fix(core): execute renamed tool definitions

packages/ai/AGENTS.md

@@ -10,7 +10,7 @@
 
 ## Conventions
 
-Per-type constructors live on the type, not as top-level re-exports. Use `Message.system(...)`, `Message.user(...)`, `Message.assistant(...)`, `Message.tool(...)`, `LanguageModel.make(...)`, `ToolDefinition.make(...)`, `ToolCallPart.make(...)`, `ToolResultPart.make(...)`, `ToolChoice.make(...)`, `ToolChoice.named(...)`, `SystemPart.make(...)`, and `GenerationOptions.make(...)` directly. The top-level `LLM` namespace is reserved for request-shaped call APIs: `LLM.request`, `LLM.generate`, `LLM.stream`, and `LLM.generateObject`. Use `LLMRequest.update(...)` when deriving canonical request data; do not add a duplicate `LLM.updateRequest(...)` path. Two ways to construct the same thing is one too many.
+Per-type constructors live on the type, not as top-level re-exports. Use `Message.system(...)`, `Message.user(...)`, `Message.assistant(...)`, `Message.tool(...)`, `LanguageModel.make(...)`, `ToolDefinition.make(...)`, `ToolCallPart.make(...)`, `ToolResultPart.make(...)`, `ToolChoice.make(...)`, `ToolChoice.named(...)`, `SystemPart.make(...)`, and `GenerationOptions.make(...)` directly. The top-level `LLM` namespace is reserved for request-shaped call APIs: `LLM.request`, `LLM.generate`, `LLM.stream`, `LLM.updateRequest`, and `LLM.generateObject`. Two ways to construct the same thing is one too many.
 
 - Keep provider-defined string enums forward-compatible. Expose known values for autocomplete while accepting future values with `Known | (string & {})`; use `Schema.String` at runtime unless rejecting unknown values is required for correctness.
 

packages/ai/README.md

@@ -3,9 +3,8 @@
 Schema-first AI primitives for opencode. Provider quirks live in adapters, not in calling code.
 
 ```ts
-import { Effect, Layer } from "effect"
+import { Effect } from "effect"
 import { LLM, LLMClient } from "@opencode-ai/ai"
-import { RequestExecutor } from "@opencode-ai/ai/route"
 import { OpenAI } from "@opencode-ai/ai/providers"
 
 const model = OpenAI.configure({ apiKey: process.env.OPENAI_API_KEY }).responses("gpt-4o-mini")
@@ -21,10 +20,6 @@ const program = Effect.gen(function* () {
   const response = yield* LLMClient.generate(request)
   console.log(response.text)
 })
-
-const llmLayer = LLMClient.layer.pipe(Layer.provide(RequestExecutor.fetchLayer))
-
-await Effect.runPromise(program.pipe(Effect.provide(llmLayer)))
 ```
 
 Run `LLMClient.stream(request)` instead of `generate` when you want incremental `LLMEvent`s. The event stream is provider-neutral — same shape across OpenAI Chat, OpenAI Responses, Anthropic Messages, Gemini, Bedrock Converse, and any OpenAI-compatible deployment.
@@ -205,32 +200,6 @@ The hosted result is represented as a provider-executed tool call and tool resul
 - **`Image.generate({...})`** — generate images through a provider-neutral image request and response model.
 - **`ImageClient`** — Effect service and layer for image execution, parallel to `LLMClient`.
 
-## Testing
-
-Use the deterministic test client from `@opencode-ai/ai/testing` to script provider-neutral responses and inspect
-the requests sent by code under test:
-
-```ts
-import { Effect } from "effect"
-import { TestLLM } from "@opencode-ai/ai/testing"
-
-const testLLM = TestLLM.layer({
-  fallback: TestLLM.text("Hello from the test model", "text-1"),
-})
-
-// TestLLM.clientLayer provides LLMClient.Service and consumes TestLLM.Service.
-const programWithTestClient = Effect.gen(function* () {
-  const result = yield* program
-  const test = yield* TestLLM.Service
-  console.log(test.requests)
-  return result
-}).pipe(Effect.provide(TestLLM.clientLayer), Effect.provide(testLLM))
-```
-
-`TestLLM.push(...)` scripts one-shot responses, `TestLLM.always(...)` changes the fallback, and
-`TestLLM.wait(...)` lets concurrent tests wait until a request has arrived. Every received canonical request is
-available on the yielded `TestLLM.Service`.
-
 ## Caching
 
 Prompt caching is **on by default**. Every `LLMRequest` resolves to `cache: "auto"` unless the caller opts out with `cache: "none"`. Each protocol translates `CacheHint`s to its wire format (`cache_control` on Anthropic, `cachePoint` on Bedrock; OpenAI and Gemini do implicit caching server-side and don't need inline markers — auto is a no-op there).

packages/ai/src/image-client.ts

@@ -15,11 +15,11 @@ export class Service extends Context.Service<Service, Interface>()("@opencode/Im
 
 export const generate = <Options extends ImageOptions>(
   request: ImageRequestFor<Options>,
-): Effect.Effect<ImageResponse, AIError, Service> =>
+): Effect.Effect<ImageResponse, AIError> =>
   Effect.gen(function* () {
     const client = yield* Service
     return yield* client.generate(request)
-  })
+  }) as Effect.Effect<ImageResponse, AIError>
 
 export const layer: Layer.Layer<Service, never, RequestExecutor.Service> = Layer.effect(
   Service,

packages/ai/src/llm.ts

@@ -1,5 +1,5 @@
 import { Effect, JsonSchema, Schema } from "effect"
-import { LLMClient, Service } from "./route/client"
+import { LLMClient } from "./route/client"
 import {
   GenerationOptions,
   HttpOptions,
@@ -151,10 +151,10 @@ const runGenerateObject = Effect.fn("LLM.generateObject")(function* (
  */
 export function generateObject<const SelectedLanguageModel extends LanguageModel, S extends ToolSchema<any>>(
   options: GenerateObjectOptions<S, SelectedLanguageModel>,
-): Effect.Effect<GenerateObjectResponse<Schema.Schema.Type<S>>, AIError, Service>
+): Effect.Effect<GenerateObjectResponse<Schema.Schema.Type<S>>, AIError>
 export function generateObject<const SelectedLanguageModel extends LanguageModel>(
   options: GenerateObjectDynamicOptions<SelectedLanguageModel>,
-): Effect.Effect<GenerateObjectResponse<unknown>, AIError, Service>
+): Effect.Effect<GenerateObjectResponse<unknown>, AIError>
 export function generateObject(options: GenerateObjectOptions<ToolSchema<any>> | GenerateObjectDynamicOptions) {
   if ("schema" in options) {
     const { schema, ...rest } = options

packages/ai/src/route/client.ts

@@ -5,7 +5,7 @@ import { Endpoint, type EndpointPatch } from "./endpoint"
 import { RequestExecutor } from "./executor"
 import { Framing } from "./framing"
 import { HttpTransport } from "./transport"
-import type { HttpMiddleware, HttpRequestTransform, Transport, TransportRuntime } from "./transport"
+import type { HttpRequestTransform, Transport, TransportRuntime } from "./transport"
 import { WebSocketExecutor } from "./transport"
 import type { Protocol } from "./protocol"
 import { applyCachePolicy } from "../cache-policy"
@@ -156,7 +156,6 @@ export interface Interface {
 
 export interface StreamOptions {
   readonly transform?: HttpRequestTransform
-  readonly http?: HttpMiddleware
 }
 
 export interface StreamMethod {
@@ -309,7 +308,6 @@ function makeFromTransport<Body, Prepared, Frame, Event, State>(
           encodeBody,
           headers: routeInput.headers,
           transform: options?.transform,
-          middleware: options?.http,
         }),
       streamPrepared: (prepared: Prepared, request: LLMRequest, runtime: TransportRuntime) => {
         const route = `${request.model.provider}/${request.model.route.id}`
@@ -424,18 +422,18 @@ const generateWith = (stream: Interface["stream"]) =>
     )
   })
 
-export function stream(request: LLMRequest, options?: StreamOptions): Stream.Stream<LLMEvent, AIError, Service> {
+export function stream(request: LLMRequest, options?: StreamOptions): Stream.Stream<LLMEvent, AIError> {
   return Stream.unwrap(
     Effect.gen(function* () {
       return (yield* Service).stream(request, options)
     }),
-  )
+  ) as Stream.Stream<LLMEvent, AIError>
 }
 
-export function generate(request: LLMRequest, options?: StreamOptions): Effect.Effect<LLMResponse, AIError, Service> {
+export function generate(request: LLMRequest, options?: StreamOptions): Effect.Effect<LLMResponse, AIError> {
   return Effect.gen(function* () {
     return yield* (yield* Service).generate(request, options)
-  })
+  }) as Effect.Effect<LLMResponse, AIError>
 }
 
 export const streamRequest = (request: LLMRequest, options?: StreamOptions) =>

packages/ai/src/route/executor.ts

@@ -20,18 +20,9 @@ import { classifyProviderFailure } from "../provider-error"
 export interface Interface {
   readonly execute: (
     request: HttpClientRequest.HttpClientRequest,
-    middleware?: HttpMiddleware,
   ) => Effect.Effect<HttpClientResponse.HttpClientResponse, AIError>
 }
 
-export type HttpHandler = (
-  request: HttpClientRequest.HttpClientRequest,
-) => Effect.Effect<HttpClientResponse.HttpClientResponse, Error>
-export type HttpMiddleware = (
-  request: HttpClientRequest.HttpClientRequest,
-  handler: HttpHandler,
-) => Effect.Effect<HttpClientResponse.HttpClientResponse, Error>
-
 export class Service extends Context.Service<Service, Interface>()("@opencode/AI/RequestExecutor") {}
 
 const BODY_LIMIT = 16_384
@@ -291,20 +282,12 @@ export const layer: Layer.Layer<Service, never, HttpClient.HttpClient> = Layer.e
   Service,
   Effect.gen(function* () {
     const http = yield* HttpClient.HttpClient
-    const executeOnce = (request: HttpClientRequest.HttpClientRequest, middleware?: HttpMiddleware) =>
+    const executeOnce = (request: HttpClientRequest.HttpClientRequest) =>
       Effect.gen(function* () {
         const redactedNames = yield* Headers.CurrentRedactedNames
-        if (!middleware)
-          return yield* http
-            .execute(request)
-            .pipe(Effect.mapError(toHttpError(redactedNames)), Effect.flatMap(statusError(request, redactedNames)))
-
-        const response = yield* middleware(request, (input) =>
-          http
-            .execute(input)
-            .pipe(Effect.mapError((cause) => (cause instanceof Error ? cause : new Error(String(cause))))),
-        ).pipe(Effect.mapError(toHttpError(redactedNames)))
-        return yield* statusError(response.request, redactedNames)(response)
+        return yield* http
+          .execute(request)
+          .pipe(Effect.mapError(toHttpError(redactedNames)), Effect.flatMap(statusError(request, redactedNames)))
       })
     return Service.of({
       execute: executeOnce,

packages/ai/src/route/index.ts

@@ -23,11 +23,4 @@ export type { ApiKeyMode, AuthOverride, ProviderAuthOption } from "./auth-option
 export type { Definition as EndpointFn, EndpointInput } from "./endpoint"
 export type { Definition as FramingDef } from "./framing"
 export type { Protocol as ProtocolDef } from "./protocol"
-export type {
-  HttpHandler,
-  HttpMiddleware,
-  HttpRequest,
-  HttpRequestTransform,
-  Transport as TransportDef,
-  TransportRuntime,
-} from "./transport"
+export type { HttpRequest, HttpRequestTransform, Transport as TransportDef, TransportRuntime } from "./transport"

packages/ai/src/route/transport/http.ts

@@ -3,7 +3,7 @@ import { Headers, HttpClientRequest } from "effect/unstable/http"
 import { Auth } from "../auth"
 import { render as renderEndpoint } from "../endpoint"
 import { Framing } from "../framing"
-import type { HttpMiddleware, Transport, TransportPrepareInput } from "./index"
+import type { Transport, TransportPrepareInput } from "./index"
 import * as ProviderShared from "../../protocols/shared"
 import { mergeJsonRecords, type LLMRequest } from "../../schema"
 
@@ -19,7 +19,6 @@ export interface JsonRequestParts<Body = unknown> {
 export interface HttpPrepared<Frame> {
   readonly request: HttpClientRequest.HttpClientRequest
   readonly framing: Framing.Definition<Frame>
-  readonly middleware?: HttpMiddleware
 }
 
 const applyQuery = (url: string, query: Record<string, string> | undefined) => {
@@ -75,23 +74,21 @@ export const httpJson = <Body, Frame>(input: HttpJsonInput<Body, Frame>): HttpJs
   prepare: (prepareInput) =>
     Effect.gen(function* () {
       const parts = yield* jsonRequestParts({ ...prepareInput })
-      const transformed = { url: parts.url, method: "POST", headers: { ...parts.headers }, body: parts.bodyText }
-      yield* prepareInput.transform?.(transformed) ?? Effect.void
-      const request = ProviderShared.jsonPost({
-        url: transformed.url,
-        body: transformed.body ?? "",
-        headers: Headers.fromInput(transformed.headers),
-      })
+      const request = { url: parts.url, method: "POST", headers: { ...parts.headers }, body: parts.bodyText }
+      yield* (prepareInput.transform?.(request) ?? Effect.void)
       return {
-        request,
+        request: ProviderShared.jsonPost({
+          url: request.url,
+          body: request.body ?? "",
+          headers: Headers.fromInput(request.headers),
+        }),
         framing: input.framing,
-        middleware: prepareInput.middleware,
       }
     }),
   frames: (prepared, request, runtime) =>
     Stream.unwrap(
       runtime.http
-        .execute(prepared.request, prepared.middleware)
+        .execute(prepared.request)
         .pipe(
           Effect.map((response) =>
             prepared.framing.frame(

packages/ai/src/route/transport/index.ts

@@ -1,7 +1,7 @@
 import type { Effect, Stream } from "effect"
 import { Endpoint } from "../endpoint"
 import { Auth } from "../auth"
-import type { HttpMiddleware, Interface as RequestExecutorInterface } from "../executor"
+import type { Interface as RequestExecutorInterface } from "../executor"
 import type { Interface as WebSocketExecutorInterface } from "./websocket"
 import type { AIError, LLMRequest } from "../../schema"
 
@@ -33,9 +33,7 @@ export interface TransportPrepareInput<Body> {
   readonly encodeBody: (body: Body) => string
   readonly headers?: (input: { readonly request: LLMRequest }) => Record<string, string>
   readonly transform?: HttpRequestTransform
-  readonly middleware?: HttpMiddleware
 }
 
 export * as HttpTransport from "./http"
-export type { HttpHandler, HttpMiddleware } from "../executor"
 export { WebSocketExecutor, WebSocketTransport } from "./websocket"

packages/ai/test/compile.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, test } from "bun:test"
-import { Effect, Ref, Schema } from "effect"
-import { HttpClientRequest, HttpClientResponse } from "effect/unstable/http"
+import { Effect, Schema } from "effect"
+import { HttpClientRequest } from "effect/unstable/http"
 import { LLM, mergeProviderOptions } from "../src"
 import { AnthropicMessages, OpenAIChat } from "../src/protocols"
 import { Auth, LLMClient } from "../src/route"
@@ -146,16 +146,12 @@ describe("request option precedence", () => {
         prompt: "Say hello.",
       }),
       {
-        http: (request, handler) =>
-          Effect.gen(function* () {
-            return yield* handler(
-              request.pipe(
-                HttpClientRequest.setUrl("https://proxy.test/v1/chat/completions"),
-                HttpClientRequest.setMethod("PUT"),
-                HttpClientRequest.setHeader("x-plugin", "transformed"),
-                HttpClientRequest.bodyText(JSON.stringify({ transformed: true }), "application/custom+json"),
-              ),
-            )
+        transform: (request) =>
+          Effect.sync(() => {
+            expect(request.headers.authorization).toBe("Bearer fresh-key")
+            request.url = "https://proxy.test/v1/chat/completions"
+            request.headers["x-plugin"] = "transformed"
+            request.body = JSON.stringify({ transformed: true })
           }),
       },
     ).pipe(
@@ -164,9 +160,7 @@ describe("request option precedence", () => {
           Effect.gen(function* () {
             const web = yield* HttpClientRequest.toWeb(input.request).pipe(Effect.orDie)
             expect(web.url).toBe("https://proxy.test/v1/chat/completions")
-            expect(web.method).toBe("PUT")
             expect(web.headers.get("x-plugin")).toBe("transformed")
-            expect(web.headers.get("content-type")).toBe("application/custom+json")
             expect(decodeJson(input.text)).toEqual({ transformed: true })
             return input.respond(sseEvents(deltaChunk({}, "stop")), {
               headers: { "content-type": "text/event-stream" },
@@ -177,82 +171,6 @@ describe("request option precedence", () => {
     ),
   )
 
-  it.effect("transforms the HTTP response before protocol decoding", () =>
-    Effect.gen(function* () {
-      const response = yield* LLMClient.generate(
-        LLM.request({
-          model: OpenAIChat.route
-            .with({ endpoint: { baseURL: "https://api.openai.test/v1/" }, auth: Auth.bearer("test") })
-            .model({ id: "gpt-4o-mini" }),
-          prompt: "Say hello.",
-        }),
-        {
-          http: (request, handler) =>
-            Effect.gen(function* () {
-              const response = yield* handler(request)
-              return HttpClientResponse.fromWeb(
-                response.request,
-                new Response((yield* response.text).replace("network", "hooked"), {
-                  status: response.status,
-                  headers: response.headers,
-                }),
-              )
-            }),
-        },
-      ).pipe(
-        Effect.provide(
-          dynamicResponse((input) =>
-            Effect.succeed(
-              input.respond(sseEvents(deltaChunk({ content: "network" }, "stop")), {
-                headers: { "content-type": "text/event-stream" },
-              }),
-            ),
-          ),
-        ),
-      )
-
-      expect(response.text).toBe("hooked")
-    }),
-  )
-
-  it.effect("can inspect an error response and retry the native request", () =>
-    Effect.gen(function* () {
-      const attempts = yield* Ref.make(0)
-      const response = yield* LLMClient.generate(
-        LLM.request({
-          model: OpenAIChat.route
-            .with({ endpoint: { baseURL: "https://api.openai.test/v1/" }, auth: Auth.bearer("stale") })
-            .model({ id: "gpt-4o-mini" }),
-          prompt: "Say hello.",
-        }),
-        {
-          http: (request, handler) =>
-            Effect.gen(function* () {
-              const response = yield* handler(request)
-              expect(response.status).toBe(401)
-              return yield* handler(HttpClientRequest.setHeader(request, "authorization", "Bearer refreshed"))
-            }),
-        },
-      ).pipe(
-        Effect.provide(
-          dynamicResponse((input) =>
-            Effect.gen(function* () {
-              yield* Ref.update(attempts, (value) => value + 1)
-              if (input.request.headers.authorization !== "Bearer refreshed")
-                return input.respond("unauthorized", { status: 401 })
-              return input.respond(sseEvents(deltaChunk({ content: "retried" }, "stop")), {
-                headers: { "content-type": "text/event-stream" },
-              })
-            }),
-          ),
-        ),
-      )
-
-      expect(response.text).toBe("retried")
-      expect(yield* Ref.get(attempts)).toBe(2)
-    }),
-  )
-
   it.effect("applies raw body overlays after protocol lowering", () =>
     LLMClient.generate(
       LLM.request({

packages/ai/test/image.types.ts

@@ -1,7 +1,5 @@
-import { Effect } from "effect"
 import {
   Image,
-  ImageClient,
   ImageInput,
   ImageModel,
   type ImageModelOptions,
@@ -9,13 +7,8 @@ import {
   type ImageRequestFor,
   type ImageRoute,
 } from "../src"
-import type { Service } from "../src/image-client"
 import { Google, OpenAI, XAI, ZAI } from "../src/providers"
 
-type Requirements<T> = T extends Effect.Effect<infer _A, infer _E, infer R> ? R : never
-type Equal<A, B> = [A, B] extends [B, A] ? true : false
-type Assert<T extends true> = T
-
 type GoogleLikeOptions = {
   readonly aspectRatio?: "1:1" | "16:9"
   readonly imageSize?: "1K" | "2K"
@@ -153,9 +146,6 @@ const request = Image.request({
 })
 const typedRequest: ImageRequestFor<GoogleLikeOptions> = request
 void typedRequest
-const generated = ImageClient.generate(request)
-type GenerateRequirements = Assert<Equal<Requirements<typeof generated>, Service>>
-void (true satisfies GenerateRequirements)
 
 // @ts-expect-error Image requests no longer expose a common count option.
 Image.generate({ model: openai, prompt: "A lighthouse", count: 2 })

packages/ai/test/llm-option-types.types.ts

@@ -1,11 +1,5 @@
-import { Effect, Schema, Stream } from "effect"
-import {
-  LLM,
-  type LLMClientService,
-  type LanguageModel,
-  type LanguageModelProviderOptions,
-  type ProviderOptions,
-} from "../src"
+import { Schema } from "effect"
+import { LLM, type LanguageModel, type LanguageModelProviderOptions, type ProviderOptions } from "../src"
 import { OpenAIChat } from "../src/protocols"
 
 interface ExampleOptions {
@@ -21,19 +15,9 @@ const model = OpenAIChat.route
   .with({ endpoint: { baseURL: "https://example.com/v1" } })
   .model<ExampleProviderOptions>({ id: "example" })
 
-type Requirements<T> = T extends Effect.Effect<infer _A, infer _E, infer R> ? R : never
-type StreamRequirements<T> = T extends Stream.Stream<infer _A, infer _E, infer R> ? R : never
-type Equal<A, B> = [A, B] extends [B, A] ? true : false
-type Assert<T extends true> = T
-
 LLM.request({ model, prompt: "Hello", providerOptions: { example: { mode: "fast" } } })
 LLM.request({ model, prompt: "Hello", providerOptions: { future: { option: true } } })
 
-const generated = LLM.generate(LLM.request({ model, prompt: "Hello" }))
-type GenerateRequirements = Assert<Equal<Requirements<typeof generated>, LLMClientService>>
-const streamed = LLM.stream(LLM.request({ model, prompt: "Hello" }))
-type StreamClientRequirements = Assert<Equal<StreamRequirements<typeof streamed>, LLMClientService>>
-
 LLM.request({
   model,
   prompt: "Hello",
@@ -41,20 +25,12 @@ LLM.request({
   providerOptions: { example: { mode: "slow" } },
 })
 
-const generatedObject = LLM.generateObject({
+LLM.generateObject({
   model,
   prompt: "Hello",
   schema: Schema.Struct({ answer: Schema.String }),
   providerOptions: { example: { mode: "thorough" } },
 })
-type GenerateObjectRequirements = Assert<Equal<Requirements<typeof generatedObject>, LLMClientService>>
-
-const generatedDynamicObject = LLM.generateObject({
-  model,
-  prompt: "Hello",
-  jsonSchema: { type: "object" },
-})
-type GenerateDynamicObjectRequirements = Assert<Equal<Requirements<typeof generatedDynamicObject>, LLMClientService>>
 
 LLM.generateObject({
   model,
@@ -68,8 +44,4 @@ declare const generic: LanguageModel
 LLM.request({ model: generic, prompt: "Hello", providerOptions: { arbitrary: { option: true } } })
 
 const options: LanguageModelProviderOptions<typeof model> = { example: { mode: "fast" } }
-void (options satisfies LanguageModelProviderOptions<typeof model>)
-void (true satisfies GenerateRequirements)
-void (true satisfies StreamClientRequirements)
-void (true satisfies GenerateObjectRequirements)
-void (true satisfies GenerateDynamicObjectRequirements)
+void options

packages/core/src/agent.ts

@@ -61,7 +61,7 @@ const layer = Layer.effect(
           draft.default = id
         },
         update: (id, fn) => {
-          const current = draft.agents.get(id) ?? (Info.default(id) as Types.DeepMutable<Info>)
+          const current = draft.agents.get(id) ?? (Info.empty(id) as Types.DeepMutable<Info>)
           if (!draft.agents.has(id)) draft.agents.set(id, current)
           fn(current)
           current.id = id

packages/core/src/config/plugin/agent.ts

@@ -58,7 +58,7 @@ export const Plugin = define({
           const files = yield* discover(fs, entry.path)
           return yield* Effect.forEach(files, (file) =>
             fs.readFileStringSafe(file.filepath).pipe(
-              Effect.map((content) => (content ? decode(file, content) : undefined)),
+              Effect.map((content) => content && decode(file, content)),
               Effect.catch(() => Effect.succeed(undefined)),
             ),
           ).pipe(

packages/core/src/session/model-request.ts

@@ -191,22 +191,31 @@ export const layer = Layer.effect(
       const messages = stepLimitReached ? [...history, Message.assistant(MAX_STEPS_PROMPT)] : history
       const toolDefinitions = tools.definitions
       const toolsByName = new Map(toolDefinitions.map((tool) => [tool.name, tool]))
+      // Object identity preserves registry provenance when a hook moves a definition to a new key.
+      const toolNamesByDefinition = new Map<object, string>()
       // Hooks may reshape available definitions but cannot advertise tools omitted by permissions or the Step limit.
+      const hookTools = Object.fromEntries(
+        toolDefinitions.map((tool) => {
+          const definition = { description: tool.description, input: { ...tool.inputSchema } }
+          toolNamesByDefinition.set(definition, tool.name)
+          return [tool.name, definition]
+        }),
+      )
       const contextEvent = yield* hooks.trigger("session", "context", {
         sessionID: session.id,
         agent: agent.id,
         model: resolved.ref,
         system,
         messages,
-        tools: Object.fromEntries(
-          toolDefinitions.map((tool) => [tool.name, { description: tool.description, input: { ...tool.inputSchema } }]),
-        ),
+        tools: hookTools,
       })
+      const executableTools = new Map<string, string>()
       const hookedTools = Object.entries(contextEvent.tools).flatMap(([name, tool]) => {
-        const registered = toolsByName.get(name)
-        return registered
-          ? [{ ...registered, description: tool.description, inputSchema: tool.input }]
-          : []
+        const registeredName = toolNamesByDefinition.get(tool)
+        const registered = registeredName ? toolsByName.get(registeredName) : undefined
+        if (!registered || !registeredName) return []
+        executableTools.set(name, registeredName)
+        return [{ ...registered, name, description: tool.description, inputSchema: tool.input }]
       })
       const request = LLM.request({
         model,
@@ -259,10 +268,14 @@ export const layer = Layer.effect(
       const executeTool: Prepared["executeTool"] = (executeInput) => {
         if (stepLimitReached)
           return new Tool.Error({ message: "Tools are disabled after the maximum agent steps" })
-        if (toolsByName.has(executeInput.call.name) && !Object.hasOwn(contextEvent.tools, executeInput.call.name))
+        const registeredName = executableTools.get(executeInput.call.name)
+        if (!registeredName && toolsByName.has(executeInput.call.name))
           return new Tool.Error({ message: `Tool is not available for this request: ${executeInput.call.name}` })
         return tools
-          .execute(executeInput)
+          .execute({
+            ...executeInput,
+            call: { ...executeInput.call, name: registeredName ?? executeInput.call.name },
+          })
           .pipe(Effect.catchCauseFilter(declineDefect, (decline) => Effect.fail(decline)))
       }
       return {

packages/core/test/agent.test.ts

@@ -120,7 +120,7 @@ describe("Agent", () => {
       const id = Agent.ID.make("custom")
 
       yield* agent.transform((editor) => editor.update(id, () => {}))
-      expect(yield* agent.get(id)).toEqual(Agent.Info.default(id))
+      expect(yield* agent.get(id)).toEqual(Agent.Info.empty(id))
 
       yield* agent.transform((editor) => editor.remove(id))
       expect(yield* agent.get(id)).toBeUndefined()

packages/core/test/config/agent.test.ts

@@ -266,7 +266,6 @@ permissions:
 Use native v2 fields.`,
             )
             await fs.writeFile(path.join(tmp.path, "agents", "disabled.md"), "---\ndisabled: true\n---\nDisabled")
-            await fs.writeFile(path.join(tmp.path, "agents", "empty.md"), "")
             await fs.writeFile(path.join(tmp.path, "modes", "plan.md"), "Make a plan.")
           })
           const agents = yield* Agent.Service
@@ -296,7 +295,6 @@ Use native v2 fields.`,
             permissions: [...defaultPermissions, { action: "edit", resource: "*", effect: "deny" }],
           })
           expect(yield* agents.get(Agent.ID.make("disabled"))).toBeUndefined()
-          expect(yield* agents.get(Agent.ID.make("empty"))).toBeUndefined()
           expect(yield* agents.get(Agent.ID.make("plan"))).toMatchObject({ system: "Make a plan.", mode: "primary" })
         }),
       ),

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

@@ -12,7 +12,7 @@ import { readInitial, readUpdate } from "./lib/instructions"
 const build = Agent.ID.make("build")
 
 const selection = (permissions: Permission.Ruleset = []) => {
-  const info = Agent.Info.make({ ...Agent.Info.default(build), permissions })
+  const info = Agent.Info.make({ ...Agent.Info.empty(build), permissions })
   return { id: info.id, info }
 }
 

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

@@ -887,6 +887,42 @@ describe("SessionRunnerLLM", () => {
     }),
   )
 
+  it.effect("advertises and executes a tool renamed by a session context hook", () =>
+    Effect.gen(function* () {
+      const session = yield* setup
+      const hooks = yield* PluginHooks.Service
+      yield* hooks.register("session", "context", (event) =>
+        Effect.sync(() => {
+          const tool = event.tools.echo
+          if (!tool) return
+          event.tools.renamed_echo = tool
+          delete event.tools.echo
+        }),
+      )
+      yield* admit(session, "Use the renamed tool")
+      yield* TestLLM.push(TestLLM.tool("call-renamed", "renamed_echo", { text: "renamed" }), [])
+
+      yield* session.resume(sessionID)
+
+      expect(requests[0]?.tools.map((tool) => tool.name)).toContain("renamed_echo")
+      expect(requests[0]?.tools.map((tool) => tool.name)).not.toContain("echo")
+      expect(executions).toEqual(["renamed"])
+      expect(yield* session.context(sessionID)).toMatchObject([
+        { type: "user", text: "Use the renamed tool" },
+        {
+          type: "assistant",
+          content: [
+            {
+              type: "tool",
+              id: "call-renamed",
+              state: { status: "completed", content: [{ type: "text", text: "renamed" }] },
+            },
+          ],
+        },
+      ])
+    }),
+  )
+
   it.effect("advertises and executes a location registered tool", () =>
     Effect.gen(function* () {
       const session = yield* setup

packages/core/test/shared-schema.test.ts

@@ -166,7 +166,7 @@ test("Core reuses the canonical shared schemas", async () => {
   ]
   for (const [core, shared] of schemas) expect(core).toBe(shared)
 
-  expect(Agent.Info.default(Agent.ID.make("test"))).toEqual(Agent.Info.default(Agent.ID.make("test")))
+  expect(Agent.Info.empty(Agent.ID.make("test"))).toEqual(Agent.Info.empty(Agent.ID.make("test")))
   expect(coreModel.Info.default(coreProvider.ID.make("test"), coreModel.ID.make("model"))).toEqual(
     Model.Info.default(Provider.ID.make("test"), Model.ID.make("model")),
   )

packages/core/test/skill/instructions.test.ts

@@ -47,7 +47,7 @@ const layer = (list: () => Skill.Info[]) =>
 describe("SkillInstructions", () => {
   it.effect("renders described agent skills and updates the complete available list", () => {
     const agent = Agent.Info.make({
-      ...Agent.Info.default(build),
+      ...Agent.Info.empty(build),
       permissions: [{ action: "skill", resource: "denied", effect: "deny" }],
     })
     let skills = [hidden, denied, manual, effect]
@@ -80,7 +80,7 @@ describe("SkillInstructions", () => {
   })
 
   it.effect("announces added and removed skills as deltas without restating the list", () => {
-    const agent = Agent.Info.make(Agent.Info.default(build))
+    const agent = Agent.Info.make(Agent.Info.empty(build))
     const debugging = Skill.Info.make({
       id: Skill.ID.make("debugging"),
       name: Skill.Name.make("Debugging"),
@@ -117,7 +117,7 @@ describe("SkillInstructions", () => {
   })
 
   it.effect("restates the full skill list when a description changes", () => {
-    const agent = Agent.Info.make(Agent.Info.default(build))
+    const agent = Agent.Info.make(Agent.Info.empty(build))
     let skills = [effect]
     return Effect.gen(function* () {
       const instructions = yield* SkillInstructions.Service
@@ -138,7 +138,7 @@ describe("SkillInstructions", () => {
 
   it.effect("omits instructions when the selected agent denies all skills", () => {
     const agent = Agent.Info.make({
-      ...Agent.Info.default(build),
+      ...Agent.Info.empty(build),
       permissions: [{ action: "skill", resource: "*", effect: "deny" }],
     })
     return Effect.gen(function* () {
@@ -149,7 +149,7 @@ describe("SkillInstructions", () => {
 
   it.effect("omits instructions when a resource-specific denial follows the global denial", () => {
     const agent = Agent.Info.make({
-      ...Agent.Info.default(build),
+      ...Agent.Info.empty(build),
       permissions: [
         { action: "skill", resource: "*", effect: "deny" },
         { action: "skill", resource: "hidden", effect: "deny" },
@@ -163,7 +163,7 @@ describe("SkillInstructions", () => {
 
   it.effect("retains specifically allowed skills after a global denial", () => {
     const agent = Agent.Info.make({
-      ...Agent.Info.default(build),
+      ...Agent.Info.empty(build),
       permissions: [
         { action: "skill", resource: "*", effect: "deny" },
         { action: "skill", resource: "effect", effect: "allow" },
@@ -179,7 +179,7 @@ describe("SkillInstructions", () => {
 
   it.effect("omits instructions when a specifically allowed skill is denied again", () => {
     const agent = Agent.Info.make({
-      ...Agent.Info.default(build),
+      ...Agent.Info.empty(build),
       permissions: [
         { action: "skill", resource: "*", effect: "deny" },
         { action: "skill", resource: "effect", effect: "allow" },

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

@@ -301,7 +301,6 @@ describe("ShellTool", () => {
       },
       (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]().then(() => undefined)),
     ),
-    { timeout: 15_000 },
   )
 
   it.live("rejects a workdir that stops being a directory during approval", () =>
@@ -473,7 +472,6 @@ describe("ShellTool", () => {
       },
       (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]().then(() => undefined)),
     ),
-    { timeout: 15_000 },
   )
 
   it.live(
@@ -540,7 +538,7 @@ describe("ShellTool", () => {
       (tmp) => {
           reset()
           return withSession(tmp.path, (registry) =>
-            executeTool(registry, call({ command: timeoutOutputCommand, timeout: isWindows ? 3_000 : 50 })),
+            executeTool(registry, call({ command: timeoutOutputCommand, timeout: isWindows ? 500 : 50 })),
           ).pipe(
             Effect.andThen((settled) =>
               Effect.sync(() => {
@@ -559,7 +557,6 @@ describe("ShellTool", () => {
       },
       (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]().then(() => undefined)),
     ),
-    { timeout: 15_000 },
   )
 
   it.live("returns the shell id for a background command", () =>

packages/schema/src/agent.ts

@@ -36,7 +36,7 @@ export const Info = Schema.Struct({
   .annotate({ identifier: "Agent.Info" })
   .pipe(
     statics(() => ({
-      default: (id: ID) =>
+      empty: (id: ID) =>
         ({
           id,
           name: Name.make(id),