fix(util): defer module-scope randomness, I/O, and import.meta paths

packages/app/src/context/server-session-v2-reducer.test.ts

@@ -69,63 +69,6 @@ describe("v2 session reducer", () => {
     })
   })
 
-  test("prefers durable selection predecessors and derives them for older events", () => {
-    const source: SessionMessageInfo[] = [
-      { id: "msg_previous_agent", type: "agent-switched", agent: "build", time: { created: 1 } },
-      {
-        id: "msg_previous_model",
-        type: "model-switched",
-        model: { id: "old", providerID: "provider" },
-        time: { created: 1 },
-      },
-    ]
-    const reducer = createV2SessionReducer()
-
-    const agent = reducer.reduce(
-      source,
-      event({
-        ...base,
-        id: "evt_agent",
-        type: "session.agent.selected",
-        data: { sessionID: "ses_1", agent: "plan", previous: "review" },
-      }),
-    )
-    const model = reducer.reduce(
-      source,
-      event({
-        ...base,
-        id: "evt_model",
-        type: "session.model.selected",
-        data: {
-          sessionID: "ses_1",
-          model: { id: "new", providerID: "provider" },
-          previous: { id: "durable", providerID: "provider" },
-        },
-      }),
-    )
-    const legacyAgent = reducer.reduce(
-      source,
-      event({
-        ...base,
-        id: "evt_legacy_agent",
-        type: "session.agent.selected",
-        data: { sessionID: "ses_1", agent: "plan" },
-      }),
-    )
-
-    expect(agent?.messages.at(-1)).toMatchObject({ type: "agent-switched", agent: "plan", previous: "review" })
-    expect(model?.messages.at(-1)).toMatchObject({
-      type: "model-switched",
-      model: { id: "new" },
-      previous: { id: "durable" },
-    })
-    expect(legacyAgent?.messages.at(-1)).toMatchObject({
-      type: "agent-switched",
-      agent: "plan",
-      previous: "build",
-    })
-  })
-
   test("folds tool, retry, and completion events", () => {
     const reducer = createV2SessionReducer()
     let messages: SessionMessageInfo[] = []

packages/app/src/context/server-session-v2-reducer.ts

@@ -61,12 +61,6 @@ export function createV2SessionReducer() {
           type: "agent-switched",
           metadata: event.metadata,
           agent: event.data.agent,
-          previous:
-            event.data.previous ??
-            source.findLast(
-              (item): item is Extract<SessionMessageInfo, { type: "agent-switched" | "assistant" }> =>
-                item.type === "agent-switched" || item.type === "assistant",
-            )?.agent,
           time: { created: event.created },
         })
       case "session.model.selected":
@@ -75,12 +69,10 @@ export function createV2SessionReducer() {
           type: "model-switched",
           metadata: event.metadata,
           model: event.data.model,
-          previous:
-            event.data.previous ??
-            source.findLast(
-              (item): item is Extract<SessionMessageInfo, { type: "model-switched" | "assistant" }> =>
-                item.type === "model-switched" || item.type === "assistant",
-            )?.model,
+          previous: source.findLast(
+            (item): item is Extract<SessionMessageInfo, { type: "model-switched" | "assistant" }> =>
+              item.type === "model-switched" || item.type === "assistant",
+          )?.model,
           time: { created: event.created },
         })
       case "session.synthetic":

packages/client/src/effect/api/api.ts

@@ -339,11 +339,7 @@ export type Endpoint5_31Output =
           readonly type: "session.agent.selected"
           readonly durable: { readonly aggregateID: string; readonly seq: Event.Seq; readonly version: Event.Version }
           readonly location?: Location.Ref | undefined
-          readonly data: {
-            readonly sessionID: Session.ID
-            readonly agent: Agent.ID
-            readonly previous?: Agent.ID | undefined
-          }
+          readonly data: { readonly sessionID: Session.ID; readonly agent: Agent.ID }
         }
       | {
           readonly id: Event.ID
@@ -352,11 +348,7 @@ export type Endpoint5_31Output =
           readonly type: "session.model.selected"
           readonly durable: { readonly aggregateID: string; readonly seq: Event.Seq; readonly version: Event.Version }
           readonly location?: Location.Ref | undefined
-          readonly data: {
-            readonly sessionID: Session.ID
-            readonly model: Model.Ref
-            readonly previous?: Model.Ref | undefined
-          }
+          readonly data: { readonly sessionID: Session.ID; readonly model: Model.Ref }
         }
       | {
           readonly id: Event.ID

packages/client/src/promise/generated/types.ts

@@ -436,7 +436,7 @@ export type SessionAgentSelected = {
   type: "session.agent.selected"
   durable: { aggregateID: string; seq: number; version: 1 }
   location?: LocationRef
-  data: { sessionID: string; agent: string; previous?: string }
+  data: { sessionID: string; agent: string }
 }
 
 export type SessionModelSelected = {
@@ -446,7 +446,7 @@ export type SessionModelSelected = {
   type: "session.model.selected"
   durable: { aggregateID: string; seq: number; version: 1 }
   location?: LocationRef
-  data: { sessionID: string; model: ModelRef; previous?: ModelRef }
+  data: { sessionID: string; model: ModelRef }
 }
 
 export type SessionMoved = {

packages/core/src/plugin/agent.ts

@@ -101,6 +101,16 @@ export const Plugin = define({
         item.permissions.push({ action: "question", resource: "*", effect: "allow" })
       })
 
+      draft.update(Agent.ID.make("plan"), (item) => {
+        item.name = Agent.Name.make("Plan")
+        item.description = "Plan mode. Disallows all edit tools."
+        item.mode = "primary"
+        item.permissions.push(
+          { action: "question", resource: "*", effect: "allow" },
+          { action: "edit", resource: "*", effect: "deny" },
+        )
+      })
+
       draft.update(Agent.ID.make("general"), (item) => {
         item.name = Agent.Name.make("General")
         item.description =

packages/core/src/plugin/internal.ts

@@ -60,7 +60,6 @@ import { WellKnown } from "../wellknown"
 import { WriteTool } from "../tool/plugin/write"
 import { AgentPlugin } from "./agent"
 import { CommandPlugin } from "./command"
-import { PlanPlugin } from "./plan"
 import { ModelsDevPlugin } from "./models-dev"
 import { ProviderPlugins } from "./provider"
 import { WebSearchPlugins } from "./websearch"
@@ -193,7 +192,6 @@ export type InternalPlugin = Plugin<Requirements | Scope.Scope>
 const pre = [
   WellKnownPlugin.Plugin,
   AgentPlugin.Plugin,
-  PlanPlugin.Plugin,
   CommandPlugin.Plugin,
   SkillPlugin.Plugin,
   ...SystemPromptPlugin.Plugins,

packages/core/src/plugin/models-dev.ts

@@ -36,7 +36,6 @@ export const ModelsDevPlugin = define({
           draft.integrationID = Integration.ID.make(provider.info.id)
         })
         for (const model of provider.models) {
-          if (model.status === "deprecated") continue
           catalog.model.update(provider.info.id, model.id, (draft) => Object.assign(draft, model))
         }
       }

packages/core/src/plugin/plan.ts

@@ -1,55 +0,0 @@
-export * as PlanPlugin from "./plan"
-
-import { ToolFailure } from "@opencode-ai/ai"
-import { define } from "@opencode-ai/plugin/effect/plugin"
-import { Effect, Stream } from "effect"
-import { Agent } from "../agent"
-
-const plan = Agent.ID.make("plan")
-
-const enter = `<system-reminder>
-You are in Plan mode. This is a READ-ONLY environment. You are not allowed to edit files, and you may not ask a subagent to edit them either.
-</system-reminder>`
-
-const leave = `<system-reminder>
-You are no longer in Plan mode. The previous read-only restrictions no longer apply. You may edit files again.
-</system-reminder>`
-
-export const Plugin = define({
-  id: "opencode.plan",
-  effect: Effect.fn(function* (ctx) {
-    yield* ctx.agent.transform((draft) => {
-      draft.update(plan, (item) => {
-        item.name = Agent.Name.make("Plan")
-        item.description = "Read-only agent for exploring the codebase and planning work before implementation."
-        item.mode = "primary"
-        item.permissions.push({ action: "question", resource: "*", effect: "allow" })
-      })
-    })
-
-    yield* ctx.tool.hook("execute.before", (event) => {
-      if (event.agent !== plan) return Effect.void
-      if (event.tool !== "edit" && event.tool !== "write" && event.tool !== "patch") return Effect.void
-      return new ToolFailure({
-        message: `Cannot use ${event.tool} in Plan mode. You are in a read-only mode and must not modify files.`,
-      })
-    })
-
-    yield* ctx.event.subscribe().pipe(
-      Stream.filter((event) => event.type === "session.agent.selected"),
-      Stream.runForEach((event) => {
-        if (event.data.agent === event.data.previous) return Effect.void
-        const text = event.data.agent === plan ? enter : event.data.previous === plan ? leave : undefined
-        if (!text) return Effect.void
-        return ctx.session
-          .synthetic({
-            sessionID: event.data.sessionID,
-            text,
-            resume: false,
-          })
-          .pipe(Effect.catch(() => Effect.void))
-      }),
-      Effect.forkScoped({ startImmediately: true }),
-    )
-  }),
-})

packages/core/src/session.ts

@@ -716,11 +716,10 @@ const layer = Layer.effect(
             .pipe(Effect.ignore, Effect.forkIn(scope, { startImmediately: true }), Effect.asVoid)
       }),
       switchAgent: Effect.fn("Session.switchAgent")(function* (input) {
-        const session = yield* result.get(input.sessionID)
+        yield* result.get(input.sessionID)
         yield* bus.publish(SessionEvent.AgentSelected, {
           sessionID: input.sessionID,
           agent: input.agent,
-          previous: session.agent,
         })
       }),
       switchModel: Effect.fn("Session.switchModel")(function* (input) {
@@ -734,7 +733,6 @@ const layer = Layer.effect(
         yield* bus.publish(SessionEvent.ModelSelected, {
           sessionID: input.sessionID,
           model: input.model,
-          previous: session.model,
         })
       }),
       rename: Effect.fn("Session.rename")(function* (input) {

packages/core/src/session/message-updater.ts

@@ -61,7 +61,7 @@ export function update(adapter: Adapter, event: SessionEvent.DurableEvent) {
       "session.usage.recorded": () => Effect.void,
       "session.agent.selected": (event) => {
         return Effect.gen(function* () {
-          const previous = event.data.previous ?? (yield* adapter.getAgent())
+          const previous = yield* adapter.getAgent()
           yield* adapter.appendMessage(
             SessionMessage.AgentSelected.make({
               id: SessionMessage.ID.fromEvent(event.id),
@@ -76,7 +76,7 @@ export function update(adapter: Adapter, event: SessionEvent.DurableEvent) {
       },
       "session.model.selected": (event) => {
         return Effect.gen(function* () {
-          const previous = event.data.previous ?? (yield* adapter.getModel())
+          const previous = yield* adapter.getModel()
           yield* adapter.appendMessage(
             SessionMessage.ModelSelected.make({
               id: SessionMessage.ID.fromEvent(event.id),

packages/core/test/agent.test.ts

@@ -165,6 +165,7 @@ describe("Agent", () => {
         "compaction",
         "explore",
         "general",
+        "plan",
         "summary",
         "title",
       ])

packages/core/test/plugin/models-dev.test.ts

@@ -215,66 +215,6 @@ describe("ModelsDevPlugin", () => {
     }),
   )
 
-  it.effect("omits deprecated models from the catalog", () =>
-    Effect.gen(function* () {
-      const integrations = yield* Integration.Service
-      const catalog = yield* Catalog.Service
-      const providerID = Provider.ID.make("acme")
-      const activeID = Model.ID.make("current")
-      const deprecatedID = Model.ID.make("legacy")
-      const model = {
-        modelID: activeID,
-        providerID,
-        name: "Current",
-        capabilities: { tools: true, input: [], output: [] },
-        variants: [],
-        time: { released: Date.parse("2026-01-01") },
-        cost: [],
-        status: "active",
-        enabled: true,
-        limit: { context: 128_000, output: 32_000 },
-      } satisfies Omit<Model.Info, "id">
-      const snapshots = [
-        {
-          info: {
-            id: providerID,
-            name: "Acme",
-            package: Provider.aisdk("@ai-sdk/openai-compatible"),
-          },
-          environment: [],
-          models: [
-            { id: activeID, ...model },
-            {
-              id: deprecatedID,
-              ...model,
-              modelID: deprecatedID,
-              name: "Legacy",
-              status: "deprecated" as const,
-            },
-          ],
-        },
-      ] satisfies readonly ModelsDev.Snapshot[]
-
-      yield* ModelsDevPlugin.effect(
-        host({
-          catalog: catalogHost(catalog),
-          integration: integrationHost(integrations),
-        }),
-      ).pipe(
-        Effect.provideService(
-          ModelsDev.Service,
-          ModelsDev.Service.of({
-            get: () => Effect.succeed(snapshots),
-            refresh: () => Effect.void,
-          }),
-        ),
-      )
-
-      expect(yield* catalog.model.get(providerID, activeID)).toBeDefined()
-      expect(yield* catalog.model.get(providerID, deprecatedID)).toBeUndefined()
-    }),
-  )
-
   it.effect("registers key methods for providers with environment variables", () =>
     Effect.gen(function* () {
       const integrations = yield* Integration.Service

packages/core/test/session-create.test.ts

@@ -654,7 +654,7 @@ describe("Session.create", () => {
       expect(yield* session.get(created.id)).toMatchObject({ agent: "plan" })
       expect(
         Array.from(yield* logEvents(session, created.id, true).pipe(Stream.drop(1), Stream.take(1), Stream.runCollect)),
-      ).toMatchObject([{ type: "session.agent.selected", data: { agent: "plan", previous: "build" } }])
+      ).toMatchObject([{ type: "session.agent.selected", data: { agent: "plan" } }])
       expect(yield* session.messages({ sessionID: created.id, order: "asc" })).toMatchObject([
         { type: "agent-switched", agent: "plan", previous: "build" },
       ])
@@ -678,12 +678,7 @@ describe("Session.create", () => {
   it.effect("switches the selected model through the durable Session event", () =>
     Effect.gen(function* () {
       const session = yield* Session.Service
-      const previous = Model.Ref.make({
-        id: Model.ID.make("haiku"),
-        providerID: Provider.ID.anthropic,
-        variant: Model.VariantID.make("default"),
-      })
-      const created = yield* session.create({ location, model: previous })
+      const created = yield* session.create({ location })
       const model = Model.Ref.make({
         id: Model.ID.make("sonnet"),
         providerID: Provider.ID.anthropic,
@@ -697,10 +692,7 @@ describe("Session.create", () => {
         yield* logEvents(session, created.id, true).pipe(Stream.drop(1), Stream.take(1), Stream.runCollect),
       )
       expect(bus).toMatchObject([{ type: "session.model.selected" }])
-      expect(bus[0]?.data).toEqual({ sessionID: created.id, model, previous })
-      expect(yield* session.messages({ sessionID: created.id, order: "asc" })).toMatchObject([
-        { type: "model-switched", model, previous },
-      ])
+      expect(bus[0]?.data).toEqual({ sessionID: created.id, model })
     }),
   )
 

packages/protocol/openapi.json

@@ -14300,15 +14300,9 @@
               "agent": {
                 "type": "string"
               },
-              "previous": {
-                "type": "string"
-              },
               "model": {
                 "$ref": "#/components/schemas/Model.Ref"
               },
-              "previous": {
-                "$ref": "#/components/schemas/Model.Ref"
-              },
               "version": {
                 "type": "string"
               }

packages/schema/src/session-event.ts

@@ -69,7 +69,6 @@ export const AgentSelected = Event.durable({
   schema: {
     ...Base,
     agent: Agent.ID,
-    previous: Agent.ID.pipe(optional),
   },
 })
 export type AgentSelected = typeof AgentSelected.Type
@@ -80,7 +79,6 @@ export const ModelSelected = Event.durable({
   schema: {
     ...Base,
     model: Model.Ref,
-    previous: Model.Ref.pipe(optional),
   },
 })
 export type ModelSelected = typeof ModelSelected.Type

packages/util/src/npm-config.ts

@@ -7,13 +7,15 @@ import Config from "@npmcli/config"
 import { definitions, flatten, nerfDarts, shorthands } from "@npmcli/config/lib/definitions/index.js"
 import { Effect } from "effect"
 
-const npmPath = fileURLToPath(new URL("..", import.meta.url))
+// Lazy: on workerd import.meta.url is undefined and constructing a URL from it
+// at module scope fails startup validation; npm config is never used there.
+const npmPath = () => fileURLToPath(new URL("..", import.meta.url))
 
 export const load = (dir: string) =>
   Effect.tryPromise({
     try: async () => {
       const config = new Config({
-        npmPath,
+        npmPath: npmPath(),
         cwd: dir,
         env: { ...process.env },
         argv: [process.execPath, process.execPath, "--prefix", dir],

packages/util/src/observability.ts

@@ -1,6 +1,6 @@
 export * as Observability from "./observability.js"
 
-import { NodeFileSystem } from "@effect/platform-node"
+import * as NodeFileSystem from "@effect/platform-node/NodeFileSystem"
 import { LayerNode } from "./effect/layer-node.js"
 import { Effect, Layer, Logger, References, Schema } from "effect"
 import { FetchHttpClient } from "effect/unstable/http"
@@ -50,4 +50,10 @@ export function layer(
   ).pipe(Layer.catchCause(() => local))
 }
 
-export const node = LayerNode.make({ name: "observability", layer: layer(), deps: [] })
+// Layer.suspend: constructing the loggers eagerly at module scope performs
+// I/O (file logger, run id) that workerd forbids in global scope.
+export const node = LayerNode.make({
+  name: "observability",
+  layer: Layer.suspend(() => layer()),
+  deps: [],
+})

packages/util/src/observability/logging.ts

@@ -3,7 +3,7 @@ import path from "path"
 import { Global } from "../global.js"
 import { runID } from "./shared.js"
 
-function formatter(id: string = runID) {
+function formatter(id: string = runID()) {
   return Logger.map(Logger.formatStructured, (output) => {
     const messages = Array.isArray(output.message) ? output.message : [output.message]
     return [
@@ -51,7 +51,7 @@ export function file(local = true, channel = "local") {
   return path.join(Global.Path.log, `opencode-${channel.replace(/[^a-zA-Z0-9._-]/g, "-")}.log`)
 }
 
-export function fileLogger(target = file(), id: string = runID) {
+export function fileLogger(target = file(), id: string = runID()) {
   // Do not set batchWindow to 0; it causes high idle CPU usage.
   return Effect.gen(function* () {
     const fs = yield* FileSystem.FileSystem

packages/util/src/observability/otlp.ts

@@ -54,8 +54,8 @@ export function resource(app: App = { client: "opencode", version: "unknown", ch
       ...resourceAttributes(),
       "deployment.environment.name": app.channel,
       "opencode.client": app.client,
-      "opencode.run": runID,
-      "service.instance.id": runID,
+      "opencode.run": runID(),
+      "service.instance.id": runID(),
     },
   }
 }

packages/util/src/observability/shared.ts

@@ -1 +1,8 @@
-export const runID = crypto.randomUUID().slice(0, 8)
+// Lazy: workerd forbids generating random values in global scope, so the id
+// materializes on first call (inside a handler) and stays stable afterwards.
+let generated: string | undefined
+
+export function runID(): string {
+  generated ??= crypto.randomUUID().slice(0, 8)
+  return generated
+}

packages/www/openapi.json

@@ -14300,15 +14300,9 @@
               "agent": {
                 "type": "string"
               },
-              "previous": {
-                "type": "string"
-              },
               "model": {
                 "$ref": "#/components/schemas/Model.Ref"
               },
-              "previous": {
-                "$ref": "#/components/schemas/Model.Ref"
-              },
               "version": {
                 "type": "string"
               }

packages/www/public/openapi.json

@@ -14300,15 +14300,9 @@
               "agent": {
                 "type": "string"
               },
-              "previous": {
-                "type": "string"
-              },
               "model": {
                 "$ref": "#/components/schemas/Model.Ref"
               },
-              "previous": {
-                "$ref": "#/components/schemas/Model.Ref"
-              },
               "version": {
                 "type": "string"
               }