feat: add v2 generate text endpoint (#34371)

packages/core/src/generate.ts

@@ -0,0 +1,109 @@
+export * as Generate from "./generate"
+
+import { LLM, LLMClient, LLMError } from "@opencode-ai/llm"
+import { Context, Effect, Layer, Schema } from "effect"
+import { Catalog } from "./catalog"
+import { makeLocationNode } from "./effect/app-node"
+import { llmClient } from "./effect/app-node-platform"
+import { Integration } from "./integration"
+import { ModelV2 } from "./model"
+import { SessionRunnerModel } from "./session/runner/model"
+
+export interface TextInput {
+  readonly prompt: string
+  readonly model?: ModelV2.Ref
+}
+
+export class ModelSelectionError extends Schema.TaggedErrorClass<ModelSelectionError>()(
+  "Generate.ModelSelectionError",
+  { message: Schema.String },
+) {}
+
+export class UnavailableError extends Schema.TaggedErrorClass<UnavailableError>()(
+  "Generate.UnavailableError",
+  { message: Schema.String, service: Schema.optional(Schema.String) },
+) {}
+
+export type Error = ModelSelectionError | UnavailableError
+
+export interface Interface {
+  readonly text: (input: TextInput) => Effect.Effect<string, Error>
+}
+
+export class Service extends Context.Service<Service, Interface>()("@opencode/v2/Generate") {}
+
+export const layer = Layer.effect(
+  Service,
+  Effect.gen(function* () {
+    const catalog = yield* Catalog.Service
+    const integrations = yield* Integration.Service
+    const llm = yield* LLMClient.Service
+
+    const selectModel = Effect.fn("Generate.selectModel")(function* (requested?: ModelV2.Ref) {
+      const selected = requested
+        ? yield* catalog.model.get(requested.providerID, requested.id)
+        : yield* catalog.model.default().pipe(
+            Effect.flatMap((model) =>
+              model && SessionRunnerModel.supported(model)
+                ? Effect.succeed(model)
+                : Effect.map(catalog.model.available(), (models) => models.find(SessionRunnerModel.supported)),
+            ),
+          )
+      if (!selected)
+        return yield* new ModelSelectionError({
+          message: requested
+            ? `Model unavailable: ${requested.providerID}/${requested.id}`
+            : "No model specified and no supported model is available",
+        })
+      return yield* SessionRunnerModel.withVariant(selected, requested?.variant).pipe(
+        Effect.mapError(
+          () =>
+            new ModelSelectionError({
+              message: `Variant unavailable for ${selected.providerID}/${selected.id}: ${requested?.variant}`,
+            }),
+        ),
+      )
+    })
+
+    const runText = Effect.fn("Generate.text")(function* (input: TextInput) {
+      const selected = yield* selectModel(input.model)
+      const provider = yield* catalog.provider.get(selected.providerID)
+      const connection = yield* integrations.connection.active(
+        provider?.integrationID ?? Integration.ID.make(selected.providerID),
+      )
+      const credential = connection ? yield* integrations.connection.resolve(connection) : undefined
+      const model = yield* SessionRunnerModel.fromCatalogModel(selected, credential).pipe(
+        Effect.mapError((error) =>
+          input.model
+            ? new ModelSelectionError({ message: error.message })
+            : new UnavailableError({ message: error.message, service: selected.providerID }),
+        ),
+      )
+      const response = yield* llm.generate(LLM.request({ model, prompt: input.prompt })).pipe(
+        Effect.mapError(
+          (error: LLMError) =>
+            new UnavailableError({
+              message: error.message,
+              service: selected.providerID,
+            }),
+        ),
+      )
+      return response.text
+    })
+
+    const text: Interface["text"] = (input) =>
+      runText(input).pipe(
+        Effect.catchTag(
+          "Integration.Authorization",
+          () =>
+            new UnavailableError({
+              message: "Generation credentials are unavailable",
+            }),
+        ),
+      )
+
+    return Service.of({ text })
+  }),
+)
+
+export const node = makeLocationNode({ service: Service, layer, deps: [Catalog.node, Integration.node, llmClient] })

packages/core/src/location-services.ts

@@ -9,6 +9,7 @@ import { Node } from "./effect/app-node"
 import { FileMutation } from "./file-mutation"
 import { FileSystem } from "./filesystem"
 import { FileSystemSearch } from "./filesystem/search"
+import { Generate } from "./generate"
 import { Watcher } from "./filesystem/watcher"
 import { Image } from "./image"
 import { Integration } from "./integration"
@@ -72,6 +73,7 @@ export const locationServices = LayerNode.group([
   ReferenceGuidance.node,
   SessionTodo.node,
   QuestionV2.node,
+  Generate.node,
   ReadToolFileSystem.node,
   BuiltInTools.node,
   SessionRunnerModel.node,

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

@@ -101,7 +101,7 @@ const withDefaults = (model: ModelV2.Info, route: AnyRoute) => {
   })
 }
 
-const withVariant = (
+export const withVariant = (
   model: ModelV2.Info,
   variantID: ModelV2.VariantID | undefined,
 ): Effect.Effect<ModelV2.Info, VariantUnavailableError> => {