diff --git a/src/services/api/claude.ts b/src/services/api/claude.ts
index af310af8f..a52df316d 100644
--- a/src/services/api/claude.ts
+++ b/src/services/api/claude.ts
@@ -1777,7 +1777,9 @@ async function* queryModel(
   // (messagesForAPI, system, allTools, betas — the entire request-building
   // context), which would otherwise be pinned until the promise resolves.
   // Also capture thinking params for Langfuse observability.
-  let langfuseThinking: { type: string; budgetTokens?: number } | undefined
+  // Pass the entire thinking config object so all fields (type, budget_tokens,
+  // and any future additions) flow through without cherry-picking.
+  let langfuseThinking: BetaMessageStreamParams['thinking'] | undefined
   {
     const queryParams = paramsFromContext({
       model: options.model,
@@ -1788,13 +1790,7 @@ async function* queryModel(
     const logThinkingType = queryParams.thinking?.type ?? 'disabled'
     const logEffortValue = queryParams.output_config?.effort
     if (queryParams.thinking && queryParams.thinking.type !== 'disabled') {
-      langfuseThinking = {
-        type: queryParams.thinking.type,
-        ...('budget_tokens' in queryParams.thinking &&
-          typeof queryParams.thinking.budget_tokens === 'number' && {
-            budgetTokens: queryParams.thinking.budget_tokens,
-          }),
-      }
+      langfuseThinking = queryParams.thinking
     }
     void options.getToolPermissionContext().then(permissionContext => {
       logAPIQuery({
diff --git a/src/services/langfuse/tracing.ts b/src/services/langfuse/tracing.ts
index ff57b334e..f0a2cebdd 100644
--- a/src/services/langfuse/tracing.ts
+++ b/src/services/langfuse/tracing.ts
@@ -78,9 +78,14 @@ export function recordLLMObservation(
     endTime?: Date
     completionStartTime?: Date
     tools?: unknown
-    /** Thinking depth configuration used for this request */
+    /** Thinking depth configuration used for this request.
+     * Accepts the full API thinking config object. Fields:
+     * - type: thinking mode ("enabled", "adaptive", "disabled")
+     * - budget_tokens (snake_case, from Anthropic API) or budgetTokens (camelCase)
+     */
     thinking?: {
       type: string
+      budget_tokens?: number
       budgetTokens?: number
     }
   },
@@ -103,8 +108,8 @@ export function recordLLMObservation(
           provider: params.provider,
           model: params.model,
           ...(params.thinking && { thinkingType: params.thinking.type }),
-          ...(params.thinking?.budgetTokens !== undefined && {
-            thinkingBudgetTokens: params.thinking.budgetTokens,
+          ...(params.thinking && (params.thinking.budget_tokens !== undefined || params.thinking.budgetTokens !== undefined) && {
+            thinkingBudgetTokens: (params.thinking.budget_tokens ?? params.thinking.budgetTokens) as number,
           }),
         },
         ...(params.completionStartTime && { completionStartTime: params.completionStartTime }),