refactor(core): separate Code Mode host wiring

packages/core/src/tool/execute.ts

@@ -50,13 +50,13 @@ export interface CodeModeTools {
 export const create = (options: {
   readonly registrations: ReadonlyMap<string, Registration>
   readonly current: (name: string) => Registration | undefined
-  readonly tools?: CodeModeTools
+  readonly tools: CodeModeTools
 }) => {
   const runtime = (
     invoke: (name: string, registration: Registration, input: unknown) => Effect.Effect<unknown, unknown>,
     hooks?: CodeMode.ToolCallHooks,
   ) => {
-    const tools: CodeModeTools = Object.assign(Object.create(null), options.tools)
+    const tools = cloneTools(options.tools)
     for (const [name, registration] of options.registrations) {
       const child = definition(name, registration.tool)
       const value = Tool.make({
@@ -168,6 +168,15 @@ export const create = (options: {
   })
 }
 
+function cloneTools(tools: CodeModeTools): CodeModeTools {
+  return Object.assign(
+    Object.create(null),
+    Object.fromEntries(
+      Object.entries(tools).map(([name, value]) => [name, Tool.isDefinition(value) ? value : cloneTools(value)]),
+    ),
+  )
+}
+
 function displayInput(input: unknown): Record<string, unknown> | undefined {
   if (input === null || input === undefined) return
   if (typeof input !== "object" || Array.isArray(input)) return { input }

packages/core/src/tool/registry.ts

@@ -15,6 +15,7 @@ import { definition, permission, registrationEntries, RegistrationError, settle,
 import { Tools } from "./tools"
 import { ToolHooks } from "./hooks"
 import { makeLocationNode } from "../effect/app-node"
+import { LayerNode } from "../effect/layer-node"
 import { SessionError } from "@opencode-ai/schema/session-error"
 import { toSessionError } from "../session/to-session-error"
 
@@ -52,10 +53,16 @@ export interface Settlement {
 }
 
 export class Service extends Context.Service<Service, Interface>()("@opencode/v2/ToolRegistry") {}
-class CodeModeCatalog extends Context.Service<CodeModeCatalog, { readonly tools?: CodeModeTools }>()(
+class CodeModeCatalog extends Context.Service<CodeModeCatalog, { readonly tools: CodeModeTools }>()(
   "@opencode/v2/CodeModeCatalog",
 ) {}
 
+const codeModeCatalogNode = makeLocationNode({
+  service: CodeModeCatalog,
+  layer: Layer.succeed(CodeModeCatalog, CodeModeCatalog.of({ tools: {} })),
+  deps: [],
+})
+
 const registryLayer = Layer.effect(
   Service,
   Effect.gen(function* () {
@@ -209,10 +216,9 @@ const registryLayer = Layer.effect(
         }
         const direct = new Map(Array.from(registrations).filter(([, registration]) => !registration.deferred))
         const deferred = new Map(Array.from(registrations).filter(([, registration]) => registration.deferred))
-        const tools = Flag.CODEMODE_ENABLED ? codeModeTools : undefined
+        const tools = Flag.CODEMODE_ENABLED ? codeModeTools : {}
         const execute =
-          (deferred.size > 0 || (tools !== undefined && Object.keys(tools).length > 0)) &&
-          !whollyDisabled("execute", input.permissions ?? [])
+          (deferred.size > 0 || Object.keys(tools).length > 0) && !whollyDisabled("execute", input.permissions ?? [])
             ? ExecuteTool.create({
                 registrations: deferred,
                 current: (name) => local.get(name)?.at(-1)?.registration,
@@ -239,37 +245,28 @@ const registryLayer = Layer.effect(
   }),
 )
 
-const makeLayer = (codeModeTools?: CodeModeTools) => {
-  return Layer.effect(
-    Tools.Service,
-    Service.use((registry) => Effect.succeed(Tools.Service.of({ register: registry.register }))),
-  ).pipe(
-    Layer.provideMerge(registryLayer),
-    Layer.provide(Layer.succeed(CodeModeCatalog, CodeModeCatalog.of({ tools: codeModeTools }))),
-  )
-}
+const layer = Layer.effect(
+  Tools.Service,
+  Service.use((registry) => Effect.succeed(Tools.Service.of({ register: registry.register }))),
+).pipe(Layer.provideMerge(registryLayer))
 
 function whollyDisabled(action: string, rules: PermissionV2.Ruleset) {
   const rule = rules.findLast((rule) => Wildcard.match(action, rule.action))
   return rule?.resource === "*" && rule.effect === "deny"
 }
 
-export function nodes(codeModeTools?: CodeModeTools) {
-  const layer = makeLayer(codeModeTools)
-  return {
-    node: makeLocationNode({
-      service: Service,
-      layer,
-      deps: [ToolOutputStore.node, ToolHooks.node],
-    }),
-    toolsNode: makeLocationNode({
-      service: Tools.Service,
-      layer,
-      deps: [ToolOutputStore.node, ToolHooks.node],
-    }),
-  }
+export function codeModeReplacement(tools: CodeModeTools): LayerNode.Replacement {
+  return [codeModeCatalogNode, Layer.succeed(CodeModeCatalog, CodeModeCatalog.of({ tools }))]
 }
 
-const defaults = nodes()
-export const node = defaults.node
-export const toolsNode = defaults.toolsNode
+export const node = makeLocationNode({
+  service: Service,
+  layer,
+  deps: [ToolOutputStore.node, ToolHooks.node, codeModeCatalogNode],
+})
+
+export const toolsNode = makeLocationNode({
+  service: Tools.Service,
+  layer,
+  deps: [ToolOutputStore.node, ToolHooks.node, codeModeCatalogNode],
+})

packages/core/test/session-runner-tool-registry.test.ts

@@ -30,7 +30,7 @@ const outputStore = Layer.mock(ToolOutputStore.Service, {
 })
 const registryLayer = AppNodeBuilder.build(ToolRegistry.node, [[ToolOutputStore.node, outputStore]])
 const it = testEffect(registryLayer)
-const codeModeNodes = ToolRegistry.nodes({
+const codeModeTools: ToolRegistry.CodeModeTools = {
   opencode: {
     v2: {
       health: {
@@ -44,8 +44,13 @@ const codeModeNodes = ToolRegistry.nodes({
       },
     },
   },
-})
-const codeModeIt = testEffect(AppNodeBuilder.build(codeModeNodes.node, [[ToolOutputStore.node, outputStore]]))
+}
+const codeModeIt = testEffect(
+  AppNodeBuilder.build(ToolRegistry.node, [
+    [ToolOutputStore.node, outputStore],
+    ToolRegistry.codeModeReplacement(codeModeTools),
+  ]),
+)
 const identity = {
   agent: AgentV2.ID.make("build"),
   assistantMessageID: SessionMessage.ID.make("msg_registry"),
@@ -91,6 +96,28 @@ describe("ToolRegistry", () => {
     }),
   )
 
+  codeModeIt.effect("keeps host Code Mode trees immutable while merging deferred tools", () =>
+    Effect.gen(function* () {
+      const service = yield* ToolRegistry.Service
+      yield* service.register({ echo: make() }, { group: "opencode", deferred: true })
+
+      expect((yield* toolDefinitions(service))[0]?.description).toContain("tools.opencode.echo")
+      expect((yield* toolDefinitions(service))[0]?.description).toContain("tools.opencode.echo")
+      expect(
+        yield* executeTool(service, {
+          sessionID,
+          ...identity,
+          call: {
+            type: "tool-call",
+            id: "call-opencode-echo",
+            name: "execute",
+            input: { code: 'return await tools.opencode.echo({ text: "hello" })' },
+          },
+        }),
+      ).toEqual({ type: "text", value: '{\n  "text": "hello"\n}' })
+    }),
+  )
+
   it.effect("filters disabled tools with edit aliases and ordered wildcard precedence", () =>
     Effect.gen(function* () {
       const service = yield* ToolRegistry.Service