fix(ai): use adaptive thinking for Kimi Coding

packages/ai/CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Fixed
 
+- Fixed Kimi Coding requests to use Anthropic adaptive thinking effort without token budgets, and enabled empty thinking signatures for K3 and `kimi-for-coding`.
 - Fixed Kimi K3 pricing metadata for Moonshot AI and Moonshot AI China.
 - Fixed Kimi Coding K3 thinking-level metadata to expose only the supported `max` level ([#6737](https://github.com/earendil-works/pi/issues/6737)).
 - Fixed catalog generation restoring xAI models removed in 0.80.9 ([#6736](https://github.com/earendil-works/pi/issues/6736)).

packages/ai/scripts/generate-models.ts

@@ -1641,6 +1641,7 @@ async function loadModelsDevData(): Promise<Model<any>[]> {
 				const normalizedId = kimiAliases.has(modelId) ? "kimi-for-coding" : modelId;
 				const normalizedName = kimiAliases.has(modelId) ? "Kimi For Coding" : m.name || normalizedId;
 				const isKimiK3 = normalizedId === "k3";
+				const allowEmptySignature = isKimiK3 || normalizedId === "kimi-for-coding";
 
 				models.push({
 					id: normalizedId,
@@ -1650,6 +1651,10 @@ async function loadModelsDevData(): Promise<Model<any>[]> {
 					// Kimi For Coding's Anthropic-compatible API - SDK appends /v1/messages
 					baseUrl: "https://api.kimi.com/coding",
 					headers: { ...KIMI_STATIC_HEADERS },
+					compat: {
+						...(allowEmptySignature ? { allowEmptySignature: true } : {}),
+						forceAdaptiveThinking: true,
+					},
 					reasoning: isKimiK3 || m.reasoning === true,
 					...(isKimiK3 ? { thinkingLevelMap: KIMI_K3_THINKING_LEVEL_MAP } : {}),
 					input: m.modalities?.input?.includes("image") ? ["text", "image"] : ["text"],

packages/ai/src/providers/kimi-coding.models.ts

@@ -11,6 +11,7 @@ export const KIMI_CODING_MODELS = {
 		provider: "kimi-coding",
 		baseUrl: "https://api.kimi.com/coding",
 		headers: {"User-Agent":"KimiCLI/1.5"},
+		compat: {"forceAdaptiveThinking":true},
 		reasoning: true,
 		input: ["text", "image"],
 		cost: {
@@ -29,6 +30,7 @@ export const KIMI_CODING_MODELS = {
 		provider: "kimi-coding",
 		baseUrl: "https://api.kimi.com/coding",
 		headers: {"User-Agent":"KimiCLI/1.5"},
+		compat: {"allowEmptySignature":true,"forceAdaptiveThinking":true},
 		reasoning: true,
 		thinkingLevelMap: {"off":null,"minimal":null,"low":null,"medium":null,"high":null,"xhigh":null,"max":"max"},
 		input: ["text", "image"],
@@ -48,6 +50,7 @@ export const KIMI_CODING_MODELS = {
 		provider: "kimi-coding",
 		baseUrl: "https://api.kimi.com/coding",
 		headers: {"User-Agent":"KimiCLI/1.5"},
+		compat: {"allowEmptySignature":true,"forceAdaptiveThinking":true},
 		reasoning: true,
 		input: ["text", "image"],
 		cost: {
@@ -66,6 +69,7 @@ export const KIMI_CODING_MODELS = {
 		provider: "kimi-coding",
 		baseUrl: "https://api.kimi.com/coding",
 		headers: {"User-Agent":"KimiCLI/1.5"},
+		compat: {"forceAdaptiveThinking":true},
 		reasoning: true,
 		input: ["text", "image"],
 		cost: {
@@ -84,6 +88,7 @@ export const KIMI_CODING_MODELS = {
 		provider: "kimi-coding",
 		baseUrl: "https://api.kimi.com/coding",
 		headers: {"User-Agent":"KimiCLI/1.5"},
+		compat: {"forceAdaptiveThinking":true},
 		reasoning: true,
 		input: ["text"],
 		cost: {

packages/ai/test/anthropic-adaptive-thinking-models.test.ts

@@ -7,6 +7,11 @@ const EXPECTED_CURRENT_ADAPTIVE_THINKING_MODELS = [
 	"anthropic/claude-opus-4-8",
 	"anthropic/claude-sonnet-5",
 	"cloudflare-ai-gateway/claude-fable-5",
+	"kimi-coding/k2p7",
+	"kimi-coding/k3",
+	"kimi-coding/kimi-for-coding",
+	"kimi-coding/kimi-for-coding-highspeed",
+	"kimi-coding/kimi-k2-thinking",
 	"opencode/claude-opus-4-8",
 	"vercel-ai-gateway/anthropic/claude-opus-4.8",
 	"vercel-ai-gateway/anthropic/claude-sonnet-5",
@@ -27,7 +32,7 @@ describe("Anthropic adaptive thinking model metadata", () => {
 		expect(flaggedModels).toEqual(expect.arrayContaining([...EXPECTED_CURRENT_ADAPTIVE_THINKING_MODELS].sort()));
 		expect(flaggedModels).toEqual(
 			flaggedModels.filter((modelId) =>
-				/(opus[-.]4[-.][678]|sonnet[-.]4[-.]6|sonnet[-.]5|fable[-.]5)/.test(modelId),
+				/(opus[-.]4[-.][678]|sonnet[-.]4[-.]6|sonnet[-.]5|fable[-.]5|kimi-coding\/)/.test(modelId),
 			),
 		);
 	});

packages/ai/test/anthropic-empty-thinking-signature-compat.test.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { streamSimple } from "../src/compat.ts";
+import { getModel, streamSimple } from "../src/compat.ts";
 import type { AssistantMessage, Context, Model } from "../src/types.ts";
 
 interface AnthropicPayload {
@@ -32,13 +32,18 @@ function makeModel(allowEmptySignature?: boolean): Model<"anthropic-messages"> {
 	};
 }
 
-function makeContext(thinkingSignature: string, thinking = "internal reasoning"): Context {
+function makeContext(
+	thinkingSignature: string,
+	thinking = "internal reasoning",
+	provider = "xiaomi-token-plan-ams",
+	model = "mimo-v2.5-pro",
+): Context {
 	const assistant: AssistantMessage = {
 		role: "assistant",
 		content: [{ type: "thinking", thinking, thinkingSignature }],
-		provider: "xiaomi-token-plan-ams",
+		provider,
 		api: "anthropic-messages",
-		model: "mimo-v2.5-pro",
+		model,
 		timestamp: Date.now(),
 		usage: {
 			input: 0,
@@ -91,4 +96,13 @@ describe("Anthropic empty thinking signature compat", () => {
 		const assistant = payload.messages?.find((message) => message.role === "assistant");
 		expect(assistant?.content).toEqual([{ type: "thinking", thinking: "internal reasoning", signature: "" }]);
 	});
+
+	it.each(["k3", "kimi-for-coding"] as const)("allows empty signatures for Kimi Coding %s", async (modelId) => {
+		const model = getModel("kimi-coding", modelId);
+		expect(model.compat?.allowEmptySignature).toBe(true);
+
+		const payload = await capturePayload(model, makeContext(" ", "internal reasoning", "kimi-coding", modelId));
+		const assistant = payload.messages?.find((message) => message.role === "assistant");
+		expect(assistant?.content).toEqual([{ type: "thinking", thinking: "internal reasoning", signature: "" }]);
+	});
 });

packages/ai/test/anthropic-force-adaptive-thinking.test.ts

@@ -89,6 +89,22 @@ describe("Anthropic forceAdaptiveThinking compat override", () => {
 		expect(payload.output_config).toEqual({ effort: "xhigh" });
 	});
 
+	it.each([
+		["k2p7", "medium", "medium"],
+		["k3", "max", "max"],
+		["kimi-for-coding", "medium", "medium"],
+		["kimi-for-coding-highspeed", "medium", "medium"],
+		["kimi-k2-thinking", "medium", "medium"],
+	] as const)(
+		"uses adaptive thinking effort without a token budget for Kimi Coding %s",
+		async (modelId, reasoning, effort) => {
+			const payload = await capturePayload(getModel("kimi-coding", modelId), { reasoning });
+
+			expect(payload.thinking).toEqual({ type: "adaptive", display: "summarized" });
+			expect(payload.output_config).toEqual({ effort });
+		},
+	);
+
 	it("allows built-in adaptive models to opt out with compat.forceAdaptiveThinking false", async () => {
 		const model: Model<"anthropic-messages"> = {
 			...getModel("anthropic", "claude-opus-4-8"),