diff --git a/packages/opencode/src/session/prompt.ts b/packages/opencode/src/session/prompt.ts
index d1f407258..6ca93979e 100644
--- a/packages/opencode/src/session/prompt.ts
+++ b/packages/opencode/src/session/prompt.ts
@@ -2,6 +2,7 @@ import path from "path"
 import os from "os"
 import fs from "fs/promises"
 import z from "zod"
+import { Filesystem } from "../util/filesystem"
 import { Identifier } from "../id/id"
 import { MessageV2 } from "./message-v2"
 import { Log } from "../util/log"
@@ -1082,11 +1083,9 @@ export namespace SessionPrompt {
               // have to normalize, symbol search returns absolute paths
               // Decode the pathname since URL constructor doesn't automatically decode it
               const filepath = fileURLToPath(part.url)
-              const stat = await Bun.file(filepath)
-                .stat()
-                .catch(() => undefined)
+              const s = Filesystem.stat(filepath)
 
-              if (stat?.isDirectory()) {
+              if (s?.isDirectory()) {
                 part.mime = "application/x-directory"
               }
 
@@ -1233,14 +1232,13 @@ export namespace SessionPrompt {
                 ]
               }
 
-              const file = Bun.file(filepath)
               FileTime.read(input.sessionID, filepath)
               return [
                 {
                   messageID: info.id,
                   sessionID: input.sessionID,
                   type: "text",
-                  text: `Called the Read tool with the following input: {\"filePath\":\"${filepath}\"}`,
+                  text: `Called the Read tool with the following input: {"filePath":"${filepath}"}`,
                   synthetic: true,
                 },
                 {
@@ -1248,7 +1246,7 @@ export namespace SessionPrompt {
                   messageID: info.id,
                   sessionID: input.sessionID,
                   type: "file",
-                  url: `data:${part.mime};base64,` + Buffer.from(await file.bytes()).toString("base64"),
+                  url: `data:${part.mime};base64,` + (await Filesystem.readBytes(filepath)).toString("base64"),
                   mime: part.mime,
                   filename: part.filename!,
                   source: part.source,
@@ -1354,7 +1352,7 @@ export namespace SessionPrompt {
     // Switching from plan mode to build mode
     if (input.agent.name !== "plan" && assistantMessage?.info.agent === "plan") {
       const plan = Session.plan(input.session)
-      const exists = await Bun.file(plan).exists()
+      const exists = await Filesystem.exists(plan)
       if (exists) {
         const part = await Session.updatePart({
           id: Identifier.ascending("part"),
@@ -1373,7 +1371,7 @@ export namespace SessionPrompt {
     // Entering plan mode
     if (input.agent.name === "plan" && assistantMessage?.info.agent !== "plan") {
       const plan = Session.plan(input.session)
-      const exists = await Bun.file(plan).exists()
+      const exists = await Filesystem.exists(plan)
       if (!exists) await fs.mkdir(path.dirname(plan), { recursive: true })
       const part = await Session.updatePart({
         id: Identifier.ascending("part"),