fix(core): expand v2 directory attachments

Co-authored-by: Aiden Cline <63023139+rekram1-node@users.noreply.github.com>

packages/core/src/session/runner/llm.ts

@@ -23,6 +23,7 @@ import { SkillGuidance } from "../../skill/guidance"
 import { ReferenceGuidance } from "../../reference/guidance"
 import { McpGuidance } from "../../mcp/guidance"
 import { ToolRegistry } from "../../tool/registry"
+import { ReadToolFileSystem } from "../../tool/read-filesystem"
 import { ToolOutputStore } from "../../tool-output-store"
 import { SessionContextEpoch } from "../context-epoch"
 import { SessionCompaction } from "../compaction"
@@ -99,6 +100,7 @@ const layer = Layer.effect(
     const llm = yield* LLMClient.Service
     const agents = yield* AgentV2.Service
     const tools = yield* ToolRegistry.Service
+    const reader = yield* ReadToolFileSystem.Service
     const models = yield* SessionRunnerModel.Service
     const store = yield* SessionStore.Service
     const location = yield* Location.Service
@@ -208,13 +210,14 @@ const layer = Layer.effect(
         ? undefined
         : yield* tools.materialize({ permissions: agent.info?.permissions, model })
       const promptCacheKey = /^ses_[0-9a-f]{64}$/.test(session.id) ? session.id.slice(4) : session.id
+      const messages = yield* toLLMMessages(context, model, reader)
       const request = LLM.request({
         model,
         providerOptions: { openai: { promptCacheKey } },
         system: [agent.info?.system ? agent.info.system : SessionRunnerSystemPrompt.provider(model), system.baseline]
           .filter((part): part is string => part !== undefined && part.length > 0)
           .map(SystemPart.make),
-        messages: [...toLLMMessages(context, model), ...(isLastStep ? [Message.assistant(MAX_STEPS_PROMPT)] : [])],
+        messages: [...messages, ...(isLastStep ? [Message.assistant(MAX_STEPS_PROMPT)] : [])],
         tools: toolMaterialization?.definitions ?? [],
         toolChoice: isLastStep ? "none" : undefined,
       })
@@ -444,5 +447,6 @@ export const node = makeLocationNode({
     Config.node,
     Snapshot.node,
     Database.node,
+    ReadToolFileSystem.node,
   ],
 })

packages/core/src/session/runner/to-llm-message.ts

@@ -7,6 +7,10 @@ import {
   type Model,
   type ProviderMetadata,
 } from "@opencode-ai/llm"
+import { Cause, Effect } from "effect"
+import { fileURLToPath } from "url"
+import { AbsolutePath, PositiveInt } from "../../schema"
+import { ReadToolFileSystem } from "../../tool/read-filesystem"
 import { SessionMessage } from "../message"
 import type { FileAttachment } from "../prompt"
 
@@ -18,6 +22,71 @@ const media = (file: FileAttachment): ContentPart => ({
   metadata: file.description === undefined ? undefined : { description: file.description },
 })
 
+const fileContent = Effect.fn("toLLMMessage.fileContent")(function* (
+  file: FileAttachment,
+  reader: ReadToolFileSystem.Interface,
+) {
+  if (file.mime !== "text/plain" && file.mime !== "application/x-directory") return [media(file)]
+  if (file.uri.startsWith("data:text/plain")) return [{ type: "text" as const, text: decodeDataUrl(file.uri) }]
+  if (!URL.canParse(file.uri)) return []
+  const url = new URL(file.uri)
+  if (url.protocol !== "file:") return []
+  const filepath = fileURLToPath(url)
+  const path = AbsolutePath.make(filepath)
+  if (file.mime === "application/x-directory") {
+    const result = yield* reader.list(path, page(url)).pipe(Effect.exit)
+    if (result._tag === "Failure")
+      return [{ type: "text" as const, text: readError(filepath, Cause.squash(result.cause)) }]
+    return [{ type: "text" as const, text: directoryText(filepath, result.value) }]
+  }
+  const result = yield* reader.read(path, filepath, page(url)).pipe(Effect.exit)
+  if (result._tag === "Failure")
+    return [{ type: "text" as const, text: readError(filepath, Cause.squash(result.cause)) }]
+  if ("type" in result.value && result.value.type === "text-page")
+    return [{ type: "text" as const, text: readText(filepath, result.value.content) }]
+  if ("encoding" in result.value && result.value.encoding === "utf8")
+    return [{ type: "text" as const, text: readText(filepath, result.value.content) }]
+  return []
+})
+
+const page = (url: URL): ReadToolFileSystem.PageInput => {
+  const start = positiveInt(url.searchParams.get("start"))
+  const end = positiveInt(url.searchParams.get("end"))
+  return {
+    ...(start === undefined ? {} : { offset: start }),
+    ...(start === undefined || end === undefined || end < start ? {} : { limit: PositiveInt.make(end - start + 1) }),
+  }
+}
+
+const positiveInt = (value: string | null) => {
+  if (value === null) return undefined
+  const parsed = Number.parseInt(value, 10)
+  return Number.isInteger(parsed) && parsed > 0 ? PositiveInt.make(parsed) : undefined
+}
+
+const readText = (filepath: string, content: string) =>
+  `Called the Read tool with the following input: ${JSON.stringify({ path: filepath })}\n\n${content}`
+
+const directoryText = (filepath: string, page: ReadToolFileSystem.ListPage) =>
+  [
+    `Called the Read tool with the following input: ${JSON.stringify({ path: filepath })}`,
+    "",
+    ...page.entries.map((entry) => `${entry.type}: ${entry.path}`),
+    ...(page.truncated ? [`... (directory listing truncated, next offset: ${page.next})`] : []),
+  ].join("\n")
+
+const readError = (filepath: string, error: unknown) =>
+  `Read tool failed to read ${filepath} with the following error: ${error instanceof Error ? error.message : String(error)}`
+
+const decodeDataUrl = (dataUrl: string) => {
+  const index = dataUrl.indexOf(",")
+  if (index === -1) return ""
+  const data = dataUrl.slice(index + 1)
+  return dataUrl.slice(0, index).toLowerCase().endsWith(";base64")
+    ? Buffer.from(data, "base64").toString("utf8")
+    : decodeURIComponent(data)
+}
+
 const toolInput = (tool: SessionMessage.AssistantTool) => {
   if (tool.state.status !== "pending") return tool.state.input
   try {
@@ -112,23 +181,31 @@ const assistant = (message: SessionMessage.Assistant, model: Model) => {
   ]
 }
 
-function toLLMMessage(message: SessionMessage.Message, model: Model): Message[] {
+const toLLMMessage = Effect.fn("toLLMMessage")(function* (
+  message: SessionMessage.Message,
+  model: Model,
+  reader: ReadToolFileSystem.Interface,
+) {
   switch (message.type) {
     case "agent-switched":
     case "model-switched":
       return []
-    case "user":
+    case "user": {
+      const files = yield* Effect.forEach(message.files ?? [], (file) => fileContent(file, reader), {
+        concurrency: "unbounded",
+      })
       return [
         Message.make({
           id: message.id,
           role: "user",
-          content: [{ type: "text", text: message.text }, ...(message.files ?? []).map(media)],
+          content: [{ type: "text", text: message.text }, ...files.flat()],
           metadata: {
             ...message.metadata,
             ...(message.agents?.length ? { agents: message.agents } : {}),
           },
         }),
       ]
+    }
     case "synthetic":
       return [Message.make({ id: message.id, role: "user", content: message.text })]
     case "skill":
@@ -166,8 +243,15 @@ ${message.recent}
         }),
       ]
   }
-}
+})
 
 /** Translate projected V2 Session history into canonical @opencode-ai/llm context. */
-export const toLLMMessages = (messages: readonly SessionMessage.Message[], model: Model) =>
-  messages.flatMap((message) => toLLMMessage(message, model))
+export const toLLMMessages = (
+  messages: readonly SessionMessage.Message[],
+  model: Model,
+  reader: ReadToolFileSystem.Interface,
+) =>
+  Effect.map(
+    Effect.forEach(messages, (message) => toLLMMessage(message, model, reader)),
+    (messages) => messages.flat(),
+  )

packages/core/test/session-instructions.test.ts

@@ -28,7 +28,7 @@ import { SessionMessage } from "@opencode-ai/core/session/message"
 import { SessionProjector } from "@opencode-ai/core/session/projector"
 import { SessionStore } from "@opencode-ai/core/session/store"
 import { SessionV2 } from "@opencode-ai/core/session"
-import { toLLMMessages } from "@opencode-ai/core/session/runner/to-llm-message"
+import { toLLMMessages as lowerLLMMessages } from "@opencode-ai/core/session/runner/to-llm-message"
 import { ToolHooks } from "@opencode-ai/core/tool/hooks"
 import { ToolOutputStore } from "@opencode-ai/core/tool-output-store"
 import { ToolRegistry } from "@opencode-ai/core/tool/registry"
@@ -36,6 +36,14 @@ import { tempLocationLayer } from "./fixture/location"
 import { testEffect } from "./lib/effect"
 import { settleTool, testModel } from "./lib/tool"
 
+const noopReader = ReadToolFileSystem.Service.of({
+  inspect: () => Effect.die("unused"),
+  read: () => Effect.die("unused"),
+  list: () => Effect.die("unused"),
+})
+const toLLMMessages = (messages: readonly SessionMessage.Message[], model: Model) =>
+  Effect.runSync(lowerLLMMessages(messages, model, noopReader))
+
 const projects = Layer.succeed(
   ProjectV2.Service,
   ProjectV2.Service.of({

packages/core/test/session-runner-message.test.ts

@@ -1,17 +1,44 @@
 import { describe, expect, test } from "bun:test"
+import { Effect } from "effect"
 import { Message, Model } from "@opencode-ai/llm"
 import * as OpenAIChat from "@opencode-ai/llm/protocols/openai-chat"
 import { ModelV2 } from "@opencode-ai/core/model"
 import { ProviderV2 } from "@opencode-ai/core/provider"
 import { SessionMessage } from "@opencode-ai/core/session/message"
 import { AgentAttachment, FileAttachment } from "@opencode-ai/core/session/prompt"
-import { toLLMMessages } from "@opencode-ai/core/session/runner/to-llm-message"
+import { toLLMMessages as lowerLLMMessages } from "@opencode-ai/core/session/runner/to-llm-message"
 import { SessionV2 } from "@opencode-ai/core/session"
 import { DateTime } from "effect"
+import { FileSystem } from "@opencode-ai/core/filesystem"
+import { RelativePath } from "@opencode-ai/core/schema"
+import { ReadToolFileSystem } from "@opencode-ai/core/tool/read-filesystem"
 
 const created = DateTime.makeUnsafe(0)
 const id = (value: string) => SessionMessage.ID.make(`msg_${value}`)
 const model = Model.make({ id: "model", provider: "provider", route: OpenAIChat.route })
+const reader = ReadToolFileSystem.Service.of({
+  inspect: () => Effect.die("unused"),
+  read: (path) =>
+    Effect.succeed({
+      uri: `file://${path}`,
+      name: "README.md",
+      content: `contents of ${path}`,
+      encoding: "utf8",
+      mime: "text/plain",
+    }),
+  list: () =>
+    Effect.succeed(
+      new ReadToolFileSystem.ListPage({
+        entries: [
+          FileSystem.Entry.make({ path: RelativePath.make("src/"), type: "directory" }),
+          FileSystem.Entry.make({ path: RelativePath.make("README.md"), type: "file" }),
+        ],
+        truncated: false,
+      }),
+    ),
+})
+const toLLMMessages = (messages: readonly SessionMessage.Message[], model: Model) =>
+  Effect.runSync(lowerLLMMessages(messages, model, reader))
 
 describe("toLLMMessages", () => {
   test("omits empty assistant turns", () => {
@@ -139,6 +166,38 @@ Recent work
     ])
   })
 
+  test("materializes text and directory prompt attachments as text", () => {
+    const messages = toLLMMessages(
+      [
+        SessionMessage.User.make({
+          id: id("user-with-directory"),
+          type: "user",
+          text: "Inspect these attachments",
+          files: [
+            FileAttachment.make({ uri: "file:///repo/README.md", mime: "text/plain", name: "README.md" }),
+            FileAttachment.make({ uri: "file:///repo/packages/core/", mime: "application/x-directory", name: "core" }),
+            FileAttachment.make({ uri: "data:image/png;base64,aGVsbG8=", mime: "image/png", name: "hello.png" }),
+          ],
+          time: { created },
+        }),
+      ],
+      model,
+    )
+
+    expect(messages[0]?.content).toEqual([
+      { type: "text", text: "Inspect these attachments" },
+      {
+        type: "text",
+        text: 'Called the Read tool with the following input: {"path":"/repo/README.md"}\n\ncontents of /repo/README.md',
+      },
+      {
+        type: "text",
+        text: 'Called the Read tool with the following input: {"path":"/repo/packages/core/"}\n\ndirectory: src/\nfile: README.md',
+      },
+      { type: "media", mediaType: "image/png", data: "data:image/png;base64,aGVsbG8=", filename: "hello.png" },
+    ])
+  })
+
   test("replays durable tool media into canonical tool messages without structured base64", () => {
     const messages = toLLMMessages(
       [