   CompositeAttachmentAdapter,
   ExportedMessageRepository,
   type ExportedMessageRepositoryItem,
+  type PendingAttachment,
   RuntimeAdapterProvider,
   SimpleImageAttachmentAdapter,
   SimpleTextAttachmentAdapter,
@@ -19,10 +22,42 @@ import {
 } from "@assistant-ui/react";
 import { createAssistantStream } from "assistant-stream";
 import { type ReactElement, type ReactNode, useEffect, useMemo } from "react";
+import { extractText, getDocumentProxy } from "unpdf";
 import { createStreamAdapter } from "./adapter";
 import { db } from "./db";
 import type { MessageRecord, ModelType } from "./types";
 
+class PDFAttachmentAdapter implements AttachmentAdapter {
+  accept = "application/pdf";
+
+  async add({ file }: { file: File }): Promise<PendingAttachment> {
+    return {
+      id: crypto.randomUUID(),
+      type: "document",
+      name: file.name,
+      contentType: file.type,
+      file,
+      status: { type: "requires-action", reason: "composer-send" },
+    };
+  }
+
+  async send(attachment: PendingAttachment): Promise<CompleteAttachment> {
+    const buffer = new Uint8Array(await attachment.file.arrayBuffer());
+    const pdf = await getDocumentProxy(buffer);
+    const { text } = await extractText(pdf, { mergePages: true });
+    return {
+      id: attachment.id,
+      type: "document",
+      name: attachment.name,
+      contentType: attachment.contentType,
+      content: [{ type: "text", text: `[PDF: ${attachment.name}]\n${text}` }],
+      status: { type: "complete" },
+    };
+  }
+
+  async remove(): Promise<void> {}
+}
+
 function toThreadMessage(m: MessageRecord): ThreadMessage {
   const base = {
     id: m.id,
@@ -200,6 +235,7 @@ function ThreadHistoryProvider({
       new CompositeAttachmentAdapter([
         new SimpleImageAttachmentAdapter(),
         new SimpleTextAttachmentAdapter(),
+        new PDFAttachmentAdapter(),
       ]),
     [],
   );