diff --git a/packages/opencode/src/session/llm.ts b/packages/opencode/src/session/llm.ts
index a6aea4ffbc..87d2e3973d 100644
--- a/packages/opencode/src/session/llm.ts
+++ b/packages/opencode/src/session/llm.ts
@@ -27,8 +27,8 @@ import { InstallationVersion } from "@opencode-ai/core/installation/version"
 import { EffectBridge } from "@/effect/bridge"
 import * as Option from "effect/Option"
 import * as OtelTracer from "@effect/opentelemetry/Tracer"
-import { LLMAISDK } from "./llm-ai-sdk"
-import { LLMNativeRuntime } from "./llm-native-runtime"
+import { LLMAISDK } from "./llm/ai-sdk"
+import { LLMNativeRuntime } from "./llm/native-runtime"
 
 const log = Log.create({ service: "llm" })
 export const OUTPUT_TOKEN_MAX = ProviderTransform.OUTPUT_TOKEN_MAX
diff --git a/packages/opencode/src/session/llm/README.md b/packages/opencode/src/session/llm/README.md
new file mode 100644
index 0000000000..139db3a52e
--- /dev/null
+++ b/packages/opencode/src/session/llm/README.md
@@ -0,0 +1,16 @@
+# Session LLM Runtime Boundaries
+
+`../llm.ts` is the opencode session LLM service. It owns opencode concerns: auth, config, model/provider resolution, plugins, permissions, telemetry headers, and runtime selection.
+
+This folder contains adapters behind that service boundary:
+
+- `ai-sdk.ts` converts AI SDK `fullStream` parts into `@opencode-ai/llm` `LLMEvent`s. This is the default runtime path.
+- `native-request.ts` converts opencode's normalized session input into a native `@opencode-ai/llm` `LLMRequest`. It does not execute requests.
+- `native-runtime.ts` is the opt-in native runtime adapter. It decides whether a selected model is supported, builds the native request, bridges opencode tools into native executable tools, and delegates transport to `LLMClient` / `RequestExecutor`.
+
+Safety boundary:
+
+- AI SDK remains the default.
+- `OPENCODE_LLM_RUNTIME=native` is an opt-in hint, not a global replacement.
+- Native execution currently runs only for OpenAI API-key auth via `@ai-sdk/openai`.
+- Unsupported providers, OpenAI OAuth, and missing API-key cases fall back to AI SDK.
diff --git a/packages/opencode/src/session/llm-ai-sdk.ts b/packages/opencode/src/session/llm/ai-sdk.ts
similarity index 99%
rename from packages/opencode/src/session/llm-ai-sdk.ts
rename to packages/opencode/src/session/llm/ai-sdk.ts
index 3c1b38cda5..8c428add65 100644
--- a/packages/opencode/src/session/llm-ai-sdk.ts
+++ b/packages/opencode/src/session/llm/ai-sdk.ts
@@ -231,4 +231,4 @@ export function toLLMEvents(
   }
 }
 
-export * as LLMAISDK from "./llm-ai-sdk"
+export * as LLMAISDK from "./ai-sdk"
diff --git a/packages/opencode/src/session/llm-native.ts b/packages/opencode/src/session/llm/native-request.ts
similarity index 99%
rename from packages/opencode/src/session/llm-native.ts
rename to packages/opencode/src/session/llm/native-request.ts
index 22725e9e76..ca3ddef173 100644
--- a/packages/opencode/src/session/llm-native.ts
+++ b/packages/opencode/src/session/llm/native-request.ts
@@ -185,4 +185,4 @@ export const request = (input: RequestInput) => {
   })
 }
 
-export * as LLMNative from "./llm-native"
+export * as LLMNative from "./native-request"
diff --git a/packages/opencode/src/session/llm-native-runtime.ts b/packages/opencode/src/session/llm/native-runtime.ts
similarity index 97%
rename from packages/opencode/src/session/llm-native-runtime.ts
rename to packages/opencode/src/session/llm/native-runtime.ts
index ba2f1a648e..a57a84c7cc 100644
--- a/packages/opencode/src/session/llm-native-runtime.ts
+++ b/packages/opencode/src/session/llm/native-runtime.ts
@@ -7,7 +7,7 @@ import { Effect } from "effect"
 import * as Stream from "effect/Stream"
 import { tool as nativeTool, ToolFailure, type JsonSchema, type LLMEvent } from "@opencode-ai/llm"
 import type { LLMClientShape } from "@opencode-ai/llm/route"
-import { LLMNative } from "./llm-native"
+import { LLMNative } from "./native-request"
 
 export type RuntimeStatus =
   | { readonly type: "supported"; readonly apiKey: string; readonly baseURL?: string }
@@ -112,4 +112,4 @@ function nativeTools(tools: Record<string, Tool>, input: Pick<StreamInput, "mess
   )
 }
 
-export * as LLMNativeRuntime from "./llm-native-runtime"
+export * as LLMNativeRuntime from "./native-runtime"
diff --git a/packages/opencode/test/session/llm-native.test.ts b/packages/opencode/test/session/llm-native.test.ts
index 21564f14ff..741c9de328 100644
--- a/packages/opencode/test/session/llm-native.test.ts
+++ b/packages/opencode/test/session/llm-native.test.ts
@@ -2,8 +2,8 @@ import { describe, expect, test } from "bun:test"
 import { LLMClient, RequestExecutor } from "@opencode-ai/llm/route"
 import { jsonSchema, tool, type ModelMessage } from "ai"
 import { Effect } from "effect"
-import { LLMNative } from "@/session/llm-native"
-import { LLMNativeRuntime } from "@/session/llm-native-runtime"
+import { LLMNative } from "@/session/llm/native-request"
+import { LLMNativeRuntime } from "@/session/llm/native-runtime"
 import type { Provider } from "@/provider/provider"
 import { ModelID, ProviderID } from "@/provider/schema"