openAgent

1diff --git a/dist/index.d.mts b/dist/index.d.mts
2index 1bde0b9f8cbe6771a52c1041095c9dddfe8e5b6c..0ca2ffb2a0c9327aed5ddcf0004500dc8b42569f 100644
3--- a/dist/index.d.mts
4+++ b/dist/index.d.mts
5@@ -13,7 +13,5 @@ declare const mistralLanguageModelOptions: z.ZodObject<{
6-    reasoningEffort: z.ZodOptional<z.ZodEnum<{
7-        none: "none";
8-        high: "high";
9-    }>>;
10+    reasoningEffort: z.ZodOptional<z.ZodString>;
11+    promptCacheKey: z.ZodOptional<z.ZodString>;
12 }, z.core.$strip>;
13 type MistralLanguageModelOptions = z.infer<typeof mistralLanguageModelOptions>;
14 
15diff --git a/dist/index.d.ts b/dist/index.d.ts
16index 1bde0b9f8cbe6771a52c1041095c9dddfe8e5b6c..0ca2ffb2a0c9327aed5ddcf0004500dc8b42569f 100644
17--- a/dist/index.d.ts
18+++ b/dist/index.d.ts
19@@ -13,7 +13,5 @@ declare const mistralLanguageModelOptions: z.ZodObject<{
20-    reasoningEffort: z.ZodOptional<z.ZodEnum<{
21-        none: "none";
22-        high: "high";
23-    }>>;
24+    reasoningEffort: z.ZodOptional<z.ZodString>;
25+    promptCacheKey: z.ZodOptional<z.ZodString>;
26 }, z.core.$strip>;
27 type MistralLanguageModelOptions = z.infer<typeof mistralLanguageModelOptions>;
28 
29diff --git a/dist/index.js b/dist/index.js
30index d3f904c12a1d582cc7b9e9a2d30273e1a8505b28..267f34e20ea392b7a85ad5259d72d50605a6f971 100644
31--- a/dist/index.js
32+++ b/dist/index.js
33@@ -128,11 +128,14 @@ function convertToMistralChatMessages(prompt) {
34       }
35       case "assistant": {
36         let text = "";
37+        const structuredContent = [];
38+        let hasNativeReasoning = false;
39         const toolCalls = [];
40         for (const part of content) {
41           switch (part.type) {
42             case "text": {
43               text += part.text;
44+              structuredContent.push({ type: "text", text: part.text });
45               break;
46             }
47             case "tool-call": {
48@@ -148,6 +151,13 @@ function convertToMistralChatMessages(prompt) {
49             }
50             case "reasoning": {
51               text += part.text;
52+              const native = part.providerOptions?.mistral?.thinking;
53+              if (native?.type === "thinking") {
54+                hasNativeReasoning = true;
55+                structuredContent.push(native);
56+                break;
57+              }
58+              structuredContent.push({ type: "text", text: part.text });
59               break;
60             }
61             default: {
62@@ -159,7 +169,7 @@ function convertToMistralChatMessages(prompt) {
63         }
64         messages.push({
65           role: "assistant",
66-          content: text,
67+          content: hasNativeReasoning ? structuredContent : text,
68           prefix: isLastMessage ? true : void 0,
69           tool_calls: toolCalls.length > 0 ? toolCalls : void 0
70         });
71@@ -268,7 +278,8 @@ var mistralLanguageModelOptions = import_v4.z.object({
72    * - `'high'`: Enable reasoning
73    * - `'none'`: Disable reasoning
74    */
75-  reasoningEffort: import_v4.z.enum(["high", "none"]).optional()
76+  reasoningEffort: import_v4.z.string().optional(),
77+  promptCacheKey: import_v4.z.string().optional()
78 });
79 
80 // src/mistral-error.ts
81@@ -407,6 +418,7 @@ var MistralChatLanguageModel = class {
82       stop: stopSequences,
83       random_seed: seed,
84       reasoning_effort: options.reasoningEffort,
85+      prompt_cache_key: options.promptCacheKey,
86       // response format:
87       response_format: (responseFormat == null ? void 0 : responseFormat.type) === "json" ? structuredOutputs && (responseFormat == null ? void 0 : responseFormat.schema) != null ? {
88         type: "json_schema",
89@@ -465,9 +477,11 @@ var MistralChatLanguageModel = class {
90       for (const part of choice.message.content) {
91         if (part.type === "thinking") {
92           const reasoningText = extractReasoningContent(part.thinking);
93-          if (reasoningText.length > 0) {
94-            content.push({ type: "reasoning", text: reasoningText });
95-          }
96+          content.push({
97+            type: "reasoning",
98+            text: reasoningText,
99+            providerMetadata: { mistral: { thinking: part } }
100+          });
101         } else if (part.type === "text") {
102           if (part.text.length > 0) {
103             content.push({ type: "text", text: part.text });
104@@ -528,6 +542,7 @@ var MistralChatLanguageModel = class {
105     let isFirstChunk = true;
106     let activeText = false;
107     let activeReasoningId = null;
108+    let activeThinking = null;
109     const generateId2 = this.generateId;
110     return {
111       stream: response.pipeThrough(
112@@ -561,18 +576,19 @@ var MistralChatLanguageModel = class {
113               for (const part of delta.content) {
114                 if (part.type === "thinking") {
115                   const reasoningDelta = extractReasoningContent(part.thinking);
116-                  if (reasoningDelta.length > 0) {
117-                    if (activeReasoningId == null) {
118-                      if (activeText) {
119-                        controller.enqueue({ type: "text-end", id: "0" });
120-                        activeText = false;
121-                      }
122-                      activeReasoningId = generateId2();
123-                      controller.enqueue({
124-                        type: "reasoning-start",
125-                        id: activeReasoningId
126-                      });
127+                  activeThinking = mergeThinking(activeThinking, part);
128+                  if (activeReasoningId == null) {
129+                    if (activeText) {
130+                      controller.enqueue({ type: "text-end", id: "0" });
131+                      activeText = false;
132                     }
133+                    activeReasoningId = generateId2();
134+                    controller.enqueue({
135+                      type: "reasoning-start",
136+                      id: activeReasoningId
137+                    });
138+                  }
139+                  if (reasoningDelta.length > 0) {
140                     controller.enqueue({
141                       type: "reasoning-delta",
142                       id: activeReasoningId,
143@@ -587,9 +603,11 @@ var MistralChatLanguageModel = class {
144                 if (activeReasoningId != null) {
145                   controller.enqueue({
146                     type: "reasoning-end",
147-                    id: activeReasoningId
148+                    id: activeReasoningId,
149+                    providerMetadata: { mistral: { thinking: activeThinking } }
150                   });
151                   activeReasoningId = null;
152+                  activeThinking = null;
153                 }
154                 controller.enqueue({ type: "text-start", id: "0" });
155                 activeText = true;
156@@ -638,7 +656,8 @@ var MistralChatLanguageModel = class {
157             if (activeReasoningId != null) {
158               controller.enqueue({
159                 type: "reasoning-end",
160-                id: activeReasoningId
161+                id: activeReasoningId,
162+                providerMetadata: { mistral: { thinking: activeThinking } }
163               });
164             }
165             if (activeText) {
166@@ -660,6 +679,13 @@ var MistralChatLanguageModel = class {
167 function extractReasoningContent(thinking) {
168   return thinking.filter((chunk) => chunk.type === "text").map((chunk) => chunk.text).join("");
169 }
170+function mergeThinking(current, next) {
171+  if (current === null) return { ...next, thinking: [...next.thinking] };
172+  current.thinking.push(...next.thinking);
173+  if (next.closed !== void 0) current.closed = next.closed;
174+  if (next.signature !== void 0) current.signature = next.signature;
175+  return current;
176+}
177 function extractTextContent(content) {
178   if (typeof content === "string") {
179     return content;
180@@ -686,6 +712,30 @@ function extractTextContent(content) {
181   }
182   return textContent.length ? textContent.join("") : void 0;
183 }
184+var mistralThinkingContentSchema = import_v43.z.discriminatedUnion("type", [
185+  import_v43.z.object({
186+    type: import_v43.z.literal("text"),
187+    text: import_v43.z.string()
188+  }),
189+  import_v43.z.object({
190+    type: import_v43.z.literal("tool_reference"),
191+    tool: import_v43.z.string(),
192+    title: import_v43.z.string(),
193+    url: import_v43.z.string().nullish(),
194+    favicon: import_v43.z.string().nullish(),
195+    description: import_v43.z.string().nullish()
196+  }),
197+  import_v43.z.object({
198+    type: import_v43.z.literal("reference"),
199+    reference_ids: import_v43.z.array(import_v43.z.union([import_v43.z.string(), import_v43.z.number().int()]))
200+  })
201+]);
202+var mistralThinkChunkSchema = import_v43.z.object({
203+  type: import_v43.z.literal("thinking"),
204+  thinking: import_v43.z.array(mistralThinkingContentSchema),
205+  closed: import_v43.z.boolean().optional(),
206+  signature: import_v43.z.string().nullish()
207+});
208 var mistralContentSchema = import_v43.z.union([
209   import_v43.z.string(),
210   import_v43.z.array(
211@@ -708,15 +758,7 @@ var mistralContentSchema = import_v43.z.union([
212         type: import_v43.z.literal("reference"),
213         reference_ids: import_v43.z.array(import_v43.z.union([import_v43.z.string(), import_v43.z.number()]))
214       }),
215-      import_v43.z.object({
216-        type: import_v43.z.literal("thinking"),
217-        thinking: import_v43.z.array(
218-          import_v43.z.object({
219-            type: import_v43.z.literal("text"),
220-            text: import_v43.z.string()
221-          })
222-        )
223-      })
224+      mistralThinkChunkSchema
225     ])
226   )
227 ]).nullish();
228diff --git a/dist/index.mjs b/dist/index.mjs
229index d2eff622c1b84a96bdeb4012cb0206a33012a04d..3bff11ddd6136ada45809568828cbc8f2493a42a 100644
230--- a/dist/index.mjs
231+++ b/dist/index.mjs
232@@ -116,11 +116,14 @@ function convertToMistralChatMessages(prompt) {
233       }
234       case "assistant": {
235         let text = "";
236+        const structuredContent = [];
237+        let hasNativeReasoning = false;
238         const toolCalls = [];
239         for (const part of content) {
240           switch (part.type) {
241             case "text": {
242               text += part.text;
243+              structuredContent.push({ type: "text", text: part.text });
244               break;
245             }
246             case "tool-call": {
247@@ -136,6 +139,13 @@ function convertToMistralChatMessages(prompt) {
248             }
249             case "reasoning": {
250               text += part.text;
251+              const native = part.providerOptions?.mistral?.thinking;
252+              if (native?.type === "thinking") {
253+                hasNativeReasoning = true;
254+                structuredContent.push(native);
255+                break;
256+              }
257+              structuredContent.push({ type: "text", text: part.text });
258               break;
259             }
260             default: {
261@@ -147,7 +157,7 @@ function convertToMistralChatMessages(prompt) {
262         }
263         messages.push({
264           role: "assistant",
265-          content: text,
266+          content: hasNativeReasoning ? structuredContent : text,
267           prefix: isLastMessage ? true : void 0,
268           tool_calls: toolCalls.length > 0 ? toolCalls : void 0
269         });
270@@ -256,7 +266,8 @@ var mistralLanguageModelOptions = z.object({
271    * - `'high'`: Enable reasoning
272    * - `'none'`: Disable reasoning
273    */
274-  reasoningEffort: z.enum(["high", "none"]).optional()
275+  reasoningEffort: z.string().optional(),
276+  promptCacheKey: z.string().optional()
277 });
278 
279 // src/mistral-error.ts
280@@ -397,6 +408,7 @@ var MistralChatLanguageModel = class {
281       stop: stopSequences,
282       random_seed: seed,
283       reasoning_effort: options.reasoningEffort,
284+      prompt_cache_key: options.promptCacheKey,
285       // response format:
286       response_format: (responseFormat == null ? void 0 : responseFormat.type) === "json" ? structuredOutputs && (responseFormat == null ? void 0 : responseFormat.schema) != null ? {
287         type: "json_schema",
288@@ -455,9 +467,11 @@ var MistralChatLanguageModel = class {
289       for (const part of choice.message.content) {
290         if (part.type === "thinking") {
291           const reasoningText = extractReasoningContent(part.thinking);
292-          if (reasoningText.length > 0) {
293-            content.push({ type: "reasoning", text: reasoningText });
294-          }
295+          content.push({
296+            type: "reasoning",
297+            text: reasoningText,
298+            providerMetadata: { mistral: { thinking: part } }
299+          });
300         } else if (part.type === "text") {
301           if (part.text.length > 0) {
302             content.push({ type: "text", text: part.text });
303@@ -518,6 +532,7 @@ var MistralChatLanguageModel = class {
304     let isFirstChunk = true;
305     let activeText = false;
306     let activeReasoningId = null;
307+    let activeThinking = null;
308     const generateId2 = this.generateId;
309     return {
310       stream: response.pipeThrough(
311@@ -551,18 +566,19 @@ var MistralChatLanguageModel = class {
312               for (const part of delta.content) {
313                 if (part.type === "thinking") {
314                   const reasoningDelta = extractReasoningContent(part.thinking);
315-                  if (reasoningDelta.length > 0) {
316-                    if (activeReasoningId == null) {
317-                      if (activeText) {
318-                        controller.enqueue({ type: "text-end", id: "0" });
319-                        activeText = false;
320-                      }
321-                      activeReasoningId = generateId2();
322-                      controller.enqueue({
323-                        type: "reasoning-start",
324-                        id: activeReasoningId
325-                      });
326+                  activeThinking = mergeThinking(activeThinking, part);
327+                  if (activeReasoningId == null) {
328+                    if (activeText) {
329+                      controller.enqueue({ type: "text-end", id: "0" });
330+                      activeText = false;
331                     }
332+                    activeReasoningId = generateId2();
333+                    controller.enqueue({
334+                      type: "reasoning-start",
335+                      id: activeReasoningId
336+                    });
337+                  }
338+                  if (reasoningDelta.length > 0) {
339                     controller.enqueue({
340                       type: "reasoning-delta",
341                       id: activeReasoningId,
342@@ -577,9 +593,11 @@ var MistralChatLanguageModel = class {
343                 if (activeReasoningId != null) {
344                   controller.enqueue({
345                     type: "reasoning-end",
346-                    id: activeReasoningId
347+                    id: activeReasoningId,
348+                    providerMetadata: { mistral: { thinking: activeThinking } }
349                   });
350                   activeReasoningId = null;
351+                  activeThinking = null;
352                 }
353                 controller.enqueue({ type: "text-start", id: "0" });
354                 activeText = true;
355@@ -628,7 +646,8 @@ var MistralChatLanguageModel = class {
356             if (activeReasoningId != null) {
357               controller.enqueue({
358                 type: "reasoning-end",
359-                id: activeReasoningId
360+                id: activeReasoningId,
361+                providerMetadata: { mistral: { thinking: activeThinking } }
362               });
363             }
364             if (activeText) {
365@@ -650,6 +669,13 @@ var MistralChatLanguageModel = class {
366 function extractReasoningContent(thinking) {
367   return thinking.filter((chunk) => chunk.type === "text").map((chunk) => chunk.text).join("");
368 }
369+function mergeThinking(current, next) {
370+  if (current === null) return { ...next, thinking: [...next.thinking] };
371+  current.thinking.push(...next.thinking);
372+  if (next.closed !== void 0) current.closed = next.closed;
373+  if (next.signature !== void 0) current.signature = next.signature;
374+  return current;
375+}
376 function extractTextContent(content) {
377   if (typeof content === "string") {
378     return content;
379@@ -676,6 +702,30 @@ function extractTextContent(content) {
380   }
381   return textContent.length ? textContent.join("") : void 0;
382 }
383+var mistralThinkingContentSchema = z3.discriminatedUnion("type", [
384+  z3.object({
385+    type: z3.literal("text"),
386+    text: z3.string()
387+  }),
388+  z3.object({
389+    type: z3.literal("tool_reference"),
390+    tool: z3.string(),
391+    title: z3.string(),
392+    url: z3.string().nullish(),
393+    favicon: z3.string().nullish(),
394+    description: z3.string().nullish()
395+  }),
396+  z3.object({
397+    type: z3.literal("reference"),
398+    reference_ids: z3.array(z3.union([z3.string(), z3.number().int()]))
399+  })
400+]);
401+var mistralThinkChunkSchema = z3.object({
402+  type: z3.literal("thinking"),
403+  thinking: z3.array(mistralThinkingContentSchema),
404+  closed: z3.boolean().optional(),
405+  signature: z3.string().nullish()
406+});
407 var mistralContentSchema = z3.union([
408   z3.string(),
409   z3.array(
410@@ -698,15 +748,7 @@ var mistralContentSchema = z3.union([
411         type: z3.literal("reference"),
412         reference_ids: z3.array(z3.union([z3.string(), z3.number()]))
413       }),
414-      z3.object({
415-        type: z3.literal("thinking"),
416-        thinking: z3.array(
417-          z3.object({
418-            type: z3.literal("text"),
419-            text: z3.string()
420-          })
421-        )
422-      })
423+      mistralThinkChunkSchema
424     ])
425   )
426 ]).nullish();
427diff --git a/src/convert-to-mistral-chat-messages.ts b/src/convert-to-mistral-chat-messages.ts
428index 3c6914f8da615d7517bc43dd56198298d0a50247..8cd6f4c7577f746ef41e8a0aee682234c473667a 100644
429--- a/src/convert-to-mistral-chat-messages.ts
430+++ b/src/convert-to-mistral-chat-messages.ts
431@@ -3,7 +3,11 @@ import {
432   type LanguageModelV3DataContent,
433   type LanguageModelV3Prompt,
434 } from '@ai-sdk/provider';
435-import type { MistralPrompt } from './mistral-chat-prompt';
436+import type {
437+  MistralAssistantMessageContent,
438+  MistralPrompt,
439+  MistralThinkChunk,
440+} from './mistral-chat-prompt';
441 import { convertToBase64 } from '@ai-sdk/provider-utils';
442 
443 function formatFileUrl({
444@@ -76,6 +80,8 @@ export function convertToMistralChatMessages(
445 
446       case 'assistant': {
447         let text = '';
448+        const structuredContent: Array<MistralAssistantMessageContent> = [];
449+        let hasNativeReasoning = false;
450         const toolCalls: Array<{
451           id: string;
452           type: 'function';
453@@ -86,6 +92,7 @@ export function convertToMistralChatMessages(
454           switch (part.type) {
455             case 'text': {
456               text += part.text;
457+              structuredContent.push({ type: 'text', text: part.text });
458               break;
459             }
460             case 'tool-call': {
461@@ -101,6 +108,14 @@ export function convertToMistralChatMessages(
462             }
463             case 'reasoning': {
464               text += part.text;
465+              const native = part.providerOptions?.mistral
466+                ?.thinking as MistralThinkChunk | undefined;
467+              if (native?.type === 'thinking') {
468+                hasNativeReasoning = true;
469+                structuredContent.push(native);
470+                break;
471+              }
472+              structuredContent.push({ type: 'text', text: part.text });
473               break;
474             }
475             default: {
476@@ -113,7 +128,7 @@ export function convertToMistralChatMessages(
477 
478         messages.push({
479           role: 'assistant',
480-          content: text,
481+          content: hasNativeReasoning ? structuredContent : text,
482           prefix: isLastMessage ? true : undefined,
483           tool_calls: toolCalls.length > 0 ? toolCalls : undefined,
484         });
485diff --git a/src/mistral-chat-language-model.ts b/src/mistral-chat-language-model.ts
486index 7e4a7ab552f1b41b7074e1b3cada8a51d791268d..847d26f9dfe03572a969a122f8c96b8bbfda8066 100644
487--- a/src/mistral-chat-language-model.ts
488+++ b/src/mistral-chat-language-model.ts
489@@ -122,6 +122,7 @@ export class MistralChatLanguageModel implements LanguageModelV3 {
490       stop: stopSequences,
491       random_seed: seed,
492       reasoning_effort: options.reasoningEffort,
493+      prompt_cache_key: options.promptCacheKey,
494 
495       // response format:
496       response_format:
497@@ -201,9 +202,11 @@ export class MistralChatLanguageModel implements LanguageModelV3 {
498       for (const part of choice.message.content) {
499         if (part.type === 'thinking') {
500           const reasoningText = extractReasoningContent(part.thinking);
501-          if (reasoningText.length > 0) {
502-            content.push({ type: 'reasoning', text: reasoningText });
503-          }
504+          content.push({
505+            type: 'reasoning',
506+            text: reasoningText,
507+            providerMetadata: { mistral: { thinking: part } },
508+          });
509         } else if (part.type === 'text') {
510           if (part.text.length > 0) {
511             content.push({ type: 'text', text: part.text });
512@@ -278,6 +281,7 @@ export class MistralChatLanguageModel implements LanguageModelV3 {
513     let isFirstChunk = true;
514     let activeText = false;
515     let activeReasoningId: string | null = null;
516+    let activeThinking: z.infer<typeof mistralThinkChunkSchema> | null = null;
517 
518     const generateId = this.generateId;
519 
520@@ -326,20 +330,21 @@ export class MistralChatLanguageModel implements LanguageModelV3 {
521               for (const part of delta.content) {
522                 if (part.type === 'thinking') {
523                   const reasoningDelta = extractReasoningContent(part.thinking);
524-                  if (reasoningDelta.length > 0) {
525-                    if (activeReasoningId == null) {
526-                      // end any active text before starting reasoning
527-                      if (activeText) {
528-                        controller.enqueue({ type: 'text-end', id: '0' });
529-                        activeText = false;
530-                      }
531-
532-                      activeReasoningId = generateId();
533-                      controller.enqueue({
534-                        type: 'reasoning-start',
535-                        id: activeReasoningId,
536-                      });
537+                  activeThinking = mergeThinking(activeThinking, part);
538+                  if (activeReasoningId == null) {
539+                    // end any active text before starting reasoning
540+                    if (activeText) {
541+                      controller.enqueue({ type: 'text-end', id: '0' });
542+                      activeText = false;
543                     }
544+
545+                    activeReasoningId = generateId();
546+                    controller.enqueue({
547+                      type: 'reasoning-start',
548+                      id: activeReasoningId,
549+                    });
550+                  }
551+                  if (reasoningDelta.length > 0) {
552                     controller.enqueue({
553                       type: 'reasoning-delta',
554                       id: activeReasoningId,
555@@ -357,8 +362,12 @@ export class MistralChatLanguageModel implements LanguageModelV3 {
556                   controller.enqueue({
557                     type: 'reasoning-end',
558                     id: activeReasoningId,
559+                    providerMetadata: {
560+                      mistral: { thinking: activeThinking },
561+                    },
562                   });
563                   activeReasoningId = null;
564+                  activeThinking = null;
565                 }
566                 controller.enqueue({ type: 'text-start', id: '0' });
567                 activeText = true;
568@@ -416,6 +425,9 @@ export class MistralChatLanguageModel implements LanguageModelV3 {
569               controller.enqueue({
570                 type: 'reasoning-end',
571                 id: activeReasoningId,
572+                providerMetadata: {
573+                  mistral: { thinking: activeThinking },
574+                },
575               });
576             }
577             if (activeText) {
578@@ -437,7 +449,7 @@ export class MistralChatLanguageModel implements LanguageModelV3 {
579 }
580 
581 function extractReasoningContent(
582-  thinking: Array<{ type: string; text: string }>,
583+  thinking: Array<z.infer<typeof mistralThinkingContentSchema>>,
584 ) {
585   return thinking
586     .filter(chunk => chunk.type === 'text')
587@@ -445,6 +457,17 @@ function extractReasoningContent(
588     .join('');
589 }
590 
591+function mergeThinking(
592+  current: z.infer<typeof mistralThinkChunkSchema> | null,
593+  next: z.infer<typeof mistralThinkChunkSchema>,
594+) {
595+  if (current === null) return { ...next, thinking: [...next.thinking] };
596+  current.thinking.push(...next.thinking);
597+  if (next.closed !== undefined) current.closed = next.closed;
598+  if (next.signature !== undefined) current.signature = next.signature;
599+  return current;
600+}
601+
602 function extractTextContent(content: z.infer<typeof mistralContentSchema>) {
603   if (typeof content === 'string') {
604     return content;
605@@ -478,6 +501,32 @@ function extractTextContent(content: z.infer<typeof mistralContentSchema>) {
606   return textContent.length ? textContent.join('') : undefined;
607 }
608 
609+const mistralThinkingContentSchema = z.discriminatedUnion('type', [
610+  z.object({
611+    type: z.literal('text'),
612+    text: z.string(),
613+  }),
614+  z.object({
615+    type: z.literal('tool_reference'),
616+    tool: z.string(),
617+    title: z.string(),
618+    url: z.string().nullish(),
619+    favicon: z.string().nullish(),
620+    description: z.string().nullish(),
621+  }),
622+  z.object({
623+    type: z.literal('reference'),
624+    reference_ids: z.array(z.union([z.string(), z.number().int()])),
625+  }),
626+]);
627+
628+const mistralThinkChunkSchema = z.object({
629+  type: z.literal('thinking'),
630+  thinking: z.array(mistralThinkingContentSchema),
631+  closed: z.boolean().optional(),
632+  signature: z.string().nullish(),
633+});
634+
635 const mistralContentSchema = z
636   .union([
637     z.string(),
638@@ -501,15 +550,7 @@ const mistralContentSchema = z
639           type: z.literal('reference'),
640           reference_ids: z.array(z.union([z.string(), z.number()])),
641         }),
642-        z.object({
643-          type: z.literal('thinking'),
644-          thinking: z.array(
645-            z.object({
646-              type: z.literal('text'),
647-              text: z.string(),
648-            }),
649-          ),
650-        }),
651+        mistralThinkChunkSchema,
652       ]),
653     ),
654   ])
655diff --git a/src/mistral-chat-options.ts b/src/mistral-chat-options.ts
656index 54b29c08517d348995b6ca093b11160e453d5c8b..de30c3e7d924889339e38b1067cb26e9ada05d11 100644
657--- a/src/mistral-chat-options.ts
658+++ b/src/mistral-chat-options.ts
659@@ -64,6 +64,11 @@ export const mistralLanguageModelOptions = z.object({
660    * - `'none'`: Disable reasoning
661    */
662-  reasoningEffort: z.enum(['high', 'none']).optional(),
663+  reasoningEffort: z.string().optional(),
664+
665+  /**
666+   * A stable identifier used to route requests with shared prompt prefixes.
667+   */
668+  promptCacheKey: z.string().optional(),
669 });
670 
671 export type MistralLanguageModelOptions = z.infer<
672diff --git a/src/mistral-chat-prompt.ts b/src/mistral-chat-prompt.ts
673index 13f1dced55ac4be084128127a57fbdd58115bc28..172b11dde3dd326c2f3befd99237474ed8c79285 100644
674--- a/src/mistral-chat-prompt.ts
675+++ b/src/mistral-chat-prompt.ts
676@@ -23,7 +23,7 @@ export type MistralUserMessageContent =
677 
678 export interface MistralAssistantMessage {
679   role: 'assistant';
680-  content: string;
681+  content: string | Array<MistralAssistantMessageContent>;
682   prefix?: boolean;
683   tool_calls?: Array<{
684     id: string;
685@@ -32,6 +32,29 @@ export interface MistralAssistantMessage {
686   }>;
687 }
688 
689+export type MistralAssistantMessageContent =
690+  | { type: 'text'; text: string }
691+  | MistralThinkChunk;
692+
693+export type MistralThinkChunk = {
694+  type: 'thinking';
695+  thinking: Array<MistralThinkingContent>;
696+  closed?: boolean;
697+  signature?: string | null;
698+};
699+
700+export type MistralThinkingContent =
701+  | { type: 'text'; text: string }
702+  | {
703+      type: 'tool_reference';
704+      tool: string;
705+      title: string;
706+      url?: string | null;
707+      favicon?: string | null;
708+      description?: string | null;
709+    }
710+  | { type: 'reference'; reference_ids: Array<string | number> };
711+
712 export interface MistralToolMessage {
713   role: 'tool';
714   name: string;
715