diff --git a/packages/opencode/test/provider/amazon-bedrock.test.ts b/packages/opencode/test/provider/amazon-bedrock.test.ts
index 26bb520fc1..cb94e8cd97 100644
--- a/packages/opencode/test/provider/amazon-bedrock.test.ts
+++ b/packages/opencode/test/provider/amazon-bedrock.test.ts
@@ -1,31 +1,25 @@
-import { afterEach, test, expect, describe } from "bun:test"
+import { afterEach, describe, expect, test } from "bun:test"
+import { Effect, Layer } from "effect"
 import path from "path"
 import { unlink } from "fs/promises"
-
-import { ProviderID } from "../../src/provider/schema"
-import { disposeAllInstances, tmpdir, withTestInstance } from "../fixture/fixture"
-import type { InstanceContext } from "../../src/project/instance-context"
-import { Provider } from "@/provider/provider"
-import { Env } from "../../src/env"
 import { Global } from "@opencode-ai/core/global"
 import { Filesystem } from "@/util/filesystem"
-import { Effect } from "effect"
-import { AppRuntime } from "../../src/effect/app-runtime"
-import { InstanceRef } from "../../src/effect/instance-ref"
-import { makeRuntime } from "../../src/effect/run-service"
+import { Env } from "../../src/env"
+import { Provider } from "@/provider/provider"
+import { ProviderID } from "../../src/provider/schema"
+import { disposeAllInstances } from "../fixture/fixture"
+import { testEffect } from "../lib/effect"
+
+const it = testEffect(Layer.mergeAll(Provider.defaultLayer, Env.defaultLayer))
 
-const env = makeRuntime(Env.Service, Env.defaultLayer)
 const originalEnv = new Map<string, string | undefined>()
 
-function rememberEnv(k: string) {
-  if (!originalEnv.has(k)) originalEnv.set(k, process.env[k])
-}
-
-const set = (ctx: InstanceContext, k: string, v: string) => {
-  rememberEnv(k)
-  process.env[k] = v
-  return env.runSync((svc) => svc.set(k, v).pipe(Effect.provideService(InstanceRef, ctx)))
-}
+const set = (k: string, v: string) =>
+  Effect.gen(function* () {
+    if (!originalEnv.has(k)) originalEnv.set(k, process.env[k])
+    process.env[k] = v
+    yield* Env.Service.use((svc) => svc.set(k, v))
+  })
 
 afterEach(async () => {
   for (const [key, value] of originalEnv) {
@@ -36,427 +30,250 @@ afterEach(async () => {
   await disposeAllInstances()
 })
 
-async function list(ctx: InstanceContext) {
-  return AppRuntime.runPromise(
-    Effect.gen(function* () {
-      const provider = yield* Provider.Service
-      return yield* provider.list()
-    }).pipe(Effect.provideService(InstanceRef, ctx)),
-  )
-}
+const list = Provider.Service.use((svc) => svc.list())
 
-test("Bedrock: config region takes precedence over AWS_REGION env var", async () => {
-  await using tmp = await tmpdir({
-    init: async (dir) => {
-      await Filesystem.write(
-        path.join(dir, "opencode.json"),
-        JSON.stringify({
-          $schema: "https://opencode.ai/config.json",
-          provider: {
-            "amazon-bedrock": {
-              options: {
-                region: "eu-west-1",
-              },
-            },
-          },
-        }),
-      )
-    },
-  })
-  await withTestInstance({
-    directory: tmp.path,
-    fn: async (ctx) => {
-      set(ctx, "AWS_REGION", "us-east-1")
-      set(ctx, "AWS_PROFILE", "default")
-      const providers = await list(ctx)
-      expect(providers[ProviderID.amazonBedrock]).toBeDefined()
-      expect(providers[ProviderID.amazonBedrock].options?.region).toBe("eu-west-1")
-    },
-  })
-})
-
-test("Bedrock: falls back to AWS_REGION env var when no config region", async () => {
-  await using tmp = await tmpdir({
-    init: async (dir) => {
-      await Filesystem.write(
-        path.join(dir, "opencode.json"),
-        JSON.stringify({
-          $schema: "https://opencode.ai/config.json",
-        }),
-      )
-    },
-  })
-  await withTestInstance({
-    directory: tmp.path,
-    fn: async (ctx) => {
-      set(ctx, "AWS_REGION", "eu-west-1")
-      set(ctx, "AWS_PROFILE", "default")
-      const providers = await list(ctx)
-      expect(providers[ProviderID.amazonBedrock]).toBeDefined()
-      expect(providers[ProviderID.amazonBedrock].options?.region).toBe("eu-west-1")
-    },
-  })
-})
-
-test("Bedrock: loads when bearer token from auth.json is present", async () => {
-  await using tmp = await tmpdir({
-    init: async (dir) => {
-      await Filesystem.write(
-        path.join(dir, "opencode.json"),
-        JSON.stringify({
-          $schema: "https://opencode.ai/config.json",
-          provider: {
-            "amazon-bedrock": {
-              options: {
-                region: "eu-west-1",
-              },
-            },
-          },
-        }),
-      )
-    },
-  })
-
-  const authPath = path.join(Global.Path.data, "auth.json")
-
-  // Save original auth.json if it exists
-  let originalAuth: string | undefined
-  try {
-    originalAuth = await Filesystem.readText(authPath)
-  } catch {
-    // File doesn't exist, that's fine
-  }
-
-  try {
-    // Write test auth.json
-    await Filesystem.write(
-      authPath,
-      JSON.stringify({
-        "amazon-bedrock": {
-          type: "api",
-          key: "test-bearer-token",
-        },
-      }),
-    )
-
-    await withTestInstance({
-      directory: tmp.path,
-      fn: async (ctx) => {
-        set(ctx, "AWS_PROFILE", "")
-        set(ctx, "AWS_ACCESS_KEY_ID", "")
-        set(ctx, "AWS_BEARER_TOKEN_BEDROCK", "")
-        const providers = await list(ctx)
-        expect(providers[ProviderID.amazonBedrock]).toBeDefined()
-        expect(providers[ProviderID.amazonBedrock].options?.region).toBe("eu-west-1")
-      },
-    })
-  } finally {
-    // Restore original or delete
-    if (originalAuth !== undefined) {
-      await Filesystem.write(authPath, originalAuth)
-    } else {
+const withAuthJson = (contents: string) =>
+  Effect.acquireRelease(
+    Effect.promise(async () => {
+      const authPath = path.join(Global.Path.data, "auth.json")
+      let original: string | undefined
       try {
-        await unlink(authPath)
+        original = await Filesystem.readText(authPath)
       } catch {
-        // Ignore errors if file doesn't exist
+        original = undefined
       }
-    }
-  }
-})
+      await Filesystem.write(authPath, contents)
+      return { authPath, original }
+    }),
+    ({ authPath, original }) =>
+      Effect.promise(async () => {
+        if (original !== undefined) {
+          await Filesystem.write(authPath, original)
+          return
+        }
+        await unlink(authPath).catch(() => undefined)
+      }),
+  )
 
-test("Bedrock: config profile takes precedence over AWS_PROFILE env var", async () => {
-  await using tmp = await tmpdir({
-    init: async (dir) => {
-      await Filesystem.write(
-        path.join(dir, "opencode.json"),
-        JSON.stringify({
-          $schema: "https://opencode.ai/config.json",
-          provider: {
-            "amazon-bedrock": {
-              options: {
-                profile: "my-custom-profile",
-                region: "us-east-1",
-              },
-            },
-          },
-        }),
-      )
-    },
-  })
-  await withTestInstance({
-    directory: tmp.path,
-    fn: async (ctx) => {
-      set(ctx, "AWS_PROFILE", "default")
-      set(ctx, "AWS_ACCESS_KEY_ID", "test-key-id")
-      const providers = await list(ctx)
+it.instance(
+  "Bedrock: config region takes precedence over AWS_REGION env var",
+  () =>
+    Effect.gen(function* () {
+      yield* set("AWS_REGION", "us-east-1")
+      yield* set("AWS_PROFILE", "default")
+      const providers = yield* list
+      expect(providers[ProviderID.amazonBedrock]).toBeDefined()
+      expect(providers[ProviderID.amazonBedrock].options?.region).toBe("eu-west-1")
+    }),
+  { config: { provider: { "amazon-bedrock": { options: { region: "eu-west-1" } } } } },
+)
+
+it.instance(
+  "Bedrock: falls back to AWS_REGION env var when no config region",
+  () =>
+    Effect.gen(function* () {
+      yield* set("AWS_REGION", "eu-west-1")
+      yield* set("AWS_PROFILE", "default")
+      const providers = yield* list
+      expect(providers[ProviderID.amazonBedrock]).toBeDefined()
+      expect(providers[ProviderID.amazonBedrock].options?.region).toBe("eu-west-1")
+    }),
+)
+
+it.instance(
+  "Bedrock: loads when bearer token from auth.json is present",
+  () =>
+    Effect.gen(function* () {
+      yield* withAuthJson(JSON.stringify({ "amazon-bedrock": { type: "api", key: "test-bearer-token" } }))
+      yield* set("AWS_PROFILE", "")
+      yield* set("AWS_ACCESS_KEY_ID", "")
+      yield* set("AWS_BEARER_TOKEN_BEDROCK", "")
+      const providers = yield* list
+      expect(providers[ProviderID.amazonBedrock]).toBeDefined()
+      expect(providers[ProviderID.amazonBedrock].options?.region).toBe("eu-west-1")
+    }),
+  { config: { provider: { "amazon-bedrock": { options: { region: "eu-west-1" } } } } },
+)
+
+it.instance(
+  "Bedrock: config profile takes precedence over AWS_PROFILE env var",
+  () =>
+    Effect.gen(function* () {
+      yield* set("AWS_PROFILE", "default")
+      yield* set("AWS_ACCESS_KEY_ID", "test-key-id")
+      const providers = yield* list
       expect(providers[ProviderID.amazonBedrock]).toBeDefined()
       expect(providers[ProviderID.amazonBedrock].options?.region).toBe("us-east-1")
+    }),
+  {
+    config: {
+      provider: { "amazon-bedrock": { options: { profile: "my-custom-profile", region: "us-east-1" } } },
     },
-  })
-})
+  },
+)
 
-test("Bedrock: includes custom endpoint in options when specified", async () => {
-  await using tmp = await tmpdir({
-    init: async (dir) => {
-      await Filesystem.write(
-        path.join(dir, "opencode.json"),
-        JSON.stringify({
-          $schema: "https://opencode.ai/config.json",
-          provider: {
-            "amazon-bedrock": {
-              options: {
-                endpoint: "https://bedrock-runtime.us-east-1.vpce-xxxxx.amazonaws.com",
-              },
-            },
-          },
-        }),
-      )
-    },
-  })
-  await withTestInstance({
-    directory: tmp.path,
-    fn: async (ctx) => {
-      set(ctx, "AWS_PROFILE", "default")
-      const providers = await list(ctx)
+it.instance(
+  "Bedrock: includes custom endpoint in options when specified",
+  () =>
+    Effect.gen(function* () {
+      yield* set("AWS_PROFILE", "default")
+      const providers = yield* list
       expect(providers[ProviderID.amazonBedrock]).toBeDefined()
       expect(providers[ProviderID.amazonBedrock].options?.endpoint).toBe(
         "https://bedrock-runtime.us-east-1.vpce-xxxxx.amazonaws.com",
       )
+    }),
+  {
+    config: {
+      provider: {
+        "amazon-bedrock": {
+          options: { endpoint: "https://bedrock-runtime.us-east-1.vpce-xxxxx.amazonaws.com" },
+        },
+      },
     },
-  })
-})
+  },
+)
 
-test("Bedrock: autoloads when AWS_WEB_IDENTITY_TOKEN_FILE is present", async () => {
-  await using tmp = await tmpdir({
-    init: async (dir) => {
-      await Filesystem.write(
-        path.join(dir, "opencode.json"),
-        JSON.stringify({
-          $schema: "https://opencode.ai/config.json",
-          provider: {
-            "amazon-bedrock": {
-              options: {
-                region: "us-east-1",
-              },
-            },
-          },
-        }),
-      )
-    },
-  })
-  await withTestInstance({
-    directory: tmp.path,
-    fn: async (ctx) => {
-      set(ctx, "AWS_WEB_IDENTITY_TOKEN_FILE", "/var/run/secrets/eks.amazonaws.com/serviceaccount/token")
-      set(ctx, "AWS_ROLE_ARN", "arn:aws:iam::123456789012:role/my-eks-role")
-      set(ctx, "AWS_PROFILE", "")
-      set(ctx, "AWS_ACCESS_KEY_ID", "")
-      const providers = await list(ctx)
+it.instance(
+  "Bedrock: autoloads when AWS_WEB_IDENTITY_TOKEN_FILE is present",
+  () =>
+    Effect.gen(function* () {
+      yield* set("AWS_WEB_IDENTITY_TOKEN_FILE", "/var/run/secrets/eks.amazonaws.com/serviceaccount/token")
+      yield* set("AWS_ROLE_ARN", "arn:aws:iam::123456789012:role/my-eks-role")
+      yield* set("AWS_PROFILE", "")
+      yield* set("AWS_ACCESS_KEY_ID", "")
+      const providers = yield* list
       expect(providers[ProviderID.amazonBedrock]).toBeDefined()
       expect(providers[ProviderID.amazonBedrock].options?.region).toBe("us-east-1")
-    },
-  })
-})
+    }),
+  { config: { provider: { "amazon-bedrock": { options: { region: "us-east-1" } } } } },
+)
 
-// Tests for cross-region inference profile prefix handling
-// Models from models.dev may come with prefixes already (e.g., us., eu., global.)
-// These should NOT be double-prefixed when passed to the SDK
+// Cross-region inference profile prefix handling.
+// Models from models.dev may come with prefixes already (e.g. us., eu., global.).
+// These should NOT be double-prefixed when passed to the SDK.
 
-test("Bedrock: model with us. prefix should not be double-prefixed", async () => {
-  await using tmp = await tmpdir({
-    init: async (dir) => {
-      await Filesystem.write(
-        path.join(dir, "opencode.json"),
-        JSON.stringify({
-          $schema: "https://opencode.ai/config.json",
-          provider: {
-            "amazon-bedrock": {
-              options: {
-                region: "us-east-1",
-              },
-              models: {
-                "us.anthropic.claude-opus-4-5-20251101-v1:0": {
-                  name: "Claude Opus 4.5 (US)",
-                },
-              },
-            },
-          },
-        }),
-      )
-    },
-  })
-  await withTestInstance({
-    directory: tmp.path,
-    fn: async (ctx) => {
-      set(ctx, "AWS_PROFILE", "default")
-      const providers = await list(ctx)
+it.instance(
+  "Bedrock: model with us. prefix should not be double-prefixed",
+  () =>
+    Effect.gen(function* () {
+      yield* set("AWS_PROFILE", "default")
+      const providers = yield* list
       expect(providers[ProviderID.amazonBedrock]).toBeDefined()
-      // The model should exist with the us. prefix
       expect(providers[ProviderID.amazonBedrock].models["us.anthropic.claude-opus-4-5-20251101-v1:0"]).toBeDefined()
+    }),
+  {
+    config: {
+      provider: {
+        "amazon-bedrock": {
+          options: { region: "us-east-1" },
+          models: { "us.anthropic.claude-opus-4-5-20251101-v1:0": { name: "Claude Opus 4.5 (US)" } },
+        },
+      },
     },
-  })
-})
+  },
+)
 
-test("Bedrock: model with global. prefix should not be prefixed", async () => {
-  await using tmp = await tmpdir({
-    init: async (dir) => {
-      await Filesystem.write(
-        path.join(dir, "opencode.json"),
-        JSON.stringify({
-          $schema: "https://opencode.ai/config.json",
-          provider: {
-            "amazon-bedrock": {
-              options: {
-                region: "us-east-1",
-              },
-              models: {
-                "global.anthropic.claude-opus-4-5-20251101-v1:0": {
-                  name: "Claude Opus 4.5 (Global)",
-                },
-              },
-            },
-          },
-        }),
-      )
-    },
-  })
-  await withTestInstance({
-    directory: tmp.path,
-    fn: async (ctx) => {
-      set(ctx, "AWS_PROFILE", "default")
-      const providers = await list(ctx)
+it.instance(
+  "Bedrock: model with global. prefix should not be prefixed",
+  () =>
+    Effect.gen(function* () {
+      yield* set("AWS_PROFILE", "default")
+      const providers = yield* list
       expect(providers[ProviderID.amazonBedrock]).toBeDefined()
       expect(providers[ProviderID.amazonBedrock].models["global.anthropic.claude-opus-4-5-20251101-v1:0"]).toBeDefined()
+    }),
+  {
+    config: {
+      provider: {
+        "amazon-bedrock": {
+          options: { region: "us-east-1" },
+          models: { "global.anthropic.claude-opus-4-5-20251101-v1:0": { name: "Claude Opus 4.5 (Global)" } },
+        },
+      },
     },
-  })
-})
+  },
+)
 
-test("Bedrock: model with eu. prefix should not be double-prefixed", async () => {
-  await using tmp = await tmpdir({
-    init: async (dir) => {
-      await Filesystem.write(
-        path.join(dir, "opencode.json"),
-        JSON.stringify({
-          $schema: "https://opencode.ai/config.json",
-          provider: {
-            "amazon-bedrock": {
-              options: {
-                region: "eu-west-1",
-              },
-              models: {
-                "eu.anthropic.claude-opus-4-5-20251101-v1:0": {
-                  name: "Claude Opus 4.5 (EU)",
-                },
-              },
-            },
-          },
-        }),
-      )
-    },
-  })
-  await withTestInstance({
-    directory: tmp.path,
-    fn: async (ctx) => {
-      set(ctx, "AWS_PROFILE", "default")
-      const providers = await list(ctx)
+it.instance(
+  "Bedrock: model with eu. prefix should not be double-prefixed",
+  () =>
+    Effect.gen(function* () {
+      yield* set("AWS_PROFILE", "default")
+      const providers = yield* list
       expect(providers[ProviderID.amazonBedrock]).toBeDefined()
       expect(providers[ProviderID.amazonBedrock].models["eu.anthropic.claude-opus-4-5-20251101-v1:0"]).toBeDefined()
+    }),
+  {
+    config: {
+      provider: {
+        "amazon-bedrock": {
+          options: { region: "eu-west-1" },
+          models: { "eu.anthropic.claude-opus-4-5-20251101-v1:0": { name: "Claude Opus 4.5 (EU)" } },
+        },
+      },
     },
-  })
-})
+  },
+)
 
-test("Bedrock: model without prefix in US region should get us. prefix added", async () => {
-  await using tmp = await tmpdir({
-    init: async (dir) => {
-      await Filesystem.write(
-        path.join(dir, "opencode.json"),
-        JSON.stringify({
-          $schema: "https://opencode.ai/config.json",
-          provider: {
-            "amazon-bedrock": {
-              options: {
-                region: "us-east-1",
-              },
-              models: {
-                "anthropic.claude-opus-4-5-20251101-v1:0": {
-                  name: "Claude Opus 4.5",
-                },
-              },
-            },
-          },
-        }),
-      )
-    },
-  })
-  await withTestInstance({
-    directory: tmp.path,
-    fn: async (ctx) => {
-      set(ctx, "AWS_PROFILE", "default")
-      const providers = await list(ctx)
+it.instance(
+  "Bedrock: model without prefix in US region should get us. prefix added",
+  () =>
+    Effect.gen(function* () {
+      yield* set("AWS_PROFILE", "default")
+      const providers = yield* list
       expect(providers[ProviderID.amazonBedrock]).toBeDefined()
-      // Non-prefixed model should still be registered
       expect(providers[ProviderID.amazonBedrock].models["anthropic.claude-opus-4-5-20251101-v1:0"]).toBeDefined()
+    }),
+  {
+    config: {
+      provider: {
+        "amazon-bedrock": {
+          options: { region: "us-east-1" },
+          models: { "anthropic.claude-opus-4-5-20251101-v1:0": { name: "Claude Opus 4.5" } },
+        },
+      },
     },
-  })
-})
-
-// Direct unit tests for cross-region inference profile prefix handling
-// These test the prefix detection logic used in getModel
+  },
+)
 
+// Direct unit tests for cross-region inference profile prefix detection.
 describe("Bedrock cross-region prefix detection", () => {
   const crossRegionPrefixes = ["global.", "us.", "eu.", "jp.", "apac.", "au."]
 
   test("should detect global. prefix", () => {
-    const modelID = "global.anthropic.claude-opus-4-5-20251101-v1:0"
-    const hasPrefix = crossRegionPrefixes.some((prefix) => modelID.startsWith(prefix))
-    expect(hasPrefix).toBe(true)
+    expect(crossRegionPrefixes.some((p) => "global.anthropic.claude-opus-4-5-20251101-v1:0".startsWith(p))).toBe(true)
   })
 
   test("should detect us. prefix", () => {
-    const modelID = "us.anthropic.claude-opus-4-5-20251101-v1:0"
-    const hasPrefix = crossRegionPrefixes.some((prefix) => modelID.startsWith(prefix))
-    expect(hasPrefix).toBe(true)
+    expect(crossRegionPrefixes.some((p) => "us.anthropic.claude-opus-4-5-20251101-v1:0".startsWith(p))).toBe(true)
   })
 
   test("should detect eu. prefix", () => {
-    const modelID = "eu.anthropic.claude-opus-4-5-20251101-v1:0"
-    const hasPrefix = crossRegionPrefixes.some((prefix) => modelID.startsWith(prefix))
-    expect(hasPrefix).toBe(true)
+    expect(crossRegionPrefixes.some((p) => "eu.anthropic.claude-opus-4-5-20251101-v1:0".startsWith(p))).toBe(true)
   })
 
   test("should detect jp. prefix", () => {
-    const modelID = "jp.anthropic.claude-sonnet-4-20250514-v1:0"
-    const hasPrefix = crossRegionPrefixes.some((prefix) => modelID.startsWith(prefix))
-    expect(hasPrefix).toBe(true)
+    expect(crossRegionPrefixes.some((p) => "jp.anthropic.claude-sonnet-4-20250514-v1:0".startsWith(p))).toBe(true)
   })
 
   test("should detect apac. prefix", () => {
-    const modelID = "apac.anthropic.claude-sonnet-4-20250514-v1:0"
-    const hasPrefix = crossRegionPrefixes.some((prefix) => modelID.startsWith(prefix))
-    expect(hasPrefix).toBe(true)
+    expect(crossRegionPrefixes.some((p) => "apac.anthropic.claude-sonnet-4-20250514-v1:0".startsWith(p))).toBe(true)
   })
 
   test("should detect au. prefix", () => {
-    const modelID = "au.anthropic.claude-sonnet-4-5-20250929-v1:0"
-    const hasPrefix = crossRegionPrefixes.some((prefix) => modelID.startsWith(prefix))
-    expect(hasPrefix).toBe(true)
+    expect(crossRegionPrefixes.some((p) => "au.anthropic.claude-sonnet-4-5-20250929-v1:0".startsWith(p))).toBe(true)
   })
 
   test("should NOT detect prefix for non-prefixed model", () => {
-    const modelID = "anthropic.claude-opus-4-5-20251101-v1:0"
-    const hasPrefix = crossRegionPrefixes.some((prefix) => modelID.startsWith(prefix))
-    expect(hasPrefix).toBe(false)
+    expect(crossRegionPrefixes.some((p) => "anthropic.claude-opus-4-5-20251101-v1:0".startsWith(p))).toBe(false)
   })
 
   test("should NOT detect prefix for amazon nova models", () => {
-    const modelID = "amazon.nova-pro-v1:0"
-    const hasPrefix = crossRegionPrefixes.some((prefix) => modelID.startsWith(prefix))
-    expect(hasPrefix).toBe(false)
+    expect(crossRegionPrefixes.some((p) => "amazon.nova-pro-v1:0".startsWith(p))).toBe(false)
   })
 
   test("should NOT detect prefix for cohere models", () => {
-    const modelID = "cohere.command-r-plus-v1:0"
-    const hasPrefix = crossRegionPrefixes.some((prefix) => modelID.startsWith(prefix))
-    expect(hasPrefix).toBe(false)
+    expect(crossRegionPrefixes.some((p) => "cohere.command-r-plus-v1:0".startsWith(p))).toBe(false)
   })
 })