Define own GoogleThinkingLevel type instead of importing from @google/genai

- Add GoogleThinkingLevel type mirroring Google's ThinkingLevel enum
- Update GoogleGeminiCliOptions and GoogleOptions to use our type
- Cast to any when assigning to Google SDK's ThinkingConfig

packages/ai/src/providers/google-gemini-cli.ts

@@ -4,7 +4,7 @@
  * Uses the Cloud Code Assist API endpoint to access Gemini and Claude models.
  */
 
-import type { Content, ThinkingConfig, ThinkingLevel } from "@google/genai";
+import type { Content, ThinkingConfig } from "@google/genai";
 import { calculateCost } from "../models.js";
 import type {
 	Api,
@@ -21,6 +21,12 @@ import { AssistantMessageEventStream } from "../utils/event-stream.js";
 import { sanitizeSurrogates } from "../utils/sanitize-unicode.js";
 import { convertMessages, convertTools, mapStopReasonString, mapToolChoice } from "./google-shared.js";
 
+/**
+ * Thinking level for Gemini 3 models.
+ * Mirrors Google's ThinkingLevel enum values.
+ */
+export type GoogleThinkingLevel = "THINKING_LEVEL_UNSPECIFIED" | "MINIMAL" | "LOW" | "MEDIUM" | "HIGH";
+
 export interface GoogleGeminiCliOptions extends StreamOptions {
 	toolChoice?: "auto" | "none" | "any";
 	/**
@@ -35,7 +41,7 @@ export interface GoogleGeminiCliOptions extends StreamOptions {
 		/** Thinking budget in tokens. Use for Gemini 2.x models. */
 		budgetTokens?: number;
 		/** Thinking level. Use for Gemini 3 models (LOW/HIGH for Pro, MINIMAL/LOW/MEDIUM/HIGH for Flash). */
-		level?: ThinkingLevel;
+		level?: GoogleThinkingLevel;
 	};
 	projectId?: string;
 }
@@ -436,7 +442,8 @@ function buildRequest(
 		};
 		// Gemini 3 models use thinkingLevel, older models use thinkingBudget
 		if (options.thinking.level !== undefined) {
-			generationConfig.thinkingConfig.thinkingLevel = options.thinking.level;
+			// Cast to any since our GoogleThinkingLevel mirrors Google's ThinkingLevel enum values
+			generationConfig.thinkingConfig.thinkingLevel = options.thinking.level as any;
 		} else if (options.thinking.budgetTokens !== undefined) {
 			generationConfig.thinkingConfig.thinkingBudget = options.thinking.budgetTokens;
 		}

packages/ai/src/providers/google.ts

@@ -3,7 +3,6 @@ import {
 	type GenerateContentParameters,
 	GoogleGenAI,
 	type ThinkingConfig,
-	type ThinkingLevel,
 } from "@google/genai";
 import { calculateCost } from "../models.js";
 import { getEnvApiKey } from "../stream.js";
@@ -20,6 +19,7 @@ import type {
 } from "../types.js";
 import { AssistantMessageEventStream } from "../utils/event-stream.js";
 import { sanitizeSurrogates } from "../utils/sanitize-unicode.js";
+import type { GoogleThinkingLevel } from "./google-gemini-cli.js";
 import { convertMessages, convertTools, mapStopReason, mapToolChoice } from "./google-shared.js";
 
 export interface GoogleOptions extends StreamOptions {
@@ -27,7 +27,7 @@ export interface GoogleOptions extends StreamOptions {
 	thinking?: {
 		enabled: boolean;
 		budgetTokens?: number; // -1 for dynamic, 0 to disable
-		level?: ThinkingLevel;
+		level?: GoogleThinkingLevel;
 	};
 }
 
@@ -299,7 +299,8 @@ function buildParams(
 	if (options.thinking?.enabled && model.reasoning) {
 		const thinkingConfig: ThinkingConfig = { includeThoughts: true };
 		if (options.thinking.level !== undefined) {
-			thinkingConfig.thinkingLevel = options.thinking.level;
+			// Cast to any since our GoogleThinkingLevel mirrors Google's ThinkingLevel enum values
+			thinkingConfig.thinkingLevel = options.thinking.level as any;
 		} else if (options.thinking.budgetTokens !== undefined) {
 			thinkingConfig.thinkingBudget = options.thinking.budgetTokens;
 		}

packages/ai/src/stream.ts

@@ -1,8 +1,11 @@
-import { ThinkingLevel } from "@google/genai";
 import { supportsXhigh } from "./models.js";
 import { type AnthropicOptions, streamAnthropic } from "./providers/anthropic.js";
 import { type GoogleOptions, streamGoogle } from "./providers/google.js";
-import { type GoogleGeminiCliOptions, streamGoogleGeminiCli } from "./providers/google-gemini-cli.js";
+import {
+	type GoogleGeminiCliOptions,
+	type GoogleThinkingLevel,
+	streamGoogleGeminiCli,
+} from "./providers/google-gemini-cli.js";
 import { type OpenAICompletionsOptions, streamOpenAICompletions } from "./providers/openai-completions.js";
 import { type OpenAIResponsesOptions, streamOpenAIResponses } from "./providers/openai-responses.js";
 import type {
@@ -256,53 +259,56 @@ function isGemini3FlashModel(model: Model<"google-generative-ai">): boolean {
 	return model.id.includes("3-flash");
 }
 
-function getGemini3ThinkingLevel(effort: ClampedReasoningEffort, model: Model<"google-generative-ai">): ThinkingLevel {
+function getGemini3ThinkingLevel(
+	effort: ClampedReasoningEffort,
+	model: Model<"google-generative-ai">,
+): GoogleThinkingLevel {
 	if (isGemini3ProModel(model)) {
 		// Gemini 3 Pro only supports LOW/HIGH (for now)
 		switch (effort) {
 			case "minimal":
 			case "low":
-				return ThinkingLevel.LOW;
+				return "LOW";
 			case "medium":
 			case "high":
-				return ThinkingLevel.HIGH;
+				return "HIGH";
 		}
 	}
 	// Gemini 3 Flash supports all four levels
 	switch (effort) {
 		case "minimal":
-			return ThinkingLevel.MINIMAL;
+			return "MINIMAL";
 		case "low":
-			return ThinkingLevel.LOW;
+			return "LOW";
 		case "medium":
-			return ThinkingLevel.MEDIUM;
+			return "MEDIUM";
 		case "high":
-			return ThinkingLevel.HIGH;
+			return "HIGH";
 	}
 }
 
-function getGeminiCliThinkingLevel(effort: ClampedReasoningEffort, modelId: string): ThinkingLevel {
+function getGeminiCliThinkingLevel(effort: ClampedReasoningEffort, modelId: string): GoogleThinkingLevel {
 	if (modelId.includes("3-pro")) {
 		// Gemini 3 Pro only supports LOW/HIGH (for now)
 		switch (effort) {
 			case "minimal":
 			case "low":
-				return ThinkingLevel.LOW;
+				return "LOW";
 			case "medium":
 			case "high":
-				return ThinkingLevel.HIGH;
+				return "HIGH";
 		}
 	}
 	// Gemini 3 Flash supports all four levels
 	switch (effort) {
 		case "minimal":
-			return ThinkingLevel.MINIMAL;
+			return "MINIMAL";
 		case "low":
-			return ThinkingLevel.LOW;
+			return "LOW";
 		case "medium":
-			return ThinkingLevel.MEDIUM;
+			return "MEDIUM";
 		case "high":
-			return ThinkingLevel.HIGH;
+			return "HIGH";
 	}
 }