refactor(core): consolidate filesystem services (#30447)

2026-06-02 16:09:26 -04:00
parent b93963e462
commit 604a5f781f
153 changed files with 2553 additions and 4312 deletions
--- a/packages/core/package.json
+++ b/packages/core/package.json
@@ -33,6 +33,15 @@
    "@types/npm-package-arg": "6.1.4",
    "@types/npmcli__arborist": "6.3.3",
    "@types/semver": "catalog:",
+    "@types/which": "3.0.4",
+    "@parcel/watcher-darwin-arm64": "2.5.1",
+    "@parcel/watcher-darwin-x64": "2.5.1",
+    "@parcel/watcher-linux-arm64-glibc": "2.5.1",
+    "@parcel/watcher-linux-arm64-musl": "2.5.1",
+    "@parcel/watcher-linux-x64-glibc": "2.5.1",
+    "@parcel/watcher-linux-x64-musl": "2.5.1",
+    "@parcel/watcher-win32-arm64": "2.5.1",
+    "@parcel/watcher-win32-x64": "2.5.1",
    "drizzle-kit": "catalog:"
  },
  "dependencies": {
@@ -68,21 +77,25 @@
    "@opentelemetry/context-async-hooks": "2.6.1",
    "@opentelemetry/exporter-trace-otlp-http": "0.214.0",
    "@opentelemetry/sdk-trace-base": "2.6.1",
+    "@parcel/watcher": "2.5.1",
    "@openrouter/ai-sdk-provider": "2.8.1",
    "ai-gateway-provider": "3.1.2",
    "cross-spawn": "catalog:",
    "drizzle-orm": "catalog:",
    "effect": "catalog:",
+    "fuzzysort": "3.1.0",
    "gitlab-ai-provider": "6.8.0",
    "glob": "13.0.5",
    "google-auth-library": "10.5.0",
    "immer": "11.1.4",
+    "ignore": "7.0.5",
    "jsonc-parser": "3.3.1",
    "mime-types": "3.0.2",
    "minimatch": "10.2.5",
    "npm-package-arg": "13.0.2",
    "semver": "^7.6.3",
    "venice-ai-sdk-provider": "2.0.2",
+    "which": "6.0.1",
    "xdg-basedir": "5.1.0",
    "zod": "catalog:"
  },
--- a/packages/core/src/auth.ts
+++ b/packages/core/src/auth.ts
@@ -5,7 +5,7 @@ import { Effect, Layer, Option, Schema, Context, SynchronizedRef } from "effect"
 import { Identifier } from "./util/identifier"
 import { NonNegativeInt, withStatics } from "./schema"
 import { Global } from "./global"
-import { AppFileSystem } from "./filesystem"
+import { FSUtil } from "./fs-util"
 import { EventV2 } from "./event"

 export const ID = Schema.String.pipe(
@@ -131,7 +131,7 @@ export class Service extends Context.Service<Service, Interface>()("@opencode/v2
 export const layer = Layer.effect(
  Service,
  Effect.gen(function* () {
-    const fsys = yield* AppFileSystem.Service
+    const fsys = yield* FSUtil.Service
    const global = yield* Global.Service
    const events = yield* EventV2.Service
    const file = path.join(global.data, "account.json")
@@ -334,7 +334,7 @@ export const layer = Layer.effect(
 )

 export const defaultLayer = layer.pipe(
-  Layer.provide(AppFileSystem.defaultLayer),
+  Layer.provide(FSUtil.defaultLayer),
  Layer.provide(Global.defaultLayer),
  Layer.provide(EventV2.defaultLayer),
 )
--- a/packages/core/src/config.ts
+++ b/packages/core/src/config.ts
@@ -3,7 +3,7 @@ export * as Config from "./config"
 import path from "path"
 import { type ParseError, parse } from "jsonc-parser"
 import { Context, Effect, Layer, Option, Schema } from "effect"
-import { AppFileSystem } from "./filesystem"
+import { FSUtil } from "./fs-util"
 import { Global } from "./global"
 import { Location } from "./location"
 import { PermissionV2 } from "./permission"
@@ -127,7 +127,7 @@ export class Service extends Context.Service<Service, Interface>()("@opencode/v2
 export const layer = Layer.effect(
  Service,
  Effect.gen(function* () {
-    const fs = yield* AppFileSystem.Service
+    const fs = yield* FSUtil.Service
    const global = yield* Global.Service
    const location = yield* Location.Service
    const policy = yield* Policy.Service
--- a/packages/core/src/filesystem.ts
+++ b/packages/core/src/filesystem.ts
@@ -1,247 +1,269 @@
-import { NodeFileSystem } from "@effect/platform-node"
-import { dirname, join, relative, resolve as pathResolve } from "path"
-import { realpathSync } from "fs"
-import * as NFS from "fs/promises"
-import { lookup } from "mime-types"
-import { Context, Effect, FileSystem, Layer, Schema } from "effect"
-import type { PlatformError } from "effect/PlatformError"
-import { Glob } from "./util/glob"
-import { serviceUse } from "./effect/service-use"
+export * as FileSystem from "./filesystem"

-export namespace AppFileSystem {
-  export class FileSystemError extends Schema.TaggedErrorClass<FileSystemError>()("FileSystemError", {
-    method: Schema.String,
-    cause: Schema.optional(Schema.Defect),
-  }) {}
+import path from "path"
+import { pathToFileURL } from "url"
+import fuzzysort from "fuzzysort"
+import ignore from "ignore"
+import { Context, Effect, Layer, Schema, Stream } from "effect"
+import { EventV2 } from "./event"
+import { FSUtil } from "./fs-util"
+import { Global } from "./global"
+import { Location } from "./location"
+import { ProjectReference } from "./project-reference"
+import { NonNegativeInt, PositiveInt, RelativePath } from "./schema"
+import { Protected } from "./filesystem/protected"
+import { Ripgrep } from "./filesystem/ripgrep"

-  export type Error = PlatformError | FileSystemError
+export const ReadInput = Schema.Struct({
+  path: RelativePath,
+  reference: Schema.String.pipe(Schema.optional),
+})
+export type ReadInput = typeof ReadInput.Type

-  export interface DirEntry {
-    readonly name: string
-    readonly type: "file" | "directory" | "symlink" | "other"
-  }
+export class TextContent extends Schema.Class<TextContent>("LocationFileSystem.TextContent")({
+  type: Schema.Literal("text"),
+  content: Schema.String,
+  mime: Schema.String,
+}) {}

-  export interface Interface extends FileSystem.FileSystem {
-    readonly isDir: (path: string) => Effect.Effect<boolean>
-    readonly isFile: (path: string) => Effect.Effect<boolean>
-    readonly existsSafe: (path: string) => Effect.Effect<boolean>
-    readonly readFileStringSafe: (path: string) => Effect.Effect<string | undefined, Error>
-    readonly readJson: (path: string) => Effect.Effect<unknown, Error>
-    readonly writeJson: (path: string, data: unknown, mode?: number) => Effect.Effect<void, Error>
-    readonly ensureDir: (path: string) => Effect.Effect<void, Error>
-    readonly writeWithDirs: (path: string, content: string | Uint8Array, mode?: number) => Effect.Effect<void, Error>
-    readonly readDirectoryEntries: (path: string) => Effect.Effect<DirEntry[], Error>
-    readonly findUp: (target: string, start: string, stop?: string) => Effect.Effect<string[], Error>
-    readonly up: (options: { targets: string[]; start: string; stop?: string }) => Effect.Effect<string[], Error>
-    readonly globUp: (pattern: string, start: string, stop?: string) => Effect.Effect<string[], Error>
-    readonly glob: (pattern: string, options?: Glob.Options) => Effect.Effect<string[], Error>
-    readonly globMatch: (pattern: string, filepath: string) => boolean
-  }
+export class BinaryContent extends Schema.Class<BinaryContent>("LocationFileSystem.BinaryContent")({
+  type: Schema.Literal("binary"),
+  content: Schema.String,
+  encoding: Schema.Literal("base64"),
+  mime: Schema.String,
+}) {}

-  export class Service extends Context.Service<Service, Interface>()("@opencode/FileSystem") {}
+export const Content = Schema.Union([TextContent, BinaryContent]).pipe(Schema.toTaggedUnion("type"))
+export type Content = typeof Content.Type

-  export const use = serviceUse(Service)
+export const ListInput = Schema.Struct({
+  path: RelativePath.pipe(Schema.optional),
+  reference: Schema.String.pipe(Schema.optional),
+})
+export type ListInput = typeof ListInput.Type

-  export const layer = Layer.effect(
-    Service,
-    Effect.gen(function* () {
-      const fs = yield* FileSystem.FileSystem
+export class Entry extends Schema.Class<Entry>("LocationFileSystem.Entry")({
+  path: RelativePath,
+  uri: Schema.String,
+  type: Schema.Literals(["file", "directory"]),
+  mime: Schema.String,
+}) {}

-      const existsSafe = Effect.fn("FileSystem.existsSafe")(function* (path: string) {
-        return yield* fs.exists(path).pipe(Effect.orElseSucceed(() => false))
+export const FindInput = Schema.Struct({
+  query: Schema.String,
+  type: Schema.Literals(["file", "directory"]).pipe(Schema.optional),
+  limit: PositiveInt.pipe(Schema.optional),
+})
+export type FindInput = typeof FindInput.Type
+
+export const GrepInput = Schema.Struct({
+  pattern: Schema.String,
+  include: Schema.String.pipe(Schema.optional),
+  limit: PositiveInt.pipe(Schema.optional),
+})
+export type GrepInput = typeof GrepInput.Type
+
+export class GrepMatch extends Schema.Class<GrepMatch>("LocationFileSystem.GrepMatch")({
+  path: RelativePath,
+  lines: Schema.String,
+  line: PositiveInt,
+  offset: NonNegativeInt,
+  submatches: Schema.Array(
+    Schema.Struct({
+      text: Schema.String,
+      start: NonNegativeInt,
+      end: NonNegativeInt,
+    }),
+  ),
+}) {}
+
+export const Event = {
+  Edited: EventV2.define({
+    type: "file.edited",
+    schema: {
+      file: Schema.String,
+    },
+  }),
+}
+
+export interface Interface {
+  readonly read: (input: ReadInput) => Effect.Effect<Content>
+  readonly list: (input?: ListInput) => Effect.Effect<Entry[]>
+  readonly find: (input: FindInput) => Effect.Effect<Entry[]>
+  readonly grep: (input: GrepInput) => Effect.Effect<GrepMatch[]>
+  readonly isIgnored: (path: RelativePath, type: "file" | "directory") => boolean
+}
+
+export class Service extends Context.Service<Service, Interface>()("@opencode/v2/FileSystem") {}
+
+export const layer = Layer.effect(
+  Service,
+  Effect.gen(function* () {
+    const fs = yield* FSUtil.Service
+    const location = yield* Location.Service
+    const references = yield* ProjectReference.Service
+    const ripgrep = yield* Ripgrep.Service
+    const root = yield* fs.realPath(location.directory).pipe(Effect.orDie)
+    const ignored = ignore()
+    const gitignore = yield* fs
+      .readFileString(path.join(location.project.directory, ".gitignore"))
+      .pipe(Effect.catch(() => Effect.succeed("")))
+    if (gitignore) ignored.add(gitignore)
+    const ignorefile = yield* fs
+      .readFileString(path.join(location.project.directory, ".ignore"))
+      .pipe(Effect.catch(() => Effect.succeed("")))
+    if (ignorefile) ignored.add(ignorefile)
+    const select = Effect.fnUntraced(function* (reference?: string) {
+      if (!reference) return { directory: location.directory, root }
+      const resolved = yield* references.get(reference)
+      if (!resolved) return yield* Effect.die(new Error(`Unknown project reference: ${reference}`))
+      if (resolved.kind === "invalid") return yield* Effect.die(new Error(resolved.message))
+      if (resolved.kind === "git") yield* references.ensurePath(resolved.path).pipe(Effect.orDie)
+      return { directory: resolved.path, root: yield* fs.realPath(resolved.path).pipe(Effect.orDie) }
+    })
+    const resolve = Effect.fnUntraced(function* (input?: RelativePath, reference?: string) {
+      if (input && path.isAbsolute(input)) return yield* Effect.die(new Error("Path must be relative to the location"))
+      const selected = yield* select(reference)
+      const absolute = path.resolve(selected.directory, input ?? ".")
+      if (!FSUtil.contains(selected.directory, absolute))
+        return yield* Effect.die(new Error("Path escapes the location"))
+      const real = yield* fs.realPath(absolute).pipe(Effect.orDie)
+      if (!FSUtil.contains(selected.root, real)) return yield* Effect.die(new Error("Path escapes the location"))
+      return { absolute, real, ...selected }
+    })
+    const entry = Effect.fnUntraced(function* (absolute: string, selected = { directory: location.directory, root }) {
+      const real = yield* fs.realPath(absolute).pipe(Effect.catch(() => Effect.void))
+      if (!real) return
+      if (!FSUtil.contains(selected.root, real)) return
+      const info = yield* fs.stat(real).pipe(Effect.catch(() => Effect.void))
+      if (!info) return
+      const type = info.type === "Directory" ? "directory" : info.type === "File" ? "file" : undefined
+      if (!type) return
+      return new Entry({
+        path: RelativePath.make(path.relative(selected.directory, absolute)),
+        uri: pathToFileURL(real).href,
+        type,
+        mime: type === "directory" ? "application/x-directory" : FSUtil.mimeType(real),
      })
+    })

-      const readFileStringSafe = Effect.fn("FileSystem.readFileStringSafe")(function* (path: string) {
-        return yield* fs
-          .readFileString(path)
-          .pipe(Effect.catchReason("PlatformError", "NotFound", () => Effect.succeed(undefined)))
-      })
+    const scan = Effect.fnUntraced(function* () {
+      if (location.directory === Global.Path.home && location.project.id === "global") {
+        const protectedNames = Protected.names()
+        const nested = new Set(["node_modules", "dist", "build", "target", "vendor"])
+        return (yield* Effect.forEach(
+          yield* fs.readDirectoryEntries(location.directory).pipe(Effect.orElseSucceed(() => [])),
+          (item) =>
+            Effect.gen(function* () {
+              if (item.type !== "directory" || item.name.startsWith(".") || protectedNames.has(item.name)) return []
+              const directory = path.join(location.directory, item.name)
+              return [
+                item.name + "/",
+                ...(yield* fs.readDirectoryEntries(directory).pipe(Effect.orElseSucceed(() => []))).flatMap((child) =>
+                  child.type === "directory" && !child.name.startsWith(".") && !nested.has(child.name)
+                    ? [`${item.name}/${child.name}/`]
+                    : [],
+                ),
+              ]
+            }),
+        )).flat()
+      }

-      const isDir = Effect.fn("FileSystem.isDir")(function* (path: string) {
-        const info = yield* fs.stat(path).pipe(Effect.catch(() => Effect.void))
-        return info?.type === "Directory"
-      })
+      const files = Array.from(yield* ripgrep.files({ cwd: location.directory }).pipe(Stream.runCollect, Effect.orDie))
+      const dirs = new Set<string>()
+      for (const file of files) {
+        let current = file
+        while (true) {
+          const directory = path.dirname(current)
+          if (directory === "." || directory === current) break
+          current = directory
+          dirs.add(directory + "/")
+        }
+      }
+      return [...files, ...dirs]
+    })

-      const isFile = Effect.fn("FileSystem.isFile")(function* (path: string) {
-        const info = yield* fs.stat(path).pipe(Effect.catch(() => Effect.void))
-        return info?.type === "File"
-      })
-
-      const readDirectoryEntries = Effect.fn("FileSystem.readDirectoryEntries")(function* (dirPath: string) {
-        return yield* Effect.tryPromise({
-          try: async () => {
-            const entries = await NFS.readdir(dirPath, { withFileTypes: true })
-            return entries.map(
-              (e): DirEntry => ({
-                name: e.name,
-                type: e.isDirectory() ? "directory" : e.isSymbolicLink() ? "symlink" : e.isFile() ? "file" : "other",
-              }),
-            )
-          },
-          catch: (cause) => new FileSystemError({ method: "readDirectoryEntries", cause }),
+    return Service.of({
+      read: Effect.fn("FileSystem.read")(function* (input) {
+        const file = yield* resolve(input.path, input.reference)
+        const info = yield* fs.stat(file.real).pipe(Effect.orDie)
+        if (info.type !== "File") return yield* Effect.die(new Error("Path is not a file"))
+        const bytes = yield* fs.readFile(file.real).pipe(Effect.orDie)
+        const mime = FSUtil.mimeType(file.real)
+        if (!bytes.includes(0)) {
+          const content = yield* Effect.sync(() => new TextDecoder("utf-8", { fatal: true }).decode(bytes)).pipe(
+            Effect.option,
+          )
+          if (content._tag === "Some") return new TextContent({ type: "text", content: content.value, mime })
+        }
+        return new BinaryContent({
+          type: "binary",
+          content: Buffer.from(bytes).toString("base64"),
+          encoding: "base64",
+          mime,
        })
-      })
-
-      const readJson = Effect.fn("FileSystem.readJson")(function* (path: string) {
-        const text = yield* fs.readFileString(path)
-        return JSON.parse(text)
-      })
-
-      const writeJson = Effect.fn("FileSystem.writeJson")(function* (path: string, data: unknown, mode?: number) {
-        const content = JSON.stringify(data, null, 2)
-        yield* fs.writeFileString(path, content)
-        if (mode) yield* fs.chmod(path, mode)
-      })
-
-      const ensureDir = Effect.fn("FileSystem.ensureDir")(function* (path: string) {
-        yield* fs.makeDirectory(path, { recursive: true })
-      })
-
-      const writeWithDirs = Effect.fn("FileSystem.writeWithDirs")(function* (
-        path: string,
-        content: string | Uint8Array,
-        mode?: number,
-      ) {
-        const write = typeof content === "string" ? fs.writeFileString(path, content) : fs.writeFile(path, content)
-
-        yield* write.pipe(
-          Effect.catchIf(
-            (e) => e.reason._tag === "NotFound",
-            () =>
-              Effect.gen(function* () {
-                yield* fs.makeDirectory(dirname(path), { recursive: true })
-                yield* write
-              }),
+      }),
+      list: Effect.fn("FileSystem.list")(function* (input = {}) {
+        const directory = yield* resolve(input.path, input.reference)
+        const info = yield* fs.stat(directory.real).pipe(Effect.orDie)
+        if (info.type !== "Directory") return yield* Effect.die(new Error("Path is not a directory"))
+        return yield* fs.readDirectoryEntries(directory.real).pipe(
+          Effect.orDie,
+          Effect.flatMap((items) =>
+            Effect.forEach(items, (item) => entry(path.join(directory.absolute, item.name), directory), {
+              concurrency: "unbounded",
+            }),
+          ),
+          Effect.map((items) =>
+            items
+              .filter((item): item is Entry => item !== undefined)
+              .sort((a, b) => (a.type === b.type ? a.path.localeCompare(b.path) : a.type === "directory" ? -1 : 1)),
          ),
        )
-        if (mode) yield* fs.chmod(path, mode)
-      })
+      }),
+      find: Effect.fn("FileSystem.find")(function* (input) {
+        const items = (yield* scan()).filter((item) => input.type !== "file" || !item.endsWith("/"))
+        const filtered = items.filter((item) => input.type !== "directory" || item.endsWith("/"))
+        const sorted = input.query.trim()
+          ? fuzzysort.go(input.query.trim(), filtered, { limit: input.limit ?? 100 }).map((item) => item.target)
+          : filtered.slice(0, input.limit)
+        return yield* Effect.forEach(sorted, (item) => entry(path.join(location.directory, item))).pipe(
+          Effect.map((items) => items.filter((item): item is Entry => item !== undefined)),
+        )
+      }),
+      grep: Effect.fn("FileSystem.grep")(function* (input) {
+        return (yield* ripgrep
+          .search({
+            cwd: location.directory,
+            pattern: input.pattern,
+            glob: input.include ? [input.include] : undefined,
+            limit: input.limit,
+          })
+          .pipe(Effect.orDie)).items.map(
+          (item) =>
+            new GrepMatch({
+              path: RelativePath.make(item.path.text),
+              lines: item.lines.text,
+              line: item.line_number,
+              offset: item.absolute_offset,
+              submatches: item.submatches.map((submatch) => ({
+                text: submatch.match.text,
+                start: submatch.start,
+                end: submatch.end,
+              })),
+            }),
+        )
+      }),
+      isIgnored: (input, type) =>
+        ignored.ignores(
+          path.relative(location.project.directory, path.join(location.directory, input)) +
+            (type === "directory" ? "/" : ""),
+        ),
+    })
+  }),
+)

-      const glob = Effect.fn("FileSystem.glob")(function* (pattern: string, options?: Glob.Options) {
-        return yield* Effect.tryPromise({
-          try: () => Glob.scan(pattern, options),
-          catch: (cause) => new FileSystemError({ method: "glob", cause }),
-        })
-      })
-
-      const findUp = Effect.fn("FileSystem.findUp")(function* (target: string, start: string, stop?: string) {
-        const result: string[] = []
-        let current = start
-        while (true) {
-          const search = join(current, target)
-          if (yield* fs.exists(search)) result.push(search)
-          if (stop === current) break
-          const parent = dirname(current)
-          if (parent === current) break
-          current = parent
-        }
-        return result
-      })
-
-      const up = Effect.fn("FileSystem.up")(function* (options: { targets: string[]; start: string; stop?: string }) {
-        const result: string[] = []
-        let current = options.start
-        while (true) {
-          for (const target of options.targets) {
-            const search = join(current, target)
-            if (yield* fs.exists(search)) result.push(search)
-          }
-          if (options.stop === current) break
-          const parent = dirname(current)
-          if (parent === current) break
-          current = parent
-        }
-        return result
-      })
-
-      const globUp = Effect.fn("FileSystem.globUp")(function* (pattern: string, start: string, stop?: string) {
-        const result: string[] = []
-        let current = start
-        while (true) {
-          const matches = yield* glob(pattern, { cwd: current, absolute: true, include: "file", dot: true }).pipe(
-            Effect.catch(() => Effect.succeed([] as string[])),
-          )
-          result.push(...matches)
-          if (stop === current) break
-          const parent = dirname(current)
-          if (parent === current) break
-          current = parent
-        }
-        return result
-      })
-
-      return Service.of({
-        ...fs,
-        existsSafe,
-        readFileStringSafe,
-        isDir,
-        isFile,
-        readDirectoryEntries,
-        readJson,
-        writeJson,
-        ensureDir,
-        writeWithDirs,
-        findUp,
-        up,
-        globUp,
-        glob,
-        globMatch: Glob.match,
-      })
-    }),
-  )
-
-  export const defaultLayer = layer.pipe(Layer.provide(NodeFileSystem.layer))
-
-  // Pure helpers that don't need Effect (path manipulation, sync operations)
-  export function mimeType(p: string): string {
-    return lookup(p) || "application/octet-stream"
-  }
-
-  export function normalizePath(p: string): string {
-    if (process.platform !== "win32") return p
-    const resolved = pathResolve(windowsPath(p))
-    try {
-      return realpathSync.native(resolved)
-    } catch {
-      return resolved
-    }
-  }
-
-  export function normalizePathPattern(p: string): string {
-    if (process.platform !== "win32") return p
-    if (p === "*") return p
-    const match = p.match(/^(.*)[\\/]\*$/)
-    if (!match) return normalizePath(p)
-    const dir = /^[A-Za-z]:$/.test(match[1]) ? match[1] + "\\" : match[1]
-    return join(normalizePath(dir), "*")
-  }
-
-  export function resolve(p: string): string {
-    const resolved = pathResolve(windowsPath(p))
-    try {
-      return normalizePath(realpathSync(resolved))
-    } catch (e: any) {
-      if (e?.code === "ENOENT") return normalizePath(resolved)
-      throw e
-    }
-  }
-
-  export function windowsPath(p: string): string {
-    if (process.platform !== "win32") return p
-    return p
-      .replace(/^\/([a-zA-Z]):(?:[\\/]|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
-      .replace(/^\/([a-zA-Z])(?:\/|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
-      .replace(/^\/cygdrive\/([a-zA-Z])(?:\/|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
-      .replace(/^\/mnt\/([a-zA-Z])(?:\/|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
-  }
-
-  export function overlaps(a: string, b: string) {
-    const relA = relative(a, b)
-    const relB = relative(b, a)
-    return !relA || !relA.startsWith("..") || !relB || !relB.startsWith("..")
-  }
-
-  export function contains(parent: string, child: string) {
-    return !relative(parent, child).startsWith("..")
-  }
-}
+export const locationLayer = layer.pipe(
+  Layer.provide(Ripgrep.defaultLayer),
+  Layer.provideMerge(ProjectReference.locationLayer),
+)
--- a/packages/core/src/filesystem/ignore.ts
+++ b/packages/core/src/filesystem/ignore.ts
@@ -0,0 +1,67 @@
+import { Glob } from "../util/glob"
+
+const FOLDERS = new Set([
+  "node_modules",
+  "bower_components",
+  ".pnpm-store",
+  "vendor",
+  ".npm",
+  "dist",
+  "build",
+  "out",
+  ".next",
+  "target",
+  "bin",
+  "obj",
+  ".git",
+  ".svn",
+  ".hg",
+  ".vscode",
+  ".idea",
+  ".turbo",
+  ".output",
+  "desktop",
+  ".sst",
+  ".cache",
+  ".webkit-cache",
+  "__pycache__",
+  ".pytest_cache",
+  "mypy_cache",
+  ".history",
+  ".gradle",
+])
+
+const FILES = [
+  "**/*.swp",
+  "**/*.swo",
+  "**/*.pyc",
+  "**/.DS_Store",
+  "**/Thumbs.db",
+  "**/logs/**",
+  "**/tmp/**",
+  "**/temp/**",
+  "**/*.log",
+  "**/coverage/**",
+  "**/.nyc_output/**",
+]
+
+export const PATTERNS = [...FILES, ...FOLDERS]
+
+export function match(filepath: string, opts?: { extra?: string[]; whitelist?: string[] }) {
+  for (const pattern of opts?.whitelist || []) {
+    if (Glob.match(pattern, filepath)) return false
+  }
+
+  const parts = filepath.split(/[/\\]/)
+  for (const part of parts) {
+    if (FOLDERS.has(part)) return true
+  }
+
+  for (const pattern of [...FILES, ...(opts?.extra || [])]) {
+    if (Glob.match(pattern, filepath)) return true
+  }
+
+  return false
+}
+
+export * as Ignore from "./ignore"
--- a/packages/core/src/filesystem/protected.ts
+++ b/packages/core/src/filesystem/protected.ts
@@ -0,0 +1,53 @@
+import os from "os"
+import path from "path"
+
+const home = os.homedir()
+
+const DARWIN_HOME = [
+  "Music",
+  "Pictures",
+  "Movies",
+  "Downloads",
+  "Desktop",
+  "Documents",
+  "Public",
+  "Applications",
+  "Library",
+]
+
+const DARWIN_LIBRARY = [
+  "Application Support/AddressBook",
+  "Calendars",
+  "Mail",
+  "Messages",
+  "Safari",
+  "Cookies",
+  "Application Support/com.apple.TCC",
+  "PersonalizationPortrait",
+  "Metadata/CoreSpotlight",
+  "Suggestions",
+]
+
+const DARWIN_ROOT = ["/.DocumentRevisions-V100", "/.Spotlight-V100", "/.Trashes", "/.fseventsd"]
+const WIN32_HOME = ["AppData", "Downloads", "Desktop", "Documents", "Pictures", "Music", "Videos", "OneDrive"]
+
+/** Directory basenames to skip when scanning the home directory. */
+export function names(): ReadonlySet<string> {
+  if (process.platform === "darwin") return new Set(DARWIN_HOME)
+  if (process.platform === "win32") return new Set(WIN32_HOME)
+  return new Set()
+}
+
+/** Absolute paths that should never be watched, stated, or scanned. */
+export function paths(): string[] {
+  if (process.platform === "darwin")
+    return [
+      ...DARWIN_HOME.map((name) => path.join(home, name)),
+      ...DARWIN_LIBRARY.map((name) => path.join(home, "Library", name)),
+      ...DARWIN_ROOT,
+    ]
+  if (process.platform === "win32") return WIN32_HOME.map((name) => path.join(home, name))
+  return []
+}
+
+export * as Protected from "./protected"
--- a/packages/core/src/filesystem/ripgrep.ts
+++ b/packages/core/src/filesystem/ripgrep.ts
@@ -0,0 +1,484 @@
+import path from "path"
+import { serviceUse } from "../effect/service-use"
+import { FSUtil } from "../fs-util"
+import { Cause, Context, Effect, Fiber, Layer, Queue, Schema, Stream } from "effect"
+import type { PlatformError } from "effect/PlatformError"
+import { FetchHttpClient, HttpClient, HttpClientRequest } from "effect/unstable/http"
+import { ChildProcess } from "effect/unstable/process"
+import { ChildProcessSpawner } from "effect/unstable/process/ChildProcessSpawner"
+
+import { CrossSpawnSpawner } from "../cross-spawn-spawner"
+import { Global } from "../global"
+import { NonNegativeInt } from "../schema"
+import * as Log from "../util/log"
+import { sanitizedProcessEnv } from "../util/opencode-process"
+import { which } from "../util/which"
+
+const log = Log.create({ service: "ripgrep" })
+const VERSION = "15.1.0"
+const PLATFORM = {
+  "arm64-darwin": { platform: "aarch64-apple-darwin", extension: "tar.gz" },
+  "arm64-linux": { platform: "aarch64-unknown-linux-gnu", extension: "tar.gz" },
+  "x64-darwin": { platform: "x86_64-apple-darwin", extension: "tar.gz" },
+  "x64-linux": { platform: "x86_64-unknown-linux-musl", extension: "tar.gz" },
+  "arm64-win32": { platform: "aarch64-pc-windows-msvc", extension: "zip" },
+  "ia32-win32": { platform: "i686-pc-windows-msvc", extension: "zip" },
+  "x64-win32": { platform: "x86_64-pc-windows-msvc", extension: "zip" },
+} as const
+
+const TimeStats = Schema.Struct({
+  secs: NonNegativeInt,
+  nanos: NonNegativeInt,
+  human: Schema.String,
+})
+
+const Stats = Schema.Struct({
+  elapsed: TimeStats,
+  searches: NonNegativeInt,
+  searches_with_match: NonNegativeInt,
+  bytes_searched: NonNegativeInt,
+  bytes_printed: NonNegativeInt,
+  matched_lines: NonNegativeInt,
+  matches: NonNegativeInt,
+})
+
+const PathText = Schema.Struct({
+  text: Schema.String,
+})
+
+const Begin = Schema.Struct({
+  type: Schema.Literal("begin"),
+  data: Schema.Struct({
+    path: PathText,
+  }),
+})
+
+export const SearchMatch = Schema.Struct({
+  path: PathText,
+  lines: Schema.Struct({
+    text: Schema.String,
+  }),
+  line_number: NonNegativeInt,
+  absolute_offset: NonNegativeInt,
+  submatches: Schema.Array(
+    Schema.Struct({
+      match: Schema.Struct({
+        text: Schema.String,
+      }),
+      start: NonNegativeInt,
+      end: NonNegativeInt,
+    }),
+  ),
+})
+
+export const Match = Schema.Struct({
+  type: Schema.Literal("match"),
+  data: SearchMatch,
+})
+
+const End = Schema.Struct({
+  type: Schema.Literal("end"),
+  data: Schema.Struct({
+    path: PathText,
+    binary_offset: Schema.NullOr(NonNegativeInt),
+    stats: Stats,
+  }),
+})
+
+const Summary = Schema.Struct({
+  type: Schema.Literal("summary"),
+  data: Schema.Struct({
+    elapsed_total: TimeStats,
+    stats: Stats,
+  }),
+})
+
+const Result = Schema.Union([Begin, Match, End, Summary])
+const decodeResult = Schema.decodeUnknownEffect(Schema.fromJsonString(Result))
+
+export type Result = Schema.Schema.Type<typeof Result>
+export type Match = Schema.Schema.Type<typeof Match>
+export type Item = Match["data"]
+export type Begin = Schema.Schema.Type<typeof Begin>
+export type End = Schema.Schema.Type<typeof End>
+export type Summary = Schema.Schema.Type<typeof Summary>
+export type Row = Match["data"]
+
+export interface SearchResult {
+  items: Item[]
+  partial: boolean
+}
+
+export interface FilesInput {
+  cwd: string
+  glob?: string[]
+  hidden?: boolean
+  follow?: boolean
+  maxDepth?: number
+  signal?: AbortSignal
+}
+
+export interface SearchInput {
+  cwd: string
+  pattern: string
+  glob?: string[]
+  limit?: number
+  follow?: boolean
+  file?: string[]
+  signal?: AbortSignal
+}
+
+export interface TreeInput {
+  cwd: string
+  limit?: number
+  signal?: AbortSignal
+}
+
+export interface Interface {
+  readonly files: (input: FilesInput) => Stream.Stream<string, PlatformError | Error>
+  readonly tree: (input: TreeInput) => Effect.Effect<string, PlatformError | Error>
+  readonly search: (input: SearchInput) => Effect.Effect<SearchResult, PlatformError | Error>
+}
+
+export class Service extends Context.Service<Service, Interface>()("@opencode/Ripgrep") {}
+
+export const use = serviceUse(Service)
+
+function env() {
+  const env = sanitizedProcessEnv()
+  delete env.RIPGREP_CONFIG_PATH
+  return env
+}
+
+function aborted(signal?: AbortSignal) {
+  const err = signal?.reason
+  if (err instanceof Error) return err
+  const out = new Error("Aborted")
+  out.name = "AbortError"
+  return out
+}
+
+function waitForAbort(signal?: AbortSignal) {
+  if (!signal) return Effect.never
+  if (signal.aborted) return Effect.fail(aborted(signal))
+  return Effect.callback<never, Error>((resume) => {
+    const onabort = () => resume(Effect.fail(aborted(signal)))
+    signal.addEventListener("abort", onabort, { once: true })
+    return Effect.sync(() => signal.removeEventListener("abort", onabort))
+  })
+}
+
+function error(stderr: string, code: number) {
+  const err = new Error(stderr.trim() || `ripgrep failed with code ${code}`)
+  err.name = "RipgrepError"
+  return err
+}
+
+function clean(file: string) {
+  return path.normalize(file.replace(/^\.[\\/]/, ""))
+}
+
+function row(data: Row): Row {
+  return {
+    ...data,
+    path: {
+      ...data.path,
+      text: clean(data.path.text),
+    },
+  }
+}
+
+function parse(line: string) {
+  return decodeResult(line).pipe(Effect.mapError((cause) => new Error("invalid ripgrep output", { cause })))
+}
+
+function fail(queue: Queue.Queue<string, PlatformError | Error | Cause.Done>, err: PlatformError | Error) {
+  Queue.failCauseUnsafe(queue, Cause.fail(err))
+}
+
+function filesArgs(input: FilesInput) {
+  const args = ["--no-config", "--files", "--glob=!.git/*"]
+  if (input.follow) args.push("--follow")
+  if (input.hidden !== false) args.push("--hidden")
+  if (input.hidden === false) args.push("--glob=!.*")
+  if (input.maxDepth !== undefined) args.push(`--max-depth=${input.maxDepth}`)
+  if (input.glob) {
+    for (const glob of input.glob) args.push(`--glob=${glob}`)
+  }
+  args.push(".")
+  return args
+}
+
+function searchArgs(input: SearchInput) {
+  const args = ["--no-config", "--json", "--hidden", "--glob=!.git/*", "--no-messages"]
+  if (input.follow) args.push("--follow")
+  if (input.glob) {
+    for (const glob of input.glob) args.push(`--glob=${glob}`)
+  }
+  if (input.limit) args.push(`--max-count=${input.limit}`)
+  args.push("--", input.pattern, ...(input.file ?? ["."]))
+  return args
+}
+
+function raceAbort<A, E, R>(effect: Effect.Effect<A, E, R>, signal?: AbortSignal) {
+  return signal ? effect.pipe(Effect.raceFirst(waitForAbort(signal))) : effect
+}
+
+export const layer: Layer.Layer<Service, never, FSUtil.Service | ChildProcessSpawner | HttpClient.HttpClient> =
+  Layer.effect(
+    Service,
+    Effect.gen(function* () {
+      const fs = yield* FSUtil.Service
+      const http = HttpClient.filterStatusOk(yield* HttpClient.HttpClient)
+      const spawner = yield* ChildProcessSpawner
+
+      const run = Effect.fnUntraced(function* (command: string, args: string[], opts?: { cwd?: string }) {
+        const handle = yield* spawner.spawn(
+          ChildProcess.make(command, args, { cwd: opts?.cwd, extendEnv: true, stdin: "ignore" }),
+        )
+        const [stdout, stderr, code] = yield* Effect.all(
+          [
+            Stream.mkString(Stream.decodeText(handle.stdout)),
+            Stream.mkString(Stream.decodeText(handle.stderr)),
+            handle.exitCode,
+          ],
+          { concurrency: "unbounded" },
+        )
+        return { stdout, stderr, code }
+      }, Effect.scoped)
+
+      const extract = Effect.fnUntraced(function* (
+        archive: string,
+        config: (typeof PLATFORM)[keyof typeof PLATFORM],
+        target: string,
+      ) {
+        const dir = yield* fs.makeTempDirectoryScoped({ directory: Global.Path.bin, prefix: "ripgrep-" })
+
+        if (config.extension === "zip") {
+          const shell = (yield* Effect.sync(() => which("powershell.exe") ?? which("pwsh.exe"))) ?? "powershell.exe"
+          const result = yield* run(shell, [
+            "-NoProfile",
+            "-NonInteractive",
+            "-Command",
+            `$global:ProgressPreference = 'SilentlyContinue'; Expand-Archive -LiteralPath '${archive.replaceAll("'", "''")}' -DestinationPath '${dir.replaceAll("'", "''")}' -Force`,
+          ])
+          if (result.code !== 0) {
+            return yield* Effect.fail(error(result.stderr || result.stdout, result.code))
+          }
+        }
+
+        if (config.extension === "tar.gz") {
+          const result = yield* run("tar", ["-xzf", archive, "-C", dir])
+          if (result.code !== 0) {
+            return yield* Effect.fail(error(result.stderr || result.stdout, result.code))
+          }
+        }
+
+        const extracted = path.join(
+          dir,
+          `ripgrep-${VERSION}-${config.platform}`,
+          process.platform === "win32" ? "rg.exe" : "rg",
+        )
+        if (!(yield* fs.isFile(extracted))) {
+          return yield* Effect.fail(new Error(`ripgrep archive did not contain executable: ${extracted}`))
+        }
+
+        yield* fs.copyFile(extracted, target)
+        if (process.platform === "win32") return
+        yield* fs.chmod(target, 0o755)
+      }, Effect.scoped)
+
+      const filepath = yield* Effect.cached(
+        Effect.gen(function* () {
+          const system = yield* Effect.sync(() => which(process.platform === "win32" ? "rg.exe" : "rg"))
+          if (system && (yield* fs.isFile(system).pipe(Effect.orDie))) return system
+
+          const target = path.join(Global.Path.bin, `rg${process.platform === "win32" ? ".exe" : ""}`)
+          if (yield* fs.isFile(target).pipe(Effect.orDie)) return target
+
+          const platformKey = `${process.arch}-${process.platform}` as keyof typeof PLATFORM
+          const config = PLATFORM[platformKey]
+          if (!config) {
+            return yield* Effect.fail(new Error(`unsupported platform for ripgrep: ${platformKey}`))
+          }
+
+          const filename = `ripgrep-${VERSION}-${config.platform}.${config.extension}`
+          const url = `https://github.com/BurntSushi/ripgrep/releases/download/${VERSION}/${filename}`
+          const archive = path.join(Global.Path.bin, filename)
+
+          log.info("downloading ripgrep", { url })
+          yield* fs.ensureDir(Global.Path.bin).pipe(Effect.orDie)
+
+          const bytes = yield* HttpClientRequest.get(url).pipe(
+            http.execute,
+            Effect.flatMap((response) => response.arrayBuffer),
+            Effect.mapError((cause) => (cause instanceof Error ? cause : new Error(String(cause)))),
+          )
+          if (bytes.byteLength === 0) {
+            return yield* Effect.fail(new Error(`failed to download ripgrep from ${url}`))
+          }
+
+          yield* fs.writeWithDirs(archive, new Uint8Array(bytes))
+          yield* extract(archive, config, target)
+          yield* fs.remove(archive, { force: true }).pipe(Effect.ignore)
+          return target
+        }),
+      )
+
+      const check = Effect.fnUntraced(function* (cwd: string) {
+        if (yield* fs.isDir(cwd).pipe(Effect.orDie)) return
+        return yield* Effect.fail(
+          Object.assign(new Error(`No such file or directory: '${cwd}'`), {
+            code: "ENOENT",
+            errno: -2,
+            path: cwd,
+          }),
+        )
+      })
+
+      const command = Effect.fnUntraced(function* (cwd: string, args: string[]) {
+        const binary = yield* filepath
+        return ChildProcess.make(binary, args, {
+          cwd,
+          env: env(),
+          extendEnv: true,
+          stdin: "ignore",
+        })
+      })
+
+      const files: Interface["files"] = (input) =>
+        Stream.callback<string, PlatformError | Error>((queue) =>
+          Effect.gen(function* () {
+            yield* Effect.forkScoped(
+              Effect.gen(function* () {
+                yield* check(input.cwd)
+                const handle = yield* spawner.spawn(yield* command(input.cwd, filesArgs(input)))
+                const stderr = yield* Stream.mkString(Stream.decodeText(handle.stderr)).pipe(Effect.forkScoped)
+                const stdout = yield* Stream.decodeText(handle.stdout).pipe(
+                  Stream.splitLines,
+                  Stream.filter((line) => line.length > 0),
+                  Stream.runForEach((line) => Effect.sync(() => Queue.offerUnsafe(queue, clean(line)))),
+                  Effect.forkScoped,
+                )
+                const code = yield* raceAbort(handle.exitCode, input.signal)
+                yield* Fiber.join(stdout)
+                if (code === 0 || code === 1) {
+                  Queue.endUnsafe(queue)
+                  return
+                }
+                fail(queue, error(yield* Fiber.join(stderr), code))
+              }).pipe(
+                Effect.catch((err) =>
+                  Effect.sync(() => {
+                    fail(queue, err)
+                  }),
+                ),
+              ),
+            )
+          }),
+        )
+
+      const search: Interface["search"] = Effect.fn("Ripgrep.search")(function* (input: SearchInput) {
+        yield* check(input.cwd)
+
+        const program = Effect.scoped(
+          Effect.gen(function* () {
+            const handle = yield* spawner.spawn(yield* command(input.cwd, searchArgs(input)))
+
+            const [items, stderr, code] = yield* Effect.all(
+              [
+                Stream.decodeText(handle.stdout).pipe(
+                  Stream.splitLines,
+                  Stream.filter((line) => line.length > 0),
+                  Stream.mapEffect(parse),
+                  Stream.filter((item): item is Match => item.type === "match"),
+                  Stream.map((item) => row(item.data)),
+                  Stream.runCollect,
+                  Effect.map((chunk) => [...chunk]),
+                ),
+                Stream.mkString(Stream.decodeText(handle.stderr)),
+                handle.exitCode,
+              ],
+              { concurrency: "unbounded" },
+            )
+
+            if (code !== 0 && code !== 1 && code !== 2) {
+              return yield* Effect.fail(error(stderr, code))
+            }
+
+            return {
+              items: code === 1 ? [] : items,
+              partial: code === 2,
+            }
+          }),
+        )
+
+        return yield* raceAbort(program, input.signal)
+      })
+
+      const tree: Interface["tree"] = Effect.fn("Ripgrep.tree")(function* (input: TreeInput) {
+        log.info("tree", input)
+        const list = Array.from(yield* files({ cwd: input.cwd, signal: input.signal }).pipe(Stream.runCollect))
+
+        interface Node {
+          name: string
+          children: Map<string, Node>
+        }
+
+        function child(node: Node, name: string) {
+          const item = node.children.get(name)
+          if (item) return item
+          const next = { name, children: new Map() }
+          node.children.set(name, next)
+          return next
+        }
+
+        function count(node: Node): number {
+          return Array.from(node.children.values()).reduce((sum, child) => sum + 1 + count(child), 0)
+        }
+
+        const root: Node = { name: "", children: new Map() }
+        for (const file of list) {
+          if (file.includes(".opencode")) continue
+          const parts = file.split(path.sep)
+          if (parts.length < 2) continue
+          let node = root
+          for (const part of parts.slice(0, -1)) {
+            node = child(node, part)
+          }
+        }
+
+        const total = count(root)
+        const limit = input.limit ?? total
+        const lines: string[] = []
+        const queue: Array<{ node: Node; path: string }> = Array.from(root.children.values())
+          .sort((a, b) => a.name.localeCompare(b.name))
+          .map((node) => ({ node, path: node.name }))
+
+        let used = 0
+        for (let i = 0; i < queue.length && used < limit; i++) {
+          const item = queue[i]
+          lines.push(item.path)
+          used++
+          queue.push(
+            ...Array.from(item.node.children.values())
+              .sort((a, b) => a.name.localeCompare(b.name))
+              .map((node) => ({ node, path: `${item.path}/${node.name}` })),
+          )
+        }
+
+        if (total > used) lines.push(`[${total - used} truncated]`)
+        return lines.join("\n")
+      })
+
+      return Service.of({ files, tree, search })
+    }),
+  )
+
+export const defaultLayer = layer.pipe(
+  Layer.provide(FetchHttpClient.layer),
+  Layer.provide(FSUtil.defaultLayer),
+  Layer.provide(CrossSpawnSpawner.defaultLayer),
+)
+
+export * as Ripgrep from "./ripgrep"
--- a/packages/core/src/filesystem/watcher.ts
+++ b/packages/core/src/filesystem/watcher.ts
@@ -0,0 +1,140 @@
+export * as Watcher from "./watcher"
+
+// @ts-ignore
+import { createWrapper } from "@parcel/watcher/wrapper"
+import type ParcelWatcher from "@parcel/watcher"
+import { Cause, Context, Effect, Layer, Schema } from "effect"
+import path from "path"
+import { Config } from "../config"
+import { EventV2 } from "../event"
+import { Flag } from "../flag/flag"
+import { FSUtil } from "../fs-util"
+import { Git } from "../git"
+import { Location } from "../location"
+import { lazy } from "../util/lazy"
+import * as Log from "../util/log"
+import { Ignore } from "./ignore"
+import { Protected } from "./protected"
+
+declare const OPENCODE_LIBC: string | undefined
+
+const log = Log.create({ service: "file.watcher" })
+const SUBSCRIBE_TIMEOUT_MS = 10_000
+
+export const Event = {
+  Updated: EventV2.define({
+    type: "file.watcher.updated",
+    schema: {
+      file: Schema.String,
+      event: Schema.Literals(["add", "change", "unlink"]),
+    },
+  }),
+}
+
+const watcher = lazy((): typeof import("@parcel/watcher") | undefined => {
+  try {
+    const libc = typeof OPENCODE_LIBC === "undefined" ? undefined : OPENCODE_LIBC
+    const binding = require(
+      `@parcel/watcher-${process.platform}-${process.arch}${process.platform === "linux" ? `-${libc || "glibc"}` : ""}`,
+    )
+    return createWrapper(binding) as typeof import("@parcel/watcher")
+  } catch (error) {
+    log.error("failed to load watcher binding", { error })
+    return
+  }
+})
+
+function getBackend() {
+  if (process.platform === "win32") return "windows"
+  if (process.platform === "darwin") return "fs-events"
+  if (process.platform === "linux") return "inotify"
+}
+
+function protecteds(dir: string) {
+  return Protected.paths().filter((item) => {
+    const relative = path.relative(dir, item)
+    return relative !== "" && !relative.startsWith("..") && !path.isAbsolute(relative)
+  })
+}
+
+export const hasNativeBinding = () => !!watcher()
+
+export interface Interface {}
+
+export class Service extends Context.Service<Service, Interface>()("@opencode/v2/FileWatcher") {}
+
+export const layer = Layer.effect(
+  Service,
+  Effect.gen(function* () {
+    if (yield* Flag.OPENCODE_EXPERIMENTAL_DISABLE_FILEWATCHER) return Service.of({})
+
+    const backend = getBackend()
+    const location = yield* Location.Service
+    if (!backend) {
+      log.error("watcher backend not supported", { directory: location.directory, platform: process.platform })
+      return Service.of({})
+    }
+
+    const w = watcher()
+    if (!w) return Service.of({})
+
+    log.info("watcher backend", { directory: location.directory, platform: process.platform, backend })
+    const events = yield* EventV2.Service
+    const fs = yield* FSUtil.Service
+    const git = yield* Git.Service
+    const context = yield* Effect.context()
+    const runFork = Effect.runForkWith(context)
+    const subscriptions: ParcelWatcher.AsyncSubscription[] = []
+    yield* Effect.addFinalizer(() =>
+      Effect.promise(() => Promise.allSettled(subscriptions.map((subscription) => subscription.unsubscribe()))),
+    )
+
+    const callback: ParcelWatcher.SubscribeCallback = (_error, updates) => {
+      for (const update of updates) {
+        if (update.type === "create") runFork(events.publish(Event.Updated, { file: update.path, event: "add" }))
+        if (update.type === "update") runFork(events.publish(Event.Updated, { file: update.path, event: "change" }))
+        if (update.type === "delete") runFork(events.publish(Event.Updated, { file: update.path, event: "unlink" }))
+      }
+    }
+
+    const subscribe = (directory: string, ignore: string[]) => {
+      const pending = w.subscribe(directory, callback, { ignore, backend })
+      return Effect.promise(() => pending).pipe(
+        Effect.tap((subscription) => Effect.sync(() => subscriptions.push(subscription))),
+        Effect.timeout(SUBSCRIBE_TIMEOUT_MS),
+        Effect.catchCause((cause) => {
+          log.error("failed to subscribe", { directory, cause: Cause.pretty(cause) })
+          pending.then((subscription) => subscription.unsubscribe()).catch(() => {})
+          return Effect.void
+        }),
+      )
+    }
+
+    const config = (yield* (yield* Config.Service).get()).flatMap((item) => item.info.watcher?.ignore ?? [])
+    if (yield* Flag.OPENCODE_EXPERIMENTAL_FILEWATCHER) {
+      yield* Effect.forkScoped(
+        subscribe(location.directory, [...Ignore.PATTERNS, ...config, ...protecteds(location.directory)]),
+      )
+    }
+
+    if (location.vcs?.type === "git") {
+      const resolved = yield* git.dir(location.directory)
+      const vcs = resolved ? yield* fs.realPath(resolved).pipe(Effect.catch(() => Effect.succeed(resolved))) : undefined
+      if (vcs && !config.includes(".git") && !config.includes(vcs) && (!resolved || !config.includes(resolved))) {
+        const ignore = (yield* fs.readDirectoryEntries(vcs).pipe(Effect.catch(() => Effect.succeed([])))).flatMap(
+          (entry) => (entry.name === "HEAD" ? [] : [entry.name]),
+        )
+        yield* Effect.forkScoped(subscribe(vcs, ignore))
+      }
+    }
+
+    return Service.of({})
+  }).pipe(
+    Effect.catchCause((cause) => {
+      log.error("failed to init watcher service", { cause: Cause.pretty(cause) })
+      return Effect.succeed(Service.of({}))
+    }),
+  ),
+)
+
+export const locationLayer = layer.pipe(Layer.provide(Config.locationLayer), Layer.provide(Git.defaultLayer))
--- a/packages/core/src/fs-util.ts
+++ b/packages/core/src/fs-util.ts
@@ -0,0 +1,247 @@
+import { NodeFileSystem } from "@effect/platform-node"
+import { dirname, join, relative, resolve as pathResolve } from "path"
+import { realpathSync } from "fs"
+import * as NFS from "fs/promises"
+import { lookup } from "mime-types"
+import { Context, Effect, FileSystem, Layer, Schema } from "effect"
+import type { PlatformError } from "effect/PlatformError"
+import { Glob } from "./util/glob"
+import { serviceUse } from "./effect/service-use"
+
+export namespace FSUtil {
+  export class FileSystemError extends Schema.TaggedErrorClass<FileSystemError>()("FileSystemError", {
+    method: Schema.String,
+    cause: Schema.optional(Schema.Defect),
+  }) {}
+
+  export type Error = PlatformError | FileSystemError
+
+  export interface DirEntry {
+    readonly name: string
+    readonly type: "file" | "directory" | "symlink" | "other"
+  }
+
+  export interface Interface extends FileSystem.FileSystem {
+    readonly isDir: (path: string) => Effect.Effect<boolean>
+    readonly isFile: (path: string) => Effect.Effect<boolean>
+    readonly existsSafe: (path: string) => Effect.Effect<boolean>
+    readonly readFileStringSafe: (path: string) => Effect.Effect<string | undefined, Error>
+    readonly readJson: (path: string) => Effect.Effect<unknown, Error>
+    readonly writeJson: (path: string, data: unknown, mode?: number) => Effect.Effect<void, Error>
+    readonly ensureDir: (path: string) => Effect.Effect<void, Error>
+    readonly writeWithDirs: (path: string, content: string | Uint8Array, mode?: number) => Effect.Effect<void, Error>
+    readonly readDirectoryEntries: (path: string) => Effect.Effect<DirEntry[], Error>
+    readonly findUp: (target: string, start: string, stop?: string) => Effect.Effect<string[], Error>
+    readonly up: (options: { targets: string[]; start: string; stop?: string }) => Effect.Effect<string[], Error>
+    readonly globUp: (pattern: string, start: string, stop?: string) => Effect.Effect<string[], Error>
+    readonly glob: (pattern: string, options?: Glob.Options) => Effect.Effect<string[], Error>
+    readonly globMatch: (pattern: string, filepath: string) => boolean
+  }
+
+  export class Service extends Context.Service<Service, Interface>()("@opencode/FileSystem") {}
+
+  export const use = serviceUse(Service)
+
+  export const layer = Layer.effect(
+    Service,
+    Effect.gen(function* () {
+      const fs = yield* FileSystem.FileSystem
+
+      const existsSafe = Effect.fn("FileSystem.existsSafe")(function* (path: string) {
+        return yield* fs.exists(path).pipe(Effect.orElseSucceed(() => false))
+      })
+
+      const readFileStringSafe = Effect.fn("FileSystem.readFileStringSafe")(function* (path: string) {
+        return yield* fs
+          .readFileString(path)
+          .pipe(Effect.catchReason("PlatformError", "NotFound", () => Effect.succeed(undefined)))
+      })
+
+      const isDir = Effect.fn("FileSystem.isDir")(function* (path: string) {
+        const info = yield* fs.stat(path).pipe(Effect.catch(() => Effect.void))
+        return info?.type === "Directory"
+      })
+
+      const isFile = Effect.fn("FileSystem.isFile")(function* (path: string) {
+        const info = yield* fs.stat(path).pipe(Effect.catch(() => Effect.void))
+        return info?.type === "File"
+      })
+
+      const readDirectoryEntries = Effect.fn("FileSystem.readDirectoryEntries")(function* (dirPath: string) {
+        return yield* Effect.tryPromise({
+          try: async () => {
+            const entries = await NFS.readdir(dirPath, { withFileTypes: true })
+            return entries.map(
+              (e): DirEntry => ({
+                name: e.name,
+                type: e.isDirectory() ? "directory" : e.isSymbolicLink() ? "symlink" : e.isFile() ? "file" : "other",
+              }),
+            )
+          },
+          catch: (cause) => new FileSystemError({ method: "readDirectoryEntries", cause }),
+        })
+      })
+
+      const readJson = Effect.fn("FileSystem.readJson")(function* (path: string) {
+        const text = yield* fs.readFileString(path)
+        return JSON.parse(text)
+      })
+
+      const writeJson = Effect.fn("FileSystem.writeJson")(function* (path: string, data: unknown, mode?: number) {
+        const content = JSON.stringify(data, null, 2)
+        yield* fs.writeFileString(path, content)
+        if (mode) yield* fs.chmod(path, mode)
+      })
+
+      const ensureDir = Effect.fn("FileSystem.ensureDir")(function* (path: string) {
+        yield* fs.makeDirectory(path, { recursive: true })
+      })
+
+      const writeWithDirs = Effect.fn("FileSystem.writeWithDirs")(function* (
+        path: string,
+        content: string | Uint8Array,
+        mode?: number,
+      ) {
+        const write = typeof content === "string" ? fs.writeFileString(path, content) : fs.writeFile(path, content)
+
+        yield* write.pipe(
+          Effect.catchIf(
+            (e) => e.reason._tag === "NotFound",
+            () =>
+              Effect.gen(function* () {
+                yield* fs.makeDirectory(dirname(path), { recursive: true })
+                yield* write
+              }),
+          ),
+        )
+        if (mode) yield* fs.chmod(path, mode)
+      })
+
+      const glob = Effect.fn("FileSystem.glob")(function* (pattern: string, options?: Glob.Options) {
+        return yield* Effect.tryPromise({
+          try: () => Glob.scan(pattern, options),
+          catch: (cause) => new FileSystemError({ method: "glob", cause }),
+        })
+      })
+
+      const findUp = Effect.fn("FileSystem.findUp")(function* (target: string, start: string, stop?: string) {
+        const result: string[] = []
+        let current = start
+        while (true) {
+          const search = join(current, target)
+          if (yield* fs.exists(search)) result.push(search)
+          if (stop === current) break
+          const parent = dirname(current)
+          if (parent === current) break
+          current = parent
+        }
+        return result
+      })
+
+      const up = Effect.fn("FileSystem.up")(function* (options: { targets: string[]; start: string; stop?: string }) {
+        const result: string[] = []
+        let current = options.start
+        while (true) {
+          for (const target of options.targets) {
+            const search = join(current, target)
+            if (yield* fs.exists(search)) result.push(search)
+          }
+          if (options.stop === current) break
+          const parent = dirname(current)
+          if (parent === current) break
+          current = parent
+        }
+        return result
+      })
+
+      const globUp = Effect.fn("FileSystem.globUp")(function* (pattern: string, start: string, stop?: string) {
+        const result: string[] = []
+        let current = start
+        while (true) {
+          const matches = yield* glob(pattern, { cwd: current, absolute: true, include: "file", dot: true }).pipe(
+            Effect.catch(() => Effect.succeed([] as string[])),
+          )
+          result.push(...matches)
+          if (stop === current) break
+          const parent = dirname(current)
+          if (parent === current) break
+          current = parent
+        }
+        return result
+      })
+
+      return Service.of({
+        ...fs,
+        existsSafe,
+        readFileStringSafe,
+        isDir,
+        isFile,
+        readDirectoryEntries,
+        readJson,
+        writeJson,
+        ensureDir,
+        writeWithDirs,
+        findUp,
+        up,
+        globUp,
+        glob,
+        globMatch: Glob.match,
+      })
+    }),
+  )
+
+  export const defaultLayer = layer.pipe(Layer.provide(NodeFileSystem.layer))
+
+  // Pure helpers that don't need Effect (path manipulation, sync operations)
+  export function mimeType(p: string): string {
+    return lookup(p) || "application/octet-stream"
+  }
+
+  export function normalizePath(p: string): string {
+    if (process.platform !== "win32") return p
+    const resolved = pathResolve(windowsPath(p))
+    try {
+      return realpathSync.native(resolved)
+    } catch {
+      return resolved
+    }
+  }
+
+  export function normalizePathPattern(p: string): string {
+    if (process.platform !== "win32") return p
+    if (p === "*") return p
+    const match = p.match(/^(.*)[\\/]\*$/)
+    if (!match) return normalizePath(p)
+    const dir = /^[A-Za-z]:$/.test(match[1]) ? match[1] + "\\" : match[1]
+    return join(normalizePath(dir), "*")
+  }
+
+  export function resolve(p: string): string {
+    const resolved = pathResolve(windowsPath(p))
+    try {
+      return normalizePath(realpathSync(resolved))
+    } catch (e: any) {
+      if (e?.code === "ENOENT") return normalizePath(resolved)
+      throw e
+    }
+  }
+
+  export function windowsPath(p: string): string {
+    if (process.platform !== "win32") return p
+    return p
+      .replace(/^\/([a-zA-Z]):(?:[\\/]|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
+      .replace(/^\/([a-zA-Z])(?:\/|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
+      .replace(/^\/cygdrive\/([a-zA-Z])(?:\/|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
+      .replace(/^\/mnt\/([a-zA-Z])(?:\/|$)/, (_, drive) => `${drive.toUpperCase()}:/`)
+  }
+
+  export function overlaps(a: string, b: string) {
+    const relA = relative(a, b)
+    const relB = relative(b, a)
+    return !relA || !relA.startsWith("..") || !relB || !relB.startsWith("..")
+  }
+
+  export function contains(parent: string, child: string) {
+    return !relative(parent, child).startsWith("..")
+  }
+}
--- a/packages/core/src/git.ts
+++ b/packages/core/src/git.ts
@@ -4,7 +4,7 @@ import path from "path"
 import { Context, Effect, Layer } from "effect"
 import { ChildProcess } from "effect/unstable/process"
 import { AbsolutePath } from "./schema"
-import { AppFileSystem } from "./filesystem"
+import { FSUtil } from "./fs-util"
 import { AppProcess } from "./process"

 export interface Repo {
@@ -32,6 +32,7 @@ export interface Interface {
  readonly roots: (repo: Repo) => Effect.Effect<string[]>
  readonly origin: (directory: string) => Effect.Effect<string | undefined>
  readonly head: (directory: string) => Effect.Effect<string | undefined>
+  readonly dir: (directory: string) => Effect.Effect<string | undefined>
  readonly branch: (directory: string) => Effect.Effect<string | undefined>
  readonly remoteHead: (directory: string) => Effect.Effect<string | undefined>
  readonly clone: (input: {
@@ -51,7 +52,7 @@ export class Service extends Context.Service<Service, Interface>()("@opencode/Gi
 export const layer = Layer.effect(
  Service,
  Effect.gen(function* () {
-    const fs = yield* AppFileSystem.Service
+    const fs = yield* FSUtil.Service
    const proc = yield* AppProcess.Service

    const find = Effect.fn("Git.find")(function* (input: AbsolutePath) {
@@ -101,6 +102,12 @@ export const layer = Layer.effect(
      return result.text.trim() || undefined
    })

+    const dir = Effect.fn("Git.dir")(function* (directory: string) {
+      const result = yield* run(directory, proc)(["rev-parse", "--git-dir"])
+      if (result.exitCode !== 0) return undefined
+      return AbsolutePath.make(resolvePath(directory, result.text))
+    })
+
    const branch = Effect.fn("Git.branch")(function* (directory: string) {
      const result = yield* run(directory, proc)(["symbolic-ref", "--quiet", "--short", "HEAD"])
      if (result.exitCode !== 0) return undefined
@@ -148,6 +155,7 @@ export const layer = Layer.effect(
      roots,
      origin,
      head,
+      dir,
      branch,
      remoteHead,
      clone,
@@ -159,10 +167,7 @@ export const layer = Layer.effect(
  }),
 )

-export const defaultLayer = layer.pipe(
-  Layer.provide(AppFileSystem.defaultLayer),
-  Layer.provide(AppProcess.defaultLayer),
-)
+export const defaultLayer = layer.pipe(Layer.provide(FSUtil.defaultLayer), Layer.provide(AppProcess.defaultLayer))

 export interface Result {
  readonly exitCode: number
@@ -200,7 +205,7 @@ function execute(cwd: string, proc: AppProcess.Interface) {
 function resolvePath(cwd: string, value: string) {
  const trimmed = value.replace(/[\r\n]+$/, "")
  if (!trimmed) return cwd
-  const normalized = AppFileSystem.windowsPath(trimmed)
+  const normalized = FSUtil.windowsPath(trimmed)
  if (path.isAbsolute(normalized)) return path.normalize(normalized)
  return path.resolve(cwd, normalized)
 }
--- a/packages/core/src/location-filesystem.ts
+++ b/packages/core/src/location-filesystem.ts
@@ -1,194 +0,0 @@
-export * as LocationFileSystem from "./location-filesystem"
-
-import path from "path"
-import { pathToFileURL } from "url"
-import { Context, Effect, Layer, Schema } from "effect"
-import { AppFileSystem } from "./filesystem"
-import { Location } from "./location"
-import { ProjectReference } from "./project-reference"
-import { NonNegativeInt, PositiveInt, RelativePath } from "./schema"
-
-export const ReadInput = Schema.Struct({
-  path: RelativePath,
-  reference: Schema.String.pipe(Schema.optional),
-})
-export type ReadInput = typeof ReadInput.Type
-
-export class TextContent extends Schema.Class<TextContent>("LocationFileSystem.TextContent")({
-  type: Schema.Literal("text"),
-  content: Schema.String,
-  mime: Schema.String,
-}) {}
-
-export class BinaryContent extends Schema.Class<BinaryContent>("LocationFileSystem.BinaryContent")({
-  type: Schema.Literal("binary"),
-  content: Schema.String,
-  encoding: Schema.Literal("base64"),
-  mime: Schema.String,
-}) {}
-
-export const Content = Schema.Union([TextContent, BinaryContent]).pipe(Schema.toTaggedUnion("type"))
-export type Content = typeof Content.Type
-
-export const ListInput = Schema.Struct({
-  path: RelativePath.pipe(Schema.optional),
-  reference: Schema.String.pipe(Schema.optional),
-})
-export type ListInput = typeof ListInput.Type
-
-export class Entry extends Schema.Class<Entry>("LocationFileSystem.Entry")({
-  path: RelativePath,
-  uri: Schema.String,
-  type: Schema.Literals(["file", "directory"]),
-  mime: Schema.String,
-}) {}
-
-export const FindInput = Schema.Struct({
-  query: Schema.String,
-  type: Schema.Literals(["file", "directory"]).pipe(Schema.optional),
-  limit: PositiveInt.pipe(Schema.optional),
-})
-export type FindInput = typeof FindInput.Type
-
-export const GrepInput = Schema.Struct({
-  pattern: Schema.String,
-  include: Schema.String.pipe(Schema.optional),
-  limit: PositiveInt.pipe(Schema.optional),
-})
-export type GrepInput = typeof GrepInput.Type
-
-export class GrepMatch extends Schema.Class<GrepMatch>("LocationFileSystem.GrepMatch")({
-  path: RelativePath,
-  lines: Schema.String,
-  line: PositiveInt,
-  offset: NonNegativeInt,
-  submatches: Schema.Array(
-    Schema.Struct({
-      text: Schema.String,
-      start: NonNegativeInt,
-      end: NonNegativeInt,
-    }),
-  ),
-}) {}
-
-export interface Interface {
-  readonly read: (input: ReadInput) => Effect.Effect<Content>
-  readonly list: (input?: ListInput) => Effect.Effect<Entry[]>
-  readonly find: (input: FindInput) => Effect.Effect<Entry[]>
-  readonly grep: (input: GrepInput) => Effect.Effect<GrepMatch[]>
-}
-
-export class Service extends Context.Service<Service, Interface>()("@opencode/v2/LocationFileSystem") {}
-
-export const layer = Layer.effect(
-  Service,
-  Effect.gen(function* () {
-    const fs = yield* AppFileSystem.Service
-    const location = yield* Location.Service
-    const references = yield* ProjectReference.Service
-    const root = yield* fs.realPath(location.directory).pipe(Effect.orDie)
-    const select = Effect.fnUntraced(function* (reference?: string) {
-      if (!reference) return { directory: location.directory, root }
-      const resolved = yield* references.get(reference)
-      if (!resolved) return yield* Effect.die(new Error(`Unknown project reference: ${reference}`))
-      if (resolved.kind === "invalid") return yield* Effect.die(new Error(resolved.message))
-      if (resolved.kind === "git") yield* references.ensurePath(resolved.path).pipe(Effect.orDie)
-      return { directory: resolved.path, root: yield* fs.realPath(resolved.path).pipe(Effect.orDie) }
-    })
-    const resolve = Effect.fnUntraced(function* (input?: RelativePath, reference?: string) {
-      if (input && path.isAbsolute(input)) return yield* Effect.die(new Error("Path must be relative to the location"))
-      const selected = yield* select(reference)
-      const absolute = path.resolve(selected.directory, input ?? ".")
-      if (!AppFileSystem.contains(selected.directory, absolute))
-        return yield* Effect.die(new Error("Path escapes the location"))
-      const real = yield* fs.realPath(absolute).pipe(Effect.orDie)
-      if (!AppFileSystem.contains(selected.root, real)) return yield* Effect.die(new Error("Path escapes the location"))
-      return { absolute, real, ...selected }
-    })
-    const entry = Effect.fnUntraced(function* (absolute: string, selected: { directory: string; root: string }) {
-      const real = yield* fs.realPath(absolute).pipe(Effect.catch(() => Effect.void))
-      if (!real) return
-      if (!AppFileSystem.contains(selected.root, real)) return
-      const info = yield* fs.stat(real).pipe(Effect.catch(() => Effect.void))
-      if (!info) return
-      const type = info.type === "Directory" ? "directory" : info.type === "File" ? "file" : undefined
-      if (!type) return
-      return new Entry({
-        path: RelativePath.make(path.relative(selected.directory, absolute)),
-        uri: pathToFileURL(real).href,
-        type,
-        mime: type === "directory" ? "application/x-directory" : AppFileSystem.mimeType(real),
-      })
-    })
-    const entries = [
-      new Entry({
-        path: RelativePath.make("README.md"),
-        uri: pathToFileURL(path.join(location.directory, "README.md")).href,
-        type: "file",
-        mime: "text/markdown",
-      }),
-      new Entry({
-        path: RelativePath.make("src"),
-        uri: pathToFileURL(path.join(location.directory, "src")).href,
-        type: "directory",
-        mime: "application/x-directory",
-      }),
-    ]
-
-    return Service.of({
-      read: Effect.fn("LocationFileSystem.read")(function* (input) {
-        const file = yield* resolve(input.path, input.reference)
-        const info = yield* fs.stat(file.real).pipe(Effect.orDie)
-        if (info.type !== "File") return yield* Effect.die(new Error("Path is not a file"))
-        const bytes = yield* fs.readFile(file.real).pipe(Effect.orDie)
-        const mime = AppFileSystem.mimeType(file.real)
-        if (!bytes.includes(0)) {
-          const content = yield* Effect.sync(() => new TextDecoder("utf-8", { fatal: true }).decode(bytes)).pipe(
-            Effect.option,
-          )
-          if (content._tag === "Some") return new TextContent({ type: "text", content: content.value, mime })
-        }
-        return new BinaryContent({
-          type: "binary",
-          content: Buffer.from(bytes).toString("base64"),
-          encoding: "base64",
-          mime,
-        })
-      }),
-      list: Effect.fn("LocationFileSystem.list")(function* (input = {}) {
-        const directory = yield* resolve(input.path, input.reference)
-        const info = yield* fs.stat(directory.real).pipe(Effect.orDie)
-        if (info.type !== "Directory") return yield* Effect.die(new Error("Path is not a directory"))
-        return yield* fs.readDirectoryEntries(directory.real).pipe(
-          Effect.orDie,
-          Effect.flatMap((items) =>
-            Effect.forEach(items, (item) => entry(path.join(directory.absolute, item.name), directory), {
-              concurrency: "unbounded",
-            }),
-          ),
-          Effect.map((items) =>
-            items
-              .filter((item): item is Entry => item !== undefined)
-              .sort((a, b) => (a.type === b.type ? a.path.localeCompare(b.path) : a.type === "directory" ? -1 : 1)),
-          ),
-        )
-      }),
-      find: Effect.fn("LocationFileSystem.find")(function* (input) {
-        return entries.filter((entry) => input.type === undefined || entry.type === input.type).slice(0, input.limit)
-      }),
-      grep: Effect.fn("LocationFileSystem.grep")(function* (input) {
-        return [
-          new GrepMatch({
-            path: RelativePath.make("README.md"),
-            lines: "# opencode",
-            line: 1,
-            offset: 0,
-            submatches: [{ text: input.pattern, start: 0, end: input.pattern.length }],
-          }),
-        ].slice(0, input.limit)
-      }),
-    })
-  }),
-)
-
-export const locationLayer = layer.pipe(Layer.provideMerge(ProjectReference.locationLayer))
--- a/packages/core/src/location-layer.ts
+++ b/packages/core/src/location-layer.ts
@@ -11,13 +11,14 @@ import { EventV2 } from "./event"
 import { Auth } from "./auth"
 import { Npm } from "./npm"
 import { ModelsDev } from "./models-dev"
-import { AppFileSystem } from "./filesystem"
+import { FSUtil } from "./fs-util"
 import { Global } from "./global"
 import { Database } from "./database/database"
 import { PermissionV2 } from "./permission"
 import { PermissionSaved } from "./permission/saved"
 import { SessionV2 } from "./session"
-import { LocationFileSystem } from "./location-filesystem"
+import { FileSystem } from "./filesystem"
+import { Watcher } from "./filesystem/watcher"
 import { ProjectReference } from "./project-reference"
 import { RepositoryCache } from "./repository-cache"

@@ -34,7 +35,8 @@ export class LocationServiceMap extends LayerMap.Service<LocationServiceMap>()("
      AgentV2.locationLayer,
      PluginBoot.locationLayer,
      PermissionV2.locationLayer,
-      LocationFileSystem.locationLayer,
+      FileSystem.locationLayer,
+      Watcher.locationLayer,
    ).pipe(Layer.provideMerge(location), Layer.fresh)
  },
  idleTimeToLive: "60 minutes",
@@ -44,7 +46,7 @@ export class LocationServiceMap extends LayerMap.Service<LocationServiceMap>()("
    Auth.defaultLayer,
    Npm.defaultLayer,
    ModelsDev.defaultLayer,
-    AppFileSystem.defaultLayer,
+    FSUtil.defaultLayer,
    Global.defaultLayer,
    Database.defaultLayer,
    SessionV2.defaultLayer,
--- a/packages/core/src/models-dev.ts
+++ b/packages/core/src/models-dev.ts
@@ -5,7 +5,7 @@ import { Global } from "./global"
 import { Flag } from "./flag/flag"
 import { Flock } from "./util/flock"
 import { Hash } from "./util/hash"
-import { AppFileSystem } from "./filesystem"
+import { FSUtil } from "./fs-util"
 import { InstallationChannel, InstallationVersion } from "./installation/version"
 import { EventV2 } from "./event"

@@ -125,7 +125,7 @@ export class Service extends Context.Service<Service, Interface>()("@opencode/Mo
 export const layer = Layer.effect(
  Service,
  Effect.gen(function* () {
-    const fs = yield* AppFileSystem.Service
+    const fs = yield* FSUtil.Service
    const events = yield* EventV2.Service
    const http = HttpClient.filterStatusOk(
      (yield* HttpClient.HttpClient).pipe(
@@ -227,7 +227,7 @@ export const layer = Layer.effect(

 export const defaultLayer = layer.pipe(
  Layer.provide(FetchHttpClient.layer),
-  Layer.provide(AppFileSystem.defaultLayer),
+  Layer.provide(FSUtil.defaultLayer),
  Layer.provide(EventV2.defaultLayer),
 )

--- a/packages/core/src/npm.ts
+++ b/packages/core/src/npm.ts
@@ -4,7 +4,7 @@ import path from "path"
 import npa from "npm-package-arg"
 import { Effect, Schema, Context, Layer, Option, FileSystem } from "effect"
 import { NodeFileSystem } from "@effect/platform-node"
-import { AppFileSystem } from "./filesystem"
+import { FSUtil } from "./fs-util"
 import { Global } from "./global"
 import { EffectFlock } from "./util/effect-flock"
 import { makeRuntime } from "./effect/runtime"
@@ -70,7 +70,7 @@ interface ArboristTree {
 export const layer = Layer.effect(
  Service,
  Effect.gen(function* () {
-    const afs = yield* AppFileSystem.Service
+    const afs = yield* FSUtil.Service
    const global = yield* Global.Service
    const fs = yield* FileSystem.FileSystem
    const flock = yield* EffectFlock.Service
@@ -246,7 +246,7 @@ export const layer = Layer.effect(

 export const defaultLayer = layer.pipe(
  Layer.provide(EffectFlock.layer),
-  Layer.provide(AppFileSystem.layer),
+  Layer.provide(FSUtil.layer),
  Layer.provide(Global.layer),
  Layer.provide(NodeFileSystem.layer),
 )
--- a/packages/core/src/project-reference.ts
+++ b/packages/core/src/project-reference.ts
@@ -4,7 +4,7 @@ import path from "path"
 import { Context, Effect, Layer } from "effect"
 import { Config } from "./config"
 import { ConfigReference } from "./config/reference"
-import { AppFileSystem } from "./filesystem"
+import { FSUtil } from "./fs-util"
 import { Flag } from "./flag/flag"
 import { Global } from "./global"
 import { Location } from "./location"
@@ -65,7 +65,7 @@ export const layer = Layer.effect(
    if (!Flag.OPENCODE_EXPERIMENTAL_REFERENCES) return Service.of(inert)

    const config = yield* Config.Service
-    const fs = yield* AppFileSystem.Service
+    const fs = yield* FSUtil.Service
    const global = yield* Global.Service
    const location = yield* Location.Service
    const cache = yield* RepositoryCache.Service
@@ -137,7 +137,7 @@ export const layer = Layer.effect(
        if (!target) return { name, kind: "reference", reference, path: reference.path }

        const resolved = path.resolve(reference.path, target)
-        if (!AppFileSystem.contains(reference.path, resolved))
+        if (!FSUtil.contains(reference.path, resolved))
          return { name, kind: "invalid", target, message: "Reference target escapes its root" }
        if (!(yield* fs.existsSafe(resolved)))
          return { name, kind: "missing", target, path: resolved, message: "Reference target does not exist" }
@@ -228,9 +228,9 @@ function uniqueGitReferences(references: Resolved[]) {

 function normalizePath(target?: string) {
  if (!target) return
-  return process.platform === "win32" ? AppFileSystem.normalizePath(target) : target
+  return process.platform === "win32" ? FSUtil.normalizePath(target) : target
 }

 function contains(parent: string, child: string) {
-  return AppFileSystem.contains(normalizePath(parent) ?? parent, normalizePath(child) ?? child)
+  return FSUtil.contains(normalizePath(parent) ?? parent, normalizePath(child) ?? child)
 }
--- a/packages/core/src/project.ts
+++ b/packages/core/src/project.ts
@@ -4,7 +4,7 @@ export * as Project from "./project"
 import { Context, Effect, Layer, Schema } from "effect"
 import path from "path"
 import { AbsolutePath, withStatics } from "./schema"
-import { AppFileSystem } from "./filesystem"
+import { FSUtil } from "./fs-util"
 import { Git } from "./git"
 import { Hash } from "./util/hash"

@@ -55,7 +55,7 @@ export class Service extends Context.Service<Service, Interface>()("@opencode/Pr
 export const layer = Layer.effect(
  Service,
  Effect.gen(function* () {
-    const fs = yield* AppFileSystem.Service
+    const fs = yield* FSUtil.Service
    const git = yield* Git.Service

    const cached = Effect.fnUntraced(function* (dir: string) {
@@ -126,4 +126,4 @@ export const layer = Layer.effect(
  }),
 )

-export const defaultLayer = layer.pipe(Layer.provide(AppFileSystem.defaultLayer), Layer.provide(Git.defaultLayer))
+export const defaultLayer = layer.pipe(Layer.provide(FSUtil.defaultLayer), Layer.provide(Git.defaultLayer))
--- a/packages/core/src/repository-cache.ts
+++ b/packages/core/src/repository-cache.ts
@@ -1,6 +1,6 @@
 import path from "path"
 import { Context, Effect, Layer, Schema } from "effect"
-import { AppFileSystem } from "./filesystem"
+import { FSUtil } from "./fs-util"
 import { Git } from "./git"
 import { Global } from "./global"
 import { Repository } from "./repository"
@@ -119,139 +119,142 @@ export const validateBranch = Effect.fn("RepositoryCache.validateBranch")(functi
  })
 })

-export const layer: Layer.Layer<
-  Service,
-  never,
-  AppFileSystem.Service | Git.Service | EffectFlock.Service | Global.Service
-> = Layer.effect(
-  Service,
-  Effect.gen(function* () {
-    const fs = yield* AppFileSystem.Service
-    const git = yield* Git.Service
-    const flock = yield* EffectFlock.Service
-    const global = yield* Global.Service
+export const layer: Layer.Layer<Service, never, FSUtil.Service | Git.Service | EffectFlock.Service | Global.Service> =
+  Layer.effect(
+    Service,
+    Effect.gen(function* () {
+      const fs = yield* FSUtil.Service
+      const git = yield* Git.Service
+      const flock = yield* EffectFlock.Service
+      const global = yield* Global.Service

-    return Service.of({
-      ensure: Effect.fn("RepositoryCache.ensure")(function* (input) {
-        if (input.branch) yield* validateBranch(input.branch)
+      return Service.of({
+        ensure: Effect.fn("RepositoryCache.ensure")(function* (input) {
+          if (input.branch) yield* validateBranch(input.branch)

-        const repository = input.reference.label
-        const localPath = Repository.cachePath(global.repos, input.reference)
-        const cloneTarget = Repository.parse(input.reference.remote) ?? input.reference
+          const repository = input.reference.label
+          const localPath = Repository.cachePath(global.repos, input.reference)
+          const cloneTarget = Repository.parse(input.reference.remote) ?? input.reference

-        return yield* flock
-          .withLock(
-            Effect.gen(function* () {
-              yield* cacheOperation(fs.ensureDir(path.dirname(localPath)), "ensure cache directory", localPath)
+          return yield* flock
+            .withLock(
+              Effect.gen(function* () {
+                yield* cacheOperation(fs.ensureDir(path.dirname(localPath)), "ensure cache directory", localPath)

-              const exists = yield* fs.existsSafe(localPath)
-              const hasGitDir = yield* fs.existsSafe(path.join(localPath, ".git"))
-              const origin = hasGitDir ? yield* git.origin(localPath) : undefined
-              const originReference = origin ? Repository.parse(origin) : undefined
-              const reuse = hasGitDir && Boolean(originReference && Repository.same(originReference, cloneTarget))
-              if (exists && !reuse) {
-                yield* cacheOperation(fs.remove(localPath, { recursive: true }), "remove stale cache", localPath)
-              }
-
-              const currentBranch = reuse ? yield* git.branch(localPath) : undefined
-              const status = statusForRepository({
-                reuse,
-                refresh: input.refresh,
-                branchMatches: input.branch ? currentBranch === input.branch : undefined,
-              })
-
-              if (status === "cloned") {
-                const result = yield* git
-                  .clone({ remote: input.reference.remote, target: localPath, branch: input.branch })
-                  .pipe(Effect.mapError((error) => new CloneFailedError({ repository, message: errorMessage(error) })))
-                if (result.exitCode !== 0) {
-                  return yield* new CloneFailedError({
-                    repository,
-                    message: resultMessage(result, `Failed to clone ${repository}`),
-                  })
-                }
-              }
-
-              if (status === "refreshed") {
-                const fetch = yield* git
-                  .fetch(localPath)
-                  .pipe(Effect.mapError((error) => new FetchFailedError({ repository, message: errorMessage(error) })))
-                if (fetch.exitCode !== 0) {
-                  return yield* new FetchFailedError({
-                    repository,
-                    message: resultMessage(fetch, `Failed to refresh ${repository}`),
-                  })
+                const exists = yield* fs.existsSafe(localPath)
+                const hasGitDir = yield* fs.existsSafe(path.join(localPath, ".git"))
+                const origin = hasGitDir ? yield* git.origin(localPath) : undefined
+                const originReference = origin ? Repository.parse(origin) : undefined
+                const reuse = hasGitDir && Boolean(originReference && Repository.same(originReference, cloneTarget))
+                if (exists && !reuse) {
+                  yield* cacheOperation(fs.remove(localPath, { recursive: true }), "remove stale cache", localPath)
                }

-                if (input.branch) {
-                  const requestedBranch = input.branch
-                  const fetchBranch = yield* git
-                    .fetchBranch(localPath, requestedBranch)
+                const currentBranch = reuse ? yield* git.branch(localPath) : undefined
+                const status = statusForRepository({
+                  reuse,
+                  refresh: input.refresh,
+                  branchMatches: input.branch ? currentBranch === input.branch : undefined,
+                })
+
+                if (status === "cloned") {
+                  const result = yield* git
+                    .clone({ remote: input.reference.remote, target: localPath, branch: input.branch })
+                    .pipe(
+                      Effect.mapError((error) => new CloneFailedError({ repository, message: errorMessage(error) })),
+                    )
+                  if (result.exitCode !== 0) {
+                    return yield* new CloneFailedError({
+                      repository,
+                      message: resultMessage(result, `Failed to clone ${repository}`),
+                    })
+                  }
+                }
+
+                if (status === "refreshed") {
+                  const fetch = yield* git
+                    .fetch(localPath)
                    .pipe(
                      Effect.mapError((error) => new FetchFailedError({ repository, message: errorMessage(error) })),
                    )
-                  if (fetchBranch.exitCode !== 0) {
+                  if (fetch.exitCode !== 0) {
                    return yield* new FetchFailedError({
                      repository,
-                      message: resultMessage(fetchBranch, `Failed to fetch ${requestedBranch}`),
+                      message: resultMessage(fetch, `Failed to refresh ${repository}`),
                    })
                  }

-                  const checkout = yield* git.checkout(localPath, requestedBranch).pipe(
-                    Effect.mapError(
-                      (error) =>
-                        new CheckoutFailedError({
-                          repository,
-                          branch: requestedBranch,
-                          message: errorMessage(error),
-                        }),
-                    ),
-                  )
-                  if (checkout.exitCode !== 0) {
-                    return yield* new CheckoutFailedError({
+                  if (input.branch) {
+                    const requestedBranch = input.branch
+                    const fetchBranch = yield* git
+                      .fetchBranch(localPath, requestedBranch)
+                      .pipe(
+                        Effect.mapError((error) => new FetchFailedError({ repository, message: errorMessage(error) })),
+                      )
+                    if (fetchBranch.exitCode !== 0) {
+                      return yield* new FetchFailedError({
+                        repository,
+                        message: resultMessage(fetchBranch, `Failed to fetch ${requestedBranch}`),
+                      })
+                    }
+
+                    const checkout = yield* git.checkout(localPath, requestedBranch).pipe(
+                      Effect.mapError(
+                        (error) =>
+                          new CheckoutFailedError({
+                            repository,
+                            branch: requestedBranch,
+                            message: errorMessage(error),
+                          }),
+                      ),
+                    )
+                    if (checkout.exitCode !== 0) {
+                      return yield* new CheckoutFailedError({
+                        repository,
+                        branch: requestedBranch,
+                        message: resultMessage(checkout, `Failed to checkout ${requestedBranch}`),
+                      })
+                    }
+                  }
+
+                  const reset = yield* git
+                    .reset(localPath, yield* resetTarget(git, localPath, input.branch))
+                    .pipe(
+                      Effect.mapError((error) => new ResetFailedError({ repository, message: errorMessage(error) })),
+                    )
+                  if (reset.exitCode !== 0) {
+                    return yield* new ResetFailedError({
                      repository,
-                      branch: requestedBranch,
-                      message: resultMessage(checkout, `Failed to checkout ${requestedBranch}`),
+                      message: resultMessage(reset, `Failed to reset ${repository}`),
                    })
                  }
                }

-                const reset = yield* git
-                  .reset(localPath, yield* resetTarget(git, localPath, input.branch))
-                  .pipe(Effect.mapError((error) => new ResetFailedError({ repository, message: errorMessage(error) })))
-                if (reset.exitCode !== 0) {
-                  return yield* new ResetFailedError({
-                    repository,
-                    message: resultMessage(reset, `Failed to reset ${repository}`),
-                  })
-                }
-              }
-
-              return {
-                repository,
-                host: input.reference.host,
-                remote: input.reference.remote,
-                localPath,
-                status,
-                head: yield* git.head(localPath),
-                branch: yield* git.branch(localPath),
-              } satisfies Result
-            }),
-            `repository-cache:${localPath}`,
-          )
-          .pipe(
-            Effect.mapError((error) =>
-              isError(error) ? error : new LockFailedError({ localPath, message: errorMessage(error) }),
-            ),
-          )
-      }),
-    })
-  }),
-)
+                return {
+                  repository,
+                  host: input.reference.host,
+                  remote: input.reference.remote,
+                  localPath,
+                  status,
+                  head: yield* git.head(localPath),
+                  branch: yield* git.branch(localPath),
+                } satisfies Result
+              }),
+              `repository-cache:${localPath}`,
+            )
+            .pipe(
+              Effect.mapError((error) =>
+                isError(error) ? error : new LockFailedError({ localPath, message: errorMessage(error) }),
+              ),
+            )
+        }),
+      })
+    }),
+  )

 export const defaultLayer: Layer.Layer<Service> = layer.pipe(
  Layer.provide(EffectFlock.defaultLayer),
-  Layer.provide(AppFileSystem.defaultLayer),
+  Layer.provide(FSUtil.defaultLayer),
  Layer.provide(Git.defaultLayer),
  Layer.provide(Global.defaultLayer),
 )
--- a/packages/core/src/util/effect-flock.ts
+++ b/packages/core/src/util/effect-flock.ts
@@ -4,7 +4,7 @@ import { randomUUID } from "crypto"
 import { Context, Effect, Function, Layer, Option, Schedule, Schema } from "effect"
 import type { FileSystem, Scope } from "effect"
 import type { PlatformError } from "effect/PlatformError"
-import { AppFileSystem } from "../filesystem"
+import { FSUtil } from "../fs-util"
 import { Global } from "../global"
 import { Hash } from "./hash"

@@ -93,11 +93,11 @@ export namespace EffectFlock {

  const isPathGone = (e: PlatformError) => e.reason._tag === "NotFound" || e.reason._tag === "Unknown"

-  export const layer: Layer.Layer<Service, never, Global.Service | AppFileSystem.Service> = Layer.effect(
+  export const layer: Layer.Layer<Service, never, Global.Service | FSUtil.Service> = Layer.effect(
    Service,
    Effect.gen(function* () {
      const global = yield* Global.Service
-      const fs = yield* AppFileSystem.Service
+      const fs = yield* FSUtil.Service
      const lockRoot = path.join(global.state, "locks")
      const hostname = os.hostname()
      const ensuredDirs = new Set<string>()
@@ -279,5 +279,5 @@ export namespace EffectFlock {
    }),
  )

-  export const defaultLayer = layer.pipe(Layer.provide(AppFileSystem.defaultLayer), Layer.provide(Global.layer))
+  export const defaultLayer = layer.pipe(Layer.provide(FSUtil.defaultLayer), Layer.provide(Global.layer))
 }
--- a/packages/core/src/util/which.ts
+++ b/packages/core/src/util/which.ts
@@ -0,0 +1,14 @@
+import whichPkg from "which"
+import path from "path"
+import { Global } from "../global"
+
+export function which(cmd: string, env?: NodeJS.ProcessEnv) {
+  const base = env?.PATH ?? env?.Path ?? process.env.PATH ?? process.env.Path ?? ""
+  const full = base ? base + path.delimiter + Global.Path.bin : Global.Path.bin
+  const result = whichPkg.sync(cmd, {
+    nothrow: true,
+    path: full,
+    pathExt: env?.PATHEXT ?? env?.PathExt ?? process.env.PATHEXT ?? process.env.PathExt,
+  })
+  return typeof result === "string" ? result : null
+}
--- a/packages/core/test/account.test.ts
+++ b/packages/core/test/account.test.ts
@@ -5,7 +5,7 @@ import { Effect, Fiber, Layer, Option, Stream } from "effect"
 import { Auth } from "@opencode-ai/core/auth"
 import { Catalog } from "@opencode-ai/core/catalog"
 import { EventV2 } from "@opencode-ai/core/event"
-import { AppFileSystem } from "@opencode-ai/core/filesystem"
+import { FSUtil } from "@opencode-ai/core/fs-util"
 import { Global } from "@opencode-ai/core/global"
 import { PluginV2 } from "@opencode-ai/core/plugin"
 import { AccountPlugin } from "@opencode-ai/core/plugin/account"
@@ -57,7 +57,7 @@ function context(

 function testLayer(dir: string) {
  return Auth.layer.pipe(
-    Layer.provide(AppFileSystem.defaultLayer),
+    Layer.provide(FSUtil.defaultLayer),
    Layer.provideMerge(EventV2.defaultLayer),
    Layer.provide(
      Global.layerWith({
--- a/packages/core/test/config/config.test.ts
+++ b/packages/core/test/config/config.test.ts
@@ -4,7 +4,7 @@ import { describe, expect } from "bun:test"
 import { Effect, Layer } from "effect"
 import { Config } from "@opencode-ai/core/config"
 import { ConfigProvider } from "@opencode-ai/core/config/provider"
-import { AppFileSystem } from "@opencode-ai/core/filesystem"
+import { FSUtil } from "@opencode-ai/core/fs-util"
 import { Global } from "@opencode-ai/core/global"
 import { Location } from "@opencode-ai/core/location"
 import { Policy } from "@opencode-ai/core/policy"
@@ -23,7 +23,7 @@ function testLayer(
  vcs?: Project.Vcs,
 ) {
  return Config.locationLayer.pipe(
-    Layer.provide(AppFileSystem.defaultLayer),
+    Layer.provide(FSUtil.defaultLayer),
    Layer.provide(Global.layerWith({ config: globalDirectory })),
    Layer.provide(
      Layer.succeed(
--- a/packages/core/test/filesystem/filesystem.test.ts
+++ b/packages/core/test/filesystem/filesystem.test.ts
@@ -1,19 +1,19 @@
 import { describe, test, expect } from "bun:test"
 import { Effect, Layer, FileSystem } from "effect"
 import { NodeFileSystem } from "@effect/platform-node"
-import { AppFileSystem } from "@opencode-ai/core/filesystem"
+import { FSUtil } from "@opencode-ai/core/fs-util"
 import { testEffect } from "../lib/effect"
 import path from "path"

-const live = AppFileSystem.layer.pipe(Layer.provideMerge(NodeFileSystem.layer))
+const live = FSUtil.layer.pipe(Layer.provideMerge(NodeFileSystem.layer))
 const { effect: it } = testEffect(live)

-describe("AppFileSystem", () => {
+describe("FSUtil", () => {
  describe("isDir", () => {
    it(
      "returns true for directories",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        expect(yield* fs.isDir(tmp)).toBe(true)
@@ -23,7 +23,7 @@ describe("AppFileSystem", () => {
    it(
      "returns false for files",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        const file = path.join(tmp, "test.txt")
@@ -35,7 +35,7 @@ describe("AppFileSystem", () => {
    it(
      "returns false for non-existent paths",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        expect(yield* fs.isDir("/tmp/nonexistent-" + Math.random())).toBe(false)
      }),
    )
@@ -45,7 +45,7 @@ describe("AppFileSystem", () => {
    it(
      "returns true for files",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        const file = path.join(tmp, "test.txt")
@@ -57,7 +57,7 @@ describe("AppFileSystem", () => {
    it(
      "returns false for directories",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        expect(yield* fs.isFile(tmp)).toBe(false)
@@ -69,7 +69,7 @@ describe("AppFileSystem", () => {
    it(
      "returns file contents when file exists",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        const file = path.join(tmp, "exists.txt")
@@ -83,7 +83,7 @@ describe("AppFileSystem", () => {
    it(
      "returns undefined for missing file (NotFound)",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()

@@ -97,7 +97,7 @@ describe("AppFileSystem", () => {
    it(
      "round-trips JSON data",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        const file = path.join(tmp, "data.json")
@@ -115,7 +115,7 @@ describe("AppFileSystem", () => {
    it(
      "creates nested directories",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        const nested = path.join(tmp, "a", "b", "c")
@@ -130,7 +130,7 @@ describe("AppFileSystem", () => {
    it(
      "is idempotent",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        const dir = path.join(tmp, "existing")
@@ -148,7 +148,7 @@ describe("AppFileSystem", () => {
    it(
      "creates parent directories if missing",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        const file = path.join(tmp, "deep", "nested", "file.txt")
@@ -162,7 +162,7 @@ describe("AppFileSystem", () => {
    it(
      "writes directly when parent exists",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        const file = path.join(tmp, "direct.txt")
@@ -176,7 +176,7 @@ describe("AppFileSystem", () => {
    it(
      "writes Uint8Array content",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        const file = path.join(tmp, "binary.bin")
@@ -194,7 +194,7 @@ describe("AppFileSystem", () => {
    it(
      "finds target in start directory",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        yield* filesys.writeFileString(path.join(tmp, "target.txt"), "found")
@@ -207,7 +207,7 @@ describe("AppFileSystem", () => {
    it(
      "finds target in parent directories",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        yield* filesys.writeFileString(path.join(tmp, "marker"), "root")
@@ -222,7 +222,7 @@ describe("AppFileSystem", () => {
    it(
      "returns empty array when not found",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        const result = yield* fs.findUp("nonexistent", tmp, tmp)
@@ -235,7 +235,7 @@ describe("AppFileSystem", () => {
    it(
      "finds multiple targets walking up",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        yield* filesys.writeFileString(path.join(tmp, "a.txt"), "a")
@@ -257,7 +257,7 @@ describe("AppFileSystem", () => {
    it(
      "finds files matching pattern",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        yield* filesys.writeFileString(path.join(tmp, "a.ts"), "a")
@@ -272,7 +272,7 @@ describe("AppFileSystem", () => {
    it(
      "supports absolute paths",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        yield* filesys.writeFileString(path.join(tmp, "file.txt"), "hello")
@@ -287,7 +287,7 @@ describe("AppFileSystem", () => {
    it(
      "matches patterns",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        expect(fs.globMatch("*.ts", "foo.ts")).toBe(true)
        expect(fs.globMatch("*.ts", "foo.json")).toBe(false)
        expect(fs.globMatch("src/**", "src/a/b.ts")).toBe(true)
@@ -299,7 +299,7 @@ describe("AppFileSystem", () => {
    it(
      "finds files walking up directories",
      Effect.gen(function* () {
-        const fs = yield* AppFileSystem.Service
+        const fs = yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        yield* filesys.writeFileString(path.join(tmp, "root.md"), "root")
@@ -318,7 +318,7 @@ describe("AppFileSystem", () => {
    it(
      "exists works",
      Effect.gen(function* () {
-        yield* AppFileSystem.Service
+        yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        const file = path.join(tmp, "exists.txt")
@@ -332,7 +332,7 @@ describe("AppFileSystem", () => {
    it(
      "remove works",
      Effect.gen(function* () {
-        yield* AppFileSystem.Service
+        yield* FSUtil.Service
        const filesys = yield* FileSystem.FileSystem
        const tmp = yield* filesys.makeTempDirectoryScoped()
        const file = path.join(tmp, "delete-me.txt")
@@ -347,20 +347,20 @@ describe("AppFileSystem", () => {

  describe("pure helpers", () => {
    test("mimeType returns correct types", () => {
-      expect(AppFileSystem.mimeType("file.json")).toBe("application/json")
-      expect(AppFileSystem.mimeType("image.png")).toBe("image/png")
-      expect(AppFileSystem.mimeType("unknown.qzx")).toBe("application/octet-stream")
+      expect(FSUtil.mimeType("file.json")).toBe("application/json")
+      expect(FSUtil.mimeType("image.png")).toBe("image/png")
+      expect(FSUtil.mimeType("unknown.qzx")).toBe("application/octet-stream")
    })

    test("contains checks path containment", () => {
-      expect(AppFileSystem.contains("/a/b", "/a/b/c")).toBe(true)
-      expect(AppFileSystem.contains("/a/b", "/a/c")).toBe(false)
+      expect(FSUtil.contains("/a/b", "/a/b/c")).toBe(true)
+      expect(FSUtil.contains("/a/b", "/a/c")).toBe(false)
    })

    test("overlaps detects overlapping paths", () => {
-      expect(AppFileSystem.overlaps("/a/b", "/a/b/c")).toBe(true)
-      expect(AppFileSystem.overlaps("/a/b/c", "/a/b")).toBe(true)
-      expect(AppFileSystem.overlaps("/a", "/b")).toBe(false)
+      expect(FSUtil.overlaps("/a/b", "/a/b/c")).toBe(true)
+      expect(FSUtil.overlaps("/a/b/c", "/a/b")).toBe(true)
+      expect(FSUtil.overlaps("/a", "/b")).toBe(false)
    })
  })
 })
--- a/packages/core/test/filesystem/ignore.test.ts
+++ b/packages/core/test/filesystem/ignore.test.ts
@@ -0,0 +1,10 @@
+import { expect, test } from "bun:test"
+import { Ignore } from "@opencode-ai/core/filesystem/ignore"
+
+test("match nested and non-nested", () => {
+  expect(Ignore.match("node_modules/index.js")).toBe(true)
+  expect(Ignore.match("node_modules")).toBe(true)
+  expect(Ignore.match("node_modules/")).toBe(true)
+  expect(Ignore.match("node_modules/bar")).toBe(true)
+  expect(Ignore.match("node_modules/bar/")).toBe(true)
+})
--- a/packages/core/test/filesystem/ripgrep.test.ts
+++ b/packages/core/test/filesystem/ripgrep.test.ts
@@ -0,0 +1,220 @@
+import { describe, expect } from "bun:test"
+import { Effect } from "effect"
+import * as Stream from "effect/Stream"
+import fs from "fs/promises"
+import os from "os"
+import path from "path"
+import { Ripgrep } from "@opencode-ai/core/filesystem/ripgrep"
+import { testEffect } from "../lib/effect"
+
+const it = testEffect(Ripgrep.defaultLayer)
+
+const tmpdir = (init?: (dir: string) => Effect.Effect<void>) =>
+  Effect.acquireRelease(
+    Effect.promise(async () => fs.realpath(await fs.mkdtemp(path.join(os.tmpdir(), "opencode-test-")))),
+    (dir) =>
+      Effect.promise(() =>
+        fs.rm(dir, {
+          recursive: true,
+          force: true,
+          maxRetries: 5,
+          retryDelay: 100,
+        }),
+      ).pipe(Effect.ignore),
+  ).pipe(Effect.tap((dir) => init?.(dir) ?? Effect.void))
+
+const write = (file: string, data: string) => Effect.promise(() => Bun.write(file, data))
+const mkdir = (dir: string) => Effect.promise(() => fs.mkdir(dir, { recursive: true }))
+const collectFiles = (input: Ripgrep.FilesInput) =>
+  Ripgrep.Service.use((rg) =>
+    rg.files(input).pipe(
+      Stream.runCollect,
+      Effect.map((c) => [...c]),
+    ),
+  )
+
+const withRipgrepConfig = <A, E, R>(value: string, effect: Effect.Effect<A, E, R>) =>
+  Effect.acquireUseRelease(
+    Effect.sync(() => {
+      const prev = process.env["RIPGREP_CONFIG_PATH"]
+      process.env["RIPGREP_CONFIG_PATH"] = value
+      return prev
+    }),
+    () => effect,
+    (prev) =>
+      Effect.sync(() => {
+        if (prev === undefined) delete process.env["RIPGREP_CONFIG_PATH"]
+        else process.env["RIPGREP_CONFIG_PATH"] = prev
+      }),
+  )
+
+describe("file.ripgrep", () => {
+  it.live("defaults to include hidden", () =>
+    Effect.gen(function* () {
+      const dir = yield* tmpdir((dir) =>
+        Effect.gen(function* () {
+          yield* write(path.join(dir, "visible.txt"), "hello")
+          yield* mkdir(path.join(dir, ".opencode"))
+          yield* write(path.join(dir, ".opencode", "thing.json"), "{}")
+        }),
+      )
+
+      const files = yield* collectFiles({ cwd: dir })
+      expect(files.includes("visible.txt")).toBe(true)
+      expect(files.includes(path.join(".opencode", "thing.json"))).toBe(true)
+    }),
+  )
+
+  it.live("hidden false excludes hidden", () =>
+    Effect.gen(function* () {
+      const dir = yield* tmpdir((dir) =>
+        Effect.gen(function* () {
+          yield* write(path.join(dir, "visible.txt"), "hello")
+          yield* mkdir(path.join(dir, ".opencode"))
+          yield* write(path.join(dir, ".opencode", "thing.json"), "{}")
+        }),
+      )
+
+      const files = yield* collectFiles({ cwd: dir, hidden: false })
+      expect(files.includes("visible.txt")).toBe(true)
+      expect(files.includes(path.join(".opencode", "thing.json"))).toBe(false)
+    }),
+  )
+
+  it.live("search returns empty when nothing matches", () =>
+    Effect.gen(function* () {
+      const dir = yield* tmpdir((dir) => write(path.join(dir, "match.ts"), "const value = 'other'\n"))
+
+      const result = yield* Ripgrep.use.search({ cwd: dir, pattern: "needle" })
+      expect(result.partial).toBe(false)
+      expect(result.items).toEqual([])
+    }),
+  )
+
+  it.live("search returns match metadata with normalized path", () =>
+    Effect.gen(function* () {
+      const dir = yield* tmpdir((dir) =>
+        Effect.gen(function* () {
+          yield* mkdir(path.join(dir, "src"))
+          yield* write(path.join(dir, "src", "match.ts"), "const needle = 1\n")
+        }),
+      )
+
+      const result = yield* Ripgrep.use.search({ cwd: dir, pattern: "needle" })
+      expect(result.partial).toBe(false)
+      expect(result.items).toHaveLength(1)
+      expect(result.items[0]?.path.text).toBe(path.join("src", "match.ts"))
+      expect(result.items[0]?.line_number).toBe(1)
+      expect(result.items[0]?.lines.text).toContain("needle")
+    }),
+  )
+
+  it.live("search returns matched rows with glob filter", () =>
+    Effect.gen(function* () {
+      const dir = yield* tmpdir((dir) =>
+        Effect.gen(function* () {
+          yield* write(path.join(dir, "match.ts"), "const value = 'needle'\n")
+          yield* write(path.join(dir, "skip.txt"), "const value = 'other'\n")
+        }),
+      )
+
+      const result = yield* Ripgrep.use.search({ cwd: dir, pattern: "needle", glob: ["*.ts"] })
+      expect(result.partial).toBe(false)
+      expect(result.items).toHaveLength(1)
+      expect(result.items[0]?.path.text).toContain("match.ts")
+      expect(result.items[0]?.lines.text).toContain("needle")
+    }),
+  )
+
+  it.live("search supports explicit file targets", () =>
+    Effect.gen(function* () {
+      const dir = yield* tmpdir((dir) =>
+        Effect.gen(function* () {
+          yield* write(path.join(dir, "match.ts"), "const value = 'needle'\n")
+          yield* write(path.join(dir, "skip.ts"), "const value = 'needle'\n")
+        }),
+      )
+
+      const file = path.join(dir, "match.ts")
+      const result = yield* Ripgrep.use.search({ cwd: dir, pattern: "needle", file: [file] })
+      expect(result.partial).toBe(false)
+      expect(result.items).toHaveLength(1)
+      expect(result.items[0]?.path.text).toBe(file)
+    }),
+  )
+
+  it.live("files returns empty when glob matches no files", () =>
+    Effect.gen(function* () {
+      const dir = yield* tmpdir((dir) =>
+        Effect.gen(function* () {
+          yield* mkdir(path.join(dir, "packages", "console"))
+          yield* write(path.join(dir, "packages", "console", "package.json"), "{}")
+        }),
+      )
+
+      const files = yield* collectFiles({ cwd: dir, glob: ["packages/*"] })
+      expect(files).toEqual([])
+    }),
+  )
+
+  it.live("files returns stream of filenames", () =>
+    Effect.gen(function* () {
+      const dir = yield* tmpdir((dir) =>
+        Effect.gen(function* () {
+          yield* write(path.join(dir, "a.txt"), "hello")
+          yield* write(path.join(dir, "b.txt"), "world")
+        }),
+      )
+
+      const files = yield* collectFiles({ cwd: dir }).pipe(Effect.map((files) => files.sort()))
+      expect(files).toEqual(["a.txt", "b.txt"])
+    }),
+  )
+
+  it.live("files respects glob filter", () =>
+    Effect.gen(function* () {
+      const dir = yield* tmpdir((dir) =>
+        Effect.gen(function* () {
+          yield* write(path.join(dir, "keep.ts"), "yes")
+          yield* write(path.join(dir, "skip.txt"), "no")
+        }),
+      )
+
+      const files = yield* collectFiles({ cwd: dir, glob: ["*.ts"] })
+      expect(files).toEqual(["keep.ts"])
+    }),
+  )
+
+  it.live("files dies on nonexistent directory", () =>
+    Effect.gen(function* () {
+      const exit = yield* Ripgrep.Service.use((rg) =>
+        rg.files({ cwd: "/tmp/nonexistent-dir-12345" }).pipe(Stream.runCollect),
+      ).pipe(Effect.exit)
+      expect(exit._tag).toBe("Failure")
+    }),
+  )
+
+  it.live("ignores RIPGREP_CONFIG_PATH in direct mode", () =>
+    Effect.gen(function* () {
+      const dir = yield* tmpdir((dir) => write(path.join(dir, "match.ts"), "const needle = 1\n"))
+
+      const result = yield* withRipgrepConfig(
+        path.join(dir, "missing-ripgreprc"),
+        Ripgrep.use.search({ cwd: dir, pattern: "needle" }),
+      )
+      expect(result.items).toHaveLength(1)
+    }),
+  )
+
+  it.live("ignores RIPGREP_CONFIG_PATH in worker mode", () =>
+    Effect.gen(function* () {
+      const dir = yield* tmpdir((dir) => write(path.join(dir, "match.ts"), "const needle = 1\n"))
+
+      const result = yield* withRipgrepConfig(
+        path.join(dir, "missing-ripgreprc"),
+        Ripgrep.use.search({ cwd: dir, pattern: "needle" }),
+      )
+      expect(result.items).toHaveLength(1)
+    }),
+  )
+})
--- a/packages/core/test/filesystem/watcher.test.ts
+++ b/packages/core/test/filesystem/watcher.test.ts
@@ -0,0 +1,272 @@
+import { $ } from "bun"
+import { describe, expect } from "bun:test"
+import fs from "fs/promises"
+import path from "path"
+import { ConfigProvider, Deferred, Duration, Effect, Fiber, Layer, Option, Stream } from "effect"
+import { Config } from "@opencode-ai/core/config"
+import { EventV2 } from "@opencode-ai/core/event"
+import { FSUtil } from "@opencode-ai/core/fs-util"
+import { Watcher } from "@opencode-ai/core/filesystem/watcher"
+import { Git } from "@opencode-ai/core/git"
+import { Location } from "@opencode-ai/core/location"
+import { AbsolutePath } from "@opencode-ai/core/schema"
+import { location } from "../fixture/location"
+import { tmpdir } from "../fixture/tmpdir"
+import { testEffect } from "../lib/effect"
+
+const describeWatcher = Watcher.hasNativeBinding() && !process.env.CI ? describe : describe.skip
+
+type WatcherEvent = { file: string; event: "add" | "change" | "unlink" }
+
+const it = testEffect(Layer.mergeAll(FSUtil.defaultLayer, EventV2.defaultLayer))
+
+const configLayer = Layer.succeed(
+  Config.Service,
+  Config.Service.of({
+    directories: () => Effect.succeed([]),
+    get: () => Effect.succeed([]),
+  }),
+)
+
+const flagsLayer = ConfigProvider.layer(
+  ConfigProvider.fromUnknown({
+    OPENCODE_EXPERIMENTAL_FILEWATCHER: "true",
+    OPENCODE_EXPERIMENTAL_DISABLE_FILEWATCHER: "false",
+  }),
+)
+
+function provide(directory: string, vcs?: Location.Interface["vcs"]) {
+  const locationLayer = Layer.succeed(
+    Location.Service,
+    Location.Service.of(location({ directory: AbsolutePath.make(directory) }, { vcs })),
+  )
+  return Effect.provide(
+    Watcher.layer.pipe(
+      Layer.provide(configLayer),
+      Layer.provide(Git.defaultLayer),
+      Layer.provide(locationLayer),
+      Layer.provide(flagsLayer),
+    ),
+  )
+}
+
+function withTmp<A, E, R>(
+  f: (directory: string, vcs?: Location.Interface["vcs"]) => Effect.Effect<A, E, R>,
+  options?: { git?: boolean; init?: (directory: string) => Promise<void> },
+) {
+  return Effect.acquireRelease(
+    Effect.promise(async () => {
+      const tmp = await tmpdir()
+      if (!options?.git) return { tmp, vcs: undefined }
+      await $`git init`.cwd(tmp.path).quiet()
+      await $`git config core.fsmonitor false`.cwd(tmp.path).quiet()
+      await $`git config commit.gpgsign false`.cwd(tmp.path).quiet()
+      await $`git config user.email test@opencode.test`.cwd(tmp.path).quiet()
+      await $`git config user.name Test`.cwd(tmp.path).quiet()
+      await $`git commit --allow-empty -m root`.cwd(tmp.path).quiet()
+      await options.init?.(tmp.path)
+      return { tmp, vcs: { type: "git" as const, store: AbsolutePath.make(path.join(tmp.path, ".git")) } }
+    }),
+    ({ tmp }) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
+  ).pipe(Effect.flatMap(({ tmp, vcs }) => f(tmp.path, vcs).pipe(provide(tmp.path, vcs))))
+}
+
+function wait(check: (event: WatcherEvent) => boolean) {
+  return Effect.gen(function* () {
+    const events = yield* EventV2.Service
+    const deferred = yield* Deferred.make<WatcherEvent>()
+    const fiber = yield* events.subscribe(Watcher.Event.Updated).pipe(
+      Stream.runForEach((event) => {
+        if (!check(event.data)) return Effect.void
+        return Deferred.succeed(deferred, event.data).pipe(Effect.asVoid)
+      }),
+      Effect.forkScoped,
+    )
+    yield* Effect.yieldNow
+    return { deferred, fiber }
+  })
+}
+
+function maybeNextUpdate<E>(
+  check: (event: WatcherEvent) => boolean,
+  trigger: Effect.Effect<void, E>,
+  timeout: Duration.Input = "5 seconds",
+) {
+  return Effect.acquireUseRelease(
+    wait(check),
+    ({ deferred }) => trigger.pipe(Effect.andThen(Deferred.await(deferred)), Effect.timeoutOption(timeout)),
+    ({ fiber }) => Fiber.interrupt(fiber),
+  )
+}
+
+function nextUpdate<E>(check: (event: WatcherEvent) => boolean, trigger: Effect.Effect<void, E>) {
+  return Effect.gen(function* () {
+    const result = yield* maybeNextUpdate(check, trigger)
+    if (Option.isSome(result)) return result.value
+    return yield* Effect.fail(new Error("timed out waiting for file watcher update"))
+  })
+}
+
+function eventuallyUpdate<E>(check: (event: WatcherEvent) => boolean, trigger: () => Effect.Effect<void, E>) {
+  return Effect.gen(function* () {
+    while (true) {
+      const result = yield* maybeNextUpdate(check, trigger(), "250 millis")
+      if (Option.isSome(result)) return result.value
+    }
+  }).pipe(
+    Effect.timeoutOrElse({
+      duration: "5 seconds",
+      orElse: () => Effect.fail(new Error("timed out waiting for file watcher readiness")),
+    }),
+  )
+}
+
+function noUpdate<E>(check: (event: WatcherEvent) => boolean, trigger: Effect.Effect<void, E>, timeout = 500) {
+  return Effect.acquireUseRelease(
+    wait(check),
+    ({ deferred }) =>
+      trigger.pipe(
+        Effect.andThen(Deferred.await(deferred)),
+        Effect.timeoutOption(`${timeout} millis`),
+        Effect.tap((result) => Effect.sync(() => expect(result).toEqual(Option.none()))),
+      ),
+    ({ fiber }) => Fiber.interrupt(fiber),
+  )
+}
+
+function ready(directory: string) {
+  const file = path.join(directory, `.watcher-${Math.random().toString(36).slice(2)}`)
+  return Effect.gen(function* () {
+    const fs = yield* FSUtil.Service
+    yield* eventuallyUpdate(
+      (event) => event.file === file,
+      () => fs.writeFileString(file, `ready-${Math.random()}`),
+    ).pipe(Effect.ensuring(fs.remove(file, { force: true }).pipe(Effect.ignore)), Effect.asVoid)
+  })
+}
+
+describeWatcher("Watcher", () => {
+  it.live("publishes root create, update, and delete events", () =>
+    withTmp(
+      (directory) =>
+        Effect.gen(function* () {
+          const fs = yield* FSUtil.Service
+          const file = path.join(directory, "watch.txt")
+          yield* ready(directory)
+          for (const item of [
+            { event: "add" as const, trigger: fs.writeFileString(file, "a") },
+            { event: "change" as const, trigger: fs.writeFileString(file, "b") },
+            { event: "unlink" as const, trigger: fs.remove(file) },
+          ]) {
+            expect(
+              yield* nextUpdate((event) => event.file === file && event.event === item.event, item.trigger),
+            ).toEqual({
+              file,
+              event: item.event,
+            })
+          }
+        }),
+      { git: true },
+    ),
+  )
+
+  it.live("watches non-git roots", () =>
+    withTmp((directory) =>
+      Effect.gen(function* () {
+        const fs = yield* FSUtil.Service
+        const file = path.join(directory, "plain.txt")
+        yield* ready(directory)
+        expect(yield* nextUpdate((event) => event.file === file, fs.writeFileString(file, "plain"))).toEqual({
+          file,
+          event: "add",
+        })
+      }),
+    ),
+  )
+
+  it.live("cleanup stops publishing events", () =>
+    Effect.gen(function* () {
+      const events = yield* EventV2.Service
+      const fs = yield* FSUtil.Service
+      const tmp = yield* Effect.acquireRelease(
+        Effect.promise(() => tmpdir()),
+        (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
+      )
+      yield* ready(tmp.path).pipe(provide(tmp.path), Effect.scoped)
+      const file = path.join(tmp.path, "after-dispose.txt")
+      yield* noUpdate((event) => event.file === file, fs.writeFileString(file, "gone")).pipe(
+        Effect.provideService(EventV2.Service, events),
+      )
+    }).pipe(Effect.provide(Layer.mergeAll(FSUtil.defaultLayer, EventV2.defaultLayer))),
+  )
+
+  it.live("ignores .git/index changes", () =>
+    withTmp(
+      (directory) =>
+        Effect.gen(function* () {
+          const fs = yield* FSUtil.Service
+          const index = path.join(directory, ".git", "index")
+          yield* ready(directory)
+          yield* noUpdate(
+            (event) => event.file === index,
+            fs
+              .writeFileString(path.join(directory, "tracked.txt"), "a")
+              .pipe(Effect.andThen(Effect.promise(() => $`git add .`.cwd(directory).quiet())), Effect.asVoid),
+          )
+        }),
+      { git: true },
+    ),
+  )
+
+  it.live("publishes .git/HEAD events", () =>
+    withTmp(
+      (directory) =>
+        Effect.gen(function* () {
+          const fs = yield* FSUtil.Service
+          const head = path.join(directory, ".git", "HEAD")
+          const branch = `watch-${Math.random().toString(36).slice(2)}`
+          yield* ready(directory)
+          yield* Effect.promise(() => $`git branch ${branch}`.cwd(directory).quiet())
+          expect(
+            yield* nextUpdate((event) => event.file === head, fs.writeFileString(head, `ref: refs/heads/${branch}\n`)),
+          ).toEqual({
+            file: head,
+            event: "change",
+          })
+        }),
+      { git: true },
+    ),
+  )
+
+  const describeSymlink = process.platform !== "win32" ? describe : describe.skip
+  describeSymlink("symlinked .git", () => {
+    it.live("publishes .git/HEAD events through a symlinked .git directory", () =>
+      withTmp(
+        (directory) =>
+          Effect.gen(function* () {
+            const afs = yield* FSUtil.Service
+            const actual = path.join(directory, "..", `actual_${path.basename(directory)}`)
+            yield* Effect.addFinalizer(() => Effect.promise(() => fs.rm(actual, { recursive: true, force: true })))
+            yield* ready(directory)
+            const head = path.join(directory, ".git", "HEAD")
+            const branch = `watch-${Math.random().toString(36).slice(2)}`
+            yield* Effect.promise(() => $`git branch ${branch}`.cwd(directory).quiet())
+            expect(
+              yield* nextUpdate(
+                (event) => event.file === path.join(actual, "HEAD"),
+                afs.writeFileString(head, `ref: refs/heads/${branch}\n`),
+              ),
+            ).toEqual({ file: path.join(actual, "HEAD"), event: "change" })
+          }),
+        {
+          git: true,
+          init: async (directory) => {
+            const actual = path.join(directory, "..", `actual_${path.basename(directory)}`)
+            await fs.rename(path.join(directory, ".git"), actual)
+            await fs.symlink(actual, path.join(directory, ".git"))
+          },
+        },
+      ),
+    )
+  })
+})
--- a/packages/core/test/fixture/effect-flock-worker.ts
+++ b/packages/core/test/fixture/effect-flock-worker.ts
@@ -1,7 +1,7 @@
 import fs from "fs/promises"
 import os from "os"
 import { Effect, Layer } from "effect"
-import { AppFileSystem } from "@opencode-ai/core/filesystem"
+import { FSUtil } from "@opencode-ai/core/fs-util"
 import { EffectFlock } from "@opencode-ai/core/util/effect-flock"
 import { Global } from "@opencode-ai/core/global"

@@ -30,7 +30,7 @@ const testGlobal = Global.layerWith({
  log: os.tmpdir(),
 })

-const testLayer = EffectFlock.layer.pipe(Layer.provide(testGlobal), Layer.provide(AppFileSystem.defaultLayer))
+const testLayer = EffectFlock.layer.pipe(Layer.provide(testGlobal), Layer.provide(FSUtil.defaultLayer))

 async function job() {
  if (msg.ready) await fs.writeFile(msg.ready, String(process.pid))
--- a/packages/core/test/location-filesystem.test.ts
+++ b/packages/core/test/location-filesystem.test.ts
@@ -3,9 +3,10 @@ import path from "path"
 import { fileURLToPath } from "url"
 import { describe, expect } from "bun:test"
 import { Effect, Exit, Layer } from "effect"
-import { AppFileSystem } from "@opencode-ai/core/filesystem"
+import { FSUtil } from "@opencode-ai/core/fs-util"
 import { Location } from "@opencode-ai/core/location"
-import { LocationFileSystem } from "@opencode-ai/core/location-filesystem"
+import { FileSystem } from "@opencode-ai/core/filesystem"
+import { Ripgrep } from "@opencode-ai/core/filesystem/ripgrep"
 import { ProjectReference } from "@opencode-ai/core/project-reference"
 import { Repository } from "@opencode-ai/core/repository"
 import { AbsolutePath, RelativePath } from "@opencode-ai/core/schema"
@@ -23,10 +24,11 @@ const inertReferences = ProjectReference.Service.of({

 function provide(directory: string, references = inertReferences) {
  return Effect.provide(
-    LocationFileSystem.layer.pipe(
+    FileSystem.layer.pipe(
      Layer.provide(
        Layer.mergeAll(
-          AppFileSystem.defaultLayer,
+          FSUtil.defaultLayer,
+          Ripgrep.defaultLayer,
          Layer.succeed(Location.Service, Location.Service.of(location({ directory: AbsolutePath.make(directory) }))),
          Layer.succeed(ProjectReference.Service, references),
        ),
@@ -42,13 +44,13 @@ function withTmp<A, E, R>(f: (directory: string) => Effect.Effect<A, E, R>) {
  ).pipe(Effect.flatMap((tmp) => f(tmp.path)))
 }

-describe("LocationFileSystem", () => {
+describe("FileSystem", () => {
  it.live("reads text and binary files", () =>
    withTmp((directory) =>
      Effect.gen(function* () {
        yield* Effect.promise(() => fs.writeFile(path.join(directory, "hello.txt"), "hello"))
        yield* Effect.promise(() => fs.writeFile(path.join(directory, "data.bin"), Buffer.from([0, 1, 2])))
-        const service = yield* LocationFileSystem.Service
+        const service = yield* FileSystem.Service

        expect(yield* service.read({ path: RelativePath.make("hello.txt") })).toEqual({
          type: "text",
@@ -70,7 +72,7 @@ describe("LocationFileSystem", () => {
      Effect.gen(function* () {
        yield* Effect.promise(() => fs.mkdir(path.join(directory, "src")))
        yield* Effect.promise(() => fs.writeFile(path.join(directory, "README.md"), "# Test"))
-        const service = yield* LocationFileSystem.Service
+        const service = yield* FileSystem.Service

        const entries = yield* service.list()
        expect(entries.map(({ uri: _uri, ...entry }) => entry)).toEqual([
@@ -99,7 +101,7 @@ describe("LocationFileSystem", () => {
  it.live("rejects paths outside the location", () =>
    withTmp((directory) =>
      Effect.gen(function* () {
-        const service = yield* LocationFileSystem.Service
+        const service = yield* FileSystem.Service
        expect(
          Exit.isFailure(yield* service.read({ path: RelativePath.make("../outside.txt") }).pipe(Effect.exit)),
        ).toBe(true)
@@ -107,6 +109,42 @@ describe("LocationFileSystem", () => {
    ),
  )

+  it.live("finds files and directories", () =>
+    withTmp((directory) =>
+      Effect.gen(function* () {
+        yield* Effect.promise(() => fs.mkdir(path.join(directory, "src")))
+        yield* Effect.promise(() => fs.writeFile(path.join(directory, "src", "index.ts"), "const needle = true\n"))
+        const service = yield* FileSystem.Service
+
+        expect((yield* service.find({ query: "index", type: "file" })).map((item) => item.path)).toEqual([
+          RelativePath.make(path.join("src", "index.ts")),
+        ])
+        expect((yield* service.find({ query: "src", type: "directory" })).map((item) => item.path)).toEqual([
+          RelativePath.make("src"),
+        ])
+      }).pipe(provide(directory)),
+    ),
+  )
+
+  it.live("greps file contents", () =>
+    withTmp((directory) =>
+      Effect.gen(function* () {
+        yield* Effect.promise(() => fs.writeFile(path.join(directory, "index.ts"), "const needle = true\n"))
+        const service = yield* FileSystem.Service
+
+        expect(yield* service.grep({ pattern: "needle" })).toEqual([
+          {
+            path: RelativePath.make("index.ts"),
+            lines: "const needle = true\n",
+            line: 1,
+            offset: 0,
+            submatches: [{ text: "needle", start: 6, end: 12 }],
+          },
+        ])
+      }).pipe(provide(directory)),
+    ),
+  )
+
  it.live("reads and lists paths relative to a local project reference", () =>
    withTmp((directory) => {
      const docs = path.join(directory, "docs")
@@ -115,7 +153,7 @@ describe("LocationFileSystem", () => {
          await fs.mkdir(docs)
          await fs.writeFile(path.join(docs, "README.md"), "docs")
        })
-        const service = yield* LocationFileSystem.Service
+        const service = yield* FileSystem.Service

        expect(yield* service.read({ reference: "docs", path: RelativePath.make("README.md") })).toMatchObject({
          type: "text",
@@ -136,7 +174,7 @@ describe("LocationFileSystem", () => {
          await fs.writeFile(path.join(docs, "README.md"), "docs")
        })
        expect(
-          yield* (yield* LocationFileSystem.Service).read({ reference: "sdk", path: RelativePath.make("README.md") }),
+          yield* (yield* FileSystem.Service).read({ reference: "sdk", path: RelativePath.make("README.md") }),
        ).toMatchObject({ content: "docs" })
        expect(ensured).toEqual([docs])
      }).pipe(
@@ -164,7 +202,7 @@ describe("LocationFileSystem", () => {
      const docs = path.join(directory, "docs")
      return Effect.gen(function* () {
        yield* Effect.promise(() => fs.mkdir(docs))
-        const service = yield* LocationFileSystem.Service
+        const service = yield* FileSystem.Service
        expect(Exit.isFailure(yield* service.list({ reference: "unknown" }).pipe(Effect.exit))).toBe(true)
        expect(Exit.isFailure(yield* service.list({ reference: "invalid" }).pipe(Effect.exit))).toBe(true)
        expect(
@@ -188,7 +226,7 @@ describe("LocationFileSystem", () => {
    withTmp((directory) =>
      Effect.gen(function* () {
        expect(
-          Exit.isFailure(yield* (yield* LocationFileSystem.Service).list({ reference: "docs" }).pipe(Effect.exit)),
+          Exit.isFailure(yield* (yield* FileSystem.Service).list({ reference: "docs" }).pipe(Effect.exit)),
        ).toBe(true)
      }).pipe(provide(directory)),
    ),
@@ -207,7 +245,7 @@ describe("LocationFileSystem", () => {
        })
        expect(
          Exit.isFailure(
-            yield* (yield* LocationFileSystem.Service)
+            yield* (yield* FileSystem.Service)
              .read({ reference: "docs", path: RelativePath.make("link.txt") })
              .pipe(Effect.exit),
          ),
--- a/packages/core/test/location-layer.test.ts
+++ b/packages/core/test/location-layer.test.ts
@@ -9,7 +9,7 @@ import { ProviderV2 } from "@opencode-ai/core/provider"
 import { AbsolutePath } from "@opencode-ai/core/schema"
 import { tmpdir } from "./fixture/tmpdir"
 import { testEffect } from "./lib/effect"
-import { AppFileSystem } from "../src/filesystem"
+import { FSUtil } from "../src/fs-util"
 import { Auth } from "../src/auth"
 import { EventV2 } from "../src/event"
 import { Global } from "../src/global"
@@ -27,7 +27,7 @@ const it = testEffect(
        Auth.defaultLayer,
        Npm.defaultLayer,
        ModelsDev.defaultLayer,
-        AppFileSystem.defaultLayer,
+        FSUtil.defaultLayer,
        Global.defaultLayer,
      ),
    ),
--- a/packages/core/test/models.test.ts
+++ b/packages/core/test/models.test.ts
@@ -1,7 +1,7 @@
 import { describe, expect, beforeAll, beforeEach, afterAll } from "bun:test"
 import { Effect, Layer, Ref } from "effect"
 import { HttpClient, HttpClientResponse } from "effect/unstable/http"
-import { AppFileSystem } from "@opencode-ai/core/filesystem"
+import { FSUtil } from "@opencode-ai/core/fs-util"
 import { Flag } from "@opencode-ai/core/flag/flag"
 import { Global } from "@opencode-ai/core/global"
 import { ModelsDev } from "@opencode-ai/core/models-dev"
@@ -92,7 +92,7 @@ const buildLayer = (state: Ref.Ref<MockState>) =>
  // every test would reuse the cachedInvalidateWithTTL state from the first run.
  Layer.fresh(ModelsDev.layer).pipe(
    Layer.provide(Layer.succeed(HttpClient.HttpClient, makeMockClient(state))),
-    Layer.provide(AppFileSystem.defaultLayer),
+    Layer.provide(FSUtil.defaultLayer),
    Layer.provide(EventV2.defaultLayer),
  )

--- a/packages/core/test/npm.test.ts
+++ b/packages/core/test/npm.test.ts
@@ -3,7 +3,7 @@ import path from "path"
 import { describe, expect, test } from "bun:test"
 import { NodeFileSystem } from "@effect/platform-node"
 import { Effect, Layer, Option } from "effect"
-import { AppFileSystem } from "@opencode-ai/core/filesystem"
+import { FSUtil } from "@opencode-ai/core/fs-util"
 import { Global } from "@opencode-ai/core/global"
 import { Npm } from "@opencode-ai/core/npm"
 import { EffectFlock } from "@opencode-ai/core/util/effect-flock"
@@ -23,7 +23,7 @@ const writePackage = (dir: string, pkg: Record<string, unknown>) =>
 const npmLayer = (cache: string) =>
  Npm.layer.pipe(
    Layer.provide(EffectFlock.layer),
-    Layer.provide(AppFileSystem.layer),
+    Layer.provide(FSUtil.layer),
    Layer.provide(Global.layerWith({ cache, state: path.join(cache, "state") })),
    Layer.provide(NodeFileSystem.layer),
  )
--- a/packages/core/test/project-reference.test.ts
+++ b/packages/core/test/project-reference.test.ts
@@ -4,7 +4,7 @@ import path from "path"
 import { Deferred, Effect, Layer, Schema } from "effect"
 import { Config } from "@opencode-ai/core/config"
 import { ConfigReference } from "@opencode-ai/core/config/reference"
-import { AppFileSystem } from "@opencode-ai/core/filesystem"
+import { FSUtil } from "@opencode-ai/core/fs-util"
 import { Flag } from "@opencode-ai/core/flag/flag"
 import { Global } from "@opencode-ai/core/global"
 import { Location } from "@opencode-ai/core/location"
@@ -243,7 +243,7 @@ function testLayer(input: {
  return ProjectReference.layer.pipe(
    Layer.provide(
      Layer.mergeAll(
-        AppFileSystem.defaultLayer,
+        FSUtil.defaultLayer,
        Global.layerWith({ home: path.join(input.directory, "home"), repos: input.repos }),
        Layer.succeed(
          Location.Service,
--- a/packages/core/test/repository-cache.test.ts
+++ b/packages/core/test/repository-cache.test.ts
@@ -3,7 +3,7 @@ import fs from "fs/promises"
 import path from "path"
 import { pathToFileURL } from "url"
 import { Effect, Layer } from "effect"
-import { AppFileSystem } from "@opencode-ai/core/filesystem"
+import { FSUtil } from "@opencode-ai/core/fs-util"
 import { Git } from "@opencode-ai/core/git"
 import { Global } from "@opencode-ai/core/global"
 import { Repository } from "@opencode-ai/core/repository"
@@ -91,7 +91,7 @@ describe("RepositoryCache", () => {
 function cacheLayer(root: string) {
  const dependencies = Layer.mergeAll(
    Global.layerWith({ state: path.join(root, "state"), repos: path.join(root, "repos") }),
-    AppFileSystem.defaultLayer,
+    FSUtil.defaultLayer,
  )
  return RepositoryCache.layer.pipe(
    Layer.provide(EffectFlock.layer.pipe(Layer.provide(dependencies))),
--- a/packages/core/test/util/effect-flock.test.ts
+++ b/packages/core/test/util/effect-flock.test.ts
@@ -5,7 +5,7 @@ import path from "path"
 import os from "os"
 import { Cause, Effect, Exit, Layer } from "effect"
 import { testEffect } from "../lib/effect"
-import { AppFileSystem } from "@opencode-ai/core/filesystem"
+import { FSUtil } from "@opencode-ai/core/fs-util"
 import { EffectFlock } from "@opencode-ai/core/util/effect-flock"
 import { Global } from "@opencode-ai/core/global"
 import { Hash } from "@opencode-ai/core/util/hash"
@@ -103,7 +103,7 @@ const testGlobal = Global.layerWith({
  log: os.tmpdir(),
 })

-const testLayer = EffectFlock.layer.pipe(Layer.provide(testGlobal), Layer.provide(AppFileSystem.defaultLayer))
+const testLayer = EffectFlock.layer.pipe(Layer.provide(testGlobal), Layer.provide(FSUtil.defaultLayer))

 // ---------------------------------------------------------------------------
 // Tests
--- a/packages/core/test/util/which.test.ts
+++ b/packages/core/test/util/which.test.ts
@@ -0,0 +1,100 @@
+import { describe, expect, test } from "bun:test"
+import fs from "fs/promises"
+import path from "path"
+import { which } from "@opencode-ai/core/util/which"
+import { tmpdir } from "../fixture/tmpdir"
+
+async function cmd(dir: string, name: string, exec = true) {
+  const ext = process.platform === "win32" ? ".cmd" : ""
+  const file = path.join(dir, name + ext)
+  const body = process.platform === "win32" ? "@echo off\r\n" : "#!/bin/sh\n"
+  await fs.writeFile(file, body)
+  if (process.platform !== "win32") {
+    await fs.chmod(file, exec ? 0o755 : 0o644)
+  }
+  return file
+}
+
+function env(PATH: string): NodeJS.ProcessEnv {
+  return {
+    PATH,
+    PATHEXT: process.env["PATHEXT"],
+  }
+}
+
+function envPath(Path: string): NodeJS.ProcessEnv {
+  return {
+    Path,
+    PathExt: process.env["PathExt"] ?? process.env["PATHEXT"],
+  }
+}
+
+function same(a: string | null, b: string) {
+  if (process.platform === "win32") {
+    expect(a?.toLowerCase()).toBe(b.toLowerCase())
+    return
+  }
+
+  expect(a).toBe(b)
+}
+
+describe("util.which", () => {
+  test("returns null when command is missing", () => {
+    expect(which("opencode-missing-command-for-test")).toBeNull()
+  })
+
+  test("finds a command from PATH override", async () => {
+    await using tmp = await tmpdir()
+    const bin = path.join(tmp.path, "bin")
+    await fs.mkdir(bin)
+    const file = await cmd(bin, "tool")
+
+    same(which("tool", env(bin)), file)
+  })
+
+  test("uses first PATH match", async () => {
+    await using tmp = await tmpdir()
+    const a = path.join(tmp.path, "a")
+    const b = path.join(tmp.path, "b")
+    await fs.mkdir(a)
+    await fs.mkdir(b)
+    const first = await cmd(a, "dupe")
+    await cmd(b, "dupe")
+
+    same(which("dupe", env([a, b].join(path.delimiter))), first)
+  })
+
+  test("returns null for non-executable file on unix", async () => {
+    if (process.platform === "win32") return
+
+    await using tmp = await tmpdir()
+    const bin = path.join(tmp.path, "bin")
+    await fs.mkdir(bin)
+    await cmd(bin, "noexec", false)
+
+    expect(which("noexec", env(bin))).toBeNull()
+  })
+
+  test("uses PATHEXT on windows", async () => {
+    if (process.platform !== "win32") return
+
+    await using tmp = await tmpdir()
+    const bin = path.join(tmp.path, "bin")
+    await fs.mkdir(bin)
+    const file = path.join(bin, "pathext.CMD")
+    await fs.writeFile(file, "@echo off\r\n")
+
+    expect(which("pathext", { PATH: bin, PATHEXT: ".CMD" })).toBe(file)
+  })
+
+  test("uses Windows Path casing fallback", async () => {
+    if (process.platform !== "win32") return
+
+    await using tmp = await tmpdir()
+    const bin = path.join(tmp.path, "bin")
+    await fs.mkdir(bin)
+    const file = await cmd(bin, "mixed")
+
+    same(which("mixed", envPath(bin)), file)
+  })
+})