refactor(core): tighten subagent model input wording

bun.lock

@@ -353,7 +353,6 @@
         "@ff-labs/fff-node": "0.10.5",
         "@lydell/node-pty": "catalog:",
         "@modelcontextprotocol/client": "2.0.0",
-        "@modelcontextprotocol/core": "2.0.0",
         "@opencode-ai/pty": "0.1.13",
         "@opencode/ai": "workspace:*",
         "@opencode/codemode": "workspace:*",

nix/hashes.json

@@ -1,8 +1,8 @@
 {
   "nodeModules": {
-    "x86_64-linux": "sha256-U9IuP/ev6w4urvogOwQyl3rdumY6W4YaY18NkFaOVHU=",
-    "aarch64-linux": "sha256-Wc8OT2DRZpVo56KaoGE0Hsj1NDknakbWXO9w2qy6j+0=",
-    "aarch64-darwin": "sha256-wAea8+jajnMDxZ6XJL+Hsrf0621hwtBtWyD1+dS45dE=",
-    "x86_64-darwin": "sha256-g8PCNBSV6rO+VQjKU9AtYqj+r18o+fhLDXEQq+X2EZ4="
+    "x86_64-linux": "sha256-E5T4o3wNivOg8q4wRV7yE4CUNaUq4QNPxZsnvLaGUcg=",
+    "aarch64-linux": "sha256-xQQi7LgxInZQVCznASfa0Pm+cNGBo5j4Tfp0E/bKnNw=",
+    "aarch64-darwin": "sha256-qxb371dCf7WG09VvQE+HZ/x3EURpFIr11bdnQwGTHhw=",
+    "x86_64-darwin": "sha256-xi1qiYr41hzbgAQl+I3xdtnkiPx2SIcA/0OMpN78qXw="
   }
 }

packages/app/e2e/regression/session-summary.spec.ts

@@ -23,7 +23,6 @@ for (const custom of [false, true]) {
     await page.goto(stressSessionHref(fixture.sourceID))
     const trigger = page.getByRole("button", { name: "Session details", exact: true })
     const summary = page.getByRole("dialog", { name: "Session details", exact: true })
-    await expect(page.locator('[data-component="composer-editor"]')).toBeEditable()
     await expect(trigger).toBeEnabled()
     await trigger.hover()
     const tooltip = page.getByRole("tooltip")

packages/app/e2e/regression/terminal-hidden.spec.ts

@@ -278,11 +278,7 @@ async function installMotionProbe(page: Page) {
           probe.resetAnchorOnMotion = false
         }
         probe.terminalAnchorGaps.push(anchorGap)
-        if (
-          panelGap &&
-          reviewRegion.getBoundingClientRect().height > 1 &&
-          terminalRegion.getBoundingClientRect().height > 1
-        )
+        if (panelGap && terminalRegion.getBoundingClientRect().height > 1)
           probe.panelGaps.push(panelGap.getBoundingClientRect().height)
         if (!review) return
         probe.paintGaps.push({

packages/cli/script/service-smoke.ts

@@ -33,7 +33,7 @@ const processes: Array<ReturnType<typeof Bun.spawn>> = []
 const errors: Array<Promise<string>> = []
 let failure: unknown
 try {
-  await fs.mkdir(path.join(root, ".opencode", "plugins"), { recursive: true })
+  await fs.mkdir(path.join(root, ".opencode"))
   spawnService()
   spawnService()
   const registration = await waitForRegistration()
@@ -54,6 +54,7 @@ try {
   if (tokenOpenApi.status !== 200) throw new Error("Compiled application rejected query authentication")
   if ((await pluginIDs(info.url, headers)).includes("smoke")) throw new Error("Smoke plugin existed before creation")
   const plugin = path.join(root, ".opencode", "plugins", "smoke.ts")
+  await fs.mkdir(path.dirname(plugin), { recursive: true })
   await fs.writeFile(plugin, pluginSource())
   await waitForPlugin(info.url, headers)
 

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

@@ -1342,7 +1342,6 @@ export type ModelCompatibility = {
   maxTokensField?: ModelMaxTokensField
   requireFinishReason?: boolean
   requireAssistantAfterTool?: boolean
-  supportsPromptCacheKey?: boolean
 }
 
 export type ProviderInfo = {
@@ -2012,7 +2011,6 @@ export type ConfigEntry =
                         scope?: string
                         callback_port?: number
                         redirect_uri?: string
-                        auth_server_metadata_url?: string
                       }
                     | false
                   disabled?: boolean
@@ -4668,7 +4666,6 @@ export type McpAddInput = {
                 readonly scope?: string
                 readonly callback_port?: number
                 readonly redirect_uri?: string
-                readonly auth_server_metadata_url?: string
               }
             | false
           readonly disabled?: boolean

packages/codemode/interpreter-support.md

@@ -22,7 +22,7 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] The host boundary is `JSON.stringify` plus a short table. The program result and tool arguments cross as
       what `JSON.stringify` would serialize: `toJSON` is honored, functions and `undefined` properties vanish,
       `undefined` array elements and non-finite numbers become `null`, a cyclic value throws the same `TypeError`,
-      and Map, RegExp, and generators serialize as `{}`. A bare `undefined` result is `null`.
+      and Map, RegExp, generators, and extension handles serialize as `{}`. A bare `undefined` result is `null`.
       Tool results come back the way `JSON.parse(JSON.stringify(result))` would. The table, where a value cannot
       be JSON but what the program meant is clear: a promise is awaited (a rejection fails the program), a Set
       crosses as an array, a URLSearchParams as its query string, an Error as `{ name, message, ...own }`, a
@@ -192,7 +192,7 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
 - [x] Prefix and postfix `++` and `--`.
 - [x] Plain, arithmetic, bitwise, and logical assignment operators.
 - [x] Property deletion on plain data objects and arrays, including computed and optional forms; deleting an array index
-      creates a hole without changing its length. Deleting a non-configurable property (`length`) or
+      creates a hole without changing its length. Deleting a non-configurable property (`length`, `lastIndex`) or
       assigning a read-only one (`Math.PI`, `fn.name`) throws a `TypeError`, as in strict mode.
 - [ ] Operators, `switch` discriminants, template interpolation, and coercion helpers such as `String` and `isNaN`
       applied to functions and namespaces; JavaScript coerces them, the interpreter rejects non-data operands.
@@ -394,9 +394,7 @@ ultimate source of truth. Upstream test262 files run verbatim from `test/test262
       `unicodeSets`, and `dotAll`.
 - [x] Captures, named groups, match `.index` and `.input`, and stateful global matching.
 - [x] Integration with supported String methods, including function replacers.
-- [x] Writable `lastIndex`, shared by `exec`, `test`, and the String methods. It is a prototype accessor that stores
-      a number, so `re.lastIndex = "12"` reads back `12`, `delete` is a no-op, and `hasOwnProperty("lastIndex")` is
-      `false`.
+- [x] Writable `lastIndex`.
 - [x] Match `indices` metadata for the `d` flag, including named groups on `exec`, `match`, and `matchAll` results.
 - [x] `RegExp.escape`.
 
@@ -454,25 +452,29 @@ with a hint to encode as text first (`TextDecoder`, `toBase64`, `toHex`).
 
 ## Extensions
 
-Host functions a host opts in through `Extension.make({ name, globals })` and `CodeMode.make({ extensions })`.
+Host classes and functions a host opts in through `Extension.make({ name, globals })` and `CodeMode.make({ extensions })`.
 Nothing is exposed unless a host provides it; extension calls are not tool calls.
 
-- [x] Each global is a function, callable but not constructible, run with `this` undefined. A global that shadows
-      a built-in or another extension throws at `make`.
+- [x] Each global is a class or a function, exposed as-is: constructors with `new`, prototype methods, accessors,
+      and statics (including through an exposed subclass, so `new this()` works), plus inheritance
+      up to the nearest exposed ancestor. A global that shadows a built-in or another extension throws at `make`.
+- [x] Instances of exposed classes stay on the host; the program holds a handle whose only members are the class's.
+      The same host instance is always the same handle within a run, so identity and `instanceof` hold. A handle
+      serializes as `{}` like any object without enumerable properties, so the host object never crosses.
 - [x] Every value crossing in either direction is converted, never shared: plain objects and arrays are copied,
       `Date`, `RegExp`, `URL`, `URLSearchParams`, `Map`, `Set`, and `Uint8Array` become fresh copies with their
       contents converted (a host `ArrayBuffer` comes in as a `Uint8Array`; other typed arrays cannot come out),
       errors cross as errors with their name and message, and a `__proto__` key is dropped. Functions, generators,
-      un-awaited promises, and symbols cannot be passed in; a class instance, a symbol, or a BigInt cannot come out.
-- [x] A host function inside a result becomes a program function whose calls cross the same way, so a result can
-      carry methods (`res.json()`) whose host closures keep the host state. Diagnostics name it by its path
-      (`fetch.json`). Like any program function it vanishes at the data boundary.
+      un-awaited promises, and symbols cannot be passed in; an instance of an unexposed class, a symbol, or a BigInt
+      cannot come out.
 - [x] A host `Promise` becomes a program promise. Whatever host code returns, resolves, throws, or rejects with
       crosses the same way, so `catch (e)` receives a copy of the thrown value (an `Error` of the matching type, or
-      plain data).
+      plain data). A getter must be synchronous.
+- [x] A prototype member runs only with a handle of its own class as `this`; a detached call, a plain object, or a
+      handle of another class throws `TypeError: Illegal invocation`. Program edits to an exposed prototype affect
+      that run only. Data properties on a class or prototype are not exposed, since a program write would change the
+      host class itself; expose one through an accessor.
 - [ ] Program functions as arguments to extension code (callbacks such as `forEach`).
-- [ ] Host classes. Stateful host objects are expressed as closures; a declared method table would be the next
-      step if `new X()` in a program is ever needed.
 
 ## Errors and diagnostics
 

packages/codemode/src/codemode.ts

@@ -37,7 +37,7 @@ export type ResolvedExecutionLimits = {
 export type Options<Provided extends Record<string, unknown> = {}> = ToolRuntime.ToolCallHooks<Services<Provided>> & {
   /** Explicit tools exposed to the program as `tools`. */
   tools?: Provided & Tools<Services<Provided>>
-  /** Host functions exposed as globals; see `Extension.make`. */
+  /** Host classes and functions exposed as globals; see `Extension.make`. */
   extensions?: ReadonlyArray<Extension>
   /** Resource limits enforced on each execution. */
   limits?: ExecutionLimits

packages/codemode/src/extension.ts

@@ -1,19 +1,20 @@
 export * as Extension from "./extension.js"
 
 /**
- * Host functions a program calls directly as globals. Values crossing in either direction are converted, never
- * shared: arguments come in as copies, results go out as copies, and a function inside a result is callable the
- * same way. Extension calls are not tool calls.
+ * Host classes and functions a program uses directly, like JavaScript. Values crossing in either direction are
+ * converted, never shared: plain data is copied, instances of the classes stay on the host behind program-side
+ * handles. Extension calls are not tool calls.
  */
 export type Extension = {
   readonly name: string
+  /** Each value is a class or a function; everything on a class is exposed, including statics and accessors. */
   readonly globals: Readonly<Record<string, Function>>
 }
 
 export const make = (options: Extension): Extension => {
   for (const [name, value] of Object.entries(options.globals)) {
     if (typeof value !== "function") {
-      throw new TypeError(`Extension "${options.name}" global "${name}" must be a function.`)
+      throw new TypeError(`Extension "${options.name}" global "${name}" must be a class or a function.`)
     }
   }
   return { name: options.name, globals: { ...options.globals } }

packages/codemode/src/interpreter/extensions.ts

@@ -5,18 +5,21 @@ import type { Interpreter } from "./interpreter.js"
 import { createErrorValue, isErrorType } from "./intrinsics.js"
 import { MAX_VALUE_DEPTH } from "./limits.js"
 import { Throw, typeError } from "./model.js"
-import { fn } from "./native.js"
+import { constructor, fn } from "./native.js"
 import {
   Callable,
   define,
+  defineAccessor,
   entries,
   get,
+  hidden,
   type Native,
   Arr,
   Bytes,
   DateObj,
   ErrorObj,
   GeneratorObj,
+  Handle,
   MapObj,
   Obj,
   PromiseObj,
@@ -27,16 +30,31 @@ import {
 } from "./objects.js"
 import { describeValue } from "./references.js"
 
+type Class = Function & { readonly prototype: object }
+
+const isClass = (value: unknown): value is Class =>
+  typeof value === "function" && typeof value.prototype === "object" && value.prototype !== null
+
+// Own keys the native function already carries.
+const ownFunctionKeys = new Set(["length", "name", "prototype"])
+const ownPrototypeKeys = new Set(["constructor"])
+
 /**
- * The global bindings of one run's extensions. Everything crossing the boundary is converted: plain data and
- * built-in wrappers are copied, a host function becomes a program function whose calls cross the same way, and a
- * host Promise becomes a program promise.
+ * The global bindings of one run's extensions. Everything crossing the boundary is converted: plain data is
+ * copied, built-in wrappers are copied, instances of exposed classes travel as handles, and a host Promise becomes
+ * a program promise. Prototypes, constructors, and handle identity are all per run.
  */
 export const extensionGlobals = <R>(
   ctx: Interpreter<R>,
   extensions: ReadonlyArray<Extension>,
 ): ReadonlyArray<readonly [string, unknown]> => {
   const builtins = ctx.builtins
+  const classes = new Set(extensions.flatMap((extension) => Object.values(extension.globals)).filter(isClass))
+  // Host prototype object → this run's program prototype, so an instance wraps as its most-derived exposed class.
+  const protoOf = new Map<object, Obj>()
+  const exposed = new Map<Class, { ctor: Native<R>; proto: Obj }>()
+  const classOf = new Map<unknown, Class>()
+  const handles = new WeakMap<object, Handle>()
 
   const toHost = (value: unknown, label: string, depth = 0, seen = new Set<object>()): unknown => {
     if (depth > MAX_VALUE_DEPTH) throw typeError(`${label} exceeds the maximum value depth of ${MAX_VALUE_DEPTH}.`)
@@ -44,6 +62,7 @@ export const extensionGlobals = <R>(
       if (isPrimitive(value)) return value
       throw typeError(`${label} contains ${describeValue(value)}, which cannot be passed to an extension.`)
     }
+    if (value instanceof Handle) return value.instance
     if (value instanceof Bytes) return new Uint8Array(value.bytes)
     if (value instanceof DateObj) return new Date(value.time)
     if (value instanceof RegExpObj) return new RegExp(value.regex.source, value.regex.flags)
@@ -64,7 +83,7 @@ export const extensionGlobals = <R>(
       const name = coerceToString(get(value, "name"))
       const message = get(value, "message")
       const text = message === undefined ? "" : coerceToString(message)
-      return name === "AggregateError" ? new AggregateError([], text) : new (hostErrors.get(name) ?? Error)(text)
+      return name === "AggregateError" ? new AggregateError([], text) : new (hostErrors[name] ?? Error)(text)
     }
     if (seen.has(value)) throw typeError(`${label} contains a circular value.`)
     seen.add(value)
@@ -83,8 +102,15 @@ export const extensionGlobals = <R>(
   const fromHost = (value: unknown, label: string, depth = 0, seen = new Set<object>()): unknown => {
     if (depth > MAX_VALUE_DEPTH) throw typeError(`${label} exceeds the maximum value depth of ${MAX_VALUE_DEPTH}.`)
     if (isPrimitive(value)) return value
-    if (typeof value === "function") return wrap(value, label)
     if (value !== null && typeof value === "object") {
+      const existing = handles.get(value)
+      if (existing !== undefined) return existing
+      const proto = handlePrototype(value)
+      if (proto !== undefined) {
+        const handle = new Handle(proto, value)
+        handles.set(value, handle)
+        return handle
+      }
       if (value instanceof Date) return new DateObj(builtins.Date, value.getTime())
       if (value instanceof RegExp) return new RegExpObj(builtins.RegExp, value.source, value.flags)
       if (value instanceof Uint8Array) return new Bytes(builtins.Uint8Array, new Uint8Array(value))
@@ -96,31 +122,28 @@ export const extensionGlobals = <R>(
       if (value instanceof URLSearchParams) {
         return new URLSearchParamsObj(builtins.URLSearchParams, new URLSearchParams(value))
       }
-      const next = (item: unknown, path: string) => fromHost(item, path, depth + 1, seen)
+      const next = (item: unknown) => fromHost(item, label, depth + 1, seen)
       if (value instanceof Map) {
         const wrapped = new MapObj(builtins.Map)
-        for (const [key, item] of value) wrapped.map.set(next(key, label), next(item, label))
+        for (const [key, item] of value) wrapped.map.set(next(key), next(item))
         return wrapped
       }
       if (value instanceof Set) {
         const wrapped = new SetObj(builtins.Set)
-        for (const item of value) wrapped.set.add(next(item, label))
+        for (const item of value) wrapped.set.add(next(item))
         return wrapped
       }
       if (seen.has(value)) throw typeError(`${label} produced a circular value.`)
       seen.add(value)
       if (Array.isArray(value)) {
-        const copied = new Arr(
-          builtins.Array,
-          value.map((item, index) => next(item, `${label}[${index}]`)),
-        )
+        const copied = new Arr(builtins.Array, value.map(next))
         seen.delete(value)
         return copied
       }
       const prototype = Object.getPrototypeOf(value)
       if (prototype === Object.prototype || prototype === null) {
         const copied = new Obj(builtins.Object)
-        for (const [key, item] of Object.entries(value)) define(copied, key, next(item, `${label}.${key}`))
+        for (const [key, item] of Object.entries(value)) define(copied, key, next(item))
         seen.delete(value)
         return copied
       }
@@ -128,37 +151,153 @@ export const extensionGlobals = <R>(
     throw typeError(`${label} produced ${describeHost(value)}, which the program cannot hold.`)
   }
 
-  // A host function as a program function: arguments cross in, and whatever it returns, resolves, throws, or
-  // rejects with crosses out, so the program catches what the author threw.
-  const wrap = (value: Function, label: string): Native<R> =>
-    fn<R>(builtins, value.name, value.length, (_, values) => {
-      const converted = values.map((item, index) => toHost(item, `Argument ${index + 1} to ${label}`))
-      const thrown = (reason: unknown) => new Throw(fromHost(reason, label))
-      let result: unknown
-      try {
-        result = value.apply(undefined, converted)
-      } catch (reason) {
-        return Effect.fail(thrown(reason))
+  const handlePrototype = (instance: object): Obj | undefined => {
+    for (let level = Object.getPrototypeOf(instance); level !== null; level = Object.getPrototypeOf(level)) {
+      const proto = protoOf.get(level)
+      if (proto !== undefined) return proto
+    }
+    return undefined
+  }
+
+  // Runs host code with already-converted inputs. Whatever it returns, resolves, throws, or rejects with crosses
+  // the same way, so the program catches what the author threw.
+  const invoke = (run: () => unknown, label: string): Effect.Effect<unknown, unknown, R> => {
+    const thrown = (reason: unknown) => new Throw(fromHost(reason, label))
+    let result: unknown
+    try {
+      result = run()
+    } catch (reason) {
+      return Effect.fail(thrown(reason))
+    }
+    if (!(result instanceof Promise)) return Effect.succeed(fromHost(result, label))
+    return ctx.pending.create(
+      Effect.map(Effect.tryPromise({ try: () => result, catch: thrown }), (settled) => fromHost(settled, label)),
+    )
+  }
+
+  const args = (values: Array<unknown>, label: string): Array<unknown> =>
+    values.map((value, index) => toHost(value, `Argument ${index + 1} to ${label}`))
+
+  // Own members of each level from `from` up to (excluding) `root`, child first, as JS resolves them.
+  const members = (
+    target: Obj,
+    from: object,
+    root: object,
+    skip: ReadonlySet<string>,
+    label: string,
+    receiver: (thisValue: unknown, member: string) => unknown,
+  ): void => {
+    for (let level: object | null = from; level !== null && level !== root; level = Object.getPrototypeOf(level)) {
+      for (const [key, descriptor] of Object.entries(Object.getOwnPropertyDescriptors(level))) {
+        if (skip.has(key) || target.props.has(key)) continue
+        const name = `${label}.${key}`
+        if (typeof descriptor.value === "function") {
+          const method: Function = descriptor.value
+          const impl = (thisValue: unknown, values: Array<unknown>) => {
+            const self = receiver(thisValue, name)
+            const converted = args(values, name)
+            return invoke(() => method.apply(self, converted), name)
+          }
+          define(target, key, fn<R>(builtins, key, method.length, impl), hidden)
+          continue
+        }
+        // Data properties stay host-side: a program write to one would change the host class itself.
+        if ("value" in descriptor) continue
+        const get = descriptor.get
+        const set = descriptor.set
+        defineAccessor(
+          target,
+          key,
+          get === undefined
+            ? undefined
+            : (thisValue) => {
+                const value = get.call(receiver(thisValue, name))
+                if (value instanceof Promise)
+                  throw typeError(`${name} returned a Promise; a getter must be synchronous.`)
+                return fromHost(value, name)
+              },
+          set === undefined
+            ? undefined
+            : (thisValue, value) => {
+                set.call(receiver(thisValue, name), toHost(value, `${name} value`))
+              },
+        )
       }
-      if (!(result instanceof Promise)) return fromHost(result, label)
-      return ctx.pending.create(
-        Effect.map(Effect.tryPromise({ try: () => result, catch: thrown }), (settled) => fromHost(settled, label)),
-      )
+    }
+  }
+
+  const expose = (cls: Class): { ctor: Native<R>; proto: Obj } => {
+    const existing = exposed.get(cls)
+    if (existing !== undefined) return existing
+    const ancestor = exposedAncestor(cls)
+    const base = ancestor === undefined ? undefined : expose(ancestor)
+    const proto = new Obj(base === undefined ? builtins.Object : base.proto)
+    protoOf.set(cls.prototype, proto)
+    const name = cls.name
+    const ctor = constructor<R>(builtins, proto, {
+      name,
+      length: cls.length,
+      call: (_, values) => {
+        const converted = args(values, name)
+        return invoke(() => cls.apply(undefined, converted), name)
+      },
+      construct: (values) => {
+        const label = `new ${name}`
+        const construct = cls as new (...values: Array<unknown>) => object
+        const converted = args(values, label)
+        return invoke(() => new construct(...converted), label)
+      },
     })
+    if (base !== undefined) ctor.proto = base.ctor
+    const entry = { ctor, proto }
+    exposed.set(cls, entry)
+    classOf.set(ctor, cls)
+    // A static called through an exposed subclass sees that subclass as `this`, like JS.
+    members(ctor, cls, ancestor ?? Function.prototype, ownFunctionKeys, name, (thisValue) => {
+      const called = classOf.get(thisValue)
+      return called !== undefined && (called === cls || called.prototype instanceof cls) ? called : cls
+    })
+    members(
+      proto,
+      cls.prototype,
+      ancestor?.prototype ?? Object.prototype,
+      ownPrototypeKeys,
+      `${name}.prototype`,
+      (thisValue, member) => {
+        if (thisValue instanceof Handle && thisValue.instance instanceof cls) return thisValue.instance
+        throw typeError(`Illegal invocation: ${member} called on ${describeValue(thisValue)}.`)
+      },
+    )
+    return entry
+  }
+
+  const exposedAncestor = (cls: Class): Class | undefined => {
+    for (let level = Object.getPrototypeOf(cls); isClass(level); level = Object.getPrototypeOf(level)) {
+      if (classes.has(level)) return level
+    }
+    return undefined
+  }
 
   return extensions.flatMap((extension) =>
-    Object.entries(extension.globals).map(([name, value]) => [name, wrap(value, name)] as const),
+    Object.entries(extension.globals).map(([name, value]) => {
+      if (isClass(value)) return [name, expose(value).ctor] as const
+      const impl = (_: unknown, values: Array<unknown>) => {
+        const converted = args(values, name)
+        return invoke(() => value.apply(undefined, converted), name)
+      }
+      return [name, fn<R>(builtins, name, value.length, impl)] as const
+    }),
   )
 }
 
-const hostErrors = new Map<string, ErrorConstructor>([
-  ["TypeError", TypeError],
-  ["RangeError", RangeError],
-  ["SyntaxError", SyntaxError],
-  ["ReferenceError", ReferenceError],
-  ["EvalError", EvalError],
-  ["URIError", URIError],
-])
+const hostErrors: Record<string, ErrorConstructor | undefined> = {
+  TypeError,
+  RangeError,
+  SyntaxError,
+  ReferenceError,
+  EvalError,
+  URIError,
+}
 
 // The primitives the interpreter operates on; symbols and BigInts are not among them.
 const isPrimitive = (value: unknown): boolean =>
@@ -169,6 +308,7 @@ const isPrimitive = (value: unknown): boolean =>
   typeof value === "boolean"
 
 const describeHost = (value: unknown): string => {
+  if (typeof value === "function") return "a function"
   if (typeof value !== "object" || value === null) return `a ${typeof value}`
   const name = (value as { constructor?: { name?: string } }).constructor?.name
   return name === undefined || name === "" ? "an object" : `a ${name}`

packages/codemode/src/interpreter/objects.ts

@@ -136,6 +136,7 @@ export class RegExpObj extends Obj {
   constructor(proto: Obj, pattern: string, flags: string) {
     super(proto)
     this.regex = new RegExp(pattern, flags)
+    define(this, "lastIndex", 0, { writable: true, enumerable: false, configurable: false })
   }
 }
 
@@ -178,6 +179,16 @@ export class Bytes extends Obj {
   }
 }
 
+/** An instance of an extension class: the host object lives in a field no property path reaches. */
+export class Handle extends Obj {
+  constructor(
+    proto: Obj,
+    readonly instance: object,
+  ) {
+    super(proto)
+  }
+}
+
 /** Built-in objects that wrap a host value; data-like, but never plain data. */
 export const isWrapper = (
   value: unknown,

packages/codemode/src/interpreter/references.ts

@@ -9,6 +9,7 @@ import {
   Bytes,
   DateObj,
   GeneratorObj,
+  Handle,
   MapObj,
   Obj,
   PromiseObj,
@@ -22,6 +23,7 @@ import {
 export const isRuntimeReference = (value: unknown): boolean =>
   value instanceof Callable ||
   value instanceof GeneratorObj ||
+  value instanceof Handle ||
   value instanceof ToolReference ||
   value instanceof PromiseObj ||
   isWrapper(value)
@@ -87,6 +89,7 @@ export const describeValue = (value: unknown): string => {
   if (value instanceof URLSearchParamsObj) return "a URLSearchParams"
   if (value instanceof Bytes) return "a Uint8Array"
   if (value instanceof GeneratorObj) return "a generator"
+  if (value instanceof Handle) return `a ${value.instance.constructor.name}`
   if (isRuntimeReference(value)) return "a function"
   if (typeof value === "object") return "a data object"
   return `a ${typeof value}`

packages/codemode/src/stdlib/regexp.ts

@@ -2,7 +2,7 @@ import { Effect } from "effect"
 import type { Builtins } from "../interpreter/intrinsics.js"
 import { constructor, type Method, methods, prototypeFrom, receiver } from "../interpreter/native.js"
 import { syntaxError, typeError } from "../interpreter/model.js"
-import { define, defineAccessor, Arr, Obj, RegExpObj, record } from "../interpreter/objects.js"
+import { define, defineAccessor, getOwn, Arr, Obj, RegExpObj, record, set } from "../interpreter/objects.js"
 import type { Interpreter } from "../interpreter/interpreter.js"
 import { coerceToNumber, coerceToString } from "./value.js"
 
@@ -75,6 +75,12 @@ export const constructRegExp = (builtins: Builtins, args: Array<unknown>, proto:
   }
 }
 
+const toLength = (value: unknown): number => {
+  const number = coerceToNumber(value)
+  if (Number.isNaN(number) || number <= 0) return 0
+  return Math.min(Math.floor(number), Number.MAX_SAFE_INTEGER)
+}
+
 // RegExp constructs identically with or without new, like JS.
 export const regexpGlobal = <R>(ctx: Interpreter<R>) => {
   const builtins = ctx.builtins
@@ -99,22 +105,18 @@ export const regexpGlobal = <R>(ctx: Interpreter<R>) => {
   const self = (thisValue: unknown, name: string) => receiver(RegExpObj, thisValue, `RegExp.prototype.${name}`)
   defineAccessor(proto, "source", (thisValue) => self(thisValue, "source").regex.source)
   defineAccessor(proto, "flags", (thisValue) => self(thisValue, "flags").regex.flags)
-  // The host regex holds the only lastIndex, so exec/test and the String methods share one counter.
-  defineAccessor(
-    proto,
-    "lastIndex",
-    (thisValue) => self(thisValue, "lastIndex").regex.lastIndex,
-    (thisValue, value) => {
-      self(thisValue, "lastIndex").regex.lastIndex = coerceToNumber(value)
-    },
-  )
   for (const name of flagProperties) defineAccessor(proto, name, (thisValue) => self(thisValue, name).regex[name])
+  // exec/test run the host regex from the program-visible lastIndex and write it back only when g or y is set.
   const run = (name: "exec" | "test"): Method => [
     name,
     1,
     (thisValue, args) => {
       const value = self(thisValue, name)
-      const matched = value.regex.exec(coerceToString(args[0]))
+      const input = coerceToString(args[0])
+      const stateful = value.regex.global || value.regex.sticky
+      value.regex.lastIndex = toLength(getOwn(value, "lastIndex"))
+      const matched = value.regex.exec(input)
+      if (stateful) set(value, "lastIndex", value.regex.lastIndex)
       if (name === "test") return matched !== null
       return matched === null ? null : matchToValue(builtins, matched)
     },

packages/codemode/test/extensions.test.ts

@@ -2,12 +2,67 @@ import { describe, expect, test } from "bun:test"
 import { Effect, Schema } from "effect"
 import { CodeMode, Extension, Tool } from "../src/index.js"
 
+class Bag {
+  static made = 0
+  static of(...items: Array<string>) {
+    return new this(items)
+  }
+  constructor(readonly items: Array<string> = []) {
+    Bag.made++
+  }
+  get size() {
+    return this.items.length
+  }
+  set size(length: number) {
+    this.items.length = length
+  }
+  add(item: string) {
+    this.items.push(item)
+    return this
+  }
+  toArray() {
+    return [...this.items]
+  }
+  pair() {
+    return { self: this, list: [this, new Bag()] }
+  }
+  async later<T>(value: T) {
+    return value
+  }
+  async reject(reason: unknown) {
+    throw reason
+  }
+  fail() {
+    throw new RangeError("boom")
+  }
+  get lazy() {
+    return Promise.resolve(1)
+  }
+  detached() {
+    return new Other()
+  }
+}
+class Other {}
+class Big extends Bag {
+  double() {
+    return this.items.length * 2
+  }
+}
+class Vault {
+  secrets = new Map<string, string>()
+  set(key: string, value: string) {
+    this.secrets.set(key, value)
+  }
+}
+
 const held: Array<unknown> = []
 const config = { retries: 3, nested: { deep: true } }
-const requests: Array<unknown> = []
 const extension = Extension.make({
-  name: "web",
+  name: "bag",
   globals: {
+    Bag,
+    Big,
+    Vault,
     keep: (value: unknown) => {
       held.push(value)
       return value
@@ -15,19 +70,6 @@ const extension = Extension.make({
     settings: () => config,
     later: async (value: number) => value + 1,
     first: (map: Map<unknown, unknown>) => map.get("k"),
-    fetch: async (url: string, init?: { method?: string }) => {
-      requests.push([url, init])
-      const bytes = new TextEncoder().encode(`{"url":"${url}"}`)
-      return {
-        status: 200,
-        ok: true,
-        headers: { get: (name: string) => (name === "content-type" ? "application/json" : null) },
-        text: () => new TextDecoder().decode(bytes),
-        json: () => JSON.parse(new TextDecoder().decode(bytes)),
-        bytes: () => bytes,
-        handlers: [(step: number) => step + 1],
-      }
-    },
   },
 })
 
@@ -45,61 +87,66 @@ const failure = async (code: string, target = runtime) => {
   return result.error
 }
 
-describe("extension functions", () => {
-  test("a global is callable, awaitable, and not constructible", async () => {
+describe("extension classes behave like JS", () => {
+  test("construct, call methods, read and write accessors", async () => {
+    expect(await value(`const b = new Bag(["a"]); b.add("b"); return [b.size, b.toArray()]`)).toEqual([2, ["a", "b"]])
+    expect(await value(`const b = new Bag(["a", "b"]); b.size = 1; return b.toArray()`)).toEqual(["a"])
+  })
+
+  test("instanceof, constructor, typeof, and prototype identity", async () => {
+    expect(
+      await value(
+        `const b = new Bag(); return [b instanceof Bag, b.constructor === Bag, typeof Bag, Bag.prototype.constructor === Bag]`,
+      ),
+    ).toEqual([true, true, "function", true])
+  })
+
+  test("statics, including `new this()` through an exposed subclass", async () => {
+    expect(await value(`return [Bag.of("x", "y").toArray(), Big.of("q") instanceof Big, Big.of === Bag.of]`)).toEqual([
+      ["x", "y"],
+      true,
+      true,
+    ])
+  })
+
+  test("data properties are invisible, so a program write never reaches the host class", async () => {
+    Bag.made = 0
+    expect(await value(`Bag.made = 999; return Bag.made`)).toBe(999)
+    expect(Bag.made).toBe(0)
+    expect(await value(`return [Bag.made, new Bag(["a"]).items]`)).toEqual([null, null])
+  })
+
+  test("inheritance chains to the exposed ancestor", async () => {
+    expect(
+      await value(`const b = new Big(["a"]); return [b.double(), b.add("b").size, b instanceof Bag, b instanceof Big]`),
+    ).toEqual([2, 2, true, true])
+  })
+
+  test("calling a class without new throws the host TypeError", async () => {
+    const error = await failure(`Bag()`)
+    expect(error.message).toStartWith("TypeError: ")
+    expect(error.message).toContain("new")
+  })
+
+  test("a function global is callable, awaitable, and not constructible", async () => {
     expect(await value(`return await later(1)`)).toBe(2)
-    expect(await value(`return [typeof later, later.name, later.length]`)).toEqual(["function", "later", 1])
     expect((await failure(`new later()`)).message).toContain("new later(...) is not supported")
   })
 
-  test("a function inside a result is callable and crosses the same way", async () => {
-    requests.length = 0
-    expect(
-      await value(
-        `const res = await fetch("https://a.test/", { method: "GET" }); return [res.status, res.ok, res.headers.get("content-type"), res.text(), res.json(), [...res.bytes()].length, typeof res.json, res.json.name, res.handlers[0](1)]`,
-      ),
-    ).toEqual([
-      200,
-      true,
-      "application/json",
-      '{"url":"https://a.test/"}',
-      { url: "https://a.test/" },
-      25,
-      "function",
-      "json",
-      2,
-    ])
-    expect(requests).toEqual([["https://a.test/", { method: "GET" }]])
-  })
-
-  test("a function inside a result is named by its path in diagnostics", async () => {
-    expect((await failure(`const res = await fetch("https://a.test/"); res.handlers[0](() => 1)`)).message).toContain(
-      "Argument 1 to fetch.handlers[0] contains a function",
-    )
-    const target = CodeMode.make({
-      extensions: [Extension.make({ name: "odd", globals: { make: () => ({ sym: () => Symbol("s") }) } })],
-    })
-    expect((await failure(`make().sym()`, target)).message).toContain("make.sym produced a symbol")
-  })
-
-  test("a function is invisible to the data boundary like any program function", async () => {
-    expect(await value(`return await fetch("https://a.test/")`)).toEqual({
-      status: 200,
-      ok: true,
-      headers: {},
-      handlers: [null],
-    })
-    expect(await value(`return JSON.stringify((await fetch("https://a.test/")).headers)`)).toBe("{}")
-  })
-
-  test("a class global is only a function; calling it throws the host TypeError", async () => {
-    const target = CodeMode.make({ extensions: [Extension.make({ name: "cls", globals: { Bag: class Bag {} } })] })
-    expect((await failure(`Bag()`, target)).message).toContain("without")
-    expect((await failure(`new Bag()`, target)).message).toContain("new Bag(...) is not supported")
+  test("a program can patch a prototype for its own run only", async () => {
+    expect(await value(`Bag.prototype.add = () => "patched"; return new Bag().add("x")`)).toBe("patched")
+    expect(await value(`return new Bag().add("x").toArray()`)).toEqual(["x"])
   })
 })
 
 describe("values are converted at the boundary, never shared", () => {
+  test("the same host instance is the same handle", async () => {
+    expect(
+      await value(`const b = new Bag(); const p = b.pair(); return [p.self === b, p.list[0] === b, keep(b) === b]`),
+    ).toEqual([true, true, true])
+    expect(await value(`const p = new Bag().pair(); return p.list[1] instanceof Bag`)).toBe(true)
+  })
+
   test("plain data passed in is a copy the program cannot change afterwards", async () => {
     held.length = 0
     await value(
@@ -116,12 +163,8 @@ describe("values are converted at the boundary, never shared", () => {
     expect(config).toEqual({ retries: 3, nested: { deep: true } })
   })
 
-  test("the same host value returned twice is two program values", async () => {
-    expect(await value(`return settings() === settings()`)).toBe(false)
-    expect(await value(`return keep(settings()) === settings()`)).toBe(false)
-  })
-
-  test("Map and Set contents are converted element-wise", async () => {
+  test("Map and Set contents are converted element-wise, so handles unwrap inside them", async () => {
+    expect(await value(`const b = new Bag(); return first(new Map([["k", b]])) === b`)).toBe(true)
     expect(await value(`return first(new Map([["k", { z: 1 }]]))`)).toEqual({ z: 1 })
     held.length = 0
     await value(`const inner = { z: 1 }; keep(new Set([inner])); inner.z = 2`)
@@ -171,13 +214,6 @@ describe("values are converted at the boundary, never shared", () => {
     expect(Object.keys(held[0] as object)).toEqual([])
   })
 
-  test("an Error with an unknown name crosses as a plain Error", async () => {
-    held.length = 0
-    await value(`const e = new Error("x"); e.name = "constructor"; keep(e); e.name = "__proto__"; keep(e)`)
-    expect(held[0]).toBeInstanceOf(Error)
-    expect(held[1]).toBeInstanceOf(Error)
-  })
-
   test("functions, promises, and symbols cannot be passed in", async () => {
     expect((await failure(`keep(() => 1)`)).message).toContain("Argument 1 to keep contains a function")
     expect((await failure(`keep(later(1))`)).message).toContain("un-awaited Promise")
@@ -192,45 +228,82 @@ describe("values are converted at the boundary, never shared", () => {
     expect((await failure(`big()`, target)).message).toContain("big produced a bigint")
   })
 
-  test("a class instance cannot come out", async () => {
-    class Other {}
-    const target = CodeMode.make({
-      extensions: [Extension.make({ name: "odd", globals: { detached: () => new Other() } })],
+  test("an instance of an unexposed class cannot come out", async () => {
+    expect((await failure(`new Bag().detached()`)).message).toContain("produced a Other, which the program cannot hold")
+  })
+
+  test("a getter must be synchronous", async () => {
+    expect((await failure(`new Bag().lazy`)).message).toContain("Bag.prototype.lazy returned a Promise")
+  })
+})
+
+describe("the host object behind a handle is unreachable", () => {
+  test("enumeration, spread, and JSON see no own properties", async () => {
+    expect(
+      await value(`const b = new Bag(["a"]); return [Object.keys(b), Object.entries({ ...b }), String(b)]`),
+    ).toEqual([[], [], "[object Object]"])
+  })
+
+  test("a handle serializes as {} when returned, stringified, or handed to a tool", async () => {
+    expect(await value(`return new Bag()`)).toEqual({})
+    expect(await value(`return JSON.stringify(new Bag())`)).toBe("{}")
+    const tools = CodeMode.make({
+      extensions: [extension],
+      tools: {
+        echo: Tool.make({
+          description: "Echo",
+          input: Schema.Struct({ v: Schema.Unknown }),
+          output: Schema.Unknown,
+          execute: (input) => Effect.succeed(input.v),
+        }),
+      },
     })
-    expect((await failure(`detached()`, target)).message).toContain("produced a Other, which the program cannot hold")
+    expect(await value(`return await tools.echo({ v: new Bag() })`, tools)).toEqual({})
+  })
+
+  test("a method only runs on a handle of its own class", async () => {
+    expect((await failure(`const add = new Bag().add; add("x")`)).message).toContain(
+      "Illegal invocation: Bag.prototype.add called on undefined",
+    )
+    expect((await failure(`const o = { add: Bag.prototype.add }; o.add("x")`)).message).toContain(
+      "called on a data object",
+    )
+    const vault = new Vault()
+    const target = CodeMode.make({
+      extensions: [Extension.make({ name: "vault", globals: { Bag, Vault, vault: () => vault } })],
+    })
+    expect((await failure(`const v = vault(); v.add = Bag.prototype.add; v.add("x")`, target)).message).toContain(
+      "Illegal invocation: Bag.prototype.add called on a Vault",
+    )
+    expect(vault.secrets.size).toBe(0)
+  })
+
+  test("reading an accessor off the prototype itself is an illegal invocation", async () => {
+    expect((await failure(`Bag.prototype.size`)).message).toContain("Illegal invocation")
   })
 })
 
 describe("host errors", () => {
   test("a synchronous throw becomes the matching program error", async () => {
-    const target = CodeMode.make({
-      extensions: [
-        Extension.make({
-          name: "odd",
-          globals: {
-            fail: () => {
-              throw new RangeError("boom")
-            },
-          },
-        }),
-      ],
-    })
-    expect(await value(`try { fail() } catch (e) { return [e instanceof RangeError, e.message] }`, target)).toEqual([
+    expect(await value(`try { new Bag().fail() } catch (e) { return [e instanceof RangeError, e.message] }`)).toEqual([
       true,
       "boom",
     ])
   })
 
   test("a thrown or rejected value crosses like a return, so the program catches what was thrown", async () => {
+    expect(
+      await value(
+        `try { await new Bag().reject(new TypeError("bad")) } catch (e) { return [e instanceof TypeError, e.message] }`,
+      ),
+    ).toEqual([true, "bad"])
+    expect(await value(`try { await new Bag().reject("plain") } catch (e) { return e }`)).toBe("plain")
     const reason = { status: 404, nested: { a: 1 } }
     const target = CodeMode.make({
       extensions: [
         Extension.make({
           name: "api",
           globals: {
-            reject: async (reason: unknown) => {
-              throw reason
-            },
             get: async () => Promise.reject(reason),
             boom: () => {
               throw reason
@@ -239,13 +312,6 @@ describe("host errors", () => {
         }),
       ],
     })
-    expect(
-      await value(
-        `try { await reject(new TypeError("bad")) } catch (e) { return [e instanceof TypeError, e.message] }`,
-        target,
-      ),
-    ).toEqual([true, "bad"])
-    expect(await value(`try { await reject("plain") } catch (e) { return e }`, target)).toBe("plain")
     expect(await value(`try { await get() } catch (e) { e.status = 0; return e }`, target)).toEqual({
       status: 0,
       nested: { a: 1 },
@@ -259,45 +325,23 @@ describe("host errors", () => {
 describe("configuration", () => {
   test("extension calls are not tool calls", async () => {
     const limited = CodeMode.make({ extensions: [extension], limits: { maxToolCalls: 0 } })
-    const result = await Effect.runPromise(
-      limited.execute(`(await fetch("https://a.test/")).json(); return await later(1)`),
-    )
+    const result = await Effect.runPromise(limited.execute(`new Bag().add("x"); return await later(1)`))
     expect(result.ok).toBe(true)
     expect(result.toolCalls).toEqual([])
   })
 
-  test("a result handed to a tool is plain data", async () => {
-    const tools = CodeMode.make({
-      extensions: [extension],
-      tools: {
-        echo: Tool.make({
-          description: "Echo",
-          input: Schema.Struct({ v: Schema.Unknown }),
-          output: Schema.Unknown,
-          execute: (input) => Effect.succeed(input.v),
-        }),
-      },
-    })
-    expect(await value(`return await tools.echo({ v: await fetch("https://a.test/") })`, tools)).toEqual({
-      status: 200,
-      ok: true,
-      headers: {},
-      handlers: [null],
-    })
-  })
-
-  test("a global must be a function", () => {
+  test("a global must be a class or a function", () => {
     expect(() => Extension.make({ name: "bad", globals: { n: 1 as never } })).toThrow(
-      'Extension "bad" global "n" must be a function.',
+      'Extension "bad" global "n" must be a class or a function.',
     )
   })
 
   test("a global may not shadow a built-in or another extension", () => {
-    expect(() => CodeMode.make({ extensions: [Extension.make({ name: "web", globals: { URL: () => 1 } })] })).toThrow(
+    expect(() => CodeMode.make({ extensions: [Extension.make({ name: "web", globals: { URL: class {} } })] })).toThrow(
       'Extension "web" global "URL" is already defined.',
     )
     expect(() =>
-      CodeMode.make({ extensions: [extension, Extension.make({ name: "again", globals: { fetch: () => 1 } })] }),
-    ).toThrow('Extension "again" global "fetch" is already defined.')
+      CodeMode.make({ extensions: [extension, Extension.make({ name: "again", globals: { Bag: class {} } })] }),
+    ).toThrow('Extension "again" global "Bag" is already defined.')
   })
 })

packages/codemode/test/stdlib.test.ts

@@ -237,7 +237,7 @@ describe("RegExp", () => {
     ).toEqual(["1", "22"])
   })
 
-  test("lastIndex is writable and stores a number", async () => {
+  test("lastIndex is writable and exec coerces its stored value", async () => {
     expect(
       await value(`
         const pattern = /(?:ab|cd)\\d?/g
@@ -247,112 +247,40 @@ describe("RegExp", () => {
         pattern.lastIndex = 0
         return [stored, match[0], match.index, pattern.lastIndex]
       `),
-    ).toEqual([[12, "number"], "ab4", 17, 0])
-    // lastIndex is a prototype accessor, so delete is a no-op rather than a TypeError.
-    expect(await value(`const re = /a/; return [delete re.lastIndex, re.lastIndex]`)).toEqual([true, 0])
+    ).toEqual([["12", "string"], "ab4", 17, 0])
+    expect((await error(`delete /a/.lastIndex`)).message).toContain("Cannot delete property 'lastIndex'")
   })
 
-  test("a non-numeric lastIndex runs from 0; non-global exec and test leave it alone", async () => {
+  test("exec coerces CodeMode data objects assigned to lastIndex", async () => {
     expect(
       await value(`
         const pattern = /a/g
         pattern.lastIndex = {}
+        const stored = pattern.lastIndex
         const match = pattern.exec("ba")
         pattern.lastIndex = 10
         const missed = pattern.exec("a")
-        const plain = /a/
-        plain.lastIndex = 5
-        return [match.index, pattern.lastIndex, missed, plain.exec("ba").index, plain.test("ba"), plain.lastIndex]
+        return [stored, match.index, pattern.lastIndex, missed]
       `),
-    ).toEqual([1, 0, null, 1, true, 5])
+    ).toEqual([{}, 1, 0, null])
   })
 
-  test("String methods read and update lastIndex like exec", async () => {
+  test("non-global exec and test coerce and preserve lastIndex", async () => {
     expect(
       await value(`
-        const re = /a/y
-        re.exec("aa")
-        re.lastIndex = 0
-        return ["aa".replace(re, "b"), re.lastIndex]
-      `),
-    ).toEqual(["ba", 1])
-    expect(
-      await value(`
-        const re = /a/g
-        re.exec("aaa")
-        return ["aaa".match(re), re.lastIndex]
-      `),
-    ).toEqual([["a", "a", "a"], 0])
-    expect(
-      await value(`
-        const re = /a/g
-        re.lastIndex = 2
-        return ["aaa".replace(re, () => "b"), re.lastIndex]
-      `),
-    ).toEqual(["bbb", 0])
-    expect(
-      await value(`
-        const re = /a/g
-        re.lastIndex = 2
-        return ["aaa".replaceAll(re, "b"), re.lastIndex]
-      `),
-    ).toEqual(["bbb", 0])
-    expect(
-      await value(`
-        const re = /a/y
-        re.lastIndex = 1
-        const m = "baa".match(re)
-        return [m.index, re.lastIndex]
-      `),
-    ).toEqual([1, 2])
-  })
+        const execPattern = /a/
+        const execIndex = {}
+        execPattern.lastIndex = execIndex
+        const match = execPattern.exec("ba")
 
-  test("split, search, and matchAll leave lastIndex unchanged like JS", async () => {
-    expect(
-      await value(`
-        const re = /a/y
-        re.lastIndex = 2
-        return ["banana".split(re), re.lastIndex]
-      `),
-    ).toEqual([["b", "n", "n", ""], 2])
-    expect(
-      await value(`
-        const re = /a/g
-        re.lastIndex = 2
-        return ["banana".search(re), re.lastIndex]
-      `),
-    ).toEqual([1, 2])
-    expect(
-      await value(`
-        const re = /a/y
-        re.lastIndex = 2
-        return ["banana".search(re), re.lastIndex]
-      `),
-    ).toEqual([-1, 2])
-    expect(
-      await value(`
-        const re = /a/g
-        re.lastIndex = 2
-        return ["banana".matchAll(re).map((m) => m.index), re.lastIndex]
-      `),
-    ).toEqual([[3, 5], 2])
-    expect(
-      await value(`
-        const re = /a/gy
-        re.lastIndex = 1
-        return ["banana".matchAll(re).map((m) => m.index), re.lastIndex]
-      `),
-    ).toEqual([[1], 1])
-  })
+        const testPattern = /a/
+        const testIndex = {}
+        testPattern.lastIndex = testIndex
+        const matched = testPattern.test("ba")
 
-  test("String methods leave lastIndex untouched without g or y", async () => {
-    expect(
-      await value(`
-        const re = /a/
-        re.lastIndex = 5
-        return ["aaa".replace(re, "b"), "aaa".match(re).index, "aaa".split(re), "aaa".search(re), re.lastIndex]
+        return [match.index, execPattern.lastIndex === execIndex, matched, testPattern.lastIndex === testIndex]
       `),
-    ).toEqual(["baa", 0, ["", "", "", ""], 0, 5])
+    ).toEqual([1, true, true, true])
   })
 
   test("an unmatched string pattern returns null", async () => {

packages/core/package.json

@@ -111,7 +111,6 @@
     "@ff-labs/fff-node": "0.10.5",
     "@lydell/node-pty": "catalog:",
     "@modelcontextprotocol/client": "2.0.0",
-    "@modelcontextprotocol/core": "2.0.0",
     "@opencode-ai/pty": "0.1.13",
     "@opencode/ai": "workspace:*",
     "@opencode/codemode": "workspace:*",

packages/core/src/integration.ts

@@ -111,13 +111,7 @@ export class CodeRequiredError extends Schema.TaggedError<CodeRequiredError>()("
 
 export class AuthorizationError extends Schema.TaggedError<AuthorizationError>()("Integration.Authorization", {
   cause: Schema.Defect(),
-}) {
-  override get message() {
-    const cause = this.cause
-    if (cause instanceof Error && cause.message) return cause.message
-    return "Authorization failed"
-  }
-}
+}) {}
 
 export class AttemptNotFoundError extends Schema.TaggedError<AttemptNotFoundError>()("Integration.AttemptNotFound", {
   integrationID: ID,

packages/core/src/job.ts

@@ -142,14 +142,9 @@ function snapshot(job: Active): Info {
   }
 }
 
-function errorText(cause: Cause.Cause<unknown>) {
-  const render = (error: Error): string => {
-    const message = error.message || error.name || "Unknown error"
-    if (!(error.cause instanceof Error)) return message
-    const detail = render(error.cause)
-    return detail === message || detail.startsWith(`${message}\n`) ? detail : `${message}\nCaused by: ${detail}`
-  }
-  return Cause.prettyErrors(cause).map(render).join("\n") || "Unknown error"
+function errorText(error: unknown) {
+  if (error instanceof Error) return error.message
+  return String(error)
 }
 
 function incrementSession(input: Map<SessionSchema.ID, number>, sessionID: SessionSchema.ID) {
@@ -210,7 +205,7 @@ export const make = Effect.gen(function* () {
             status,
             completed_at,
             ...(Exit.isSuccess(exit) ? { output: exit.value } : {}),
-            ...(Exit.isFailure(exit) ? { error: errorText(exit.cause) } : {}),
+            ...(Exit.isFailure(exit) ? { error: errorText(Cause.squash(exit.cause)) } : {}),
           },
         }
         if (status !== "cancelled") yield* persistBackground(next)

packages/core/src/mcp/oauth.ts

@@ -7,7 +7,6 @@ import {
   discoverOAuthServerInfo,
   extractWWWAuthenticateParams,
   parseErrorResponse,
-  resourceUrlFromServerUrl,
   UnauthorizedError,
   type FetchLike,
   type OAuthClientProvider,
@@ -15,7 +14,6 @@ import {
   type StoredOAuthClientInformation,
   type StoredOAuthTokens,
 } from "@modelcontextprotocol/client"
-import { OAuthMetadataSchema, OpenIdProviderDiscoveryMetadataSchema } from "@modelcontextprotocol/core"
 import { Cause, Deferred, Effect } from "effect"
 import { ConfigMCP } from "@opencode/schema/config/mcp"
 import { Credential } from "../credential.js"
@@ -101,25 +99,6 @@ export const loggedFetch = (fields: { readonly server: string; readonly director
     return request
   })
 
-// A configured authorization server document stands in for RFC 9728 discovery: the SDK reuses this
-// state instead of probing the resource server, whose well-known path may not exist.
-export const configuredDiscovery = async (input: {
-  readonly config: typeof ConfigMCP.Remote.Type
-  readonly fetchFn: FetchLike
-}): Promise<OAuthDiscoveryState | undefined> => {
-  const url = input.config.oauth ? input.config.oauth.auth_server_metadata_url : undefined
-  if (!url) return undefined
-  const response = await input.fetchFn(url, { headers: { accept: "application/json" } })
-  if (!response.ok) throw new Error(`HTTP ${response.status} trying to load OAuth authorization server metadata`)
-  const body = await response.json()
-  const metadata = OAuthMetadataSchema.safeParse(body).data ?? OpenIdProviderDiscoveryMetadataSchema.parse(body)
-  return {
-    authorizationServerUrl: metadata.issuer,
-    authorizationServerMetadata: metadata,
-    resourceMetadata: { resource: resourceUrlFromServerUrl(input.config.url).toString() },
-  }
-}
-
 export interface Store {
   readonly tokens: () => Promise<StoredOAuthTokens | undefined>
   readonly saveTokens: (tokens: StoredOAuthTokens) => Promise<void>
@@ -155,10 +134,7 @@ export const provider = (options: Options): OAuthClientProvider => {
   let discovery: OAuthDiscoveryState | undefined = options.discovery
   return {
     redirectUrl,
-    discoveryState: async () => {
-      discovery ??= await configuredDiscovery({ config: options.config, fetchFn: send })
-      return discovery
-    },
+    discoveryState: () => discovery,
     saveDiscoveryState: (state) => {
       discovery = state
     },
@@ -412,9 +388,7 @@ export const authorize = (input: {
     // CIMD needs the server to advertise it and accept public clients, and our published document only
     // lists the loopback redirect; a configured client_id always wins.
     const discovery = yield* Effect.tryPromise({
-      try: async () =>
-        (await configuredDiscovery({ config: input.config, fetchFn })) ??
-        discoverOAuthServerInfo(input.config.url, { resourceMetadataUrl, fetchFn }),
+      try: () => discoverOAuthServerInfo(input.config.url, { resourceMetadataUrl, fetchFn }),
       catch: (error) => (error instanceof Error ? error : new Error(String(error))),
     })
     const cimd =

packages/core/src/tool/plugin/opencode.ts

@@ -3,6 +3,7 @@ export * as OpenCodeTools from "./opencode.js"
 import { SystemPart, ToolFailure } from "@opencode/ai"
 import type { Context } from "@opencode/plugin/effect/plugin"
 import type { SessionHooks } from "@opencode/plugin/effect/session"
+import { Model } from "@opencode/schema/model"
 import { AbsolutePath } from "@opencode/schema/schema"
 import { Session } from "@opencode/schema/session"
 import { Effect, Schema } from "effect"
@@ -23,6 +24,14 @@ export const MoveInput = Schema.Struct({
 
 const MoveOutput = Schema.Struct({ sessionID: Session.ID, directory: AbsolutePath })
 
+export const ModelsInput = Schema.Struct({
+  provider: Schema.optionalKey(Schema.String).annotate({
+    description: 'Only list models from this provider, for example "anthropic".',
+  }),
+})
+
+const ModelsOutput = Schema.Struct({ models: Schema.Array(Model.Info) })
+
 export const Plugin = {
   id: "opencode.tools",
   effect: Effect.fn("OpenCodeTools.Plugin")(function* (ctx: Context) {
@@ -85,6 +94,27 @@ export const Plugin = {
               ),
             ),
         })
+        draft.add({
+          name: "models",
+          description:
+            'List the models available to you. Reference one as "provider/model", or "provider/model#variant" using an entry from its variants. Pass the reference anywhere a model is accepted, such as the subagent tool.',
+          input: ModelsInput,
+          output: ModelsOutput,
+          options: { namespace: "opencode", codemode: true },
+          execute: (input) =>
+            ctx.model.list().pipe(
+              Effect.map((list) => {
+                const models = list.data.filter(
+                  (model) => input.provider === undefined || model.providerID === input.provider,
+                )
+                return {
+                  output: { models },
+                  content: models.map((model) => `${model.providerID}/${model.id}: ${model.name}`).join("\n"),
+                }
+              }),
+              Effect.mapError((error) => new ToolFailure({ message: "Unable to list models", error })),
+            ),
+        })
       })
       .pipe(Effect.orDie)
   }),

packages/core/src/tool/plugin/subagent.ts

@@ -7,6 +7,7 @@ import { Effect, Schema } from "effect"
 import { Agent } from "../../agent.js"
 import { Config } from "../../config.js"
 import { Job } from "../../job.js"
+import { Model } from "../../model.js"
 import { Permission } from "../../permission.js"
 import { Session } from "../../session.js"
 import { SessionSchema } from "../../session/schema.js"
@@ -29,6 +30,10 @@ export const Input = Schema.Struct({
   agent: Schema.String.annotate({ description: "The type of specialized agent to use for this task" }),
   description: Schema.String.annotate({ description: "A short 3-5 word label for the task, displayed to the user" }),
   prompt: Schema.String.annotate({ description: "The task for the subagent to perform" }),
+  model: Schema.optionalKey(Schema.String).annotate({
+    description:
+      'Set only when the user explicitly requests a model, and add "#variant" only when they request a variant too. Format "provider/model" or "provider/model#variant". Omitted, the subagent uses the agent\'s configured model, or your own. Use the models tool to find the reference for a requested model.',
+  }),
   sessionID: Schema.optionalKey(SessionSchema.ID).annotate({
     description:
       "Continue a specific previous subagent conversation by passing its sessionID. Calls without a sessionID start a new conversation.",
@@ -61,8 +66,29 @@ export const Plugin = {
     const agents = yield* Agent.Service
     const config = yield* Config.Service
     const permission = yield* Permission.Service
+    const models = yield* Model.Service
     const subagents = yield* SubagentJob.make
 
+    const resolveModel = Effect.fn("SubagentTool.resolveModel")(function* (input: string) {
+      const ref = yield* Effect.try({
+        try: () => Model.Ref.parse(input),
+        catch: () =>
+          new ToolFailure({ message: `Invalid model "${input}". Use "provider/model" or "provider/model#variant".` }),
+      })
+      const model = (yield* models.available()).find(
+        (model) => model.providerID === ref.providerID && model.id === ref.id,
+      )
+      if (model === undefined)
+        return yield* new ToolFailure({
+          message: `Model "${ref.providerID}/${ref.id}" is not available. Use the models tool to see what is available.`,
+        })
+      if (ref.variant !== undefined && !model.variants.some((variant) => variant.id === ref.variant))
+        return yield* new ToolFailure({
+          message: `Variant "${ref.variant}" is not available for "${ref.providerID}/${ref.id}". Available: ${model.variants.map((variant) => variant.id).join(", ") || "none"}.`,
+        })
+      return ref
+    })
+
     yield* ctx.tool
       .transform((editor) =>
         editor.add({
@@ -131,24 +157,23 @@ export const Plugin = {
                 return yield* new ToolFailure({
                   message: `Session ${existing.id} is not a child of the current session`,
                 })
+              const override = input.model === undefined ? undefined : yield* resolveModel(input.model)
               // Continuing with a different agent switches the child, mirroring create semantics
-              // where the agent's configured model wins over the inherited one.
-              if (existing !== undefined && existing.agent !== agent.id) {
-                yield* sessions.switchAgent({ sessionID: existing.id, agent: agent.id }).pipe(
-                  Effect.andThen(
-                    agent.model === undefined
-                      ? Effect.void
-                      : sessions.switchModel({ sessionID: existing.id, model: agent.model }),
-                  ),
+              // where an explicit model wins over the agent's configured model, which wins over the inherited one.
+              if (existing !== undefined) {
+                const switched = existing.agent !== agent.id
+                const model = override ?? (switched ? agent.model : undefined)
+                yield* Effect.all([
+                  switched ? sessions.switchAgent({ sessionID: existing.id, agent: agent.id }) : Effect.void,
+                  model === undefined ? Effect.void : sessions.switchModel({ sessionID: existing.id, model }),
+                ]).pipe(
                   Effect.mapError(
-                    (error) =>
-                      new ToolFailure({ message: `Failed to switch subagent session agent: ${existing.id}`, error }),
+                    (error) => new ToolFailure({ message: `Failed to switch subagent session: ${existing.id}`, error }),
                   ),
                 )
               }
 
-              // Model selection is policy/config/session state, not an LLM-facing tool argument.
-              const model = agent.model ?? parent.model
+              const model = override ?? agent.model ?? parent.model
               const child =
                 existing ??
                 (yield* sessions

packages/core/test/integration.test.ts

@@ -1,4 +1,4 @@
-import { describe, expect, test } from "bun:test"
+import { describe, expect } from "bun:test"
 import { Cause, Clock, Duration, Effect, Exit, Fiber, Layer, Scope, Stream } from "effect"
 import { TestClock } from "effect/testing"
 import { Credential } from "@opencode/core/credential"
@@ -674,16 +674,3 @@ describe("Integration", () => {
     )
   })
 })
-
-describe("AuthorizationError", () => {
-  test("reports the underlying cause message", () => {
-    expect(new Integration.AuthorizationError({ cause: new Error("Request failed: 401") }).message).toBe(
-      "Request failed: 401",
-    )
-  })
-
-  test("falls back when the cause carries no message", () => {
-    expect(new Integration.AuthorizationError({ cause: new Error() }).message).toBe("Authorization failed")
-    expect(new Integration.AuthorizationError({ cause: undefined }).message).toBe("Authorization failed")
-  })
-})

packages/core/test/job.test.ts

@@ -2,9 +2,8 @@ import { describe, expect } from "bun:test"
 import { Job } from "@opencode/core/job"
 import { KV } from "@opencode/core/kv"
 import { AppNodeBuilder } from "@opencode/core/effect/app-node-builder"
-import { Integration } from "@opencode/core/integration"
 import { LayerNode } from "@opencode/util/effect/layer-node"
-import { Cause, Deferred, Effect, Exit, Fiber, Scope } from "effect"
+import { Deferred, Effect, Exit, Fiber, Scope } from "effect"
 import { SessionSchema } from "@opencode/core/session/schema"
 import { testEffect } from "./lib/effect"
 
@@ -65,30 +64,6 @@ describe("Job", () => {
     }),
   )
 
-  it.live("preserves authorization and complete failure details without stacks", () =>
-    Effect.gen(function* () {
-      const jobs = yield* Job.Service
-      const job = yield* jobs.start({
-        type: "test",
-        run: Effect.failCause(
-          Cause.combine(
-            Cause.fail(
-              new Integration.AuthorizationError({
-                cause: new Error("authorization failed", { cause: new Error("token expired") }),
-              }),
-            ),
-            Cause.die({ code: "cleanup_failed" }),
-          ),
-        ),
-      })
-
-      expect((yield* jobs.wait({ id: job.id })).info).toMatchObject({
-        status: "error",
-        error: 'authorization failed\nCaused by: token expired\n{"code":"cleanup_failed"}',
-      })
-    }),
-  )
-
   it.live("reuses running work when started again with the same ID", () =>
     Effect.gen(function* () {
       const jobs = yield* Job.Service

packages/core/test/mcp-oauth.test.ts

@@ -352,38 +352,6 @@ describe("MCP OAuth", () => {
     expect(url.pathname).toBe("/as/authorize")
   })
 
-  test("uses configured authorization server metadata when the resource publishes none", async () => {
-    const { server: issuer } = authorizationServer({})
-    const resource = Bun.serve({ port: 0, fetch: () => new Response(null, { status: 404 }) })
-    const url = `${resource.url.origin}/mcp`
-    const oauth = {
-      client_id: "client",
-      auth_server_metadata_url: `${issuer.url.origin}/.well-known/oauth-authorization-server`,
-    }
-
-    const { url: authorization } = await Effect.runPromise(Effect.scoped(start(url, oauth)))
-    expect(authorization.origin).toBe(issuer.url.origin)
-    expect(authorization.pathname).toBe("/authorize")
-    expect(authorization.searchParams.get("resource")).toBe(url)
-
-    const { server, tokenRequests } = authorizationServer({})
-    const store = memoryCredentials([credential({ access: "expired", refresh: "refresh", url })])
-    const oauthProvider = await connectProvider(
-      new ConfigMCP.Remote({
-        type: "remote",
-        url,
-        oauth: { ...oauth, auth_server_metadata_url: `${server.url.origin}/.well-known/oauth-authorization-server` },
-      }),
-      store,
-    )
-    await auth(oauthProvider, { serverUrl: url }).finally(() => {
-      resource.stop(true)
-      issuer.stop(true)
-      server.stop(true)
-    })
-    expect(tokenRequests[0]?.get("grant_type")).toBe("refresh_token")
-  })
-
   test("forwards iss from the redirect so issuer-advertising servers can complete", async () => {
     const { server } = authorizationServer({ authorization_response_iss_parameter_supported: true })
     const result = await Effect.runPromise(

packages/core/test/tool-opencode.test.ts

@@ -0,0 +1,54 @@
+import { expect } from "bun:test"
+import { Plugin } from "@opencode/core/plugin"
+import { PluginHost } from "@opencode/core/plugin/host"
+import { Provider } from "@opencode/core/provider"
+import { Session } from "@opencode/core/session"
+import { Tool } from "@opencode/core/tool"
+import { OpenCodeTools } from "@opencode/core/tool/plugin/opencode"
+import { Model } from "@opencode/schema/model"
+import { Effect } from "effect"
+import { testEffect } from "./lib/effect"
+import { executeTool, toolIdentity } from "./lib/tool"
+import { PluginTestLayer } from "./plugin/fixture"
+
+const it = testEffect(PluginTestLayer)
+
+it.effect("lists available models through the opencode namespace", () =>
+  Effect.gen(function* () {
+    const catalog = yield* Provider.Service
+    const plugins = yield* Plugin.Service
+    const pluginHost = yield* PluginHost.make(plugins)
+    yield* catalog.transform((editor) => {
+      editor.models.update(Provider.ID.make("test"), Model.ID.make("alpha"), (model) => {
+        model.name = "Alpha"
+        model.variants = [{ id: Model.VariantID.make("fast") }]
+      })
+      editor.models.update(Provider.ID.make("other"), Model.ID.make("beta"), (model) => {
+        model.name = "Beta"
+      })
+      editor.models.update(Provider.ID.make("other"), Model.ID.make("disabled"), (model) => {
+        model.enabled = false
+      })
+    })
+    yield* OpenCodeTools.Plugin.effect(pluginHost)
+    const registry = yield* Tool.Service
+    const run = (code: string) =>
+      executeTool(registry, {
+        sessionID: Session.ID.make("ses_tool_opencode"),
+        ...toolIdentity,
+        call: { type: "tool-call", id: `call-${code.length}`, name: "execute", input: { code } },
+      })
+
+    const all = yield* run(
+      "const list = await tools.opencode.models({}); return list.models.map((model) => `${model.providerID}/${model.id}: ${model.name} [${model.variants.map((variant) => variant.id)}]`).sort()",
+    )
+    expect(all.content).toEqual([
+      { type: "text", text: JSON.stringify(["other/beta: Beta []", "test/alpha: Alpha [fast]"], null, 2) },
+    ])
+
+    const filtered = yield* run(
+      'const list = await tools.opencode.models({ provider: "other" }); return list.models.map((model) => model.id)',
+    )
+    expect(filtered.content).toEqual([{ type: "text", text: JSON.stringify(["beta"], null, 2) }])
+  }),
+)

packages/core/test/tool-subagent.test.ts

@@ -45,6 +45,11 @@ const completedOutput = (sessionID: Session.ID) =>
   `<subagent sessionID="${sessionID}" state="completed">\n${childText}\n</subagent>`
 const childModel = Model.Ref.make({ id: Model.ID.make("child"), providerID: Provider.ID.make("test") })
 const parentModel = Model.Ref.make({ id: Model.ID.make("parent"), providerID: Provider.ID.make("test") })
+const overrideModel = Model.Ref.make({
+  id: Model.ID.make("override"),
+  providerID: Provider.ID.make("test"),
+  variant: Model.VariantID.make("fast"),
+})
 const tokens = { input: 0, output: 0, reasoning: 0, cache: { read: 0, write: 0 } }
 
 const outputSessionID = (value: unknown) =>
@@ -107,7 +112,7 @@ const executionNode = makeGlobalNode({
 const subagentPluginSupervisor = makeLocationNode({
   name: "test/subagent-plugins",
   layer: Layer.effectDiscard(registerToolPlugin(SubagentTool.Plugin)),
-  deps: [Agent.node, Config.node, Permission.node, Session.node, Job.node, Tool.node],
+  deps: [Agent.node, Config.node, Model.node, Permission.node, Session.node, Job.node, Tool.node],
 })
 
 const nodes = LayerNode.group([
@@ -155,6 +160,13 @@ const withSubagent = (location: Location.Ref) =>
   Effect.gen(function* () {
     const locations = yield* LocationServiceMap.Service
     yield* Plugin.Service.use((plugins) => plugins.awaitActivation).pipe(Effect.provide(locations.get(location)))
+    yield* Provider.Service.use((providers) =>
+      providers.transform((editor) => {
+        editor.models.update(overrideModel.providerID, overrideModel.id, (model) => {
+          model.variants = [{ id: Model.VariantID.make("fast") }]
+        })
+      }),
+    ).pipe(Effect.provide(locations.get(location)))
     yield* Agent.Service.use((agents) =>
       agents.transform((editor) => {
         // The caller identity used by executeTool; subagent permission asserts against it.
@@ -615,6 +627,62 @@ describe("SubagentTool", () => {
     ),
   )
 
+  it.live("runs the child on an explicitly requested model", () =>
+    Effect.acquireRelease(
+      Effect.promise(() => tmpdir()),
+      (dir) => Effect.promise(() => dir[Symbol.asyncDispose]()),
+    ).pipe(
+      Effect.flatMap((dir) =>
+        Effect.gen(function* () {
+          const location = Location.Ref.make({ directory: AbsolutePath.make(dir.path) })
+          const sessions = yield* Session.Service
+          const parent = yield* sessions.create({ location, model: parentModel })
+          yield* withSubagent(parent.location)
+          const locations = yield* LocationServiceMap.Service
+          const registry = yield* Tool.Service.pipe(Effect.provide(locations.get(parent.location)))
+          const call = (id: string, input: Record<string, unknown>) =>
+            executeTool(registry, {
+              sessionID: parent.id,
+              ...toolIdentity,
+              call: {
+                type: "tool-call" as const,
+                id,
+                name: SubagentTool.name,
+                input: { agent: "reviewer", description: "review", prompt: "review this", ...input },
+              },
+            })
+
+          // The requested model beats the agent's configured model.
+          const spawned = yield* call("call-override", { model: "test/override#fast" })
+          expect(spawned).toMatchObject({ status: "completed", metadata: { status: "completed" } })
+          const child = yield* sessions.get(outputSessionID(spawned.metadata))
+          expect(child).toMatchObject({ agent: "reviewer", model: overrideModel })
+
+          // Continuing with a model switches the existing child even when the agent is unchanged.
+          const continued = yield* call("call-override-continue", { sessionID: child.id, model: "test/override" })
+          expect(continued).toMatchObject({ status: "completed", metadata: { sessionID: child.id } })
+          expect((yield* sessions.get(child.id)).model).toEqual({
+            id: overrideModel.id,
+            providerID: overrideModel.providerID,
+            variant: Model.VariantID.make("default"),
+          })
+
+          const failures = [
+            ["not-a-ref", 'Invalid model "not-a-ref". Use "provider/model" or "provider/model#variant".'],
+            ["test/missing", 'Model "test/missing" is not available. Use the models tool to see what is available.'],
+            ["test/override#slow", 'Variant "slow" is not available for "test/override". Available: fast.'],
+          ] as const
+          for (const [model, message] of failures) {
+            expect(yield* call(`call-${model}`, { model })).toEqual({
+              status: "error",
+              error: { type: "tool.execution", message },
+            })
+          }
+        }),
+      ),
+    ),
+  )
+
   it.live("returns child runner failures as tool errors", () =>
     Effect.acquireRelease(
       Effect.promise(() => tmpdir()),

packages/plugin/src/source.bun.ts

@@ -4,7 +4,6 @@ import path from "node:path"
 import { fileURLToPath, pathToFileURL } from "node:url"
 import { Host } from "./host.js"
 import { localSource } from "./source.js"
-import { missingPackageTarget } from "./source.package.js"
 
 let generation = Date.now()
 
@@ -38,15 +37,7 @@ export async function prepareSource(entrypoint: string, track: (file: string, di
         item.path.startsWith("./") || item.path.startsWith("../")
           ? new URL(item.path, pathToFileURL(file))
           : localSource(item.path, path.dirname(file))
-      if (!local) {
-        try {
-          Bun.resolveSync(item.path, path.dirname(file))
-        } catch {
-          const target = missingPackageTarget(item.path, file)
-          if (target) track(target, true)
-        }
-        continue
-      }
+      if (!local) continue
       const requested = fileURLToPath(local)
       // Resolving a workspace symlink can erase its node_modules boundary.
       if (requested.split(path.sep).includes("node_modules")) continue

packages/plugin/src/source.node.ts

@@ -2,7 +2,6 @@ import { registerHooks } from "node:module"
 import path from "node:path"
 import { fileURLToPath } from "node:url"
 import { localSource } from "./source.js"
-import { missingPackageTarget } from "./source.package.js"
 import { Host } from "./host.js"
 
 let generation = Date.now()
@@ -22,15 +21,7 @@ export async function prepareSource(entrypoint: string, track: (file: string, di
         specifier.startsWith("./") || specifier.startsWith("../")
           ? new URL(specifier, context.parentURL)
           : localSource(specifier, path.dirname(fileURLToPath(context.parentURL)))
-      if (!local) {
-        try {
-          return nextResolve(specifier, context)
-        } catch (error) {
-          const target = missingPackageTarget(specifier, fileURLToPath(context.parentURL))
-          if (target) track(target, true)
-          throw error
-        }
-      }
+      if (!local) return nextResolve(specifier, context)
       if (fileURLToPath(local).split(path.sep).includes("node_modules")) return nextResolve(specifier, context)
       const resolved = (() => {
         try {

packages/plugin/src/source.package.ts

@@ -1,13 +0,0 @@
-import { existsSync } from "node:fs"
-import path from "node:path"
-
-export function missingPackageTarget(specifier: string, importer: string) {
-  if (specifier.startsWith("#")) return undefined
-  const parts = specifier.split("/")
-  const name = specifier.startsWith("@") ? parts.slice(0, 2).join("/") : parts[0]
-  const start = path.dirname(importer)
-  for (let directory = start; ; directory = path.dirname(directory)) {
-    if (existsSync(path.join(directory, "package.json"))) return path.join(directory, "node_modules", name)
-    if (path.dirname(directory) === directory) return path.join(start, "node_modules", name)
-  }
-}

packages/protocol/openapi.json

@@ -15250,9 +15250,6 @@
           },
           "redirect_uri": {
             "type": "string"
-          },
-          "auth_server_metadata_url": {
-            "type": "string"
           }
         },
         "additionalProperties": false
@@ -15552,9 +15549,6 @@
           },
           "requireAssistantAfterTool": {
             "type": "boolean"
-          },
-          "supportsPromptCacheKey": {
-            "type": "boolean"
           }
         },
         "additionalProperties": false

packages/schema/src/mcp.ts

@@ -44,10 +44,6 @@ export class OAuthConfig extends Schema.Class<OAuthConfig>("Mcp.OAuthConfig")({
   scope: Schema.String.pipe(optional),
   callback_port: Schema.Int.check(Schema.isBetween({ minimum: 1, maximum: 65535 })).pipe(optional),
   redirect_uri: Schema.String.pipe(optional),
-  auth_server_metadata_url: Schema.String.pipe(optional).annotate({
-    description:
-      "URL of the OAuth or OpenID Connect authorization server metadata document. Set when the MCP server does not publish protected resource metadata that names its authorization server.",
-  }),
 }) {}
 
 export class RemoteConfig extends Schema.Class<RemoteConfig>("Mcp.RemoteConfig")({

packages/tui/src/util/collapse-tool-output.ts

@@ -42,12 +42,8 @@ function collapseTail(output: string, maxLines: number, maxChars: number) {
   const lines = output.split("\n")
   if (lines.length <= maxLines && Array.from(output).length <= maxChars) return output
 
-  const count = Math.max(1, lines.length - Math.max(0, maxLines - 1))
-  const label = `(${count} earlier ${count === 1 ? "line" : "lines"})`
-  if (maxLines <= 1) return label
-
-  const preview = Array.from(lines.slice(-(maxLines - 1)).join("\n"))
-  const available = maxChars - Array.from(label).length - 1
-  if (available <= 0) return label
-  return `${label}\n${preview.slice(-available).join("")}`
+  const preview = lines.slice(-maxLines).join("\n")
+  const visible = Array.from(preview)
+  if (visible.length < maxChars) return `…${preview}`
+  return `…${visible.slice(-Math.max(0, maxChars - 1)).join("")}`
 }

packages/tui/test/command-selection.test.tsx

@@ -87,9 +87,8 @@ test("custom commands commit the captured agent, model and variant before execut
     expect(mutations).toEqual([{ type: "agent", body: { agent: "plan" } }])
 
     // A later local edit must not change the in-flight command's selection.
-    await waitForFrame(setup, (frame) => frame.includes("Plan · second model Demo · low"))
     setup.mockInput.pressKey("F7")
-    await waitForFrame(setup, (frame) => frame.includes("high"))
+    await setup.waitForFrame((frame) => frame.includes("high"))
     agent.resolve(new Response(null, { status: 204 }))
     await setup.waitFor(() => mutations.length === 2)
     expect(mutations[1]).toEqual({
@@ -107,11 +106,3 @@ test("custom commands commit the captured agent, model and variant before execut
     model.resolve(new Response(null, { status: 204 }))
   }
 })
-
-async function waitForFrame(setup: Awaited<ReturnType<typeof createAppFixture>>, matches: (frame: string) => boolean) {
-  const started = Date.now()
-  while (!matches(setup.captureCharFrame())) {
-    if (Date.now() - started > 2_000) throw new Error("Timed out waiting for command selection frame")
-    await Bun.sleep(10)
-  }
-}

packages/tui/test/fixture/local.tsx

@@ -88,7 +88,7 @@ export async function renderLocal(
     ),
     { width: 100, height: 30, kittyKeyboard: true },
   )
-  await waitForModel(() => local !== undefined && local.model.ready)
+  await setup.waitFor(() => local !== undefined && local.model.ready)
   await data.location.sync()
   return {
     ...setup,
@@ -106,14 +106,6 @@ export async function renderLocal(
   }
 }
 
-async function waitForModel(ready: () => boolean) {
-  const started = Date.now()
-  while (!ready()) {
-    if (Date.now() - started > 2_000) throw new Error("Timed out waiting for local model data")
-    await Bun.sleep(10)
-  }
-}
-
 export function model(id: string, variants: string[] = []): ModelInfo {
   return {
     id,

packages/tui/test/plugin-source.test.ts

@@ -89,30 +89,6 @@ test("renamed exports, failed loads, and new dependencies recover without cached
   expect((await sources.read(entry.href)).module).toMatchObject({ default: 3 })
 })
 
-test("a missing package dependency reloads when it is installed", async () => {
-  let changes = 0
-  const watcher = createSourceWatcher(() => {
-    changes++
-  })
-  using _watcher = { [Symbol.dispose]: watcher.dispose }
-  await using sources = await fixture(watcher.wait)
-  const entry = new URL("tui.ts", sources.url)
-  await Bun.write(entry, 'export { default } from "example"')
-  await expect(sources.read(entry.href)).rejects.toThrow("example")
-
-  const count = changes
-  await Bun.write(new URL("node_modules/example/package.json", sources.url), '{"type":"module","main":"index.js"}')
-  await Bun.write(new URL("node_modules/example/index.js", sources.url), 'export default "installed"')
-  const deadline = Date.now() + 3000
-  while (Date.now() < deadline) {
-    if (changes > count) break
-    await Bun.sleep(10)
-  }
-
-  expect(changes).toBeGreaterThan(count)
-  expect((await sources.read(entry.href)).module).toMatchObject({ default: "installed" })
-})
-
 test("shared runtime and ordinary package identities survive plugin generations", async () => {
   await using sources = await fixture()
   const entry = new URL("tui.ts", sources.url)
@@ -247,13 +223,6 @@ test.each(["", "?mode=plugin", "?mode=plugin#section"])(
       assert.equal(new URL(updated.source).pathname, helper.pathname)
       assert.equal(new URL(updated.source).searchParams.get("mode"), suffix ? "plugin" : null)
       assert.equal(new URL(updated.source).hash, suffix.includes("#") ? "#section" : "")
-      const missing = new URL("./missing.mjs", import.meta.url)
-      await writeFile(missing, 'export { default } from "later"')
-      await assert.rejects(sources.read(missing.href), /later/)
-      await mkdir(new URL("./node_modules/later", import.meta.url), { recursive: true })
-      await writeFile(new URL("./node_modules/later/package.json", import.meta.url), '{"type":"module","main":"index.js"}')
-      await writeFile(new URL("./node_modules/later/index.js", import.meta.url), 'export default "installed"')
-      assert.equal((await sources.read(missing.href)).module.default, "installed")
       console.log("node graph reload passed")
     } finally { sources.dispose() }
   `,

services/www/openapi.json

@@ -15250,9 +15250,6 @@
           },
           "redirect_uri": {
             "type": "string"
-          },
-          "auth_server_metadata_url": {
-            "type": "string"
           }
         },
         "additionalProperties": false
@@ -15552,9 +15549,6 @@
           },
           "requireAssistantAfterTool": {
             "type": "boolean"
-          },
-          "supportsPromptCacheKey": {
-            "type": "boolean"
           }
         },
         "additionalProperties": false

services/www/public/openapi.json

@@ -15250,9 +15250,6 @@
           },
           "redirect_uri": {
             "type": "string"
-          },
-          "auth_server_metadata_url": {
-            "type": "string"
           }
         },
         "additionalProperties": false
@@ -15552,9 +15549,6 @@
           },
           "requireAssistantAfterTool": {
             "type": "boolean"
-          },
-          "supportsPromptCacheKey": {
-            "type": "boolean"
           }
         },
         "additionalProperties": false

services/www/src/docs/assets/fonts/IBM-Plex-Mono-LICENSE

@@ -1,8 +1,8 @@
-Copyright © 2017 IBM Corp. with Reserved Font Name "Plex"
+Google Inc.
 
 This Font Software is licensed under the SIL Open Font License, Version 1.1.
-
-This license is copied below, and is also available with a FAQ at: http://scripts.sil.org/OFL
+This license is copied below, and is also available with a FAQ at:
+http://scripts.sil.org/OFL
 
 
 -----------------------------------------------------------

services/www/src/docs/content/mcp-servers.mdx

@@ -230,7 +230,6 @@ When a provider gives you client credentials, use V2's snake_case OAuth fields:
 | `scope` | Space-delimited scopes to request. |
 | `callback_port` | Local callback port from `1` through `65535`. An available ephemeral port is the default. |
 | `redirect_uri` | Pre-registered loopback URI whose path and port reach the local callback listener. |
-| `auth_server_metadata_url` | URL of the authorization server's OAuth or OpenID Connect metadata document. Set it when the MCP server does not publish protected resource metadata that names its authorization server. |
 
 Remove stored OAuth credentials when you need to sign in again or switch accounts:
 

services/www/src/docs/styles/global.css

@@ -1,23 +1,39 @@
 @font-face {
   font-family: "IBM Plex Mono";
-  src: url("../assets/fonts/IBMPlexMonoVariable-Roman.woff2") format("woff2");
-  font-weight: 100 700;
+  src: url("../assets/fonts/ibm-plex-mono-latin-400-normal.woff2") format("woff2");
+  font-weight: 400;
   font-style: normal;
   font-display: swap;
 }
 
 @font-face {
   font-family: "IBM Plex Mono";
-  src: url("../assets/fonts/IBMPlexMonoVariable-Italic.woff2") format("woff2");
-  font-weight: 100 700;
+  src: url("../assets/fonts/ibm-plex-mono-latin-700-normal.woff2") format("woff2");
+  font-weight: 700;
+  font-style: normal;
+  font-display: swap;
+}
+
+@font-face {
+  font-family: "IBM Plex Mono";
+  src: url("../assets/fonts/ibm-plex-mono-latin-400-italic.woff2") format("woff2");
+  font-weight: 400;
+  font-style: italic;
+  font-display: swap;
+}
+
+@font-face {
+  font-family: "IBM Plex Mono";
+  src: url("../assets/fonts/ibm-plex-mono-latin-700-italic.woff2") format("woff2");
+  font-weight: 700;
   font-style: italic;
   font-display: swap;
 }
 
 :root {
   color-scheme: dark;
-  --background: #000000;
-  --foreground: #efefef;
+  --background: #090909;
+  --foreground: #ededed;
   --muted: #929292;
   --border: #303030;
   --surface: #101010;
@@ -62,8 +78,7 @@ body {
   color: var(--foreground);
   font-family: "IBM Plex Mono", monospace;
   font-size: 0.875rem;
-  font-weight: 400;
-  line-height: 1.8em;
+  line-height: 1.5;
   letter-spacing: 0.02em;
 }