diff --git a/packages/opencode/test/fixture/fixture.ts b/packages/opencode/test/fixture/fixture.ts
index a36a3f9d84..96f5e3f084 100644
--- a/packages/opencode/test/fixture/fixture.ts
+++ b/packages/opencode/test/fixture/fixture.ts
@@ -3,9 +3,12 @@ import * as fs from "fs/promises"
 import os from "os"
 import path from "path"
 import { Effect, FileSystem, ServiceMap } from "effect"
+import type * as PlatformError from "effect/PlatformError"
+import type * as Scope from "effect/Scope"
 import { ChildProcess, ChildProcessSpawner } from "effect/unstable/process"
 import type { Config } from "../../src/config/config"
 import { Instance } from "../../src/project/instance"
+import { TestLLMServer } from "../lib/llm-server"
 
 // Strip null bytes from paths (defensive fix for CI environment issues)
 function sanitizePath(p: string): string {
@@ -139,3 +142,20 @@ export function provideTmpdirInstance<A, E, R>(
     return yield* self(path).pipe(provideInstance(path))
   })
 }
+
+export function provideTmpdirServer<A, E, R>(
+  self: (input: { dir: string; llm: TestLLMServer["Service"] }) => Effect.Effect<A, E, R>,
+  options?: { git?: boolean; config?: (url: string) => Partial<Config.Info> },
+): Effect.Effect<
+  A,
+  E | PlatformError.PlatformError,
+  R | TestLLMServer | FileSystem.FileSystem | ChildProcessSpawner.ChildProcessSpawner | Scope.Scope
+> {
+  return Effect.gen(function* () {
+    const llm = yield* TestLLMServer
+    return yield* provideTmpdirInstance((dir) => self({ dir, llm }), {
+      git: options?.git,
+      config: options?.config?.(llm.url),
+    })
+  })
+}
diff --git a/packages/opencode/test/lib/llm-server.ts b/packages/opencode/test/lib/llm-server.ts
index c4a8722ee7..fad97bbd5b 100644
--- a/packages/opencode/test/lib/llm-server.ts
+++ b/packages/opencode/test/lib/llm-server.ts
@@ -14,6 +14,13 @@ type Step =
       tool: string
       input: unknown
     }
+  | {
+      type: "fail"
+      message: string
+    }
+  | {
+      type: "hang"
+    }
 
 type Hit = {
   url: URL
@@ -105,16 +112,34 @@ function tool(step: Extract<Step, { type: "tool" }>, seq: number) {
   ])
 }
 
-export class TestLLMServer extends ServiceMap.Service<
-  TestLLMServer,
-  {
+function fail(step: Extract<Step, { type: "fail" }>) {
+  return HttpServerResponse.text(step.message, { status: 500 })
+}
+
+function hang() {
+  return HttpServerResponse.stream(
+    Stream.fromIterable([
+      'data: {"id":"chatcmpl-test","object":"chat.completion.chunk","choices":[{"delta":{"role":"assistant"}}]}\n\n',
+    ]).pipe(Stream.encodeText, Stream.concat(Stream.never)),
+    { contentType: "text/event-stream" },
+  )
+}
+
+namespace TestLLMServer {
+  export interface Service {
     readonly url: string
     readonly text: (value: string) => Effect.Effect<void>
     readonly tool: (tool: string, input: unknown) => Effect.Effect<void>
+    readonly fail: (message?: string) => Effect.Effect<void>
+    readonly hang: Effect.Effect<void>
     readonly hits: Effect.Effect<Hit[]>
+    readonly calls: Effect.Effect<number>
+    readonly inputs: Effect.Effect<Record<string, unknown>[]>
     readonly pending: Effect.Effect<number>
   }
->()("@test/LLMServer") {
+}
+
+export class TestLLMServer extends ServiceMap.Service<TestLLMServer, TestLLMServer.Service>()("@test/LLMServer") {
   static readonly layer = Layer.effect(
     TestLLMServer,
     Effect.gen(function* () {
@@ -153,7 +178,9 @@ export class TestLLMServer extends ServiceMap.Service<
             },
           ]
           if (next.step.type === "text") return text(next.step)
-          return tool(next.step, next.seq)
+          if (next.step.type === "tool") return tool(next.step, next.seq)
+          if (next.step.type === "fail") return fail(next.step)
+          return hang()
         }),
       )
 
@@ -170,7 +197,15 @@ export class TestLLMServer extends ServiceMap.Service<
         tool: Effect.fn("TestLLMServer.tool")(function* (tool: string, input: unknown) {
           push({ type: "tool", tool, input })
         }),
+        fail: Effect.fn("TestLLMServer.fail")(function* (message = "boom") {
+          push({ type: "fail", message })
+        }),
+        hang: Effect.gen(function* () {
+          push({ type: "hang" })
+        }).pipe(Effect.withSpan("TestLLMServer.hang")),
         hits: Effect.sync(() => [...hits]),
+        calls: Effect.sync(() => hits.length),
+        inputs: Effect.sync(() => hits.map((hit) => hit.body)),
         pending: Effect.sync(() => list.length),
       })
     }),
diff --git a/packages/opencode/test/session/prompt-effect.test.ts b/packages/opencode/test/session/prompt-effect.test.ts
index 0db9b760cf..847d00f961 100644
--- a/packages/opencode/test/session/prompt-effect.test.ts
+++ b/packages/opencode/test/session/prompt-effect.test.ts
@@ -31,7 +31,7 @@ import { ToolRegistry } from "../../src/tool/registry"
 import { Truncate } from "../../src/tool/truncate"
 import { Log } from "../../src/util/log"
 import * as CrossSpawnSpawner from "../../src/effect/cross-spawn-spawner"
-import { provideTmpdirInstance } from "../fixture/fixture"
+import { provideTmpdirInstance, provideTmpdirServer } from "../fixture/fixture"
 import { testEffect } from "../lib/effect"
 import { TestLLMServer } from "../lib/llm-server"
 
@@ -451,36 +451,32 @@ it.live("loop exits immediately when last assistant has stop finish", () =>
 )
 
 http.live("loop calls LLM and returns assistant message", () =>
-  Effect.gen(function* () {
-    const llm = yield* TestLLMServer
-    return yield* provideTmpdirInstance(
-      () =>
-        Effect.gen(function* () {
-          const chat = yield* Effect.promise(() =>
-            Session.create({
-              title: "Pinned",
-              permission: [{ permission: "*", pattern: "*", action: "allow" }],
-            }),
-          )
-          yield* Effect.promise(() =>
-            SessionPrompt.prompt({
-              sessionID: chat.id,
-              agent: "build",
-              noReply: true,
-              parts: [{ type: "text", text: "hello" }],
-            }),
-          )
-          yield* llm.text("world")
-
-          const result = yield* Effect.promise(() => SessionPrompt.loop({ sessionID: chat.id }))
-          expect(result.info.role).toBe("assistant")
-          const parts = result.parts.filter((p) => p.type === "text")
-          expect(parts.some((p) => p.type === "text" && p.text === "world")).toBe(true)
-          expect(yield* llm.hits).toHaveLength(1)
+  provideTmpdirServer(
+    Effect.fnUntraced(function* ({ llm }: { dir: string; llm: TestLLMServer["Service"] }) {
+      const chat = yield* Effect.promise(() =>
+        Session.create({
+          title: "Pinned",
+          permission: [{ permission: "*", pattern: "*", action: "allow" }],
         }),
-      { git: true, config: providerCfg(llm.url) },
-    )
-  }),
+      )
+      yield* Effect.promise(() =>
+        SessionPrompt.prompt({
+          sessionID: chat.id,
+          agent: "build",
+          noReply: true,
+          parts: [{ type: "text", text: "hello" }],
+        }),
+      )
+      yield* llm.text("world")
+
+      const result = yield* Effect.promise(() => SessionPrompt.loop({ sessionID: chat.id }))
+      expect(result.info.role).toBe("assistant")
+      const parts = result.parts.filter((p) => p.type === "text")
+      expect(parts.some((p) => p.type === "text" && p.text === "world")).toBe(true)
+      expect(yield* llm.hits).toHaveLength(1)
+    }),
+    { git: true, config: providerCfg },
+  ),
 )
 
 it.live("loop continues when finish is tool-calls", () =>
@@ -1039,74 +1035,82 @@ unix(
   30_000,
 )
 
-unix(
+http.live(
   "loop waits while shell runs and starts after shell exits",
   () =>
-    provideTmpdirInstance(
-      (dir) =>
-        Effect.gen(function* () {
-          const { test, prompt, chat } = yield* boot()
-          yield* test.reply(...replyStop("after-shell"))
+    provideTmpdirServer(
+      Effect.fnUntraced(function* ({ llm }: { dir: string; llm: TestLLMServer["Service"] }) {
+        const chat = yield* Effect.promise(() =>
+          Session.create({
+            title: "Pinned",
+            permission: [{ permission: "*", pattern: "*", action: "allow" }],
+          }),
+        )
+        yield* llm.text("after-shell")
 
-          const sh = yield* prompt
-            .shell({ sessionID: chat.id, agent: "build", command: "sleep 0.2" })
-            .pipe(Effect.forkChild)
-          yield* waitMs(50)
+        const sh = yield* Effect.promise(() =>
+          SessionPrompt.shell({ sessionID: chat.id, agent: "build", command: "sleep 0.2" }),
+        ).pipe(Effect.forkChild)
+        yield* waitMs(50)
 
-          const run = yield* prompt.loop({ sessionID: chat.id }).pipe(Effect.forkChild)
-          yield* waitMs(50)
+        const run = yield* Effect.promise(() => SessionPrompt.loop({ sessionID: chat.id })).pipe(Effect.forkChild)
+        yield* waitMs(50)
 
-          expect(yield* test.calls).toBe(0)
+        expect(yield* llm.calls).toBe(0)
 
-          yield* Fiber.await(sh)
-          const exit = yield* Fiber.await(run)
+        yield* Fiber.await(sh)
+        const exit = yield* Fiber.await(run)
 
-          expect(Exit.isSuccess(exit)).toBe(true)
-          if (Exit.isSuccess(exit)) {
-            expect(exit.value.info.role).toBe("assistant")
-            expect(exit.value.parts.some((part) => part.type === "text" && part.text === "after-shell")).toBe(true)
-          }
-          expect(yield* test.calls).toBe(1)
-        }),
-      { git: true, config: cfg },
+        expect(Exit.isSuccess(exit)).toBe(true)
+        if (Exit.isSuccess(exit)) {
+          expect(exit.value.info.role).toBe("assistant")
+          expect(exit.value.parts.some((part) => part.type === "text" && part.text === "after-shell")).toBe(true)
+        }
+        expect(yield* llm.calls).toBe(1)
+      }),
+      { git: true, config: providerCfg },
     ),
-  30_000,
+  5_000,
 )
 
-unix(
+http.live(
   "shell completion resumes queued loop callers",
   () =>
-    provideTmpdirInstance(
-      (dir) =>
-        Effect.gen(function* () {
-          const { test, prompt, chat } = yield* boot()
-          yield* test.reply(...replyStop("done"))
+    provideTmpdirServer(
+      Effect.fnUntraced(function* ({ llm }: { dir: string; llm: TestLLMServer["Service"] }) {
+        const chat = yield* Effect.promise(() =>
+          Session.create({
+            title: "Pinned",
+            permission: [{ permission: "*", pattern: "*", action: "allow" }],
+          }),
+        )
+        yield* llm.text("done")
 
-          const sh = yield* prompt
-            .shell({ sessionID: chat.id, agent: "build", command: "sleep 0.2" })
-            .pipe(Effect.forkChild)
-          yield* waitMs(50)
+        const sh = yield* Effect.promise(() =>
+          SessionPrompt.shell({ sessionID: chat.id, agent: "build", command: "sleep 0.2" }),
+        ).pipe(Effect.forkChild)
+        yield* waitMs(50)
 
-          const a = yield* prompt.loop({ sessionID: chat.id }).pipe(Effect.forkChild)
-          const b = yield* prompt.loop({ sessionID: chat.id }).pipe(Effect.forkChild)
-          yield* waitMs(50)
+        const a = yield* Effect.promise(() => SessionPrompt.loop({ sessionID: chat.id })).pipe(Effect.forkChild)
+        const b = yield* Effect.promise(() => SessionPrompt.loop({ sessionID: chat.id })).pipe(Effect.forkChild)
+        yield* waitMs(50)
 
-          expect(yield* test.calls).toBe(0)
+        expect(yield* llm.calls).toBe(0)
 
-          yield* Fiber.await(sh)
-          const [ea, eb] = yield* Effect.all([Fiber.await(a), Fiber.await(b)])
+        yield* Fiber.await(sh)
+        const [ea, eb] = yield* Effect.all([Fiber.await(a), Fiber.await(b)])
 
-          expect(Exit.isSuccess(ea)).toBe(true)
-          expect(Exit.isSuccess(eb)).toBe(true)
-          if (Exit.isSuccess(ea) && Exit.isSuccess(eb)) {
-            expect(ea.value.info.id).toBe(eb.value.info.id)
-            expect(ea.value.info.role).toBe("assistant")
-          }
-          expect(yield* test.calls).toBe(1)
-        }),
-      { git: true, config: cfg },
+        expect(Exit.isSuccess(ea)).toBe(true)
+        expect(Exit.isSuccess(eb)).toBe(true)
+        if (Exit.isSuccess(ea) && Exit.isSuccess(eb)) {
+          expect(ea.value.info.id).toBe(eb.value.info.id)
+          expect(ea.value.info.role).toBe("assistant")
+        }
+        expect(yield* llm.calls).toBe(1)
+      }),
+      { git: true, config: providerCfg },
     ),
-  30_000,
+  5_000,
 )
 
 unix(
diff --git a/packages/opencode/test/session/prompt-provider.test.ts b/packages/opencode/test/session/prompt-provider.test.ts
index 0cf90f2bd5..a7d2fa32f5 100644
--- a/packages/opencode/test/session/prompt-provider.test.ts
+++ b/packages/opencode/test/session/prompt-provider.test.ts
@@ -6,7 +6,7 @@ import { Session } from "../../src/session"
 import { SessionPrompt } from "../../src/session/prompt"
 import { Log } from "../../src/util/log"
 import { testEffect } from "../lib/effect"
-import { provideTmpdirInstance } from "../fixture/fixture"
+import { provideTmpdirServer } from "../fixture/fixture"
 import { TestLLMServer } from "../lib/llm-server"
 import { Layer } from "effect"
 
@@ -53,88 +53,80 @@ function makeConfig(url: string) {
 
 describe("session.prompt provider integration", () => {
   it.live("loop returns assistant text through local provider", () =>
-    Effect.gen(function* () {
-      const llm = yield* TestLLMServer
-      return yield* provideTmpdirInstance(
-        () =>
-          Effect.gen(function* () {
-            const session = yield* Effect.promise(() =>
-              Session.create({
-                title: "Prompt provider",
-                permission: [{ permission: "*", pattern: "*", action: "allow" }],
-              }),
-            )
-
-            yield* Effect.promise(() =>
-              SessionPrompt.prompt({
-                sessionID: session.id,
-                agent: "build",
-                noReply: true,
-                parts: [{ type: "text", text: "hello" }],
-              }),
-            )
-
-            yield* llm.text("world")
-
-            const result = yield* Effect.promise(() => SessionPrompt.loop({ sessionID: session.id }))
-            expect(result.info.role).toBe("assistant")
-            expect(result.parts.some((part) => part.type === "text" && part.text === "world")).toBe(true)
-            expect(yield* llm.hits).toHaveLength(1)
-            expect(yield* llm.pending).toBe(0)
+    provideTmpdirServer(
+      Effect.fnUntraced(function* ({ llm }: { dir: string; llm: TestLLMServer["Service"] }) {
+        const session = yield* Effect.promise(() =>
+          Session.create({
+            title: "Prompt provider",
+            permission: [{ permission: "*", pattern: "*", action: "allow" }],
           }),
-        { git: true, config: makeConfig(llm.url) },
-      )
-    }),
+        )
+
+        yield* Effect.promise(() =>
+          SessionPrompt.prompt({
+            sessionID: session.id,
+            agent: "build",
+            noReply: true,
+            parts: [{ type: "text", text: "hello" }],
+          }),
+        )
+
+        yield* llm.text("world")
+
+        const result = yield* Effect.promise(() => SessionPrompt.loop({ sessionID: session.id }))
+        expect(result.info.role).toBe("assistant")
+        expect(result.parts.some((part) => part.type === "text" && part.text === "world")).toBe(true)
+        expect(yield* llm.hits).toHaveLength(1)
+        expect(yield* llm.pending).toBe(0)
+      }),
+      { git: true, config: makeConfig },
+    ),
   )
 
   it.live("loop consumes queued replies across turns", () =>
-    Effect.gen(function* () {
-      const llm = yield* TestLLMServer
-      return yield* provideTmpdirInstance(
-        () =>
-          Effect.gen(function* () {
-            const session = yield* Effect.promise(() =>
-              Session.create({
-                title: "Prompt provider turns",
-                permission: [{ permission: "*", pattern: "*", action: "allow" }],
-              }),
-            )
-
-            yield* Effect.promise(() =>
-              SessionPrompt.prompt({
-                sessionID: session.id,
-                agent: "build",
-                noReply: true,
-                parts: [{ type: "text", text: "hello one" }],
-              }),
-            )
-
-            yield* llm.text("world one")
-
-            const first = yield* Effect.promise(() => SessionPrompt.loop({ sessionID: session.id }))
-            expect(first.info.role).toBe("assistant")
-            expect(first.parts.some((part) => part.type === "text" && part.text === "world one")).toBe(true)
-
-            yield* Effect.promise(() =>
-              SessionPrompt.prompt({
-                sessionID: session.id,
-                agent: "build",
-                noReply: true,
-                parts: [{ type: "text", text: "hello two" }],
-              }),
-            )
-
-            yield* llm.text("world two")
-
-            const second = yield* Effect.promise(() => SessionPrompt.loop({ sessionID: session.id }))
-            expect(second.info.role).toBe("assistant")
-            expect(second.parts.some((part) => part.type === "text" && part.text === "world two")).toBe(true)
-
-            expect(yield* llm.hits).toHaveLength(2)
-            expect(yield* llm.pending).toBe(0)
+    provideTmpdirServer(
+      Effect.fnUntraced(function* ({ llm }: { dir: string; llm: TestLLMServer["Service"] }) {
+        const session = yield* Effect.promise(() =>
+          Session.create({
+            title: "Prompt provider turns",
+            permission: [{ permission: "*", pattern: "*", action: "allow" }],
           }),
-        { git: true, config: makeConfig(llm.url) },
-      )
-    }),
+        )
+
+        yield* Effect.promise(() =>
+          SessionPrompt.prompt({
+            sessionID: session.id,
+            agent: "build",
+            noReply: true,
+            parts: [{ type: "text", text: "hello one" }],
+          }),
+        )
+
+        yield* llm.text("world one")
+
+        const first = yield* Effect.promise(() => SessionPrompt.loop({ sessionID: session.id }))
+        expect(first.info.role).toBe("assistant")
+        expect(first.parts.some((part) => part.type === "text" && part.text === "world one")).toBe(true)
+
+        yield* Effect.promise(() =>
+          SessionPrompt.prompt({
+            sessionID: session.id,
+            agent: "build",
+            noReply: true,
+            parts: [{ type: "text", text: "hello two" }],
+          }),
+        )
+
+        yield* llm.text("world two")
+
+        const second = yield* Effect.promise(() => SessionPrompt.loop({ sessionID: session.id }))
+        expect(second.info.role).toBe("assistant")
+        expect(second.parts.some((part) => part.type === "text" && part.text === "world two")).toBe(true)
+
+        expect(yield* llm.hits).toHaveLength(2)
+        expect(yield* llm.pending).toBe(0)
+      }),
+      { git: true, config: makeConfig },
+    ),
   )
 })