diff --git a/packages/core/src/database/database.ts b/packages/core/src/database/database.ts
index ab86a37e74c..78585ce8a87 100644
--- a/packages/core/src/database/database.ts
+++ b/packages/core/src/database/database.ts
@@ -2,9 +2,9 @@ export * as Database from "./database"
 
 import { EffectDrizzleSqlite } from "@opencode-ai/effect-drizzle-sqlite"
 import { layer as sqliteLayer } from "#sqlite"
-import { Config, Context, Effect, Layer, Option } from "effect"
+import { Config, Context, Effect, Layer } from "effect"
 import { Global } from "../global"
-import { truthy } from "../flag/flag"
+import { truthy, truthyConfig } from "../flag/flag"
 import { isAbsolute, join } from "path"
 import { DatabaseMigration } from "./migration"
 import { InstallationChannel } from "../installation/version"
@@ -61,12 +61,14 @@ export function path() {
 
 // Placement is resolved through Effect Config when the layer is built, not at
 // module import, so tests and tooling can override it with a ConfigProvider.
+// truthyConfig shares the `truthy` grammar so this layer and the V1 `path()`
+// helper always agree on the same environment.
 const configuredLayer = Layer.unwrap(
   Effect.gen(function* () {
-    const file = yield* Config.option(Config.string("OPENCODE_DB"))
-    const disableChannelDb = yield* Config.boolean("OPENCODE_DISABLE_CHANNEL_DB").pipe(Config.withDefault(false))
-    return layerFromPath(resolvePath({ file: Option.getOrUndefined(file), disableChannelDb }))
-  }).pipe(Effect.orDie),
-)
+    const file = yield* Config.string("OPENCODE_DB").pipe(Config.withDefault(undefined))
+    const disableChannelDb = yield* truthyConfig("OPENCODE_DISABLE_CHANNEL_DB")
+    return layerFromPath(resolvePath({ file, disableChannelDb }))
+  }),
+).pipe(Layer.orDie)
 
 export const node = makeGlobalNode({ service: Service, layer: configuredLayer, deps: [] })
diff --git a/packages/core/src/flag/flag.ts b/packages/core/src/flag/flag.ts
index 47222a5e40f..f7c1d9aaa46 100644
--- a/packages/core/src/flag/flag.ts
+++ b/packages/core/src/flag/flag.ts
@@ -1,10 +1,24 @@
 import { Config } from "effect"
 
-export function truthy(key: string) {
-  const value = process.env[key]?.toLowerCase()
-  return value === "true" || value === "1"
+function truthyValue(value: string) {
+  const lower = value.toLowerCase()
+  return lower === "true" || lower === "1"
 }
 
+export function truthy(key: string) {
+  const value = process.env[key]
+  return value !== undefined && truthyValue(value)
+}
+
+/**
+ * The `truthy` grammar read through Effect Config, so layer builds can be
+ * steered by a ConfigProvider. Missing or malformed values are false, exactly
+ * like `truthy`; strict boolean decoding would turn a stray env value into a
+ * startup defect.
+ */
+export const truthyConfig = (name: string) =>
+  Config.string(name).pipe(Config.map(truthyValue), Config.withDefault(false))
+
 const copy = process.env["OPENCODE_EXPERIMENTAL_DISABLE_COPY_ON_SELECT"]
 const fff = process.env["OPENCODE_DISABLE_FFF"]
 
diff --git a/packages/core/src/tool/websearch.ts b/packages/core/src/tool/websearch.ts
index efd126f253a..661ecdcd0d4 100644
--- a/packages/core/src/tool/websearch.ts
+++ b/packages/core/src/tool/websearch.ts
@@ -1,10 +1,11 @@
 export * as WebSearchTool from "./websearch"
 
 import { ToolFailure } from "@opencode-ai/llm"
-import { Config, Context, Duration, Effect, Layer, Option, Redacted, Schema } from "effect"
+import { Config, Context, Duration, Effect, Layer, Schema } from "effect"
 import { HttpClient, HttpClientRequest } from "effect/unstable/http"
 import { makeLocationNode } from "../effect/app-node"
 import { LayerNodePlatform } from "../effect/app-node-platform"
+import { truthyConfig } from "../flag/flag"
 import { InstallationVersion } from "../installation/version"
 import { PositiveInt } from "../schema"
 import { PermissionV2 } from "../permission"
@@ -68,30 +69,36 @@ export interface Config {
 
 export class ConfigService extends Context.Service<ConfigService, Config>()("@opencode/v2/WebSearchConfig") {}
 
-const flag = (name: string) => Config.boolean(name).pipe(Config.withDefault(false))
-
 /**
  * Isolates the retained product environment contract from the generic tool
  * implementation. Reads through Effect `Config` when the layer is built, so
  * tests can override values with a `ConfigProvider` instead of mutating
- * `process.env`. Malformed values fail the layer instead of silently
- * disabling a provider the user asked for.
+ * `process.env`. Parsing keeps the legacy lenient grammar: missing or
+ * malformed values disable rather than fail, because this layer builds at
+ * Location boot where a defect would surface as opaque session failures.
  */
 export const defaultConfigLayer = Layer.effect(
   ConfigService,
   Effect.gen(function* () {
-    const provider = yield* Config.option(Config.literals(["exa", "parallel"], "OPENCODE_WEBSEARCH_PROVIDER"))
-    const exaApiKey = yield* Config.option(Config.redacted("EXA_API_KEY"))
-    const parallelApiKey = yield* Config.option(Config.redacted("PARALLEL_API_KEY"))
+    const env = yield* Config.all({
+      provider: Config.string("OPENCODE_WEBSEARCH_PROVIDER").pipe(Config.withDefault(undefined)),
+      experimental: truthyConfig("OPENCODE_EXPERIMENTAL"),
+      enableExa: truthyConfig("OPENCODE_ENABLE_EXA"),
+      experimentalExa: truthyConfig("OPENCODE_EXPERIMENTAL_EXA"),
+      enableParallel: truthyConfig("OPENCODE_ENABLE_PARALLEL"),
+      experimentalParallel: truthyConfig("OPENCODE_EXPERIMENTAL_PARALLEL"),
+      exaApiKey: Config.string("EXA_API_KEY").pipe(Config.withDefault(undefined)),
+      parallelApiKey: Config.string("PARALLEL_API_KEY").pipe(Config.withDefault(undefined)),
+    })
+    const provider = env.provider !== undefined && Schema.is(Provider)(env.provider) ? env.provider : undefined
+    if (env.provider !== undefined && provider === undefined)
+      yield* Effect.logWarning("ignoring invalid OPENCODE_WEBSEARCH_PROVIDER", { value: env.provider })
     return ConfigService.of({
-      provider: Option.getOrUndefined(provider),
-      enableExa:
-        (yield* flag("OPENCODE_EXPERIMENTAL")) ||
-        (yield* flag("OPENCODE_ENABLE_EXA")) ||
-        (yield* flag("OPENCODE_EXPERIMENTAL_EXA")),
-      enableParallel: (yield* flag("OPENCODE_ENABLE_PARALLEL")) || (yield* flag("OPENCODE_EXPERIMENTAL_PARALLEL")),
-      exaApiKey: Option.getOrUndefined(Option.map(exaApiKey, Redacted.value)),
-      parallelApiKey: Option.getOrUndefined(Option.map(parallelApiKey, Redacted.value)),
+      provider,
+      enableExa: env.experimental || env.enableExa || env.experimentalExa,
+      enableParallel: env.enableParallel || env.experimentalParallel,
+      exaApiKey: env.exaApiKey,
+      parallelApiKey: env.parallelApiKey,
     })
   }),
 ).pipe(Layer.orDie)
diff --git a/packages/core/test/tool-websearch.test.ts b/packages/core/test/tool-websearch.test.ts
index 55345b1a51e..8b7093b213b 100644
--- a/packages/core/test/tool-websearch.test.ts
+++ b/packages/core/test/tool-websearch.test.ts
@@ -1,5 +1,5 @@
 import { beforeEach, describe, expect, test } from "bun:test"
-import { ConfigProvider, Effect, Exit, Layer, Schema } from "effect"
+import { ConfigProvider, Effect, Layer, Schema } from "effect"
 import { HttpClient, HttpClientResponse } from "effect/unstable/http"
 import { AppNodeBuilder } from "@opencode-ai/core/effect/app-node-builder"
 import { LayerNode } from "@opencode-ai/core/effect/layer-node"
@@ -48,12 +48,9 @@ describe("WebSearchTool provider selection", () => {
 })
 
 const readDefaultConfig = (env: Record<string, string>) =>
-  Effect.gen(function* () {
-    return yield* WebSearchTool.ConfigService
-  }).pipe(
-    Effect.provide(
-      WebSearchTool.defaultConfigLayer.pipe(Layer.provide(ConfigProvider.layer(ConfigProvider.fromUnknown(env)))),
-    ),
+  Effect.provide(
+    WebSearchTool.ConfigService,
+    WebSearchTool.defaultConfigLayer.pipe(Layer.provide(ConfigProvider.layer(ConfigProvider.fromUnknown(env)))),
   )
 
 describe("WebSearchTool default config", () => {
@@ -87,9 +84,17 @@ describe("WebSearchTool default config", () => {
     })
   })
 
-  test("fails on an invalid provider instead of silently ignoring it", async () => {
-    const exit = await Effect.runPromiseExit(readDefaultConfig({ OPENCODE_WEBSEARCH_PROVIDER: "bing" }))
-    expect(Exit.isFailure(exit)).toBe(true)
+  test("keeps the legacy lenient truthiness grammar", async () => {
+    const decoded = await Effect.runPromise(
+      readDefaultConfig({ OPENCODE_ENABLE_EXA: "TRUE", OPENCODE_ENABLE_PARALLEL: "banana" }),
+    )
+    expect(decoded.enableExa).toBe(true)
+    expect(decoded.enableParallel).toBe(false)
+  })
+
+  test("ignores an invalid provider instead of failing the Location layer", async () => {
+    const decoded = await Effect.runPromise(readDefaultConfig({ OPENCODE_WEBSEARCH_PROVIDER: "bing" }))
+    expect(decoded.provider).toBeUndefined()
   })
 })
 
diff --git a/packages/opencode/test/server/httpapi-exercise/environment.ts b/packages/opencode/test/server/httpapi-exercise/environment.ts
index 985215c451a..bc40dcabdfc 100644
--- a/packages/opencode/test/server/httpapi-exercise/environment.ts
+++ b/packages/opencode/test/server/httpapi-exercise/environment.ts
@@ -18,6 +18,9 @@ const preserveExerciseDatabase = !!process.env.OPENCODE_HTTPAPI_EXERCISE_DB
 export const exerciseDatabasePath =
   process.env.OPENCODE_HTTPAPI_EXERCISE_DB ??
   path.join(process.env.TMPDIR ?? "/tmp", `opencode-httpapi-exercise-${process.pid}.db`)
+// Must run before the first Effect Config read anywhere in the process: the
+// default ConfigProvider snapshots process.env on first use, so a Config read
+// during an earlier module import would freeze the wrong database path.
 process.env.OPENCODE_DB = exerciseDatabasePath
 
 export const original = {