feat(session): execute tools in native LLM runtime

packages/llm/src/tool-runtime.ts

@@ -200,17 +200,17 @@ const dispatch = (tools: Tools, call: ToolCallPart): Effect.Effect<ToolResultVal
   if (!tool.execute)
     return Effect.succeed({ type: "error" as const, value: `Tool has no execute handler: ${call.name}` })
 
-  return decodeAndExecute(tool, call.input).pipe(
+  return decodeAndExecute(tool, call).pipe(
     Effect.catchTag("LLM.ToolFailure", (failure) =>
       Effect.succeed({ type: "error" as const, value: failure.message } satisfies ToolResultValue),
     ),
   )
 }
 
-const decodeAndExecute = (tool: AnyTool, input: unknown): Effect.Effect<ToolResultValue, ToolFailure> =>
-  tool._decode(input).pipe(
+const decodeAndExecute = (tool: AnyTool, call: ToolCallPart): Effect.Effect<ToolResultValue, ToolFailure> =>
+  tool._decode(call.input).pipe(
     Effect.mapError((error) => new ToolFailure({ message: `Invalid tool input: ${error.message}` })),
-    Effect.flatMap((decoded) => tool.execute!(decoded)),
+    Effect.flatMap((decoded) => tool.execute!(decoded, { id: call.id, name: call.name })),
     Effect.flatMap((value) =>
       tool._encode(value).pipe(
         Effect.mapError(

packages/llm/src/tool.ts

@@ -11,6 +11,7 @@ export type ToolSchema<T> = Schema.Codec<T, any, never, never>
 
 export type ToolExecute<Parameters extends ToolSchema<any>, Success extends ToolSchema<any>> = (
   params: Schema.Schema.Type<Parameters>,
+  context?: { readonly id: string; readonly name: string },
 ) => Effect.Effect<Schema.Schema.Type<Success>, ToolFailure>
 
 /**
@@ -61,7 +62,10 @@ type TypedToolConfig = {
 type DynamicToolConfig = {
   readonly description: string
   readonly jsonSchema: JsonSchema.JsonSchema
-  readonly execute?: (params: unknown) => Effect.Effect<unknown, ToolFailure>
+  readonly execute?: (
+    params: unknown,
+    context?: { readonly id: string; readonly name: string },
+  ) => Effect.Effect<unknown, ToolFailure>
 }
 
 /**
@@ -110,7 +114,10 @@ export function make<Parameters extends ToolSchema<any>, Success extends ToolSch
 export function make(config: {
   readonly description: string
   readonly jsonSchema: JsonSchema.JsonSchema
-  readonly execute: (params: unknown) => Effect.Effect<unknown, ToolFailure>
+  readonly execute: (
+    params: unknown,
+    context?: { readonly id: string; readonly name: string },
+  ) => Effect.Effect<unknown, ToolFailure>
 }): AnyExecutableTool
 export function make(config: {
   readonly description: string

packages/opencode/src/session/llm.ts

@@ -2,8 +2,8 @@ import { Provider } from "@/provider/provider"
 import * as Log from "@opencode-ai/core/util/log"
 import { Context, Effect, Layer, Record } from "effect"
 import * as Stream from "effect/Stream"
-import { streamText, wrapLanguageModel, type ModelMessage, type Tool, tool, jsonSchema } from "ai"
-import type { LLMEvent } from "@opencode-ai/llm"
+import { streamText, wrapLanguageModel, type ModelMessage, type Tool, tool as aiTool, jsonSchema, asSchema } from "ai"
+import { tool as nativeTool, ToolFailure, type JsonSchema, type LLMEvent } from "@opencode-ai/llm"
 import { LLMClient, RequestExecutor } from "@opencode-ai/llm/route"
 import { mergeDeep } from "remeda"
 import { GitLabWorkflowLanguageModel } from "gitlab-ai-provider"
@@ -18,6 +18,7 @@ import { Flag } from "@opencode-ai/core/flag/flag"
 import { Permission } from "@/permission"
 import { PermissionID } from "@/permission/schema"
 import { Bus } from "@/bus"
+import { errorMessage } from "@/util/error"
 import { Wildcard } from "@/util/wildcard"
 import { SessionID } from "@/session/schema"
 import { Auth } from "@/auth"
@@ -216,7 +217,7 @@ const live: Layer.Layer<
         Object.keys(tools).length === 0 &&
         hasToolCalls(input.messages)
       ) {
-        tools["_noop"] = tool({
+        tools["_noop"] = aiTool({
           description: "Do not call this tool. It exists only for API compatibility and must never be invoked.",
           inputSchema: jsonSchema({
             type: "object",
@@ -358,31 +359,31 @@ const live: Layer.Layer<
         if (input.model.providerID !== "openai" || input.model.api.npm !== "@ai-sdk/openai") {
           return yield* Effect.fail(new Error("Native LLM runtime currently only supports OpenAI models"))
         }
-        if (Object.keys(sortedTools).length > 0) {
-          return yield* Effect.fail(new Error("Native LLM runtime does not support tools yet"))
-        }
         const apiKey =
           info?.type === "api" ? info.key : typeof item.options.apiKey === "string" ? item.options.apiKey : undefined
         if (!apiKey) return yield* Effect.fail(new Error("Native LLM runtime requires API key auth for OpenAI"))
         const baseURL = typeof item.options.baseURL === "string" ? item.options.baseURL : undefined
+        const request = LLMNative.request({
+          model: input.model,
+          apiKey,
+          baseURL,
+          system: isOpenaiOauth ? system : [],
+          messages: ProviderTransform.message(messages, input.model, options),
+          tools: sortedTools,
+          toolChoice: input.toolChoice,
+          temperature: params.temperature,
+          topP: params.topP,
+          topK: params.topK,
+          maxOutputTokens: params.maxOutputTokens,
+          providerOptions: ProviderTransform.providerOptions(input.model, params.options),
+          headers: requestHeaders,
+        })
         return {
           type: "native" as const,
-          stream: LLMClient.stream(
-            LLMNative.request({
-              model: input.model,
-              apiKey,
-              baseURL,
-              system: isOpenaiOauth ? system : [],
-              messages: ProviderTransform.message(messages, input.model, options),
-              toolChoice: input.toolChoice,
-              temperature: params.temperature,
-              topP: params.topP,
-              topK: params.topK,
-              maxOutputTokens: params.maxOutputTokens,
-              providerOptions: ProviderTransform.providerOptions(input.model, params.options),
-              headers: requestHeaders,
-            }),
-          ).pipe(Stream.provide(LLMClient.layer), Stream.provide(RequestExecutor.defaultLayer)),
+          stream: LLMClient.stream({ request, tools: nativeTools(sortedTools, input) }).pipe(
+            Stream.provide(LLMClient.layer),
+            Stream.provide(RequestExecutor.defaultLayer),
+          ),
         }
       }
 
@@ -502,6 +503,37 @@ function resolveTools(input: Pick<StreamInput, "tools" | "agent" | "permission"
   return Record.filter(input.tools, (_, k) => input.user.tools?.[k] !== false && !disabled.has(k))
 }
 
+function nativeSchema(value: unknown): JsonSchema {
+  if (!value || typeof value !== "object") return { type: "object", properties: {} }
+  if ("jsonSchema" in value && value.jsonSchema && typeof value.jsonSchema === "object")
+    return value.jsonSchema as JsonSchema
+  return asSchema(value as Parameters<typeof asSchema>[0]).jsonSchema as JsonSchema
+}
+
+function nativeTools(tools: Record<string, Tool>, input: StreamRequest) {
+  return Object.fromEntries(
+    Object.entries(tools).map(([name, item]) => [
+      name,
+      nativeTool({
+        description: item.description ?? "",
+        jsonSchema: nativeSchema(item.inputSchema),
+        execute: (args: unknown, ctx?: { readonly id: string; readonly name: string }) =>
+          Effect.tryPromise({
+            try: () => {
+              if (!item.execute) throw new Error(`Tool has no execute handler: ${name}`)
+              return item.execute(args, {
+                toolCallId: ctx?.id ?? name,
+                messages: input.messages,
+                abortSignal: input.abort,
+              })
+            },
+            catch: (error) => new ToolFailure({ message: errorMessage(error) }),
+          }),
+      }),
+    ]),
+  )
+}
+
 // Check if messages contain any tool-call content
 // Used to determine if a dummy tool should be added for LiteLLM proxy compatibility
 export function hasToolCalls(messages: ModelMessage[]): boolean {

packages/opencode/test/session/llm.test.ts

@@ -802,6 +802,134 @@ describe("session.llm.stream", () => {
     })
   })
 
+  test("executes OpenAI tool calls through native runtime", async () => {
+    const server = state.server
+    if (!server) {
+      throw new Error("Server not initialized")
+    }
+
+    const source = await loadFixture("openai", "gpt-5.2")
+    const model = source.model
+    const chunks = [
+      {
+        type: "response.output_item.added",
+        item: { type: "function_call", id: "item-native-tool", call_id: "call-native-tool", name: "lookup" },
+      },
+      {
+        type: "response.function_call_arguments.delta",
+        item_id: "item-native-tool",
+        delta: '{"query":"weather"}',
+      },
+      {
+        type: "response.output_item.done",
+        item: {
+          type: "function_call",
+          id: "item-native-tool",
+          call_id: "call-native-tool",
+          name: "lookup",
+          arguments: '{"query":"weather"}',
+        },
+      },
+      {
+        type: "response.completed",
+        response: { incomplete_details: null, usage: { input_tokens: 1, output_tokens: 1 } },
+      },
+    ]
+    const request = waitRequest("/responses", createEventResponse(chunks, true))
+    let executed: unknown
+
+    await using tmp = await tmpdir({
+      init: async (dir) => {
+        await Bun.write(
+          path.join(dir, "opencode.json"),
+          JSON.stringify({
+            $schema: "https://opencode.ai/config.json",
+            enabled_providers: ["openai"],
+            provider: {
+              openai: {
+                name: "OpenAI",
+                env: ["OPENAI_API_KEY"],
+                npm: "@ai-sdk/openai",
+                api: "https://api.openai.com/v1",
+                models: {
+                  [model.id]: model,
+                },
+                options: {
+                  apiKey: "test-openai-key",
+                  baseURL: `${server.url.origin}/v1`,
+                },
+              },
+            },
+          }),
+        )
+      },
+    })
+
+    await WithInstance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const previous = process.env.OPENCODE_LLM_RUNTIME
+        process.env.OPENCODE_LLM_RUNTIME = "native"
+        try {
+          const resolved = await getModel(ProviderID.openai, ModelID.make(model.id))
+          const sessionID = SessionID.make("session-test-native-tool")
+          const agent = {
+            name: "test",
+            mode: "primary",
+            options: {},
+            permission: [{ permission: "*", pattern: "*", action: "allow" }],
+          } satisfies Agent.Info
+
+          await drain({
+            user: {
+              id: MessageID.make("msg_user-native-tool"),
+              sessionID,
+              role: "user",
+              time: { created: Date.now() },
+              agent: agent.name,
+              model: { providerID: ProviderID.make("openai"), modelID: resolved.id },
+            } satisfies MessageV2.User,
+            sessionID,
+            model: resolved,
+            agent,
+            system: [],
+            messages: [{ role: "user", content: "Use lookup" }],
+            tools: {
+              lookup: tool({
+                description: "Lookup data",
+                inputSchema: z.object({ query: z.string() }),
+                execute: async (args, options) => {
+                  executed = { args, toolCallId: options.toolCallId }
+                  return { output: "looked up" }
+                },
+              }),
+            },
+          })
+        } finally {
+          if (previous === undefined) delete process.env.OPENCODE_LLM_RUNTIME
+          else process.env.OPENCODE_LLM_RUNTIME = previous
+        }
+
+        const capture = await request
+        expect(capture.body.tools).toEqual([
+          {
+            type: "function",
+            name: "lookup",
+            description: "Lookup data",
+            parameters: {
+              type: "object",
+              properties: { query: { type: "string" } },
+              required: ["query"],
+              additionalProperties: false,
+              $schema: "http://json-schema.org/draft-07/schema#",
+            },
+          },
+        ])
+        expect(executed).toEqual({ args: { query: "weather" }, toolCallId: "call-native-tool" })
+      },
+    })
+  })
+
   test("accepts user image attachments as data URLs for OpenAI models", async () => {
     const server = state.server
     if (!server) {