fix(ai): disable Kimi thinking for forced tools

packages/ai/CHANGELOG.md

@@ -2,6 +2,9 @@
 
 ## [Unreleased]
 
+### Fixed
+- Fixed Moonshot Kimi K2.6 forced tool calls to send `thinking: { type: "disabled" }`, avoiding `tool_choice 'specified' is incompatible with thinking enabled` 400s while preserving the requested named tool ([#1077](https://github.com/can1357/oh-my-pi/issues/1077)).
+
 ## [15.0.1] - 2026-05-14
 ### Breaking Changes
 

packages/ai/src/providers/openai-completions-compat.ts

@@ -53,6 +53,12 @@ export function detectOpenAICompat(model: Model<"openai-completions">, resolvedB
 	const isZai = provider === "zai" || baseUrl.includes("api.z.ai");
 	const isKilo = provider === "kilo" || baseUrl.includes("api.kilo.ai");
 	const isKimiModel = model.id.includes("moonshotai/kimi") || /^kimi[-.]/i.test(model.id);
+	const isMoonshotKimi =
+		isKimiModel &&
+		(provider === "moonshot" ||
+			provider === "kimi-code" ||
+			baseUrl.includes("api.moonshot.ai") ||
+			baseUrl.includes("api.kimi.com"));
 	const isAnthropicModel =
 		provider === "anthropic" ||
 		baseUrl.includes("api.anthropic.com") ||
@@ -173,13 +179,14 @@ export function detectOpenAICompat(model: Model<"openai-completions">, resolvedB
 		requiresAssistantAfterToolResult: false,
 		requiresThinkingAsText: isMistral,
 		requiresMistralToolIds: isMistral,
-		thinkingFormat: isZai
-			? "zai"
-			: provider === "openrouter" || baseUrl.includes("openrouter.ai")
-				? "openrouter"
-				: isAlibaba || isQwen
-					? "qwen"
-					: "openai",
+		thinkingFormat:
+			isZai || isMoonshotKimi
+				? "zai"
+				: provider === "openrouter" || baseUrl.includes("openrouter.ai")
+					? "openrouter"
+					: isAlibaba || isQwen
+						? "qwen"
+						: "openai",
 		reasoningContentField: "reasoning_content",
 		// Backends that 400 follow-up requests when prior assistant tool-call turns lack `reasoning_content`:
 		//   - Kimi: documented invariant on its native API and via OpenCode-Go.

packages/ai/src/providers/openai-completions.ts

@@ -1019,12 +1019,14 @@ function buildParams(
 	}
 
 	if (compat.disableReasoningOnForcedToolChoice && isForcedToolChoice(params.tool_choice)) {
-		// Mirrors anthropic.ts:disableThinkingIfToolChoiceForced — backends like
-		// Kimi 400 with `tool_choice 'specified' is incompatible with thinking
-		// enabled`. Drop reasoning for this turn instead of dropping tool_choice;
-		// the agent still gets the forced tool call, just without thinking.
+		// Backends like Kimi 400 with `tool_choice 'specified' is incompatible
+		// with thinking enabled`. Suppress thinking for this single forced-tool
+		// turn while keeping the tool-selection contract intact.
 		delete params.reasoning_effort;
 		delete params.reasoning;
+		if (compat.thinkingFormat === "zai") {
+			params.thinking = { type: "disabled" };
+		}
 	}
 
 	// OpenRouter provider routing preferences

packages/ai/src/types.ts

@@ -613,7 +613,7 @@ export interface OpenAICompat {
 	requiresThinkingAsText?: boolean;
 	/** Whether tool call IDs must be normalized to Mistral format (exactly 9 alphanumeric chars). Default: auto-detected from URL. */
 	requiresMistralToolIds?: boolean;
-	/** Format for reasoning/thinking parameter. "openai" uses reasoning_effort, "openrouter" uses reasoning: { effort }, "zai" uses thinking: { type: "enabled" }, "qwen" uses top-level enable_thinking, and "qwen-chat-template" uses chat_template_kwargs.enable_thinking. Default: "openai". */
+	/** Format for reasoning/thinking parameter. "openai" uses reasoning_effort, "openrouter" uses reasoning: { effort }, "zai" uses thinking: { type: "enabled" | "disabled" } (also used by Moonshot Kimi), "qwen" uses top-level enable_thinking, and "qwen-chat-template" uses chat_template_kwargs.enable_thinking. Default: "openai". */
 	thinkingFormat?: "openai" | "openrouter" | "zai" | "qwen" | "qwen-chat-template";
 	/** Which reasoning content field to emit on assistant messages. Default: auto-detected. */
 	reasoningContentField?: "reasoning_content" | "reasoning" | "reasoning_text";

packages/ai/test/issue-827-repro.test.ts

@@ -79,6 +79,7 @@ interface CompletionsBody {
 	tools?: unknown[];
 	reasoning_effort?: unknown;
 	reasoning?: unknown;
+	thinking?: unknown;
 }
 
 describe("issue #827 — kimi reasoning models drop reasoning under forced tool_choice", () => {
@@ -114,6 +115,25 @@ describe("issue #827 — kimi reasoning models drop reasoning under forced tool_
 		expect(body.reasoning).toBeUndefined();
 		expect(body.reasoning_effort).toBeUndefined();
 	});
+	it("sends explicit thinking disabled for Moonshot Kimi K2.6 when a named tool is forced", async () => {
+		const model: Model<"openai-completions"> = {
+			...getBundledModel("openai", "gpt-4o-mini"),
+			api: "openai-completions",
+			provider: "moonshot",
+			baseUrl: "https://api.moonshot.ai/v1",
+			id: "kimi-k2.6",
+			name: "Kimi K2.6",
+			reasoning: false,
+		};
+		const body = (await captureBody(model, {
+			toolChoice: { type: "tool", name: "echo" },
+		})) as CompletionsBody;
+
+		expect(body.tool_choice).toMatchObject({ type: "function", function: { name: "echo" } });
+		expect(body.thinking).toEqual({ type: "disabled" });
+		expect(body.reasoning).toBeUndefined();
+		expect(body.reasoning_effort).toBeUndefined();
+	});
 
 	it("strips reasoning_effort for Anthropic Claude models served via openai-completions (e.g. LiteLLM/OpenRouter proxies)", async () => {
 		// LiteLLM / Vertex proxies often expose Claude through chat-completions; Anthropic