test(skill): migrate skill tests to effect fixtures (#29046)

packages/core/src/effect/service-use.ts

@@ -15,6 +15,7 @@ type ServiceUse<Identifier, Shape> = {
 }
 
 export const serviceUse = <Identifier, Shape>(tag: Context.Service<Identifier, Shape>) => {
+  const cache = new Map<string, (...args: unknown[]) => Effect.Effect<unknown, unknown, unknown>>()
   // This is the only dynamic boundary: TypeScript knows the accessor shape,
   // but Proxy property names are runtime values.
   const access = new Proxy(
@@ -22,7 +23,9 @@ export const serviceUse = <Identifier, Shape>(tag: Context.Service<Identifier, S
     {
       get: (_, key) => {
         if (typeof key !== "string") return undefined
-        return (...args: unknown[]) =>
+        const cached = cache.get(key)
+        if (cached) return cached
+        const accessor = (...args: unknown[]) =>
           tag.use((service) => {
             // oxlint-disable-next-line typescript-eslint/no-unsafe-type-assertion -- Proxy keys are checked at runtime.
             const method = service[key as keyof Shape]
@@ -30,6 +33,8 @@ export const serviceUse = <Identifier, Shape>(tag: Context.Service<Identifier, S
             // oxlint-disable-next-line typescript-eslint/no-unsafe-type-assertion -- ServiceUse exposes only Effect-returning methods.
             return (method as (...args: unknown[]) => Effect.Effect<unknown, unknown, unknown>)(...args)
           })
+        cache.set(key, accessor)
+        return accessor
       },
     },
   )

packages/core/src/filesystem.ts

@@ -3,9 +3,10 @@ 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 { Effect, FileSystem, Layer, Schema, Context } from "effect"
+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 AppFileSystem {
   export class FileSystemError extends Schema.TaggedErrorClass<FileSystemError>()("FileSystemError", {
@@ -39,6 +40,8 @@ export namespace AppFileSystem {
 
   export class Service extends Context.Service<Service, Interface>()("@opencode/FileSystem") {}
 
+  export const use = serviceUse(Service)
+
   export const layer = Layer.effect(
     Service,
     Effect.gen(function* () {

packages/opencode/src/account/account.ts

@@ -1,5 +1,5 @@
 import { Cache, Clock, Duration, Effect, Layer, Option, Schema, SchemaGetter, Context } from "effect"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import {
   FetchHttpClient,
   HttpClient,

packages/opencode/src/account/repo.ts

@@ -1,5 +1,5 @@
 import { eq } from "drizzle-orm"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { Effect, Layer, Option, Schema, Context } from "effect"
 
 import { Database } from "@/storage/db"

packages/opencode/src/agent/agent.ts

@@ -1,5 +1,5 @@
 import { Config } from "@/config/config"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { Provider } from "@/provider/provider"
 import { ModelID, ProviderID } from "../provider/schema"
 import { generateObject, streamObject, type ModelMessage } from "ai"

packages/opencode/src/bus/index.ts

@@ -5,7 +5,7 @@ import { BusEvent } from "./bus-event"
 import { GlobalBus } from "./global"
 import { InstanceState } from "@/effect/instance-state"
 import { makeRuntime } from "@/effect/run-service"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { Identifier } from "@/id/id"
 import type { InstanceContext } from "@/project/instance-context"
 import { InstanceRef } from "@/effect/instance-ref"

packages/opencode/src/config/config.ts

@@ -1,5 +1,5 @@
 import * as Log from "@opencode-ai/core/util/log"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import path from "path"
 import { pathToFileURL } from "url"
 import os from "os"

packages/opencode/src/control-plane/workspace.ts

@@ -1,5 +1,5 @@
 import { Context, Effect, FiberMap, Iterable, Layer, Schema, Stream } from "effect"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { FetchHttpClient, HttpBody, HttpClient, HttpClientError, HttpClientRequest } from "effect/unstable/http"
 import { Database } from "@/storage/db"
 import { asc } from "drizzle-orm"

packages/opencode/src/env/index.ts

@@ -1,5 +1,5 @@
 import { Context, Effect, Layer } from "effect"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { InstanceState } from "@/effect/instance-state"
 
 type State = Record<string, string | undefined>

packages/opencode/src/file/index.ts

@@ -1,5 +1,5 @@
 import { BusEvent } from "@/bus/bus-event"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { InstanceState } from "@/effect/instance-state"
 
 import { AppFileSystem } from "@opencode-ai/core/filesystem"

packages/opencode/src/file/ripgrep.ts

@@ -1,5 +1,5 @@
 import path from "path"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { AppFileSystem } from "@opencode-ai/core/filesystem"
 import { Cause, Context, Effect, Fiber, Layer, Queue, Schema, Stream } from "effect"
 import type { PlatformError } from "effect/PlatformError"

packages/opencode/src/format/index.ts

@@ -1,5 +1,5 @@
 import { Effect, Layer, Context, Schema } from "effect"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { ChildProcess } from "effect/unstable/process"
 import { AppProcess } from "@opencode-ai/core/process"
 import { InstanceState } from "@/effect/instance-state"

packages/opencode/src/installation/index.ts

@@ -1,5 +1,5 @@
 import { Effect, Layer, Schema, Context, Stream } from "effect"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { FetchHttpClient, HttpClient, HttpClientRequest, HttpClientResponse } from "effect/unstable/http"
 import { withTransientReadRetry } from "@/util/effect-http-client"
 import { errorMessage } from "@/util/error"

packages/opencode/src/mcp/auth.ts

@@ -1,5 +1,5 @@
 import path from "path"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { Global } from "@opencode-ai/core/global"
 import { Effect, Layer, Context, Option, Schema } from "effect"
 import { AppFileSystem } from "@opencode-ai/core/filesystem"

packages/opencode/src/mcp/index.ts

@@ -1,5 +1,5 @@
 import { dynamicTool, type Tool, jsonSchema, type JSONSchema7 } from "ai"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { Client } from "@modelcontextprotocol/sdk/client/index.js"
 import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js"
 import { SSEClientTransport } from "@modelcontextprotocol/sdk/client/sse.js"

packages/opencode/src/project/instance-store.ts

@@ -1,5 +1,5 @@
 import { GlobalBus } from "@/bus/global"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { WorkspaceContext } from "@/control-plane/workspace-context"
 import { InstanceRef } from "@/effect/instance-ref"
 import { disposeInstance as runDisposers } from "@/effect/instance-registry"

packages/opencode/src/project/project.ts

@@ -20,7 +20,7 @@ import { AppProcess } from "@opencode-ai/core/process"
 import { Project as ProjectV2 } from "@opencode-ai/core/project"
 import { CrossSpawnSpawner } from "@opencode-ai/core/cross-spawn-spawner"
 import { AbsolutePath, NonNegativeInt, optionalOmitUndefined } from "@opencode-ai/core/schema"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { RuntimeFlags } from "@/effect/runtime-flags"
 
 const log = Log.create({ service: "project" })

packages/opencode/src/provider/auth.ts

@@ -1,5 +1,5 @@
 import type { AuthOAuthResult, Hooks } from "@opencode-ai/plugin"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { Auth } from "@/auth"
 import { InstanceState } from "@/effect/instance-state"
 import { optionalOmitUndefined } from "@opencode-ai/core/schema"

packages/opencode/src/provider/provider.ts

@@ -7,7 +7,7 @@ import * as Log from "@opencode-ai/core/util/log"
 import { Npm } from "@opencode-ai/core/npm"
 import { Hash } from "@opencode-ai/core/util/hash"
 import { Plugin } from "../plugin"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { type LanguageModelV3 } from "@ai-sdk/provider"
 import * as ModelsDev from "@opencode-ai/core/models-dev"
 import { Auth } from "../auth"

packages/opencode/src/session/compaction.ts

@@ -16,7 +16,7 @@ import { Effect, Layer, Context, Schema } from "effect"
 import * as DateTime from "effect/DateTime"
 import { InstanceState } from "@/effect/instance-state"
 import { isOverflow as overflow, usable } from "./overflow"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { RuntimeFlags } from "@/effect/runtime-flags"
 import { EventV2Bridge } from "@/event-v2-bridge"
 import { SessionEvent } from "@opencode-ai/core/session-event"

packages/opencode/src/session/llm.ts

@@ -1,5 +1,5 @@
 import { Provider } from "@/provider/provider"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import * as Log from "@opencode-ai/core/util/log"
 import { Context, Effect, Layer } from "effect"
 import * as Stream from "effect/Stream"

packages/opencode/src/session/session.ts

@@ -1,5 +1,5 @@
 import { Slug } from "@opencode-ai/core/util/slug"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import path from "path"
 import { BackgroundJob } from "@/background/job"
 import { BusEvent } from "@/bus/bus-event"

packages/opencode/src/share/share-next.ts

@@ -1,5 +1,5 @@
 import type * as SDK from "@opencode-ai/sdk/v2"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { Effect, Exit, Layer, Option, Schema, Scope, Context, Stream } from "effect"
 import { FetchHttpClient, HttpClient, HttpClientRequest, HttpClientResponse } from "effect/unstable/http"
 import { Account } from "@/account/account"

packages/opencode/src/skill/index.ts

@@ -16,6 +16,7 @@ import * as Log from "@opencode-ai/core/util/log"
 import { Discovery } from "./discovery"
 import CUSTOMIZE_OPENCODE_SKILL_BODY from "./prompt/customize-opencode.md" with { type: "text" }
 import { isRecord } from "@/util/record"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 
 const log = Log.create({ service: "skill" })
 const CLAUDE_EXTERNAL_DIR = ".claude"
@@ -243,6 +244,8 @@ const loadSkills = Effect.fnUntraced(function* (state: State, discovered: Discov
 
 export class Service extends Context.Service<Service, Interface>()("@opencode/Skill") {}
 
+export const use = serviceUse(Service)
+
 export const layer = Layer.effect(
   Service,
   Effect.gen(function* () {

packages/opencode/src/sync/index.ts

@@ -12,7 +12,7 @@ import { EventID } from "./schema"
 import { Context, Effect, Layer, Schema as EffectSchema } from "effect"
 import type { DeepMutable } from "@opencode-ai/core/schema"
 import { EventV2 } from "@opencode-ai/core/event"
-import { serviceUse } from "@/effect/service-use"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 import { InstanceState } from "@/effect/instance-state"
 import { RuntimeFlags } from "@/effect/runtime-flags"
 import { EffectBridge } from "@/effect/bridge"

packages/opencode/src/tool/registry.ts

@@ -55,6 +55,7 @@ import { Reference } from "@/reference/reference"
 import { BackgroundJob } from "@/background/job"
 import { SessionStatus } from "@/session/status"
 import { RuntimeFlags } from "@/effect/runtime-flags"
+import { serviceUse } from "@opencode-ai/core/effect/service-use"
 
 const log = Log.create({ service: "tool.registry" })
 
@@ -81,6 +82,8 @@ export interface Interface {
 
 export class Service extends Context.Service<Service, Interface>()("@opencode/ToolRegistry") {}
 
+export const use = serviceUse(Service)
+
 export const layer: Layer.Layer<
   Service,
   never,

packages/opencode/test/file/index.test.ts

@@ -3,7 +3,6 @@ import { AppFileSystem } from "@opencode-ai/core/filesystem"
 import { $ } from "bun"
 import { Cause, Effect, Exit, Layer } from "effect"
 import path from "path"
-import fs from "fs/promises"
 import { File } from "../../src/file"
 import { disposeAllInstances, TestInstance, withTmpdirInstance } from "../fixture/fixture"
 import { testEffect } from "../lib/effect"
@@ -48,6 +47,11 @@ const gitAddAll = (directory: string) => Effect.promise(() => $`git add .`.cwd(d
 const gitCommit = (directory: string, message: string) =>
   Effect.promise(() => $`git commit -m ${message}`.cwd(directory).quiet())
 
+const writeFixtureFile = (directory: string, file: string, content: string | Uint8Array) =>
+  AppFileSystem.use.writeWithDirs(path.join(directory, file), content)
+
+const removeFixtureFile = (directory: string, file: string) => AppFileSystem.use.remove(path.join(directory, file))
+
 const failureMessage = <A, E, R>(self: Effect.Effect<A, E, R>) =>
   Effect.gen(function* () {
     const exit = yield* self.pipe(Effect.exit)
@@ -72,7 +76,7 @@ describe("file/index Filesystem patterns", () => {
     it.instance("reads text file via Filesystem.readText()", () =>
       Effect.gen(function* () {
         const test = yield* TestInstance
-        yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "test.txt"), "Hello World", "utf-8"))
+        yield* writeFixtureFile(test.directory, "test.txt", "Hello World")
 
         const result = yield* read("test.txt")
         expect(result.type).toBe("text")
@@ -91,9 +95,7 @@ describe("file/index Filesystem patterns", () => {
     it.instance("trims whitespace from text content", () =>
       Effect.gen(function* () {
         const test = yield* TestInstance
-        yield* Effect.promise(() =>
-          fs.writeFile(path.join(test.directory, "test.txt"), "  content with spaces  \n\n", "utf-8"),
-        )
+        yield* writeFixtureFile(test.directory, "test.txt", "  content with spaces  \n\n")
 
         const result = yield* read("test.txt")
         expect(result.content).toBe("content with spaces")
@@ -103,7 +105,7 @@ describe("file/index Filesystem patterns", () => {
     it.instance("handles empty text file", () =>
       Effect.gen(function* () {
         const test = yield* TestInstance
-        yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "empty.txt"), "", "utf-8"))
+        yield* writeFixtureFile(test.directory, "empty.txt", "")
 
         const result = yield* read("empty.txt")
         expect(result.type).toBe("text")
@@ -114,9 +116,7 @@ describe("file/index Filesystem patterns", () => {
     it.instance("handles multi-line text files", () =>
       Effect.gen(function* () {
         const test = yield* TestInstance
-        yield* Effect.promise(() =>
-          fs.writeFile(path.join(test.directory, "multiline.txt"), "line1\nline2\nline3", "utf-8"),
-        )
+        yield* writeFixtureFile(test.directory, "multiline.txt", "line1\nline2\nline3")
 
         const result = yield* read("multiline.txt")
         expect(result.content).toBe("line1\nline2\nline3")
@@ -129,7 +129,7 @@ describe("file/index Filesystem patterns", () => {
       Effect.gen(function* () {
         const test = yield* TestInstance
         const binaryContent = Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a])
-        yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "image.png"), binaryContent))
+        yield* writeFixtureFile(test.directory, "image.png", binaryContent)
 
         const result = yield* read("image.png")
         expect(result.type).toBe("text")
@@ -142,9 +142,7 @@ describe("file/index Filesystem patterns", () => {
     it.instance("returns empty for binary non-image files", () =>
       Effect.gen(function* () {
         const test = yield* TestInstance
-        yield* Effect.promise(() =>
-          fs.writeFile(path.join(test.directory, "binary.so"), Buffer.from([0x7f, 0x45, 0x4c, 0x46])),
-        )
+        yield* writeFixtureFile(test.directory, "binary.so", Buffer.from([0x7f, 0x45, 0x4c, 0x46]))
 
         const result = yield* read("binary.so")
         expect(result.type).toBe("binary")
@@ -158,7 +156,7 @@ describe("file/index Filesystem patterns", () => {
       Effect.gen(function* () {
         const test = yield* TestInstance
         const filepath = path.join(test.directory, "test.json")
-        yield* Effect.promise(() => fs.writeFile(filepath, '{"key": "value"}', "utf-8"))
+        yield* AppFileSystem.use.writeWithDirs(filepath, '{"key": "value"}')
 
         expect(AppFileSystem.mimeType(filepath)).toContain("application/json")
 
@@ -179,7 +177,7 @@ describe("file/index Filesystem patterns", () => {
 
         for (const testCase of testCases) {
           const filepath = path.join(test.directory, `test.${testCase.ext}`)
-          yield* Effect.promise(() => fs.writeFile(filepath, Buffer.from([0x00, 0x00, 0x00, 0x00])))
+          yield* AppFileSystem.use.writeWithDirs(filepath, Buffer.from([0x00, 0x00, 0x00, 0x00]))
           expect(AppFileSystem.mimeType(filepath)).toContain(testCase.mime)
         }
       }),
@@ -288,9 +286,7 @@ describe("file/index Filesystem patterns", () => {
     it.instance("treats .ts files as text", () =>
       Effect.gen(function* () {
         const test = yield* TestInstance
-        yield* Effect.promise(() =>
-          fs.writeFile(path.join(test.directory, "test.ts"), "export const value = 1", "utf-8"),
-        )
+        yield* writeFixtureFile(test.directory, "test.ts", "export const value = 1")
 
         const result = yield* read("test.ts")
         expect(result.type).toBe("text")
@@ -301,9 +297,7 @@ describe("file/index Filesystem patterns", () => {
     it.instance("treats .mts files as text", () =>
       Effect.gen(function* () {
         const test = yield* TestInstance
-        yield* Effect.promise(() =>
-          fs.writeFile(path.join(test.directory, "test.mts"), "export const value = 1", "utf-8"),
-        )
+        yield* writeFixtureFile(test.directory, "test.mts", "export const value = 1")
 
         const result = yield* read("test.mts")
         expect(result.type).toBe("text")
@@ -314,9 +308,7 @@ describe("file/index Filesystem patterns", () => {
     it.instance("treats .sh files as text", () =>
       Effect.gen(function* () {
         const test = yield* TestInstance
-        yield* Effect.promise(() =>
-          fs.writeFile(path.join(test.directory, "test.sh"), "#!/usr/bin/env bash\necho hello", "utf-8"),
-        )
+        yield* writeFixtureFile(test.directory, "test.sh", "#!/usr/bin/env bash\necho hello")
 
         const result = yield* read("test.sh")
         expect(result.type).toBe("text")
@@ -327,7 +319,7 @@ describe("file/index Filesystem patterns", () => {
     it.instance("treats Dockerfile as text", () =>
       Effect.gen(function* () {
         const test = yield* TestInstance
-        yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "Dockerfile"), "FROM alpine:3.20", "utf-8"))
+        yield* writeFixtureFile(test.directory, "Dockerfile", "FROM alpine:3.20")
 
         const result = yield* read("Dockerfile")
         expect(result.type).toBe("text")
@@ -338,7 +330,7 @@ describe("file/index Filesystem patterns", () => {
     it.instance("returns encoding info for text files", () =>
       Effect.gen(function* () {
         const test = yield* TestInstance
-        yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "test.txt"), "simple text", "utf-8"))
+        yield* writeFixtureFile(test.directory, "test.txt", "simple text")
 
         const result = yield* read("test.txt")
         expect(result.encoding).toBeUndefined()
@@ -349,9 +341,7 @@ describe("file/index Filesystem patterns", () => {
     it.instance("returns base64 encoding for images", () =>
       Effect.gen(function* () {
         const test = yield* TestInstance
-        yield* Effect.promise(() =>
-          fs.writeFile(path.join(test.directory, "test.jpg"), Buffer.from([0xff, 0xd8, 0xff, 0xe0])),
-        )
+        yield* writeFixtureFile(test.directory, "test.jpg", Buffer.from([0xff, 0xd8, 0xff, 0xe0]))
 
         const result = yield* read("test.jpg")
         expect(result.encoding).toBe("base64")
@@ -381,10 +371,10 @@ describe("file/index Filesystem patterns", () => {
         Effect.gen(function* () {
           const test = yield* TestInstance
           const filepath = path.join(test.directory, "file.txt")
-          yield* Effect.promise(() => fs.writeFile(filepath, "original\n", "utf-8"))
+          yield* AppFileSystem.use.writeWithDirs(filepath, "original\n")
           yield* gitAddAll(test.directory)
           yield* gitCommit(test.directory, "add file")
-          yield* Effect.promise(() => fs.writeFile(filepath, "modified\nextra line\n", "utf-8"))
+          yield* AppFileSystem.use.writeWithDirs(filepath, "modified\nextra line\n")
 
           const result = yield* status()
           const entry = result.find((file) => file.path === "file.txt")
@@ -401,9 +391,7 @@ describe("file/index Filesystem patterns", () => {
       () =>
         Effect.gen(function* () {
           const test = yield* TestInstance
-          yield* Effect.promise(() =>
-            fs.writeFile(path.join(test.directory, "new.txt"), "line1\nline2\nline3\n", "utf-8"),
-          )
+          yield* writeFixtureFile(test.directory, "new.txt", "line1\nline2\nline3\n")
 
           const result = yield* status()
           const entry = result.find((file) => file.path === "new.txt")
@@ -421,10 +409,10 @@ describe("file/index Filesystem patterns", () => {
         Effect.gen(function* () {
           const test = yield* TestInstance
           const filepath = path.join(test.directory, "gone.txt")
-          yield* Effect.promise(() => fs.writeFile(filepath, "content\n", "utf-8"))
+          yield* AppFileSystem.use.writeWithDirs(filepath, "content\n")
           yield* gitAddAll(test.directory)
           yield* gitCommit(test.directory, "add file")
-          yield* Effect.promise(() => fs.rm(filepath))
+          yield* AppFileSystem.use.remove(filepath)
 
           const result = yield* status()
           const entries = result.filter((file) => file.path === "gone.txt")
@@ -438,14 +426,14 @@ describe("file/index Filesystem patterns", () => {
       () =>
         Effect.gen(function* () {
           const test = yield* TestInstance
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "keep.txt"), "keep\n", "utf-8"))
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "remove.txt"), "remove\n", "utf-8"))
+          yield* writeFixtureFile(test.directory, "keep.txt", "keep\n")
+          yield* writeFixtureFile(test.directory, "remove.txt", "remove\n")
           yield* gitAddAll(test.directory)
           yield* gitCommit(test.directory, "initial")
 
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "keep.txt"), "changed\n", "utf-8"))
-          yield* Effect.promise(() => fs.rm(path.join(test.directory, "remove.txt")))
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "brand-new.txt"), "hello\n", "utf-8"))
+          yield* writeFixtureFile(test.directory, "keep.txt", "changed\n")
+          yield* removeFixtureFile(test.directory, "remove.txt")
+          yield* writeFixtureFile(test.directory, "brand-new.txt", "hello\n")
 
           const result = yield* status()
           expect(result.some((file) => file.path === "keep.txt" && file.status === "modified")).toBe(true)
@@ -476,13 +464,15 @@ describe("file/index Filesystem patterns", () => {
         Effect.gen(function* () {
           const test = yield* TestInstance
           const filepath = path.join(test.directory, "data.bin")
-          yield* Effect.promise(() =>
-            fs.writeFile(filepath, Buffer.from(Array.from({ length: 256 }, (_, index) => index))),
+          yield* AppFileSystem.use.writeWithDirs(
+            filepath,
+            Buffer.from(Array.from({ length: 256 }, (_, index) => index)),
           )
           yield* gitAddAll(test.directory)
           yield* gitCommit(test.directory, "add binary")
-          yield* Effect.promise(() =>
-            fs.writeFile(filepath, Buffer.from(Array.from({ length: 512 }, (_, index) => index % 256))),
+          yield* AppFileSystem.use.writeWithDirs(
+            filepath,
+            Buffer.from(Array.from({ length: 512 }, (_, index) => index % 256)),
           )
 
           const result = yield* status()
@@ -502,11 +492,9 @@ describe("file/index Filesystem patterns", () => {
       () =>
         Effect.gen(function* () {
           const test = yield* TestInstance
-          yield* Effect.promise(() => fs.mkdir(path.join(test.directory, "subdir")))
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "file.txt"), "content", "utf-8"))
-          yield* Effect.promise(() =>
-            fs.writeFile(path.join(test.directory, "subdir", "nested.txt"), "nested", "utf-8"),
-          )
+          yield* AppFileSystem.use.ensureDir(path.join(test.directory, "subdir"))
+          yield* writeFixtureFile(test.directory, "file.txt", "content")
+          yield* writeFixtureFile(test.directory, path.join("subdir", "nested.txt"), "nested")
 
           const nodes = yield* list()
           expect(nodes.length).toBeGreaterThanOrEqual(2)
@@ -527,10 +515,10 @@ describe("file/index Filesystem patterns", () => {
       () =>
         Effect.gen(function* () {
           const test = yield* TestInstance
-          yield* Effect.promise(() => fs.mkdir(path.join(test.directory, "beta")))
-          yield* Effect.promise(() => fs.mkdir(path.join(test.directory, "alpha")))
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "zz.txt"), "", "utf-8"))
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "aa.txt"), "", "utf-8"))
+          yield* AppFileSystem.use.ensureDir(path.join(test.directory, "beta"))
+          yield* AppFileSystem.use.ensureDir(path.join(test.directory, "alpha"))
+          yield* writeFixtureFile(test.directory, "zz.txt", "")
+          yield* writeFixtureFile(test.directory, "aa.txt", "")
 
           const nodes = yield* list()
           const dirs = nodes.filter((node) => node.type === "directory")
@@ -551,8 +539,8 @@ describe("file/index Filesystem patterns", () => {
       () =>
         Effect.gen(function* () {
           const test = yield* TestInstance
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, ".DS_Store"), "", "utf-8"))
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "visible.txt"), "", "utf-8"))
+          yield* writeFixtureFile(test.directory, ".DS_Store", "")
+          yield* writeFixtureFile(test.directory, "visible.txt", "")
 
           const names = (yield* list()).map((node) => node.name)
           expect(names).not.toContain(".git")
@@ -567,10 +555,10 @@ describe("file/index Filesystem patterns", () => {
       () =>
         Effect.gen(function* () {
           const test = yield* TestInstance
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, ".gitignore"), "*.log\nbuild/\n", "utf-8"))
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "app.log"), "log data", "utf-8"))
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "main.ts"), "code", "utf-8"))
-          yield* Effect.promise(() => fs.mkdir(path.join(test.directory, "build")))
+          yield* writeFixtureFile(test.directory, ".gitignore", "*.log\nbuild/\n")
+          yield* writeFixtureFile(test.directory, "app.log", "log data")
+          yield* writeFixtureFile(test.directory, "main.ts", "code")
+          yield* AppFileSystem.use.ensureDir(path.join(test.directory, "build"))
 
           const nodes = yield* list()
           expect(nodes.find((node) => node.name === "app.log")?.ignored).toBe(true)
@@ -585,9 +573,9 @@ describe("file/index Filesystem patterns", () => {
       () =>
         Effect.gen(function* () {
           const test = yield* TestInstance
-          yield* Effect.promise(() => fs.mkdir(path.join(test.directory, "sub")))
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "sub", "a.txt"), "", "utf-8"))
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "sub", "b.txt"), "", "utf-8"))
+          yield* AppFileSystem.use.ensureDir(path.join(test.directory, "sub"))
+          yield* writeFixtureFile(test.directory, path.join("sub", "a.txt"), "")
+          yield* writeFixtureFile(test.directory, path.join("sub", "b.txt"), "")
 
           const nodes = yield* list("sub")
           expect(nodes.length).toBe(2)
@@ -609,7 +597,7 @@ describe("file/index Filesystem patterns", () => {
     it.instance("works without git", () =>
       Effect.gen(function* () {
         const test = yield* TestInstance
-        yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "file.txt"), "hi", "utf-8"))
+        yield* writeFixtureFile(test.directory, "file.txt", "hi")
 
         const nodes = yield* list()
         expect(nodes.length).toBeGreaterThanOrEqual(1)
@@ -755,7 +743,7 @@ describe("file/index Filesystem patterns", () => {
           yield* init()
           expect(yield* search({ query: "fresh", type: "file" })).toEqual([])
 
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "fresh.ts"), "fresh", "utf-8"))
+          yield* writeFixtureFile(test.directory, "fresh.ts", "fresh")
 
           expect(yield* search({ query: "fresh", type: "file" })).toContain("fresh.ts")
         }),
@@ -770,10 +758,10 @@ describe("file/index Filesystem patterns", () => {
         Effect.gen(function* () {
           const test = yield* TestInstance
           const filepath = path.join(test.directory, "file.txt")
-          yield* Effect.promise(() => fs.writeFile(filepath, "original content\n", "utf-8"))
+          yield* AppFileSystem.use.writeWithDirs(filepath, "original content\n")
           yield* gitAddAll(test.directory)
           yield* gitCommit(test.directory, "add file")
-          yield* Effect.promise(() => fs.writeFile(filepath, "modified content\n", "utf-8"))
+          yield* AppFileSystem.use.writeWithDirs(filepath, "modified content\n")
 
           const result = yield* read("file.txt")
           expect(result.type).toBe("text")
@@ -793,10 +781,10 @@ describe("file/index Filesystem patterns", () => {
         Effect.gen(function* () {
           const test = yield* TestInstance
           const filepath = path.join(test.directory, "staged.txt")
-          yield* Effect.promise(() => fs.writeFile(filepath, "before\n", "utf-8"))
+          yield* AppFileSystem.use.writeWithDirs(filepath, "before\n")
           yield* gitAddAll(test.directory)
           yield* gitCommit(test.directory, "add file")
-          yield* Effect.promise(() => fs.writeFile(filepath, "after\n", "utf-8"))
+          yield* AppFileSystem.use.writeWithDirs(filepath, "after\n")
           yield* gitAddAll(test.directory)
 
           const result = yield* read("staged.txt")
@@ -812,7 +800,7 @@ describe("file/index Filesystem patterns", () => {
         Effect.gen(function* () {
           const test = yield* TestInstance
           const filepath = path.join(test.directory, "clean.txt")
-          yield* Effect.promise(() => fs.writeFile(filepath, "unchanged\n", "utf-8"))
+          yield* AppFileSystem.use.writeWithDirs(filepath, "unchanged\n")
           yield* gitAddAll(test.directory)
           yield* gitCommit(test.directory, "add file")
 
@@ -832,14 +820,14 @@ describe("file/index Filesystem patterns", () => {
       () =>
         Effect.gen(function* () {
           const one = yield* TestInstance
-          yield* Effect.promise(() => fs.writeFile(path.join(one.directory, "a.ts"), "one", "utf-8"))
+          yield* writeFixtureFile(one.directory, "a.ts", "one")
           yield* init()
           expect(yield* search({ query: "a.ts", type: "file" })).toContain("a.ts")
           expect(yield* search({ query: "b.ts", type: "file" })).not.toContain("b.ts")
 
           yield* Effect.gen(function* () {
             const two = yield* TestInstance
-            yield* Effect.promise(() => fs.writeFile(path.join(two.directory, "b.ts"), "two", "utf-8"))
+            yield* writeFixtureFile(two.directory, "b.ts", "two")
             yield* init()
             expect(yield* search({ query: "b.ts", type: "file" })).toContain("b.ts")
             expect(yield* search({ query: "a.ts", type: "file" })).not.toContain("a.ts")
@@ -853,14 +841,14 @@ describe("file/index Filesystem patterns", () => {
       () =>
         Effect.gen(function* () {
           const test = yield* TestInstance
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "before.ts"), "before", "utf-8"))
+          yield* writeFixtureFile(test.directory, "before.ts", "before")
           yield* init()
           expect(yield* search({ query: "before", type: "file" })).toContain("before.ts")
 
           yield* Effect.promise(() => disposeAllInstances())
 
-          yield* Effect.promise(() => fs.writeFile(path.join(test.directory, "after.ts"), "after", "utf-8"))
-          yield* Effect.promise(() => fs.rm(path.join(test.directory, "before.ts")))
+          yield* writeFixtureFile(test.directory, "after.ts", "after")
+          yield* removeFixtureFile(test.directory, "before.ts")
 
           yield* init()
           expect(yield* search({ query: "after", type: "file" })).toContain("after.ts")

packages/opencode/test/lsp/client.test.ts

@@ -1,11 +1,16 @@
-import { beforeEach, describe, expect, test } from "bun:test"
+import { beforeEach, describe, expect } from "bun:test"
+import { AppFileSystem } from "@opencode-ai/core/filesystem"
 import path from "path"
 import { pathToFileURL } from "url"
-import { tmpdir, withTestInstance } from "../fixture/fixture"
+import { Effect } from "effect"
+import { pollWithTimeout, testEffect } from "../lib/effect"
+import { requireInstance, TestInstance } from "../fixture/fixture"
 import { LSPClient } from "@/lsp/client"
 import * as LSPServer from "@/lsp/server"
 import * as Log from "@opencode-ai/core/util/log"
 
+const it = testEffect(AppFileSystem.defaultLayer)
+
 function spawnFakeServer() {
   const { spawn } = require("child_process")
   const serverPath = path.join(__dirname, "../fixture/lsp/fake-lsp-server.js")
@@ -16,202 +21,164 @@ function spawnFakeServer() {
   }
 }
 
+const createClient = (handle: LSPServer.Handle, initialization?: LSPServer.Handle["initialization"]) =>
+  Effect.gen(function* () {
+    const test = yield* TestInstance
+    const instance = yield* requireInstance
+    return yield* Effect.promise(() =>
+      LSPClient.create({
+        serverID: "fake",
+        server: initialization ? { ...handle, initialization } : handle,
+        root: test.directory,
+        directory: test.directory,
+        instance,
+      }),
+    )
+  })
+
+const createScopedClient = (handle: LSPServer.Handle, initialization?: LSPServer.Handle["initialization"]) =>
+  Effect.gen(function* () {
+    const client = yield* createClient(handle, initialization)
+    yield* Effect.addFinalizer(() => Effect.promise(() => client.shutdown()).pipe(Effect.ignore))
+    return client
+  })
+
+const writeFile = (file: string, content: string) => AppFileSystem.use.writeWithDirs(file, content)
+
 describe("LSPClient interop", () => {
   beforeEach(async () => {
     await Log.init({ print: true })
   })
 
-  test("handles workspace/workspaceFolders request", async () => {
-    const handle = spawnFakeServer() as any
+  it.instance("handles workspace/workspaceFolders request", () =>
+    Effect.gen(function* () {
+      const client = yield* createScopedClient(spawnFakeServer())
 
-    const client = await withTestInstance({
-      directory: process.cwd(),
-      fn: (ctx) =>
-        LSPClient.create({
-          serverID: "fake",
-          server: handle as unknown as LSPServer.Handle,
-          root: process.cwd(),
-          directory: process.cwd(),
-          instance: ctx,
+      yield* Effect.promise(() =>
+        client.connection.sendNotification("test/trigger", {
+          method: "workspace/workspaceFolders",
         }),
-    })
+      )
 
-    await client.connection.sendNotification("test/trigger", {
-      method: "workspace/workspaceFolders",
-    })
+      yield* Effect.promise(() => client.connection.sendRequest("test/get-diagnostic-request-count", {}))
+      expect(client.connection).toBeDefined()
+    }),
+  )
 
-    await new Promise((resolve) => setTimeout(resolve, 100))
-    expect(client.connection).toBeDefined()
-    await client.shutdown()
-  })
+  it.instance("handles client/registerCapability request", () =>
+    Effect.gen(function* () {
+      const client = yield* createScopedClient(spawnFakeServer())
 
-  test("handles client/registerCapability request", async () => {
-    const handle = spawnFakeServer() as any
-
-    const client = await withTestInstance({
-      directory: process.cwd(),
-      fn: (ctx) =>
-        LSPClient.create({
-          serverID: "fake",
-          server: handle as unknown as LSPServer.Handle,
-          root: process.cwd(),
-          directory: process.cwd(),
-          instance: ctx,
+      yield* Effect.promise(() =>
+        client.connection.sendNotification("test/trigger", {
+          method: "client/registerCapability",
         }),
-    })
+      )
 
-    await client.connection.sendNotification("test/trigger", {
-      method: "client/registerCapability",
-    })
+      yield* Effect.promise(() => client.connection.sendRequest("test/get-diagnostic-request-count", {}))
+      expect(client.connection).toBeDefined()
+    }),
+  )
 
-    await new Promise((resolve) => setTimeout(resolve, 100))
-    expect(client.connection).toBeDefined()
-    await client.shutdown()
-  })
+  it.instance("handles client/unregisterCapability request", () =>
+    Effect.gen(function* () {
+      const client = yield* createScopedClient(spawnFakeServer())
 
-  test("handles client/unregisterCapability request", async () => {
-    const handle = spawnFakeServer() as any
-
-    const client = await withTestInstance({
-      directory: process.cwd(),
-      fn: (ctx) =>
-        LSPClient.create({
-          serverID: "fake",
-          server: handle as unknown as LSPServer.Handle,
-          root: process.cwd(),
-          directory: process.cwd(),
-          instance: ctx,
+      yield* Effect.promise(() =>
+        client.connection.sendNotification("test/trigger", {
+          method: "client/unregisterCapability",
         }),
-    })
+      )
 
-    await client.connection.sendNotification("test/trigger", {
-      method: "client/unregisterCapability",
-    })
+      yield* Effect.promise(() => client.connection.sendRequest("test/get-diagnostic-request-count", {}))
+      expect(client.connection).toBeDefined()
+    }),
+  )
 
-    await new Promise((resolve) => setTimeout(resolve, 100))
-    expect(client.connection).toBeDefined()
-    await client.shutdown()
-  })
+  it.instance("initialize does not overclaim unsupported diagnostics capabilities", () =>
+    Effect.gen(function* () {
+      const client = yield* createScopedClient(spawnFakeServer())
 
-  test("initialize does not overclaim unsupported diagnostics capabilities", async () => {
-    const handle = spawnFakeServer() as any
+      const params = yield* Effect.promise(() =>
+        client.connection.sendRequest<{
+          capabilities: {
+            workspace: { diagnostics: { refreshSupport: boolean } }
+            textDocument: { publishDiagnostics: { versionSupport: boolean } }
+          }
+        }>("test/get-initialize-params", {}),
+      )
+      expect(params.capabilities.workspace.diagnostics.refreshSupport).toBe(false)
+      expect(params.capabilities.textDocument.publishDiagnostics.versionSupport).toBe(false)
+    }),
+  )
 
-    const client = await withTestInstance({
-      directory: process.cwd(),
-      fn: (ctx) =>
-        LSPClient.create({
-          serverID: "fake",
-          server: handle as unknown as LSPServer.Handle,
-          root: process.cwd(),
-          directory: process.cwd(),
-          instance: ctx,
+  it.instance("workspace/configuration returns one result per requested item", () =>
+    Effect.gen(function* () {
+      const initialization = {
+        alpha: {
+          beta: 1,
+        },
+        gamma: true,
+      }
+
+      const client = yield* createScopedClient(spawnFakeServer(), initialization)
+
+      const response = yield* Effect.promise(() =>
+        client.connection.sendRequest<unknown[]>("test/request-configuration", {
+          items: [{ section: "alpha" }, { section: "alpha.beta" }, { section: "missing" }, {}],
         }),
-    })
+      )
 
-    const params = await client.connection.sendRequest<any>("test/get-initialize-params", {})
-    expect(params.capabilities.workspace.diagnostics.refreshSupport).toBe(false)
-    expect(params.capabilities.textDocument.publishDiagnostics.versionSupport).toBe(false)
+      expect(response).toEqual([{ beta: 1 }, 1, null, initialization])
+    }),
+  )
 
-    await client.shutdown()
-  })
+  it.instance("sends ranged didChange for incremental sync servers", () =>
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      const file = path.join(test.directory, "client.ts")
+      yield* writeFile(file, "first\n")
 
-  test("workspace/configuration returns one result per requested item", async () => {
-    const handle = spawnFakeServer() as any
-    const initialization = {
-      alpha: {
-        beta: 1,
-      },
-      gamma: true,
-    }
+      const client = yield* createScopedClient(spawnFakeServer())
 
-    const client = await withTestInstance({
-      directory: process.cwd(),
-      fn: (ctx) =>
-        LSPClient.create({
-          serverID: "fake",
-          server: {
-            ...(handle as unknown as LSPServer.Handle),
-            initialization,
-          },
-          root: process.cwd(),
-          directory: process.cwd(),
-          instance: ctx,
-        }),
-    })
+      yield* Effect.promise(() => client.notify.open({ path: file }))
+      yield* writeFile(file, "second\nthird\n")
+      yield* Effect.promise(() => client.notify.open({ path: file }))
 
-    const response = await client.connection.sendRequest<any[]>("test/request-configuration", {
-      items: [{ section: "alpha" }, { section: "alpha.beta" }, { section: "missing" }, {}],
-    })
-
-    expect(response).toEqual([{ beta: 1 }, 1, null, initialization])
-
-    await client.shutdown()
-  })
-
-  test("sends ranged didChange for incremental sync servers", async () => {
-    const handle = spawnFakeServer() as any
-    await using tmp = await tmpdir()
-    const file = path.join(tmp.path, "client.ts")
-    await Bun.write(file, "first\n")
-
-    await withTestInstance({
-      directory: tmp.path,
-      fn: async (ctx) => {
-        const client = await LSPClient.create({
-          serverID: "fake",
-          server: handle as unknown as LSPServer.Handle,
-          root: tmp.path,
-          directory: tmp.path,
-          instance: ctx,
-        })
-
-        await client.notify.open({ path: file })
-        await Bun.write(file, "second\nthird\n")
-        await client.notify.open({ path: file })
-
-        const change = await client.connection.sendRequest<{
+      const change = yield* Effect.promise(() =>
+        client.connection.sendRequest<{
           textDocument: { version: number }
           contentChanges: {
             range?: { start: { line: number; character: number }; end: { line: number; character: number } }
             text: string
           }[]
-        }>("test/get-last-change", {})
-        expect(change.textDocument.version).toBe(1)
-        expect(change.contentChanges).toEqual([
-          {
-            range: {
-              start: { line: 0, character: 0 },
-              end: { line: 1, character: 0 },
-            },
-            text: "second\nthird\n",
+        }>("test/get-last-change", {}),
+      )
+      expect(change.textDocument.version).toBe(1)
+      expect(change.contentChanges).toEqual([
+        {
+          range: {
+            start: { line: 0, character: 0 },
+            end: { line: 1, character: 0 },
           },
-        ])
+          text: "second\nthird\n",
+        },
+      ])
+    }),
+  )
 
-        await client.shutdown()
-      },
-    })
-  })
+  it.instance("document mode falls back to push diagnostics", () =>
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      const file = path.join(test.directory, "client.ts")
+      yield* writeFile(file, "const x = 1\n")
 
-  test("document mode falls back to push diagnostics", async () => {
-    const handle = spawnFakeServer() as any
-    await using tmp = await tmpdir()
-    const file = path.join(tmp.path, "client.ts")
-    await Bun.write(file, "const x = 1\n")
+      const client = yield* createScopedClient(spawnFakeServer())
 
-    await withTestInstance({
-      directory: tmp.path,
-      fn: async (ctx) => {
-        const client = await LSPClient.create({
-          serverID: "fake",
-          server: handle as unknown as LSPServer.Handle,
-          root: tmp.path,
-          directory: tmp.path,
-          instance: ctx,
-        })
-
-        const version = await client.notify.open({ path: file })
-        const wait = client.waitForDiagnostics({ path: file, version, mode: "document" })
-        await client.connection.sendNotification("test/publish-diagnostics", {
+      const version = yield* Effect.promise(() => client.notify.open({ path: file }))
+      const wait = client.waitForDiagnostics({ path: file, version, mode: "document" })
+      yield* Effect.promise(() =>
+        client.connection.sendNotification("test/publish-diagnostics", {
           uri: pathToFileURL(file).href,
           version,
           diagnostics: [
@@ -224,40 +191,30 @@ describe("LSPClient interop", () => {
               severity: 1,
             },
           ],
-        })
-        await wait
+        }),
+      )
+      yield* Effect.promise(() => wait)
 
-        const diagnostics = client.diagnostics.get(file) ?? []
-        expect(diagnostics).toHaveLength(1)
-        expect(diagnostics[0]?.message).toBe("push diagnostic")
+      const diagnostics = client.diagnostics.get(file) ?? []
+      expect(diagnostics).toHaveLength(1)
+      expect(diagnostics[0]?.message).toBe("push diagnostic")
 
-        const count = await client.connection.sendRequest("test/get-diagnostic-request-count", {})
-        expect(count).toBe(0)
+      const count = yield* Effect.promise(() => client.connection.sendRequest("test/get-diagnostic-request-count", {}))
+      expect(count).toBe(0)
+    }),
+  )
 
-        await client.shutdown()
-      },
-    })
-  })
+  it.instance("document mode accepts matching push diagnostics published before waiting", () =>
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      const file = path.join(test.directory, "client.ts")
+      yield* writeFile(file, "const x = 1\n")
 
-  test("document mode accepts matching push diagnostics published before waiting", async () => {
-    const handle = spawnFakeServer() as any
-    await using tmp = await tmpdir()
-    const file = path.join(tmp.path, "client.ts")
-    await Bun.write(file, "const x = 1\n")
+      const client = yield* createScopedClient(spawnFakeServer())
 
-    await withTestInstance({
-      directory: tmp.path,
-      fn: async (ctx) => {
-        const client = await LSPClient.create({
-          serverID: "fake",
-          server: handle as unknown as LSPServer.Handle,
-          root: tmp.path,
-          directory: tmp.path,
-          instance: ctx,
-        })
-
-        const version = await client.notify.open({ path: file })
-        await client.connection.sendNotification("test/publish-diagnostics", {
+      const version = yield* Effect.promise(() => client.notify.open({ path: file }))
+      yield* Effect.promise(() =>
+        client.connection.sendNotification("test/publish-diagnostics", {
           uri: pathToFileURL(file).href,
           version,
           diagnostics: [
@@ -270,41 +227,31 @@ describe("LSPClient interop", () => {
               severity: 1,
             },
           ],
-        })
+        }),
+      )
 
-        for (let i = 0; i < 20 && (client.diagnostics.get(file)?.length ?? 0) === 0; i++) {
-          await new Promise((resolve) => setTimeout(resolve, 25))
-        }
+      const diagnostic = yield* pollWithTimeout(
+        Effect.sync(() => client.diagnostics.get(file)?.[0]),
+        "push diagnostic was not published",
+      )
+      expect(diagnostic.message).toBe("push diagnostic")
 
-        expect(client.diagnostics.get(file)?.[0]?.message).toBe("push diagnostic")
+      const started = Date.now()
+      yield* Effect.promise(() => client.waitForDiagnostics({ path: file, version, mode: "document" }))
+      expect(Date.now() - started).toBeLessThan(1_000)
+    }),
+  )
 
-        const started = Date.now()
-        await client.waitForDiagnostics({ path: file, version, mode: "document" })
-        expect(Date.now() - started).toBeLessThan(1_000)
+  it.instance("document mode waits for pull diagnostics", () =>
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      const file = path.join(test.directory, "client.cs")
+      yield* writeFile(file, "class C {}\n")
 
-        await client.shutdown()
-      },
-    })
-  })
+      const client = yield* createScopedClient(spawnFakeServer())
 
-  test("document mode waits for pull diagnostics", async () => {
-    const handle = spawnFakeServer() as any
-    await using tmp = await tmpdir()
-    const file = path.join(tmp.path, "client.cs")
-    await Bun.write(file, "class C {}\n")
-
-    await withTestInstance({
-      directory: tmp.path,
-      fn: async (ctx) => {
-        const client = await LSPClient.create({
-          serverID: "fake",
-          server: handle as unknown as LSPServer.Handle,
-          root: tmp.path,
-          directory: tmp.path,
-          instance: ctx,
-        })
-
-        await client.connection.sendRequest("test/configure-pull-diagnostics", {
+      yield* Effect.promise(() =>
+        client.connection.sendRequest("test/configure-pull-diagnostics", {
           registerOn: "didOpen",
           registrations: [{ identifier: "DocumentCompilerSemantic" }],
           documentDiagnosticsByIdentifier: {
@@ -319,41 +266,31 @@ describe("LSPClient interop", () => {
               },
             ],
           },
-        })
+        }),
+      )
 
-        const version = await client.notify.open({ path: file })
-        await client.waitForDiagnostics({ path: file, version, mode: "document" })
+      const version = yield* Effect.promise(() => client.notify.open({ path: file }))
+      yield* Effect.promise(() => client.waitForDiagnostics({ path: file, version, mode: "document" }))
 
-        const diagnostics = client.diagnostics.get(file) ?? []
-        expect(diagnostics).toHaveLength(1)
-        expect(diagnostics[0]?.message).toBe("pull diagnostic")
+      const diagnostics = client.diagnostics.get(file) ?? []
+      expect(diagnostics).toHaveLength(1)
+      expect(diagnostics[0]?.message).toBe("pull diagnostic")
 
-        const count = await client.connection.sendRequest("test/get-diagnostic-request-count", {})
-        expect(count).toBeGreaterThan(0)
+      const count = yield* Effect.promise(() => client.connection.sendRequest("test/get-diagnostic-request-count", {}))
+      expect(count).toBeGreaterThan(0)
+    }),
+  )
 
-        await client.shutdown()
-      },
-    })
-  })
+  it.instance("document mode does not wait for the slowest pull identifier after current-file diagnostics arrive", () =>
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      const file = path.join(test.directory, "client.cs")
+      yield* writeFile(file, "class C {}\n")
 
-  test("document mode does not wait for the slowest pull identifier after current-file diagnostics arrive", async () => {
-    const handle = spawnFakeServer() as any
-    await using tmp = await tmpdir()
-    const file = path.join(tmp.path, "client.cs")
-    await Bun.write(file, "class C {}\n")
+      const client = yield* createScopedClient(spawnFakeServer())
 
-    await withTestInstance({
-      directory: tmp.path,
-      fn: async (ctx) => {
-        const client = await LSPClient.create({
-          serverID: "fake",
-          server: handle as unknown as LSPServer.Handle,
-          root: tmp.path,
-          directory: tmp.path,
-          instance: ctx,
-        })
-
-        await client.connection.sendRequest("test/configure-pull-diagnostics", {
+      yield* Effect.promise(() =>
+        client.connection.sendRequest("test/configure-pull-diagnostics", {
           registrations: [{ identifier: "fast" }, { identifier: "slow" }],
           documentDiagnosticsByIdentifier: {
             fast: [
@@ -371,43 +308,34 @@ describe("LSPClient interop", () => {
           documentDelayMsByIdentifier: {
             slow: 2_500,
           },
-        })
+        }),
+      )
 
-        const version = await client.notify.open({ path: file })
-        await client.connection.sendRequest("test/register-configured-pull-diagnostics", {})
-        await new Promise((resolve) => setTimeout(resolve, 100))
-        const started = Date.now()
-        await client.waitForDiagnostics({ path: file, version, mode: "document" })
+      const version = yield* Effect.promise(() => client.notify.open({ path: file }))
+      yield* Effect.promise(() => client.connection.sendRequest("test/register-configured-pull-diagnostics", {}))
+      const started = Date.now()
+      yield* Effect.promise(() => client.waitForDiagnostics({ path: file, version, mode: "document" }))
 
-        expect(Date.now() - started).toBeLessThan(1_000)
-        expect(client.diagnostics.get(file)?.[0]?.message).toBe("fast diagnostic")
-        expect(await client.connection.sendRequest("test/get-diagnostic-request-count", {})).toBeGreaterThan(1)
+      expect(Date.now() - started).toBeLessThan(1_000)
+      expect(client.diagnostics.get(file)?.[0]?.message).toBe("fast diagnostic")
+      expect(
+        yield* Effect.promise(() => client.connection.sendRequest("test/get-diagnostic-request-count", {})),
+      ).toBeGreaterThan(1)
+    }),
+  )
 
-        await client.shutdown()
-      },
-    })
-  })
+  it.instance("full mode includes workspace pull diagnostics", () =>
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      const file = path.join(test.directory, "client.cs")
+      const related = path.join(test.directory, "other.cs")
+      yield* writeFile(file, "class C {}\n")
+      yield* writeFile(related, "class D {}\n")
 
-  test("full mode includes workspace pull diagnostics", async () => {
-    const handle = spawnFakeServer() as any
-    await using tmp = await tmpdir()
-    const file = path.join(tmp.path, "client.cs")
-    const related = path.join(tmp.path, "other.cs")
-    await Bun.write(file, "class C {}\n")
-    await Bun.write(related, "class D {}\n")
+      const client = yield* createScopedClient(spawnFakeServer())
 
-    await withTestInstance({
-      directory: tmp.path,
-      fn: async (ctx) => {
-        const client = await LSPClient.create({
-          serverID: "fake",
-          server: handle as unknown as LSPServer.Handle,
-          root: tmp.path,
-          directory: tmp.path,
-          instance: ctx,
-        })
-
-        await client.connection.sendRequest("test/configure-pull-diagnostics", {
+      yield* Effect.promise(() =>
+        client.connection.sendRequest("test/configure-pull-diagnostics", {
           registerOn: "didOpen",
           registrations: [
             { identifier: "DocumentCompilerSemantic" },
@@ -442,52 +370,40 @@ describe("LSPClient interop", () => {
               },
             ],
           },
-        })
+        }),
+      )
 
-        const version = await client.notify.open({ path: file })
-        await client.waitForDiagnostics({ path: file, version, mode: "full" })
+      const version = yield* Effect.promise(() => client.notify.open({ path: file }))
+      yield* Effect.promise(() => client.waitForDiagnostics({ path: file, version, mode: "full" }))
 
-        expect(client.diagnostics.get(file)?.[0]?.message).toBe("current file")
-        expect(client.diagnostics.get(related)?.[0]?.message).toBe("workspace file")
+      expect(client.diagnostics.get(file)?.[0]?.message).toBe("current file")
+      expect(client.diagnostics.get(related)?.[0]?.message).toBe("workspace file")
+    }),
+  )
 
-        await client.shutdown()
-      },
-    })
-  })
+  it.instance("full mode treats an empty workspace pull response as handled", () =>
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      const file = path.join(test.directory, "client.cs")
+      yield* writeFile(file, "class C {}\n")
 
-  test("full mode treats an empty workspace pull response as handled", async () => {
-    const handle = spawnFakeServer() as any
-    await using tmp = await tmpdir()
-    const file = path.join(tmp.path, "client.cs")
-    await Bun.write(file, "class C {}\n")
+      const client = yield* createScopedClient(spawnFakeServer())
 
-    await withTestInstance({
-      directory: tmp.path,
-      fn: async (ctx) => {
-        const client = await LSPClient.create({
-          serverID: "fake",
-          server: handle as unknown as LSPServer.Handle,
-          root: tmp.path,
-          directory: tmp.path,
-          instance: ctx,
-        })
-
-        await client.connection.sendRequest("test/configure-pull-diagnostics", {
+      yield* Effect.promise(() =>
+        client.connection.sendRequest("test/configure-pull-diagnostics", {
           registerOn: "didOpen",
           registrations: [{ identifier: "WorkspaceDocumentsAndProject", workspaceDiagnostics: true }],
           workspaceDiagnosticsByIdentifier: {
             WorkspaceDocumentsAndProject: [],
           },
-        })
+        }),
+      )
 
-        const version = await client.notify.open({ path: file })
-        const started = Date.now()
-        await client.waitForDiagnostics({ path: file, version, mode: "full" })
+      const version = yield* Effect.promise(() => client.notify.open({ path: file }))
+      const started = Date.now()
+      yield* Effect.promise(() => client.waitForDiagnostics({ path: file, version, mode: "full" }))
 
-        expect(Date.now() - started).toBeLessThan(1_000)
-
-        await client.shutdown()
-      },
-    })
-  })
+      expect(Date.now() - started).toBeLessThan(1_000)
+    }),
+  )
 })

packages/opencode/test/project/project.test.ts

@@ -30,16 +30,9 @@ void Log.init({ print: false })
 
 const encoder = new TextEncoder()
 
-const layer = Layer.mergeAll(Project.defaultLayer, CrossSpawnSpawner.defaultLayer)
+const layer = Layer.mergeAll(Project.defaultLayer, CrossSpawnSpawner.defaultLayer, AppFileSystem.defaultLayer)
 const it = testEffect(layer)
 
-function run<A, E>(fn: (svc: Project.Interface) => Effect.Effect<A, E>) {
-  return Effect.gen(function* () {
-    const svc = yield* Project.Service
-    return yield* fn(svc)
-  })
-}
-
 function remoteProjectID(remote: string) {
   return ProjectID.make(Hash.fast(`git-remote:${remote}`))
 }
@@ -103,10 +96,18 @@ function projectLayerWithRuntimeFlags(flags: Parameters<typeof RuntimeFlags.laye
 }
 
 const failureIt = (failArg: string) =>
-  testEffect(Layer.mergeAll(projectLayerWithFailure(failArg), CrossSpawnSpawner.defaultLayer))
+  testEffect(
+    Layer.mergeAll(projectLayerWithFailure(failArg), CrossSpawnSpawner.defaultLayer, AppFileSystem.defaultLayer),
+  )
 
 const iconDiscoveryIt = testEffect(
-  Layer.provideMerge(projectLayerWithRuntimeFlags({ experimentalIconDiscovery: true }), CrossSpawnSpawner.defaultLayer),
+  Layer.mergeAll(
+    Layer.provideMerge(
+      projectLayerWithRuntimeFlags({ experimentalIconDiscovery: true }),
+      CrossSpawnSpawner.defaultLayer,
+    ),
+    AppFileSystem.defaultLayer,
+  ),
 )
 
 function waitForProjectIcon(id: ProjectID, attempts = 50): Effect.Effect<Project.Info> {
@@ -125,7 +126,7 @@ describe("Project.fromDirectory", () => {
       const tmp = yield* tmpdirScoped()
       yield* Effect.promise(() => $`git init`.cwd(tmp).quiet())
 
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
       expect(project).toBeDefined()
       expect(project.id).toBe(ProjectID.global)
@@ -133,7 +134,7 @@ describe("Project.fromDirectory", () => {
       expect(project.worktree).toBe(tmp)
 
       const opencodeFile = path.join(tmp, ".git", "opencode")
-      expect(yield* Effect.promise(() => Bun.file(opencodeFile).exists())).toBe(false)
+      expect(yield* AppFileSystem.use.existsSafe(opencodeFile)).toBe(false)
     }),
   )
 
@@ -141,7 +142,7 @@ describe("Project.fromDirectory", () => {
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
 
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
       expect(project).toBeDefined()
       expect(project.id).not.toBe(ProjectID.global)
@@ -153,7 +154,7 @@ describe("Project.fromDirectory", () => {
   it.live("returns global for non-git directory", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped()
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
       expect(project.id).toBe(ProjectID.global)
     }),
   )
@@ -161,8 +162,8 @@ describe("Project.fromDirectory", () => {
   it.live("derives stable project ID from root commit", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project: a } = yield* run((svc) => svc.fromDirectory(tmp))
-      const { project: b } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project: a } = yield* Project.use.fromDirectory(tmp)
+      const { project: b } = yield* Project.use.fromDirectory(tmp)
       expect(b.id).toBe(a.id)
     }),
   )
@@ -172,7 +173,7 @@ describe("Project.fromDirectory", () => {
       const tmp = yield* tmpdirScoped({ git: true })
       yield* Effect.promise(() => $`git remote add origin git@github.com:Test-Org/Test-Repo.git`.cwd(tmp).quiet())
 
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
       expect(project.id).toBe(remoteProjectID("github.com/Test-Org/Test-Repo"))
     }),
@@ -185,8 +186,8 @@ describe("Project.fromDirectory", () => {
       yield* Effect.promise(() => $`git remote add origin git@github.com:owner/repo.git`.cwd(ssh).quiet())
       yield* Effect.promise(() => $`git remote add origin https://github.com/owner/repo.git`.cwd(https).quiet())
 
-      const { project: a } = yield* run((svc) => svc.fromDirectory(ssh))
-      const { project: b } = yield* run((svc) => svc.fromDirectory(https))
+      const { project: a } = yield* Project.use.fromDirectory(ssh)
+      const { project: b } = yield* Project.use.fromDirectory(https)
 
       expect(a.id).toBe(remoteProjectID("github.com/owner/repo"))
       expect(b.id).toBe(a.id)
@@ -196,8 +197,7 @@ describe("Project.fromDirectory", () => {
   it.live("migrates cached root project data when origin becomes available", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const projects = yield* Project.Service
-      const { project: rootProject } = yield* projects.fromDirectory(tmp)
+      const { project: rootProject } = yield* Project.use.fromDirectory(tmp)
       const remoteID = remoteProjectID("github.com/acme/app")
       const sessionID = crypto.randomUUID() as SessionID
       const workspaceID = WorkspaceID.ascending()
@@ -236,7 +236,7 @@ describe("Project.fromDirectory", () => {
       })
       yield* Effect.promise(() => $`git remote add origin git@github.com:acme/app.git`.cwd(tmp).quiet())
 
-      const { project } = yield* projects.fromDirectory(tmp)
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
       expect(project.id).toBe(remoteID)
       expect(
@@ -263,7 +263,7 @@ describe("Project.fromDirectory git failure paths", () => {
       yield* Effect.promise(() => $`git init`.cwd(tmp).quiet())
 
       // rev-list fails because HEAD doesn't exist yet: this is the natural scenario.
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
       expect(project.vcs).toBe("git")
       expect(project.id).toBe(ProjectID.global)
       expect(project.worktree).toBe(tmp)
@@ -274,7 +274,7 @@ describe("Project.fromDirectory git failure paths", () => {
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
 
-      const { project, sandbox } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project, sandbox } = yield* Project.use.fromDirectory(tmp)
       expect(project.worktree).toBe(tmp)
       expect(sandbox).toBe(tmp)
     }),
@@ -284,7 +284,7 @@ describe("Project.fromDirectory git failure paths", () => {
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
 
-      const { project, sandbox } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project, sandbox } = yield* Project.use.fromDirectory(tmp)
       expect(project.worktree).toBe(tmp)
       expect(sandbox).toBe(tmp)
     }),
@@ -296,7 +296,7 @@ describe("Project.fromDirectory with worktrees", () => {
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
 
-      const { project, sandbox } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project, sandbox } = yield* Project.use.fromDirectory(tmp)
 
       expect(project.worktree).toBe(tmp)
       expect(sandbox).toBe(tmp)
@@ -319,7 +319,7 @@ describe("Project.fromDirectory with worktrees", () => {
       )
       yield* Effect.promise(() => $`git worktree add ${worktreePath} -b test-branch-${Date.now()}`.cwd(tmp).quiet())
 
-      const { project, sandbox } = yield* run((svc) => svc.fromDirectory(worktreePath))
+      const { project, sandbox } = yield* Project.use.fromDirectory(worktreePath)
 
       expect(project.worktree).toBe(worktreePath)
       expect(sandbox).toBe(worktreePath)
@@ -332,7 +332,7 @@ describe("Project.fromDirectory with worktrees", () => {
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
 
-      const { project: main } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project: main } = yield* Project.use.fromDirectory(tmp)
 
       const worktreePath = path.join(tmp, "..", path.basename(tmp) + "-wt-shared")
       yield* Effect.addFinalizer(() =>
@@ -345,12 +345,12 @@ describe("Project.fromDirectory with worktrees", () => {
       )
       yield* Effect.promise(() => $`git worktree add ${worktreePath} -b shared-${Date.now()}`.cwd(tmp).quiet())
 
-      const { project: wt } = yield* run((svc) => svc.fromDirectory(worktreePath))
+      const { project: wt } = yield* Project.use.fromDirectory(worktreePath)
 
       expect(wt.id).toBe(main.id)
 
       const cache = path.join(tmp, ".git", "opencode")
-      const exists = yield* Effect.promise(() => Bun.file(cache).exists())
+      const exists = yield* AppFileSystem.use.existsSafe(cache)
       expect(exists).toBe(true)
     }),
   )
@@ -368,8 +368,8 @@ describe("Project.fromDirectory with worktrees", () => {
       yield* Effect.promise(() => $`git clone --bare ${tmp} ${bare}`.quiet())
       yield* Effect.promise(() => $`git clone ${bare} ${clone}`.quiet())
 
-      const { project: a } = yield* run((svc) => svc.fromDirectory(tmp))
-      const { project: b } = yield* run((svc) => svc.fromDirectory(clone))
+      const { project: a } = yield* Project.use.fromDirectory(tmp)
+      const { project: b } = yield* Project.use.fromDirectory(clone)
 
       expect(b.id).toBe(a.id)
     }),
@@ -400,8 +400,8 @@ describe("Project.fromDirectory with worktrees", () => {
       yield* Effect.promise(() => $`git worktree add ${worktree1} -b branch-${Date.now()}`.cwd(tmp).quiet())
       yield* Effect.promise(() => $`git worktree add ${worktree2} -b branch-${Date.now() + 1}`.cwd(tmp).quiet())
 
-      yield* run((svc) => svc.fromDirectory(worktree1))
-      const { project } = yield* run((svc) => svc.fromDirectory(worktree2))
+      yield* Project.use.fromDirectory(worktree1)
+      const { project } = yield* Project.use.fromDirectory(worktree2)
 
       expect(project.worktree).toBe(worktree1)
       expect(project.sandboxes).toContain(worktree2)
@@ -415,9 +415,9 @@ describe("Project.discover", () => {
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
       const pngData = Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a])
-      yield* Effect.promise(() => Bun.write(path.join(tmp, "favicon.png"), pngData))
+      yield* AppFileSystem.use.writeWithDirs(path.join(tmp, "favicon.png"), pngData)
 
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
       const updated = yield* waitForProjectIcon(project.id)
 
       expect(updated.icon?.url).toStartWith("data:")
@@ -428,12 +428,12 @@ describe("Project.discover", () => {
   it.live("should discover favicon.png in root", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
       const pngData = Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a])
-      yield* Effect.promise(() => Bun.write(path.join(tmp, "favicon.png"), pngData))
+      yield* AppFileSystem.use.writeWithDirs(path.join(tmp, "favicon.png"), pngData)
 
-      yield* run((svc) => svc.discover(project))
+      yield* Project.use.discover(project)
 
       const updated = Project.get(project.id)
       expect(updated).toBeDefined()
@@ -447,11 +447,11 @@ describe("Project.discover", () => {
   it.live("should not discover non-image files", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
-      yield* Effect.promise(() => Bun.write(path.join(tmp, "favicon.txt"), "not an image"))
+      yield* AppFileSystem.use.writeWithDirs(path.join(tmp, "favicon.txt"), "not an image")
 
-      yield* run((svc) => svc.discover(project))
+      yield* Project.use.discover(project)
 
       const updated = Project.get(project.id)
       expect(updated).toBeDefined()
@@ -462,22 +462,20 @@ describe("Project.discover", () => {
   it.live("should not discover favicon when override is set", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
-      yield* run((svc) =>
-        svc.update({
-          projectID: project.id,
-          icon: { override: "data:image/png;base64,override" },
-        }),
-      )
+      yield* Project.use.update({
+        projectID: project.id,
+        icon: { override: "data:image/png;base64,override" },
+      })
 
-      const updatedProject = yield* run((svc) => svc.get(project.id))
+      const updatedProject = yield* Project.use.get(project.id)
       if (!updatedProject) throw new Error("Project not found")
 
       const pngData = Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a])
-      yield* Effect.promise(() => Bun.write(path.join(tmp, "favicon.png"), pngData))
+      yield* AppFileSystem.use.writeWithDirs(path.join(tmp, "favicon.png"), pngData)
 
-      yield* run((svc) => svc.discover(updatedProject))
+      yield* Project.use.discover(updatedProject)
 
       const updated = Project.get(project.id)
       expect(updated).toBeDefined()
@@ -491,14 +489,12 @@ describe("Project.update", () => {
   it.live("should update name", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
-      const updated = yield* run((svc) =>
-        svc.update({
-          projectID: project.id,
-          name: "New Project Name",
-        }),
-      )
+      const updated = yield* Project.use.update({
+        projectID: project.id,
+        name: "New Project Name",
+      })
 
       expect(updated.name).toBe("New Project Name")
 
@@ -510,14 +506,12 @@ describe("Project.update", () => {
   it.live("should update icon url", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
-      const updated = yield* run((svc) =>
-        svc.update({
-          projectID: project.id,
-          icon: { url: "https://example.com/icon.png" },
-        }),
-      )
+      const updated = yield* Project.use.update({
+        projectID: project.id,
+        icon: { url: "https://example.com/icon.png" },
+      })
 
       expect(updated.icon?.url).toBe("https://example.com/icon.png")
 
@@ -529,14 +523,12 @@ describe("Project.update", () => {
   it.live("should update icon color", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
-      const updated = yield* run((svc) =>
-        svc.update({
-          projectID: project.id,
-          icon: { color: "#ff0000" },
-        }),
-      )
+      const updated = yield* Project.use.update({
+        projectID: project.id,
+        icon: { color: "#ff0000" },
+      })
 
       expect(updated.icon?.color).toBe("#ff0000")
 
@@ -548,14 +540,12 @@ describe("Project.update", () => {
   it.live("should update icon override", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
-      const updated = yield* run((svc) =>
-        svc.update({
-          projectID: project.id,
-          icon: { override: "data:image/png;base64,abc123" },
-        }),
-      )
+      const updated = yield* Project.use.update({
+        projectID: project.id,
+        icon: { override: "data:image/png;base64,abc123" },
+      })
 
       expect(updated.icon?.override).toBe("data:image/png;base64,abc123")
 
@@ -567,14 +557,12 @@ describe("Project.update", () => {
   it.live("should update commands", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
-      const updated = yield* run((svc) =>
-        svc.update({
-          projectID: project.id,
-          commands: { start: "npm run dev" },
-        }),
-      )
+      const updated = yield* Project.use.update({
+        projectID: project.id,
+        commands: { start: "npm run dev" },
+      })
 
       expect(updated.commands?.start).toBe("npm run dev")
 
@@ -585,12 +573,12 @@ describe("Project.update", () => {
 
   it.live("should fail when project not found", () =>
     Effect.gen(function* () {
-      const exit = yield* run((svc) =>
-        svc.update({
+      const exit = yield* Project.use
+        .update({
           projectID: ProjectID.make("nonexistent-project-id"),
           name: "Should Fail",
-        }),
-      ).pipe(Effect.exit)
+        })
+        .pipe(Effect.exit)
       expect(Exit.isFailure(exit)).toBe(true)
       if (Exit.isFailure(exit)) {
         const error = Cause.squash(exit.cause)
@@ -602,7 +590,7 @@ describe("Project.update", () => {
   it.live("should emit GlobalBus event on update", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
       let eventPayload: any = null
       const on = (data: any) => {
@@ -611,7 +599,7 @@ describe("Project.update", () => {
       GlobalBus.on("event", on)
       yield* Effect.addFinalizer(() => Effect.sync(() => GlobalBus.off("event", on)))
 
-      yield* run((svc) => svc.update({ projectID: project.id, name: "Updated Name" }))
+      yield* Project.use.update({ projectID: project.id, name: "Updated Name" })
 
       expect(eventPayload).not.toBeNull()
       expect(eventPayload.payload.type).toBe("project.updated")
@@ -622,16 +610,14 @@ describe("Project.update", () => {
   it.live("should update multiple fields at once", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
-      const updated = yield* run((svc) =>
-        svc.update({
-          projectID: project.id,
-          name: "Multi Update",
-          icon: { url: "https://example.com/favicon.ico", override: "data:image/png;base64,abc123", color: "#00ff00" },
-          commands: { start: "make start" },
-        }),
-      )
+      const updated = yield* Project.use.update({
+        projectID: project.id,
+        name: "Multi Update",
+        icon: { url: "https://example.com/favicon.ico", override: "data:image/png;base64,abc123", color: "#00ff00" },
+        commands: { start: "make start" },
+      })
 
       expect(updated.name).toBe("Multi Update")
       expect(updated.icon?.url).toBe("https://example.com/favicon.ico")
@@ -646,7 +632,7 @@ describe("Project.list and Project.get", () => {
   it.live("list returns all projects", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
       const all = Project.list()
       expect(all.length).toBeGreaterThan(0)
@@ -657,7 +643,7 @@ describe("Project.list and Project.get", () => {
   it.live("get returns project by id", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
       const found = Project.get(project.id)
       expect(found).toBeDefined()
@@ -675,7 +661,7 @@ describe("Project.setInitialized", () => {
   it.live("sets time_initialized on project", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
 
       expect(project.time.initialized).toBeUndefined()
 
@@ -691,15 +677,15 @@ describe("Project.addSandbox and Project.removeSandbox", () => {
   it.live("addSandbox adds directory and removeSandbox removes it", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
       const sandboxDir = path.join(tmp, "sandbox-test")
 
-      yield* run((svc) => svc.addSandbox(project.id, sandboxDir))
+      yield* Project.use.addSandbox(project.id, sandboxDir)
 
       let found = Project.get(project.id)
       expect(found?.sandboxes).toContain(sandboxDir)
 
-      yield* run((svc) => svc.removeSandbox(project.id, sandboxDir))
+      yield* Project.use.removeSandbox(project.id, sandboxDir)
 
       found = Project.get(project.id)
       expect(found?.sandboxes).not.toContain(sandboxDir)
@@ -709,7 +695,7 @@ describe("Project.addSandbox and Project.removeSandbox", () => {
   it.live("addSandbox emits GlobalBus event", () =>
     Effect.gen(function* () {
       const tmp = yield* tmpdirScoped({ git: true })
-      const { project } = yield* run((svc) => svc.fromDirectory(tmp))
+      const { project } = yield* Project.use.fromDirectory(tmp)
       const sandboxDir = path.join(tmp, "sandbox-event")
 
       const events: any[] = []
@@ -717,7 +703,7 @@ describe("Project.addSandbox and Project.removeSandbox", () => {
       GlobalBus.on("event", on)
       yield* Effect.addFinalizer(() => Effect.sync(() => GlobalBus.off("event", on)))
 
-      yield* run((svc) => svc.addSandbox(project.id, sandboxDir))
+      yield* Project.use.addSandbox(project.id, sandboxDir)
 
       expect(events.some((e) => e.payload.type === Project.Event.Updated.type)).toBe(true)
     }),
@@ -739,7 +725,7 @@ describe("Project.fromDirectory with bare repos", () => {
       yield* Effect.promise(() => $`git clone --bare ${tmp} ${barePath}`.quiet())
       yield* Effect.promise(() => $`git worktree add ${worktreePath} HEAD`.cwd(barePath).quiet())
 
-      const { project } = yield* run((svc) => svc.fromDirectory(worktreePath))
+      const { project } = yield* Project.use.fromDirectory(worktreePath)
 
       expect(project.id).not.toBe(ProjectID.global)
       expect(project.worktree).toBe(worktreePath)
@@ -747,8 +733,8 @@ describe("Project.fromDirectory with bare repos", () => {
       const correctCache = path.join(barePath, "opencode")
       const wrongCache = path.join(parentDir, ".git", "opencode")
 
-      expect(yield* Effect.promise(() => Bun.file(correctCache).exists())).toBe(true)
-      expect(yield* Effect.promise(() => Bun.file(wrongCache).exists())).toBe(false)
+      expect(yield* AppFileSystem.use.existsSafe(correctCache)).toBe(true)
+      expect(yield* AppFileSystem.use.existsSafe(wrongCache)).toBe(false)
     }),
   )
 
@@ -773,8 +759,8 @@ describe("Project.fromDirectory with bare repos", () => {
       yield* Effect.promise(() => $`git worktree add ${worktreeA} HEAD`.cwd(bareA).quiet())
       yield* Effect.promise(() => $`git worktree add ${worktreeB} HEAD`.cwd(bareB).quiet())
 
-      const { project: projA } = yield* run((svc) => svc.fromDirectory(worktreeA))
-      const { project: projB } = yield* run((svc) => svc.fromDirectory(worktreeB))
+      const { project: projA } = yield* Project.use.fromDirectory(worktreeA)
+      const { project: projB } = yield* Project.use.fromDirectory(worktreeB)
 
       expect(projA.id).not.toBe(projB.id)
 
@@ -782,9 +768,9 @@ describe("Project.fromDirectory with bare repos", () => {
       const cacheB = path.join(bareB, "opencode")
       const wrongCache = path.join(parentDir, ".git", "opencode")
 
-      expect(yield* Effect.promise(() => Bun.file(cacheA).exists())).toBe(true)
-      expect(yield* Effect.promise(() => Bun.file(cacheB).exists())).toBe(true)
-      expect(yield* Effect.promise(() => Bun.file(wrongCache).exists())).toBe(false)
+      expect(yield* AppFileSystem.use.existsSafe(cacheA)).toBe(true)
+      expect(yield* AppFileSystem.use.existsSafe(cacheB)).toBe(true)
+      expect(yield* AppFileSystem.use.existsSafe(wrongCache)).toBe(false)
     }),
   )
 
@@ -802,13 +788,13 @@ describe("Project.fromDirectory with bare repos", () => {
       yield* Effect.promise(() => $`git clone --bare ${tmp} ${barePath}`.quiet())
       yield* Effect.promise(() => $`git worktree add ${worktreePath} HEAD`.cwd(barePath).quiet())
 
-      const { project } = yield* run((svc) => svc.fromDirectory(worktreePath))
+      const { project } = yield* Project.use.fromDirectory(worktreePath)
 
       expect(project.id).not.toBe(ProjectID.global)
       expect(project.worktree).toBe(worktreePath)
 
       const correctCache = path.join(barePath, "opencode")
-      expect(yield* Effect.promise(() => Bun.file(correctCache).exists())).toBe(true)
+      expect(yield* AppFileSystem.use.existsSafe(correctCache)).toBe(true)
     }),
   )
 })

packages/opencode/test/skill/skill.test.ts

@@ -8,14 +8,13 @@ import { Config } from "../../src/config/config"
 import { CrossSpawnSpawner } from "@opencode-ai/core/cross-spawn-spawner"
 import { AppFileSystem } from "@opencode-ai/core/filesystem"
 import { Global } from "@opencode-ai/core/global"
-import { provideInstance, provideTmpdirInstance, tmpdir } from "../fixture/fixture"
+import { TestInstance } from "../fixture/fixture"
 import { testEffect } from "../lib/effect"
 import path from "path"
-import fs from "fs/promises"
 
 const node = CrossSpawnSpawner.defaultLayer
 
-const it = testEffect(Layer.mergeAll(Skill.defaultLayer, node))
+const it = testEffect(Layer.mergeAll(Skill.defaultLayer, AppFileSystem.defaultLayer, node))
 const itWithoutClaudeCodeSkills = testEffect(
   Layer.mergeAll(
     Skill.layer.pipe(
@@ -26,6 +25,7 @@ const itWithoutClaudeCodeSkills = testEffect(
       Layer.provide(Global.layer),
       Layer.provide(RuntimeFlags.layer({ disableClaudeCodeSkills: true })),
     ),
+    AppFileSystem.defaultLayer,
     node,
   ),
 )
@@ -39,15 +39,18 @@ const itWithoutExternalSkills = testEffect(
       Layer.provide(Global.layer),
       Layer.provide(RuntimeFlags.layer({ disableExternalSkills: true })),
     ),
+    AppFileSystem.defaultLayer,
     node,
   ),
 )
 
-async function createGlobalSkill(homeDir: string) {
-  const skillDir = path.join(homeDir, ".claude", "skills", "global-test-skill")
-  await fs.mkdir(skillDir, { recursive: true })
-  await Bun.write(
-    path.join(skillDir, "SKILL.md"),
+const writeSkill = (dir: string, parts: string[], content: string) =>
+  AppFileSystem.use.writeWithDirs(path.join(dir, ...parts, "SKILL.md"), content)
+
+const createGlobalSkill = (homeDir: string) =>
+  writeSkill(
+    homeDir,
+    [".claude", "skills", "global-test-skill"],
     `---
 name: global-test-skill
 description: A global skill from ~/.claude/skills for testing.
@@ -58,7 +61,6 @@ description: A global skill from ~/.claude/skills for testing.
 This skill is loaded from the global home directory.
 `,
   )
-}
 
 const withHome = <A, E, R>(home: string, self: Effect.Effect<A, E, R>) =>
   Effect.acquireUseRelease(
@@ -75,14 +77,14 @@ const withHome = <A, E, R>(home: string, self: Effect.Effect<A, E, R>) =>
   )
 
 describe("skill", () => {
-  it.live("discovers skills from .opencode/skill/ directory", () =>
-    provideTmpdirInstance(
-      (dir) =>
-        Effect.gen(function* () {
-          yield* Effect.promise(() =>
-            Bun.write(
-              path.join(dir, ".opencode", "skill", "test-skill", "SKILL.md"),
-              `---
+  it.instance(
+    "discovers skills from .opencode/skill/ directory",
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      yield* writeSkill(
+        test.directory,
+        [".opencode", "skill", "test-skill"],
+        `---
 name: test-skill
 description: A test skill for verification.
 ---
@@ -91,118 +93,111 @@ description: A test skill for verification.
 
 Instructions here.
 `,
-            ),
-          )
+      )
 
-          const skill = yield* Skill.Service
-          const list = (yield* skill.all()).filter((s) => s.location !== "<built-in>")
-          expect(list.length).toBe(1)
-          const item = list.find((x) => x.name === "test-skill")
-          expect(item).toBeDefined()
-          expect(item!.description).toBe("A test skill for verification.")
-          expect(item!.location).toContain(path.join("skill", "test-skill", "SKILL.md"))
-        }),
-      { git: true },
-    ),
+      const list = (yield* Skill.use.all()).filter((s) => s.location !== "<built-in>")
+      expect(list.length).toBe(1)
+      const item = list.find((x) => x.name === "test-skill")
+      expect(item).toBeDefined()
+      expect(item!.description).toBe("A test skill for verification.")
+      expect(item!.location).toContain(path.join("skill", "test-skill", "SKILL.md"))
+    }),
+    { git: true },
   )
 
-  it.live("returns skill directories from Skill.dirs", () =>
-    provideTmpdirInstance(
-      (dir) =>
-        withHome(
-          dir,
-          Effect.gen(function* () {
-            yield* Effect.promise(() =>
-              Bun.write(
-                path.join(dir, ".opencode", "skill", "dir-skill", "SKILL.md"),
-                `---
+  it.instance(
+    "returns skill directories from Skill.dirs",
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      yield* withHome(
+        test.directory,
+        Effect.gen(function* () {
+          yield* writeSkill(
+            test.directory,
+            [".opencode", "skill", "dir-skill"],
+            `---
 name: dir-skill
 description: Skill for dirs test.
 ---
 
 # Dir Skill
 `,
-              ),
-            )
+          )
 
-            const skill = yield* Skill.Service
-            const dirs = yield* skill.dirs()
-            expect(dirs).toContain(path.join(dir, ".opencode", "skill", "dir-skill"))
-            expect(dirs.length).toBe(1)
-          }),
-        ),
-      { git: true },
-    ),
+          const dirs = yield* Skill.use.dirs()
+          expect(dirs).toContain(path.join(test.directory, ".opencode", "skill", "dir-skill"))
+          expect(dirs.length).toBe(1)
+        }),
+      )
+    }),
+    { git: true },
   )
 
-  it.live("discovers multiple skills from .opencode/skill/ directory", () =>
-    provideTmpdirInstance(
-      (dir) =>
-        Effect.gen(function* () {
-          yield* Effect.promise(() =>
-            Promise.all([
-              Bun.write(
-                path.join(dir, ".opencode", "skill", "skill-one", "SKILL.md"),
-                `---
+  it.instance(
+    "discovers multiple skills from .opencode/skill/ directory",
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      yield* Effect.all(
+        [
+          writeSkill(
+            test.directory,
+            [".opencode", "skill", "skill-one"],
+            `---
 name: skill-one
 description: First test skill.
 ---
 
 # Skill One
 `,
-              ),
-              Bun.write(
-                path.join(dir, ".opencode", "skill", "skill-two", "SKILL.md"),
-                `---
+          ),
+          writeSkill(
+            test.directory,
+            [".opencode", "skill", "skill-two"],
+            `---
 name: skill-two
 description: Second test skill.
 ---
 
 # Skill Two
 `,
-              ),
-            ]),
-          )
+          ),
+        ],
+      )
 
-          const skill = yield* Skill.Service
-          const list = (yield* skill.all()).filter((s) => s.location !== "<built-in>")
-          expect(list.length).toBe(2)
-          expect(list.find((x) => x.name === "skill-one")).toBeDefined()
-          expect(list.find((x) => x.name === "skill-two")).toBeDefined()
-        }),
-      { git: true },
-    ),
+      const list = (yield* Skill.use.all()).filter((s) => s.location !== "<built-in>")
+      expect(list.length).toBe(2)
+      expect(list.find((x) => x.name === "skill-one")).toBeDefined()
+      expect(list.find((x) => x.name === "skill-two")).toBeDefined()
+    }),
+    { git: true },
   )
 
-  it.live("skips skills with missing frontmatter", () =>
-    provideTmpdirInstance(
-      (dir) =>
-        Effect.gen(function* () {
-          yield* Effect.promise(() =>
-            Bun.write(
-              path.join(dir, ".opencode", "skill", "no-frontmatter", "SKILL.md"),
-              `# No Frontmatter
+  it.instance(
+    "skips skills with missing frontmatter",
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      yield* writeSkill(
+        test.directory,
+        [".opencode", "skill", "no-frontmatter"],
+        `# No Frontmatter
 
 Just some content without YAML frontmatter.
 `,
-            ),
-          )
+      )
 
-          const skill = yield* Skill.Service
-          expect((yield* skill.all()).filter((s) => s.location !== "<built-in>")).toEqual([])
-        }),
-      { git: true },
-    ),
+      expect((yield* Skill.use.all()).filter((s) => s.location !== "<built-in>")).toEqual([])
+    }),
+    { git: true },
   )
 
-  it.live("discovers skills without descriptions", () =>
-    provideTmpdirInstance(
-      (dir) =>
-        Effect.gen(function* () {
-          yield* Effect.promise(() =>
-            Bun.write(
-              path.join(dir, ".opencode", "skill", "manual-skill", "SKILL.md"),
-              `---
+  it.instance(
+    "discovers skills without descriptions",
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      yield* writeSkill(
+        test.directory,
+        [".opencode", "skill", "manual-skill"],
+        `---
 name: manual-skill
 ---
 
@@ -210,98 +205,81 @@ name: manual-skill
 
 Instructions here.
 `,
-            ),
-          )
+      )
 
-          const skill = yield* Skill.Service
-          const list = (yield* skill.all()).filter((s) => s.location !== "<built-in>")
-          expect(list.length).toBe(1)
-          const item = list.find((x) => x.name === "manual-skill")
-          expect(item).toBeDefined()
-          expect(item!.description).toBeUndefined()
-          expect(Skill.fmt(list, { verbose: false })).toBe("No skills are currently available.")
-          expect(Skill.fmt(list, { verbose: true })).toBe("No skills are currently available.")
-        }),
-      { git: true },
-    ),
+      const list = (yield* Skill.use.all()).filter((s) => s.location !== "<built-in>")
+      expect(list.length).toBe(1)
+      const item = list.find((x) => x.name === "manual-skill")
+      expect(item).toBeDefined()
+      expect(item!.description).toBeUndefined()
+      expect(Skill.fmt(list, { verbose: false })).toBe("No skills are currently available.")
+      expect(Skill.fmt(list, { verbose: true })).toBe("No skills are currently available.")
+    }),
+    { git: true },
   )
 
-  it.live("discovers skills from .claude/skills/ directory", () =>
-    provideTmpdirInstance(
-      (dir) =>
-        Effect.gen(function* () {
-          yield* Effect.promise(() =>
-            Bun.write(
-              path.join(dir, ".claude", "skills", "claude-skill", "SKILL.md"),
-              `---
+  it.instance(
+    "discovers skills from .claude/skills/ directory",
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      yield* writeSkill(
+        test.directory,
+        [".claude", "skills", "claude-skill"],
+        `---
 name: claude-skill
 description: A skill in the .claude/skills directory.
 ---
 
 # Claude Skill
 `,
-            ),
-          )
-
-          const skill = yield* Skill.Service
-          const list = (yield* skill.all()).filter((s) => s.location !== "<built-in>")
-          expect(list.length).toBe(1)
-          const item = list.find((x) => x.name === "claude-skill")
-          expect(item).toBeDefined()
-          expect(item!.location).toContain(path.join(".claude", "skills", "claude-skill", "SKILL.md"))
-        }),
-      { git: true },
-    ),
-  )
-
-  it.live("discovers global skills from ~/.claude/skills/ directory", () =>
-    Effect.gen(function* () {
-      const tmp = yield* Effect.acquireRelease(
-        Effect.promise(() => tmpdir({ git: true })),
-        (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
       )
 
+      const list = (yield* Skill.use.all()).filter((s) => s.location !== "<built-in>")
+      expect(list.length).toBe(1)
+      const item = list.find((x) => x.name === "claude-skill")
+      expect(item).toBeDefined()
+      expect(item!.location).toContain(path.join(".claude", "skills", "claude-skill", "SKILL.md"))
+    }),
+    { git: true },
+  )
+
+  it.instance(
+    "discovers global skills from ~/.claude/skills/ directory",
+    Effect.gen(function* () {
+      const test = yield* TestInstance
       yield* withHome(
-        tmp.path,
+        test.directory,
         Effect.gen(function* () {
-          yield* Effect.promise(() => createGlobalSkill(tmp.path))
-          yield* Effect.gen(function* () {
-            const skill = yield* Skill.Service
-            const list = (yield* skill.all()).filter((s) => s.location !== "<built-in>")
-            expect(list.length).toBe(1)
-            expect(list[0].name).toBe("global-test-skill")
-            expect(list[0].description).toBe("A global skill from ~/.claude/skills for testing.")
-            expect(list[0].location).toContain(path.join(".claude", "skills", "global-test-skill", "SKILL.md"))
-          }).pipe(provideInstance(tmp.path))
+          yield* createGlobalSkill(test.directory)
+          const list = (yield* Skill.use.all()).filter((s) => s.location !== "<built-in>")
+          expect(list.length).toBe(1)
+          expect(list[0].name).toBe("global-test-skill")
+          expect(list[0].description).toBe("A global skill from ~/.claude/skills for testing.")
+          expect(list[0].location).toContain(path.join(".claude", "skills", "global-test-skill", "SKILL.md"))
         }),
       )
     }),
+    { git: true },
   )
 
-  it.live("returns empty array when no skills exist", () =>
-    provideTmpdirInstance(
-      () =>
-        Effect.gen(function* () {
-          const skill = yield* Skill.Service
-          expect((yield* skill.all()).filter((s) => s.location !== "<built-in>")).toEqual([])
-        }),
-      { git: true },
-    ),
+  it.instance(
+    "returns empty array when no skills exist",
+    Effect.gen(function* () {
+      expect((yield* Skill.use.all()).filter((s) => s.location !== "<built-in>")).toEqual([])
+    }),
+    { git: true },
   )
 
-  it.live("fails with typed error when requiring a missing skill", () =>
-    provideTmpdirInstance(
-      () =>
-        Effect.gen(function* () {
-          const skill = yield* Skill.Service
-          const error = yield* Effect.flip(skill.require("missing-skill"))
-          expect(error).toBeInstanceOf(Skill.NotFoundError)
-          expect(error._tag).toBe("Skill.NotFoundError")
-          expect(error.name).toBe("missing-skill")
-          expect(error.message).toContain('Skill "missing-skill" not found.')
-        }),
-      { git: true },
-    ),
+  it.instance(
+    "fails with typed error when requiring a missing skill",
+    Effect.gen(function* () {
+      const error = yield* Effect.flip(Skill.use.require("missing-skill"))
+      expect(error).toBeInstanceOf(Skill.NotFoundError)
+      expect(error._tag).toBe("Skill.NotFoundError")
+      expect(error.name).toBe("missing-skill")
+      expect(error.message).toContain('Skill "missing-skill" not found.')
+    }),
+    { git: true },
   )
 
   it.effect("exposes tagged expected skill failure classes", () =>
@@ -320,50 +298,42 @@ description: A skill in the .claude/skills directory.
     }),
   )
 
-  it.live("discovers skills from .agents/skills/ directory", () =>
-    provideTmpdirInstance(
-      (dir) =>
-        Effect.gen(function* () {
-          yield* Effect.promise(() =>
-            Bun.write(
-              path.join(dir, ".agents", "skills", "agent-skill", "SKILL.md"),
-              `---
+  it.instance(
+    "discovers skills from .agents/skills/ directory",
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      yield* writeSkill(
+        test.directory,
+        [".agents", "skills", "agent-skill"],
+        `---
 name: agent-skill
 description: A skill in the .agents/skills directory.
 ---
 
 # Agent Skill
 `,
-            ),
-          )
-
-          const skill = yield* Skill.Service
-          const list = (yield* skill.all()).filter((s) => s.location !== "<built-in>")
-          expect(list.length).toBe(1)
-          const item = list.find((x) => x.name === "agent-skill")
-          expect(item).toBeDefined()
-          expect(item!.location).toContain(path.join(".agents", "skills", "agent-skill", "SKILL.md"))
-        }),
-      { git: true },
-    ),
-  )
-
-  it.live("discovers global skills from ~/.agents/skills/ directory", () =>
-    Effect.gen(function* () {
-      const tmp = yield* Effect.acquireRelease(
-        Effect.promise(() => tmpdir({ git: true })),
-        (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
       )
 
+      const list = (yield* Skill.use.all()).filter((s) => s.location !== "<built-in>")
+      expect(list.length).toBe(1)
+      const item = list.find((x) => x.name === "agent-skill")
+      expect(item).toBeDefined()
+      expect(item!.location).toContain(path.join(".agents", "skills", "agent-skill", "SKILL.md"))
+    }),
+    { git: true },
+  )
+
+  it.instance(
+    "discovers global skills from ~/.agents/skills/ directory",
+    Effect.gen(function* () {
+      const test = yield* TestInstance
       yield* withHome(
-        tmp.path,
+        test.directory,
         Effect.gen(function* () {
-          const skillDir = path.join(tmp.path, ".agents", "skills", "global-agent-skill")
-          yield* Effect.promise(() => fs.mkdir(skillDir, { recursive: true }))
-          yield* Effect.promise(() =>
-            Bun.write(
-              path.join(skillDir, "SKILL.md"),
-              `---
+          yield* writeSkill(
+            test.directory,
+            [".agents", "skills", "global-agent-skill"],
+            `---
 name: global-agent-skill
 description: A global skill from ~/.agents/skills for testing.
 ---
@@ -372,198 +342,198 @@ description: A global skill from ~/.agents/skills for testing.
 
 This skill is loaded from the global home directory.
 `,
-            ),
           )
 
-          yield* Effect.gen(function* () {
-            const skill = yield* Skill.Service
-            const list = (yield* skill.all()).filter((s) => s.location !== "<built-in>")
-            expect(list.length).toBe(1)
-            expect(list[0].name).toBe("global-agent-skill")
-            expect(list[0].description).toBe("A global skill from ~/.agents/skills for testing.")
-            expect(list[0].location).toContain(path.join(".agents", "skills", "global-agent-skill", "SKILL.md"))
-          }).pipe(provideInstance(tmp.path))
+          const list = (yield* Skill.use.all()).filter((s) => s.location !== "<built-in>")
+          expect(list.length).toBe(1)
+          expect(list[0].name).toBe("global-agent-skill")
+          expect(list[0].description).toBe("A global skill from ~/.agents/skills for testing.")
+          expect(list[0].location).toContain(path.join(".agents", "skills", "global-agent-skill", "SKILL.md"))
         }),
       )
     }),
+    { git: true },
   )
 
-  it.live("discovers skills from both .claude/skills/ and .agents/skills/", () =>
-    provideTmpdirInstance(
-      (dir) =>
-        Effect.gen(function* () {
-          yield* Effect.promise(() =>
-            Promise.all([
-              Bun.write(
-                path.join(dir, ".claude", "skills", "claude-skill", "SKILL.md"),
-                `---
+  it.instance(
+    "discovers skills from both .claude/skills/ and .agents/skills/",
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      yield* Effect.all(
+        [
+          writeSkill(
+            test.directory,
+            [".claude", "skills", "claude-skill"],
+            `---
 name: claude-skill
 description: A skill in the .claude/skills directory.
 ---
 
 # Claude Skill
 `,
-              ),
-              Bun.write(
-                path.join(dir, ".agents", "skills", "agent-skill", "SKILL.md"),
-                `---
+          ),
+          writeSkill(
+            test.directory,
+            [".agents", "skills", "agent-skill"],
+            `---
 name: agent-skill
 description: A skill in the .agents/skills directory.
 ---
 
 # Agent Skill
 `,
-              ),
-            ]),
-          )
+          ),
+        ],
+      )
 
-          const skill = yield* Skill.Service
-          const list = (yield* skill.all()).filter((s) => s.location !== "<built-in>")
-          expect(list.length).toBe(2)
-          expect(list.find((x) => x.name === "claude-skill")).toBeDefined()
-          expect(list.find((x) => x.name === "agent-skill")).toBeDefined()
-        }),
-      { git: true },
-    ),
+      const list = (yield* Skill.use.all()).filter((s) => s.location !== "<built-in>")
+      expect(list.length).toBe(2)
+      expect(list.find((x) => x.name === "claude-skill")).toBeDefined()
+      expect(list.find((x) => x.name === "agent-skill")).toBeDefined()
+    }),
+    { git: true },
   )
 
-  itWithoutClaudeCodeSkills.live("skips Claude Code skills when disabled", () =>
-    provideTmpdirInstance(
-      (dir) =>
-        Effect.gen(function* () {
-          yield* Effect.promise(() =>
-            Promise.all([
-              Bun.write(
-                path.join(dir, ".claude", "skills", "claude-skill", "SKILL.md"),
-                `---
+  itWithoutClaudeCodeSkills.instance(
+    "skips Claude Code skills when disabled",
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      yield* Effect.all(
+        [
+          writeSkill(
+            test.directory,
+            [".claude", "skills", "claude-skill"],
+            `---
 name: claude-skill
 description: A skill in the .claude/skills directory.
 ---
 
 # Claude Skill
 `,
-              ),
-              Bun.write(
-                path.join(dir, ".agents", "skills", "agent-skill", "SKILL.md"),
-                `---
+          ),
+          writeSkill(
+            test.directory,
+            [".agents", "skills", "agent-skill"],
+            `---
 name: agent-skill
 description: A skill in the .agents/skills directory.
 ---
 
 # Agent Skill
 `,
-              ),
-            ]),
-          )
+          ),
+        ],
+      )
 
-          const skill = yield* Skill.Service
-          const list = (yield* skill.all()).filter((s) => s.location !== "<built-in>")
-          expect(list.map((s) => s.name)).toEqual(["agent-skill"])
-        }),
-      { git: true },
-    ),
+      const list = (yield* Skill.use.all()).filter((s) => s.location !== "<built-in>")
+      expect(list.map((s) => s.name)).toEqual(["agent-skill"])
+    }),
+    { git: true },
   )
 
-  itWithoutExternalSkills.live("skips external skill directories when disabled", () =>
-    provideTmpdirInstance(
-      (dir) =>
-        Effect.gen(function* () {
-          yield* Effect.promise(() =>
-            Promise.all([
-              Bun.write(
-                path.join(dir, ".claude", "skills", "claude-skill", "SKILL.md"),
-                `---
+  itWithoutExternalSkills.instance(
+    "skips external skill directories when disabled",
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      yield* Effect.all(
+        [
+          writeSkill(
+            test.directory,
+            [".claude", "skills", "claude-skill"],
+            `---
 name: claude-skill
 description: A skill in the .claude/skills directory.
 ---
 
 # Claude Skill
 `,
-              ),
-              Bun.write(
-                path.join(dir, ".agents", "skills", "agent-skill", "SKILL.md"),
-                `---
+          ),
+          writeSkill(
+            test.directory,
+            [".agents", "skills", "agent-skill"],
+            `---
 name: agent-skill
 description: A skill in the .agents/skills directory.
 ---
 
 # Agent Skill
 `,
-              ),
-              Bun.write(
-                path.join(dir, ".opencode", "skill", "opencode-skill", "SKILL.md"),
-                `---
+          ),
+          writeSkill(
+            test.directory,
+            [".opencode", "skill", "opencode-skill"],
+            `---
 name: opencode-skill
 description: A skill in the .opencode/skill directory.
 ---
 
 # OpenCode Skill
 `,
-              ),
-            ]),
-          )
+          ),
+        ],
+      )
 
-          const skill = yield* Skill.Service
-          const list = (yield* skill.all()).filter((s) => s.location !== "<built-in>")
-          expect(list.map((s) => s.name)).toEqual(["opencode-skill"])
-        }),
-      { git: true },
-    ),
+      const list = (yield* Skill.use.all()).filter((s) => s.location !== "<built-in>")
+      expect(list.map((s) => s.name)).toEqual(["opencode-skill"])
+    }),
+    { git: true },
   )
 
-  it.live("properly resolves directories that skills live in", () =>
-    provideTmpdirInstance(
-      (dir) =>
-        Effect.gen(function* () {
-          yield* Effect.promise(() =>
-            Promise.all([
-              Bun.write(
-                path.join(dir, ".claude", "skills", "claude-skill", "SKILL.md"),
-                `---
+  it.instance(
+    "properly resolves directories that skills live in",
+    Effect.gen(function* () {
+      const test = yield* TestInstance
+      yield* Effect.all(
+        [
+          writeSkill(
+            test.directory,
+            [".claude", "skills", "claude-skill"],
+            `---
 name: claude-skill
 description: A skill in the .claude/skills directory.
 ---
 
 # Claude Skill
 `,
-              ),
-              Bun.write(
-                path.join(dir, ".agents", "skills", "agent-skill", "SKILL.md"),
-                `---
+          ),
+          writeSkill(
+            test.directory,
+            [".agents", "skills", "agent-skill"],
+            `---
 name: agent-skill
 description: A skill in the .agents/skills directory.
 ---
 
 # Agent Skill
 `,
-              ),
-              Bun.write(
-                path.join(dir, ".opencode", "skill", "agent-skill", "SKILL.md"),
-                `---
+          ),
+          writeSkill(
+            test.directory,
+            [".opencode", "skill", "agent-skill"],
+            `---
 name: opencode-skill
 description: A skill in the .opencode/skill directory.
 ---
 
 # OpenCode Skill
 `,
-              ),
-              Bun.write(
-                path.join(dir, ".opencode", "skills", "agent-skill", "SKILL.md"),
-                `---
+          ),
+          writeSkill(
+            test.directory,
+            [".opencode", "skills", "agent-skill"],
+            `---
 name: opencode-skill
 description: A skill in the .opencode/skills directory.
 ---
 
 # OpenCode Skill
 `,
-              ),
-            ]),
-          )
+          ),
+        ],
+      )
 
-          const skill = yield* Skill.Service
-          expect((yield* skill.dirs()).length).toBe(4)
-        }),
-      { git: true },
-    ),
+      expect((yield* Skill.use.dirs()).length).toBe(4)
+    }),
+    { git: true },
   )
 })

packages/opencode/test/tool/registry.test.ts

@@ -95,15 +95,25 @@ const brokenPluginLayer = Layer.succeed(
   }),
 )
 
-const it = testEffect(Layer.mergeAll(registryLayer(), node, Agent.defaultLayer))
+const it = testEffect(Layer.mergeAll(registryLayer(), node, Agent.defaultLayer, AppFileSystem.defaultLayer))
 const scout = testEffect(
-  Layer.mergeAll(registryLayer({ flags: { experimentalScout: true } }), node, Agent.defaultLayer),
+  Layer.mergeAll(
+    registryLayer({ flags: { experimentalScout: true } }),
+    node,
+    Agent.defaultLayer,
+    AppFileSystem.defaultLayer,
+  ),
 )
 const background = testEffect(
-  Layer.mergeAll(registryLayer({ flags: { experimentalBackgroundSubagents: true } }), node, Agent.defaultLayer),
+  Layer.mergeAll(
+    registryLayer({ flags: { experimentalBackgroundSubagents: true } }),
+    node,
+    Agent.defaultLayer,
+    AppFileSystem.defaultLayer,
+  ),
 )
 const withBrokenPlugin = testEffect(
-  Layer.mergeAll(registryLayer({ plugin: brokenPluginLayer }), node, Agent.defaultLayer),
+  Layer.mergeAll(registryLayer({ plugin: brokenPluginLayer }), node, Agent.defaultLayer, AppFileSystem.defaultLayer),
 )
 
 afterEach(async () => {
@@ -113,8 +123,7 @@ afterEach(async () => {
 describe("tool.registry", () => {
   it.instance("hides repo research tools unless experimental", () =>
     Effect.gen(function* () {
-      const registry = yield* ToolRegistry.Service
-      const ids = yield* registry.ids()
+      const ids = yield* ToolRegistry.use.ids()
 
       expect(ids).not.toContain("repo_clone")
       expect(ids).not.toContain("repo_overview")
@@ -123,8 +132,7 @@ describe("tool.registry", () => {
 
   scout.instance("shows repo research tools when experimental scout is enabled", () =>
     Effect.gen(function* () {
-      const registry = yield* ToolRegistry.Service
-      const ids = yield* registry.ids()
+      const ids = yield* ToolRegistry.use.ids()
 
       expect(ids).toContain("repo_clone")
       expect(ids).toContain("repo_overview")
@@ -133,8 +141,7 @@ describe("tool.registry", () => {
 
   it.instance("hides task_status unless experimental background subagents are enabled", () =>
     Effect.gen(function* () {
-      const registry = yield* ToolRegistry.Service
-      const ids = yield* registry.ids()
+      const ids = yield* ToolRegistry.use.ids()
 
       expect(ids).not.toContain("task_status")
     }),
@@ -142,11 +149,10 @@ describe("tool.registry", () => {
 
   it.instance("hides task background parameter unless experimental background subagents are enabled", () =>
     Effect.gen(function* () {
-      const registry = yield* ToolRegistry.Service
       const agent = yield* Agent.Service
       const build = yield* agent.get("build")
       if (!build) throw new Error("build agent not found")
-      const task = (yield* registry.tools({
+      const task = (yield* ToolRegistry.use.tools({
         providerID: ProviderID.opencode,
         modelID: ModelID.make("test"),
         agent: build,
@@ -159,8 +165,7 @@ describe("tool.registry", () => {
 
   background.instance("shows task_status when experimental background subagents are enabled", () =>
     Effect.gen(function* () {
-      const registry = yield* ToolRegistry.Service
-      const ids = yield* registry.ids()
+      const ids = yield* ToolRegistry.use.ids()
 
       expect(ids).toContain("task_status")
     }),
@@ -169,26 +174,20 @@ describe("tool.registry", () => {
   it.instance("loads tools from .opencode/tool (singular)", () =>
     Effect.gen(function* () {
       const test = yield* TestInstance
-      const opencode = path.join(test.directory, ".opencode")
-      const tool = path.join(opencode, "tool")
-      yield* Effect.promise(() => fs.mkdir(tool, { recursive: true }))
-      yield* Effect.promise(() =>
-        Bun.write(
-          path.join(tool, "hello.ts"),
-          [
-            "export default {",
-            "  description: 'hello tool',",
-            "  args: {},",
-            "  execute: async () => {",
-            "    return 'hello world'",
-            "  },",
-            "}",
-            "",
-          ].join("\n"),
-        ),
+      yield* AppFileSystem.use.writeWithDirs(
+        path.join(test.directory, ".opencode", "tool", "hello.ts"),
+        [
+          "export default {",
+          "  description: 'hello tool',",
+          "  args: {},",
+          "  execute: async () => {",
+          "    return 'hello world'",
+          "  },",
+          "}",
+          "",
+        ].join("\n"),
       )
-      const registry = yield* ToolRegistry.Service
-      const ids = yield* registry.ids()
+      const ids = yield* ToolRegistry.use.ids()
       expect(ids).toContain("hello")
     }),
   )
@@ -196,25 +195,20 @@ describe("tool.registry", () => {
   it.instance("ignores non-tool exports in .opencode/tool files", () =>
     Effect.gen(function* () {
       const test = yield* TestInstance
-      const tool = path.join(test.directory, ".opencode", "tool")
-      yield* Effect.promise(() => fs.mkdir(tool, { recursive: true }))
-      yield* Effect.promise(() =>
-        Bun.write(
-          path.join(tool, "mixed.ts"),
-          [
-            "export const helper = 'not a tool'",
-            "export default {",
-            "  description: 'mixed tool',",
-            "  args: {},",
-            "  execute: async () => 'ok',",
-            "}",
-            "",
-          ].join("\n"),
-        ),
+      yield* AppFileSystem.use.writeWithDirs(
+        path.join(test.directory, ".opencode", "tool", "mixed.ts"),
+        [
+          "export const helper = 'not a tool'",
+          "export default {",
+          "  description: 'mixed tool',",
+          "  args: {},",
+          "  execute: async () => 'ok',",
+          "}",
+          "",
+        ].join("\n"),
       )
 
-      const registry = yield* ToolRegistry.Service
-      const ids = yield* registry.ids()
+      const ids = yield* ToolRegistry.use.ids()
       expect(ids).toContain("mixed")
       expect(ids).not.toContain("mixed_helper")
     }),
@@ -229,28 +223,23 @@ describe("tool.registry", () => {
   it.instance("tolerates a custom tool exporting null/undefined args (no-args fallback)", () =>
     Effect.gen(function* () {
       const test = yield* TestInstance
-      const tool = path.join(test.directory, ".opencode", "tool")
-      yield* Effect.promise(() => fs.mkdir(tool, { recursive: true }))
-      yield* Effect.promise(() =>
-        Bun.write(
-          path.join(tool, "noargs.ts"),
-          [
-            "export default {",
-            "  description: 'tool with no args',",
-            "  args: undefined,",
-            "  execute: async () => 'ok',",
-            "}",
-            "",
-          ].join("\n"),
-        ),
+      yield* AppFileSystem.use.writeWithDirs(
+        path.join(test.directory, ".opencode", "tool", "noargs.ts"),
+        [
+          "export default {",
+          "  description: 'tool with no args',",
+          "  args: undefined,",
+          "  execute: async () => 'ok',",
+          "}",
+          "",
+        ].join("\n"),
       )
 
-      const registry = yield* ToolRegistry.Service
-      const ids = yield* registry.ids()
+      const ids = yield* ToolRegistry.use.ids()
       // Built-in tools must still load — a single malformed custom tool must
       // not poison the whole registry.
       expect(ids).toContain("read")
-      const loaded = (yield* registry.all()).find((t) => t.id === "noargs")
+      const loaded = (yield* ToolRegistry.use.all()).find((t) => t.id === "noargs")
       if (!loaded) throw new Error("noargs tool was not loaded")
       expect(loaded.jsonSchema).toMatchObject({ type: "object", properties: {} })
     }),
@@ -264,8 +253,7 @@ describe("tool.registry", () => {
   // protection.
   withBrokenPlugin.instance("tolerates a plugin tool registered with null/undefined args", () =>
     Effect.gen(function* () {
-      const registry = yield* ToolRegistry.Service
-      const ids = yield* registry.ids()
+      const ids = yield* ToolRegistry.use.ids()
       expect(ids).toContain("read")
       expect(ids).toContain("broken_plugin_tool")
     }),
@@ -274,26 +262,20 @@ describe("tool.registry", () => {
   it.instance("loads tools from .opencode/tools (plural)", () =>
     Effect.gen(function* () {
       const test = yield* TestInstance
-      const opencode = path.join(test.directory, ".opencode")
-      const tools = path.join(opencode, "tools")
-      yield* Effect.promise(() => fs.mkdir(tools, { recursive: true }))
-      yield* Effect.promise(() =>
-        Bun.write(
-          path.join(tools, "hello.ts"),
-          [
-            "export default {",
-            "  description: 'hello tool',",
-            "  args: {},",
-            "  execute: async () => {",
-            "    return 'hello world'",
-            "  },",
-            "}",
-            "",
-          ].join("\n"),
-        ),
+      yield* AppFileSystem.use.writeWithDirs(
+        path.join(test.directory, ".opencode", "tools", "hello.ts"),
+        [
+          "export default {",
+          "  description: 'hello tool',",
+          "  args: {},",
+          "  execute: async () => {",
+          "    return 'hello world'",
+          "  },",
+          "}",
+          "",
+        ].join("\n"),
       )
-      const registry = yield* ToolRegistry.Service
-      const ids = yield* registry.ids()
+      const ids = yield* ToolRegistry.use.ids()
       expect(ids).toContain("hello")
     }),
   )
@@ -301,26 +283,21 @@ describe("tool.registry", () => {
   it.instance("loads Zod-schema custom tools with JSON Schema and validation", () =>
     Effect.gen(function* () {
       const test = yield* TestInstance
-      const customTools = path.join(test.directory, ".opencode", "tools")
       const pluginTool = pathToFileURL(path.resolve(import.meta.dir, "../../../plugin/src/tool.ts")).href
-      yield* Effect.promise(() => fs.mkdir(customTools, { recursive: true }))
-      yield* Effect.promise(() =>
-        Bun.write(
-          path.join(customTools, "sql.ts"),
-          [
-            `import { tool } from ${JSON.stringify(pluginTool)}`,
-            "export default tool({",
-            "  description: 'query database',",
-            "  args: { query: tool.schema.string().describe('SQL query to execute') },",
-            "  execute: async ({ query }) => query,",
-            "})",
-            "",
-          ].join("\n"),
-        ),
+      yield* AppFileSystem.use.writeWithDirs(
+        path.join(test.directory, ".opencode", "tools", "sql.ts"),
+        [
+          `import { tool } from ${JSON.stringify(pluginTool)}`,
+          "export default tool({",
+          "  description: 'query database',",
+          "  args: { query: tool.schema.string().describe('SQL query to execute') },",
+          "  execute: async ({ query }) => query,",
+          "})",
+          "",
+        ].join("\n"),
       )
 
-      const registry = yield* ToolRegistry.Service
-      const loaded = (yield* registry.all()).find((tool) => tool.id === "sql")
+      const loaded = (yield* ToolRegistry.use.all()).find((tool) => tool.id === "sql")
       if (!loaded) throw new Error("custom sql tool was not loaded")
       expect(loaded?.jsonSchema).toMatchObject({
         type: "object",
@@ -333,7 +310,7 @@ describe("tool.registry", () => {
       expect(Result.isSuccess(Schema.decodeUnknownResult(loaded.parameters)({}))).toBe(false)
 
       const agents = yield* Agent.Service
-      const promptTools = yield* registry.tools({
+      const promptTools = yield* ToolRegistry.use.tools({
         providerID: ProviderID.opencode,
         modelID: ModelID.make("test"),
         agent: yield* agents.defaultInfo(),
@@ -357,53 +334,44 @@ describe("tool.registry", () => {
         const opencode = path.join(test.directory, ".opencode")
         const customTools = path.join(opencode, "tools")
         const plugin = path.join(opencode, "node_modules", "@opencode-ai", "plugin")
-        yield* Effect.promise(() => fs.mkdir(path.join(plugin, "dist"), { recursive: true }))
-        yield* Effect.promise(() => fs.mkdir(customTools, { recursive: true }))
         yield* Effect.promise(() =>
           fs.cp(path.dirname(fileURLToPath(import.meta.resolve("zod"))), path.join(opencode, "node_modules", "zod"), {
             dereference: true,
             recursive: true,
           }),
         )
-        yield* Effect.promise(() =>
-          Bun.write(
-            path.join(plugin, "package.json"),
-            JSON.stringify({ name: "@opencode-ai/plugin", type: "module", exports: { ".": "./dist/index.js" } }),
-          ),
+        yield* AppFileSystem.use.writeWithDirs(
+          path.join(plugin, "package.json"),
+          JSON.stringify({ name: "@opencode-ai/plugin", type: "module", exports: { ".": "./dist/index.js" } }),
         )
-        yield* Effect.promise(() =>
-          Bun.write(
-            path.join(plugin, "dist", "index.js"),
-            [
-              "import { z } from 'zod'",
-              "export function tool(input) {",
-              "  return input",
-              "}",
-              "tool.schema = z",
-              "",
-            ].join("\n"),
-          ),
+        yield* AppFileSystem.use.writeWithDirs(
+          path.join(plugin, "dist", "index.js"),
+          [
+            "import { z } from 'zod'",
+            "export function tool(input) {",
+            "  return input",
+            "}",
+            "tool.schema = z",
+            "",
+          ].join("\n"),
         )
-        yield* Effect.promise(() =>
-          Bun.write(
-            path.join(customTools, "addition.ts"),
-            [
-              'import { tool } from "@opencode-ai/plugin"',
-              "export default tool({",
-              "  description: 'Use this tool to add two numbers and return their sum.',",
-              "  args: {",
-              "    left: tool.schema.number().describe('The first number to add'),",
-              "    right: tool.schema.number().describe('The second number to add'),",
-              "  },",
-              "  execute: async (args) => `${args.left} + ${args.right} = ${args.left + args.right}`,",
-              "})",
-              "",
-            ].join("\n"),
-          ),
+        yield* AppFileSystem.use.writeWithDirs(
+          path.join(customTools, "addition.ts"),
+          [
+            'import { tool } from "@opencode-ai/plugin"',
+            "export default tool({",
+            "  description: 'Use this tool to add two numbers and return their sum.',",
+            "  args: {",
+            "    left: tool.schema.number().describe('The first number to add'),",
+            "    right: tool.schema.number().describe('The second number to add'),",
+            "  },",
+            "  execute: async (args) => `${args.left} + ${args.right} = ${args.left + args.right}`,",
+            "})",
+            "",
+          ].join("\n"),
         )
 
-        const registry = yield* ToolRegistry.Service
-        const loaded = (yield* registry.all()).find((tool) => tool.id === "addition")
+        const loaded = (yield* ToolRegistry.use.all()).find((tool) => tool.id === "addition")
         if (!loaded) throw new Error("custom addition tool was not loaded")
 
         expect(ToolJsonSchema.fromTool(loaded)).toMatchObject({
@@ -419,29 +387,24 @@ describe("tool.registry", () => {
   it.instance("preserves attachments from structured custom tool results", () =>
     Effect.gen(function* () {
       const test = yield* TestInstance
-      const customTools = path.join(test.directory, ".opencode", "tools")
       const pluginTool = pathToFileURL(path.resolve(import.meta.dir, "../../../plugin/src/tool.ts")).href
-      yield* Effect.promise(() => fs.mkdir(customTools, { recursive: true }))
-      yield* Effect.promise(() =>
-        Bun.write(
-          path.join(customTools, "image.ts"),
-          [
-            `import { tool } from ${JSON.stringify(pluginTool)}`,
-            "export default tool({",
-            "  description: 'image tool',",
-            "  args: {},",
-            "  execute: async () => ({",
-            "    output: 'here is an image',",
-            "    attachments: [{ type: 'file', mime: 'image/png', filename: 'picture.png', url: 'data:image/png;base64,AAAA' }],",
-            "  }),",
-            "})",
-            "",
-          ].join("\n"),
-        ),
+      yield* AppFileSystem.use.writeWithDirs(
+        path.join(test.directory, ".opencode", "tools", "image.ts"),
+        [
+          `import { tool } from ${JSON.stringify(pluginTool)}`,
+          "export default tool({",
+          "  description: 'image tool',",
+          "  args: {},",
+          "  execute: async () => ({",
+          "    output: 'here is an image',",
+          "    attachments: [{ type: 'file', mime: 'image/png', filename: 'picture.png', url: 'data:image/png;base64,AAAA' }],",
+          "  }),",
+          "})",
+          "",
+        ].join("\n"),
       )
 
-      const registry = yield* ToolRegistry.Service
-      const loaded = (yield* registry.all()).find((tool) => tool.id === "image")
+      const loaded = (yield* ToolRegistry.use.all()).find((tool) => tool.id === "image")
       if (!loaded) throw new Error("custom image tool was not loaded")
       const agents = yield* Agent.Service
       const result = yield* loaded.execute({}, {
@@ -464,24 +427,19 @@ describe("tool.registry", () => {
   it.instance("loads legacy JSON-schema-shaped custom tools with wire schema", () =>
     Effect.gen(function* () {
       const test = yield* TestInstance
-      const tools = path.join(test.directory, ".opencode", "tools")
-      yield* Effect.promise(() => fs.mkdir(tools, { recursive: true }))
-      yield* Effect.promise(() =>
-        Bun.write(
-          path.join(tools, "legacy.ts"),
-          [
-            "export default {",
-            "  description: 'legacy schema tool',",
-            "  args: { text: { type: 'string', description: 'Text to render' } },",
-            "  execute: async ({ text }) => text,",
-            "}",
-            "",
-          ].join("\n"),
-        ),
+      yield* AppFileSystem.use.writeWithDirs(
+        path.join(test.directory, ".opencode", "tools", "legacy.ts"),
+        [
+          "export default {",
+          "  description: 'legacy schema tool',",
+          "  args: { text: { type: 'string', description: 'Text to render' } },",
+          "  execute: async ({ text }) => text,",
+          "}",
+          "",
+        ].join("\n"),
       )
 
-      const registry = yield* ToolRegistry.Service
-      const loaded = (yield* registry.all()).find((tool) => tool.id === "legacy")
+      const loaded = (yield* ToolRegistry.use.all()).find((tool) => tool.id === "legacy")
       if (!loaded) throw new Error("legacy custom tool was not loaded")
       expect(ToolJsonSchema.fromTool(loaded)).toMatchObject({
         type: "object",
@@ -498,73 +456,60 @@ describe("tool.registry", () => {
       const test = yield* TestInstance
       const opencode = path.join(test.directory, ".opencode")
       const tools = path.join(opencode, "tools")
-      yield* Effect.promise(() => fs.mkdir(tools, { recursive: true }))
-      yield* Effect.promise(() =>
-        Bun.write(
-          path.join(opencode, "package.json"),
-          JSON.stringify({
-            name: "custom-tools",
-            dependencies: {
-              "@opencode-ai/plugin": "^0.0.0",
-              cowsay: "^1.6.0",
-            },
-          }),
-        ),
+      yield* AppFileSystem.use.writeWithDirs(
+        path.join(opencode, "package.json"),
+        JSON.stringify({
+          name: "custom-tools",
+          dependencies: {
+            "@opencode-ai/plugin": "^0.0.0",
+            cowsay: "^1.6.0",
+          },
+        }),
       )
-      yield* Effect.promise(() =>
-        Bun.write(
-          path.join(opencode, "package-lock.json"),
-          JSON.stringify({
-            name: "custom-tools",
-            lockfileVersion: 3,
-            packages: {
-              "": {
-                dependencies: {
-                  "@opencode-ai/plugin": "^0.0.0",
-                  cowsay: "^1.6.0",
-                },
+      yield* AppFileSystem.use.writeWithDirs(
+        path.join(opencode, "package-lock.json"),
+        JSON.stringify({
+          name: "custom-tools",
+          lockfileVersion: 3,
+          packages: {
+            "": {
+              dependencies: {
+                "@opencode-ai/plugin": "^0.0.0",
+                cowsay: "^1.6.0",
               },
             },
-          }),
-        ),
+          },
+        }),
       )
 
       const cowsay = path.join(opencode, "node_modules", "cowsay")
-      yield* Effect.promise(() => fs.mkdir(cowsay, { recursive: true }))
-      yield* Effect.promise(() =>
-        Bun.write(
-          path.join(cowsay, "package.json"),
-          JSON.stringify({
-            name: "cowsay",
-            type: "module",
-            exports: "./index.js",
-          }),
-        ),
+      yield* AppFileSystem.use.writeWithDirs(
+        path.join(cowsay, "package.json"),
+        JSON.stringify({
+          name: "cowsay",
+          type: "module",
+          exports: "./index.js",
+        }),
       )
-      yield* Effect.promise(() =>
-        Bun.write(
-          path.join(cowsay, "index.js"),
-          ["export function say({ text }) {", "  return `moo ${text}`", "}", ""].join("\n"),
-        ),
+      yield* AppFileSystem.use.writeWithDirs(
+        path.join(cowsay, "index.js"),
+        ["export function say({ text }) {", "  return `moo ${text}`", "}", ""].join("\n"),
       )
-      yield* Effect.promise(() =>
-        Bun.write(
-          path.join(tools, "cowsay.ts"),
-          [
-            "import { say } from 'cowsay'",
-            "export default {",
-            "  description: 'tool that imports cowsay at top level',",
-            "  args: { text: { type: 'string' } },",
-            "  execute: async ({ text }: { text: string }) => {",
-            "    return say({ text })",
-            "  },",
-            "}",
-            "",
-          ].join("\n"),
-        ),
+      yield* AppFileSystem.use.writeWithDirs(
+        path.join(tools, "cowsay.ts"),
+        [
+          "import { say } from 'cowsay'",
+          "export default {",
+          "  description: 'tool that imports cowsay at top level',",
+          "  args: { text: { type: 'string' } },",
+          "  execute: async ({ text }: { text: string }) => {",
+          "    return say({ text })",
+          "  },",
+          "}",
+          "",
+        ].join("\n"),
       )
-      const registry = yield* ToolRegistry.Service
-      const ids = yield* registry.ids()
+      const ids = yield* ToolRegistry.use.ids()
       expect(ids).toContain("cowsay")
     }),
   )

packages/opencode/test/tool/skill.test.ts

@@ -1,4 +1,5 @@
 import { CrossSpawnSpawner } from "@opencode-ai/core/cross-spawn-spawner"
+import { AppFileSystem } from "@opencode-ai/core/filesystem"
 import { Cause, Effect, Exit, Layer } from "effect"
 import { afterEach, describe, expect } from "bun:test"
 import path from "path"
@@ -7,6 +8,7 @@ import type { Permission } from "../../src/permission"
 import type { Tool } from "@/tool/tool"
 import { SkillTool } from "../../src/tool/skill"
 import { ToolRegistry } from "@/tool/registry"
+import { ModelID, ProviderID } from "../../src/provider/schema"
 import { disposeAllInstances, provideTmpdirInstance } from "../fixture/fixture"
 import { SessionID, MessageID } from "../../src/session/schema"
 import { testEffect } from "../lib/effect"
@@ -27,17 +29,16 @@ afterEach(async () => {
 
 const node = CrossSpawnSpawner.defaultLayer
 
-const it = testEffect(Layer.mergeAll(ToolRegistry.defaultLayer, node))
+const it = testEffect(Layer.mergeAll(ToolRegistry.defaultLayer, node, AppFileSystem.defaultLayer))
 
 describe("tool.skill", () => {
   it.live("execute returns skill content block with files", () =>
     provideTmpdirInstance((dir) =>
       Effect.gen(function* () {
         const skill = path.join(dir, ".opencode", "skill", "tool-skill")
-        yield* Effect.promise(() =>
-          Bun.write(
-            path.join(skill, "SKILL.md"),
-            `---
+        yield* AppFileSystem.use.writeWithDirs(
+          path.join(skill, "SKILL.md"),
+          `---
 name: tool-skill
 description: Skill for tool tests.
 ---
@@ -46,9 +47,8 @@ description: Skill for tool tests.
 
 Use this skill.
 `,
-          ),
         )
-        yield* Effect.promise(() => Bun.write(path.join(skill, "scripts", "demo.txt"), "demo"))
+        yield* AppFileSystem.use.writeWithDirs(path.join(skill, "scripts", "demo.txt"), "demo")
 
         const home = process.env.OPENCODE_TEST_HOME
         process.env.OPENCODE_TEST_HOME = dir
@@ -61,8 +61,8 @@ Use this skill.
         const registry = yield* ToolRegistry.Service
         const agent = { name: "build", mode: "primary" as const, permission: [], options: {} }
         const tool = (yield* registry.tools({
-          providerID: "opencode" as any,
-          modelID: "gpt-5" as any,
+          providerID: ProviderID.opencode,
+          modelID: ModelID.make("gpt-5"),
           agent,
         })).find((tool) => tool.id === SkillTool.id)
         if (!tool) throw new Error("Skill tool not found")
@@ -105,8 +105,8 @@ Use this skill.
         const registry = yield* ToolRegistry.Service
         const agent = { name: "build", mode: "primary" as const, permission: [], options: {} }
         const tool = (yield* registry.tools({
-          providerID: "opencode" as any,
-          modelID: "gpt-5" as any,
+          providerID: ProviderID.opencode,
+          modelID: ModelID.make("gpt-5"),
           agent,
         })).find((tool) => tool.id === SkillTool.id)
         if (!tool) throw new Error("Skill tool not found")