fix(provider/xai): correct usage token calculation for reasoning models

.changeset/swift-berries-confess.md

@@ -0,0 +1,5 @@
+---
+'@ai-sdk/xai': patch
+---
+
+fix(provider/xai): correct usage token calculation for reasoning models

examples/ai-functions/src/generate-text/xai-usage-full.ts

@@ -0,0 +1,44 @@
+import { xai } from '@ai-sdk/xai';
+import { generateText } from 'ai';
+import { run } from '../lib/run';
+
+const models = [
+  'grok-4',
+  'grok-4-1-fast-reasoning',
+  'grok-4-1-fast-non-reasoning',
+  'grok-4-fast-reasoning',
+  'grok-4-fast-non-reasoning',
+  'grok-code-fast-1',
+  'grok-3',
+  'grok-3-fast',
+  'grok-3-mini',
+  'grok-3-mini-fast',
+];
+
+run(async () => {
+  for (const modelId of models) {
+    try {
+      const result = await generateText({
+        model: xai(modelId),
+        prompt: 'Say a single word.',
+      });
+
+      const body = result.response.body as Record<string, any>;
+      const raw = body.usage;
+      const sdk = result.usage;
+
+      console.log(`--- ${modelId} ---`);
+      console.log(
+        `raw: completion_tokens=${raw.completion_tokens}, reasoning_tokens=${raw.completion_tokens_details?.reasoning_tokens ?? 0}, total_tokens=${raw.total_tokens}`,
+      );
+      console.log(
+        `sdk: outputTokens=${sdk.outputTokens}, textTokens=${sdk.outputTokenDetails?.textTokens}, reasoningTokens=${sdk.outputTokenDetails?.reasoningTokens}, totalTokens=${sdk.totalTokens}`,
+      );
+      console.log();
+    } catch (e: any) {
+      console.log(`--- ${modelId} ---`);
+      console.log(`error: ${e.message?.slice(0, 80)}`);
+      console.log();
+    }
+  }
+});

examples/ai-functions/src/generate-text/xai-usage.ts

@@ -0,0 +1,16 @@
+import { xai } from '@ai-sdk/xai';
+import { generateText } from 'ai';
+import { run } from '../lib/run';
+
+run(async () => {
+  const result = await generateText({
+    model: xai('grok-3-mini'),
+    prompt: 'Say a single word.',
+  });
+
+  console.log('text:', result.text);
+  console.log();
+  console.log('raw usage:', JSON.stringify(result.response.body, null, 2));
+  console.log();
+  console.log('sdk usage:', JSON.stringify(result.usage, null, 2));
+});

examples/ai-functions/src/stream-text/xai-usage-full.ts

@@ -0,0 +1,43 @@
+import { xai } from '@ai-sdk/xai';
+import { streamText } from 'ai';
+import { run } from '../lib/run';
+
+const models = [
+  'grok-4',
+  'grok-4-1-fast-reasoning',
+  'grok-4-1-fast-non-reasoning',
+  'grok-4-fast-reasoning',
+  'grok-4-fast-non-reasoning',
+  'grok-code-fast-1',
+  'grok-3',
+  'grok-3-fast',
+  'grok-3-mini',
+  'grok-3-mini-fast',
+];
+
+run(async () => {
+  for (const modelId of models) {
+    try {
+      const result = streamText({
+        model: xai(modelId),
+        prompt: 'Say a single word.',
+      });
+
+      for await (const textPart of result.textStream) {
+        void textPart;
+      }
+
+      const sdk = await result.usage;
+
+      console.log(`--- ${modelId} ---`);
+      console.log(
+        `sdk: outputTokens=${sdk.outputTokens}, textTokens=${sdk.outputTokenDetails?.textTokens}, reasoningTokens=${sdk.outputTokenDetails?.reasoningTokens}, totalTokens=${sdk.totalTokens}`,
+      );
+      console.log();
+    } catch (e: any) {
+      console.log(`--- ${modelId} ---`);
+      console.log(`error: ${e.message?.slice(0, 80)}`);
+      console.log();
+    }
+  }
+});

examples/ai-functions/src/stream-text/xai-usage.ts

@@ -0,0 +1,18 @@
+import { xai } from '@ai-sdk/xai';
+import { streamText } from 'ai';
+import { run } from '../lib/run';
+
+run(async () => {
+  const result = streamText({
+    model: xai('grok-3-mini'),
+    prompt: 'Say a single word.',
+  });
+
+  for await (const textPart of result.textStream) {
+    process.stdout.write(textPart);
+  }
+
+  console.log();
+  console.log();
+  console.log('sdk usage:', JSON.stringify(await result.usage, null, 2));
+});

packages/xai/src/__snapshots__/xai-chat-language-model.test.ts.snap

@@ -97,8 +97,8 @@ Response: I'll go with "Hello" as it's a common greeting and keeps it simple.",
     },
     "outputTokens": {
       "reasoning": 228,
-      "text": -227,
-      "total": 1,
+      "text": 1,
+      "total": 229,
     },
     "raw": {
       "completion_tokens": 1,
@@ -235,8 +235,8 @@ I should call this function to advance the user's request.",
     },
     "outputTokens": {
       "reasoning": 189,
-      "text": -163,
-      "total": 26,
+      "text": 26,
+      "total": 215,
     },
     "raw": {
       "completion_tokens": 26,
@@ -333,8 +333,8 @@ exports[`XaiChatLanguageModel > doStream > text > should stream text content 1`]
       },
       "outputTokens": {
         "reasoning": 290,
-        "text": -289,
-        "total": 1,
+        "text": 1,
+        "total": 291,
       },
       "raw": {
         "completion_tokens": 1,
@@ -438,8 +438,8 @@ exports[`XaiChatLanguageModel > doStream > tool call > should stream tool call c
       },
       "outputTokens": {
         "reasoning": 196,
-        "text": -170,
-        "total": 26,
+        "text": 26,
+        "total": 222,
       },
       "raw": {
         "completion_tokens": 26,