refactor(plugin): scope context hook to session (#37175)

Co-authored-by: Dax Raad <d@ironbay.co>

packages/core/src/plugin/hooks.ts

@@ -1,15 +1,15 @@
 export * as PluginHooks from "./hooks"
 
-import type { AIHooks } from "@opencode-ai/plugin/v2/effect/ai"
 import type { AISDKHooks } from "@opencode-ai/plugin/v2/effect/aisdk"
+import type { SessionHooks } from "@opencode-ai/plugin/v2/effect/session"
 import type { ToolHooks } from "@opencode-ai/plugin/v2/effect/tool"
 import { Context, Effect, Layer, Scope } from "effect"
 import { makeLocationNode } from "../effect/app-node"
 import { State } from "../state"
 
 export interface Domains {
-  readonly ai: AIHooks
   readonly aisdk: AISDKHooks
+  readonly session: SessionHooks
   readonly tool: ToolHooks
 }
 

packages/core/src/plugin/host.ts

@@ -80,9 +80,6 @@ export const make = Effect.fn("PluginHost.make")(function* (plugin: PluginV2.Int
           })
         }),
     },
-    ai: {
-      hook: (name, callback) => hooks.register("ai", name, callback),
-    },
     aisdk: {
       hook: (name, callback) => {
         if (name === "sdk") {
@@ -370,6 +367,7 @@ export const make = Effect.fn("PluginHost.make")(function* (plugin: PluginV2.Int
       },
     },
     session: {
+      hook: (name, callback) => hooks.register("session", name, callback),
       create: (input) =>
         runtime.session.create({
           id: input?.id,

packages/core/src/plugin/promise.ts

@@ -63,10 +63,6 @@ export function fromPromise(plugin: Plugin) {
             transform: transform(host.agent),
             reload: () => run(host.agent.reload()),
           },
-          ai: {
-            hook: (name, callback) =>
-              register(host.ai.hook(name, (event) => Effect.promise(() => Promise.resolve(callback(event))))),
-          },
           aisdk: {
             hook: (name, callback) =>
               register(host.aisdk.hook(name, (event) => Effect.promise(() => Promise.resolve(callback(event))))),
@@ -166,6 +162,8 @@ export function fromPromise(plugin: Plugin) {
               register(host.tool.hook(name, (event) => Effect.promise(() => Promise.resolve(callback(event))))),
           },
           session: {
+            hook: (name, callback) =>
+              register(host.session.hook(name, (event) => Effect.promise(() => Promise.resolve(callback(event))))),
             create: (input) =>
               run(
                 host.session.create(

packages/core/src/session/runner/llm.ts

@@ -10,7 +10,7 @@ import {
   isContextOverflowFailure,
   type ProviderErrorEvent,
 } from "@opencode-ai/ai"
-import type { AIHooks } from "@opencode-ai/plugin/v2/effect/ai"
+import type { SessionHooks } from "@opencode-ai/plugin/v2/effect/session"
 import { SessionError } from "@opencode-ai/schema/session-error"
 import { Money } from "@opencode-ai/schema/money"
 import { Cause, Effect, Exit, Fiber, FiberSet, Layer, Option, Semaphore, Stream } from "effect"
@@ -216,7 +216,7 @@ const layer = Layer.effect(
         toolChoice: isLastStep ? "none" : undefined,
       })
       const availableTools = new Map(request.tools.map((tool) => [tool.name, tool]))
-      const requestEvent: AIHooks["request"] = {
+      const contextEvent: SessionHooks["context"] = {
         sessionID: session.id,
         agent: agent.id,
         model: resolved.ref,
@@ -228,11 +228,11 @@ const layer = Layer.effect(
       }
       // Plugins may reshape the draft but cannot advertise tools excluded by
       // permissions, registration state, or the selected agent's step limit.
-      yield* hooks.trigger("ai", "request", requestEvent)
+      yield* hooks.trigger("session", "context", contextEvent)
       const hookedRequest = LLM.updateRequest(request, {
-        system: requestEvent.system,
-        messages: requestEvent.messages,
-        tools: Object.entries(requestEvent.tools).flatMap(([name, tool]) => {
+        system: contextEvent.system,
+        messages: contextEvent.messages,
+        tools: Object.entries(contextEvent.tools).flatMap(([name, tool]) => {
           const registered = availableTools.get(name)
           if (!registered) return []
           return [{ ...registered, description: tool.description, inputSchema: tool.input }]

packages/core/src/tool/patch.ts

@@ -196,7 +196,7 @@ export const Plugin = {
       )
       .pipe(Effect.orDie)
 
-    yield* ctx.ai.hook("request", (event) =>
+    yield* ctx.session.hook("context", (event) =>
       Effect.sync(() => {
         const usePatch =
           event.model.providerID.toLowerCase() === "openai" || event.model.id.toLowerCase().includes("gpt")

packages/core/src/tool/subagent.ts

@@ -216,7 +216,7 @@ export const Plugin = {
       )
       .pipe(Effect.orDie)
 
-    yield* ctx.ai.hook("request", (event) =>
+    yield* ctx.session.hook("context", (event) =>
       Effect.gen(function* () {
         const tool = event.tools[name]
         if (!tool) return