diff --git a/packages/scrawn/src/core/scrawn.ts b/packages/scrawn/src/core/scrawn.ts
index 7e041e9..93c8f36 100644
--- a/packages/scrawn/src/core/scrawn.ts
+++ b/packages/scrawn/src/core/scrawn.ts
@@ -1024,6 +1024,14 @@ export class Scrawn<
               expr: payload.inputCacheDebit.expr?._expr,
             }
           : undefined,
+        outputCacheTokens: payload.outputCacheTokens,
+        outputCacheDebit: payload.outputCacheDebit
+          ? {
+              amount: payload.outputCacheDebit.amount,
+              tag: payload.outputCacheDebit.tag,
+              expr: payload.outputCacheDebit.expr?._expr,
+            }
+          : undefined,
       };
 
       // Validate each payload
@@ -1147,6 +1155,14 @@ export class Scrawn<
               resolveTokens(validated.inputCacheDebit.expr, tokenContext)
             )
           : undefined,
+        outputCacheTokens: validated.outputCacheTokens ?? 0,
+        outputCacheAmount: validated.outputCacheDebit?.amount ?? undefined,
+        outputCacheTag: validated.outputCacheDebit?.tag ?? undefined,
+        outputCacheExpr: validated.outputCacheDebit?.expr
+          ? serializeExpr(
+              resolveTokens(validated.outputCacheDebit.expr, tokenContext)
+            )
+          : undefined,
       } as AITokenUsage;
 
       const eventId = randomUUID();
diff --git a/packages/scrawn/src/core/types/event.ts b/packages/scrawn/src/core/types/event.ts
index 191fb33..5c6629a 100644
--- a/packages/scrawn/src/core/types/event.ts
+++ b/packages/scrawn/src/core/types/event.ts
@@ -361,6 +361,8 @@ const DebitFieldSchema = z
  * - provider: optional non-empty string
  * - inputCacheTokens: optional non-negative integer
  * - inputCacheDebit: optional one of amount, tag, or expr
+ * - outputCacheTokens: optional non-negative integer
+ * - outputCacheDebit: optional one of amount, tag, or expr
  */
 export const AITokenUsagePayloadSchema = z.object({
   userId: z.string().min(1, "userId must be a non-empty string"),
@@ -383,6 +385,12 @@ export const AITokenUsagePayloadSchema = z.object({
     .nonnegative("inputCacheTokens must be non-negative")
     .optional(),
   inputCacheDebit: DebitFieldSchema.optional(),
+  outputCacheTokens: z
+    .number()
+    .int("outputCacheTokens must be an integer")
+    .nonnegative("outputCacheTokens must be non-negative")
+    .optional(),
+  outputCacheDebit: DebitFieldSchema.optional(),
 });
 
 /**
@@ -403,6 +411,8 @@ export const AITokenUsagePayloadSchema = z.object({
  * @property provider - (Optional) LLM provider identifier (e.g. 'openai', 'anthropic')
  * @property inputCacheTokens - (Optional) Cached input tokens count (typically cheaper)
  * @property inputCacheDebit - (Optional) Debit pricing for cached input tokens
+ * @property outputCacheTokens - (Optional) Cached output tokens count (typically cheaper)
+ * @property outputCacheDebit - (Optional) Debit pricing for cached output tokens
  *
  * @example
  * ```typescript
@@ -454,4 +464,8 @@ export type AITokenUsagePayload<TTag extends string = string> = {
   inputCacheTokens?: number;
   /** Debit pricing for cached input tokens (oneof amount, tag, or expr). */
   inputCacheDebit?: DebitField<TTag>;
+  /** Number of cached output tokens used (typically cheaper). */
+  outputCacheTokens?: number;
+  /** Debit pricing for cached output tokens (oneof amount, tag, or expr). */
+  outputCacheDebit?: DebitField<TTag>;
 };
diff --git a/packages/scrawn/src/gen/event/v1/event.ts b/packages/scrawn/src/gen/event/v1/event.ts
index 5f59bdd..3e1384d 100644
--- a/packages/scrawn/src/gen/event/v1/event.ts
+++ b/packages/scrawn/src/gen/event/v1/event.ts
@@ -151,6 +151,11 @@ export interface AITokenUsage {
   inputCacheTag?: string | undefined;
   /** Pricing expression for input cache tokens */
   inputCacheExpr?: string | undefined;
+  outputCacheTokens: number;
+  outputCacheAmount?: number | undefined;
+  outputCacheTag?: string | undefined;
+  /** Pricing expression for output cache tokens */
+  outputCacheExpr?: string | undefined;
   metadata?: string | undefined;
 }
 
@@ -747,6 +752,10 @@ function createBaseAITokenUsage(): AITokenUsage {
     inputCacheAmount: undefined,
     inputCacheTag: undefined,
     inputCacheExpr: undefined,
+    outputCacheTokens: 0,
+    outputCacheAmount: undefined,
+    outputCacheTag: undefined,
+    outputCacheExpr: undefined,
     metadata: undefined,
   };
 }
@@ -798,6 +807,18 @@ export const AITokenUsage: MessageFns<AITokenUsage> = {
     if (message.inputCacheExpr !== undefined) {
       writer.uint32(114).string(message.inputCacheExpr);
     }
+    if (message.outputCacheTokens !== 0) {
+      writer.uint32(128).int32(message.outputCacheTokens);
+    }
+    if (message.outputCacheAmount !== undefined) {
+      writer.uint32(136).int32(message.outputCacheAmount);
+    }
+    if (message.outputCacheTag !== undefined) {
+      writer.uint32(146).string(message.outputCacheTag);
+    }
+    if (message.outputCacheExpr !== undefined) {
+      writer.uint32(154).string(message.outputCacheExpr);
+    }
     if (message.metadata !== undefined) {
       writer.uint32(122).string(message.metadata);
     }
@@ -924,6 +945,38 @@ export const AITokenUsage: MessageFns<AITokenUsage> = {
           message.inputCacheExpr = reader.string();
           continue;
         }
+        case 16: {
+          if (tag !== 128) {
+            break;
+          }
+
+          message.outputCacheTokens = reader.int32();
+          continue;
+        }
+        case 17: {
+          if (tag !== 136) {
+            break;
+          }
+
+          message.outputCacheAmount = reader.int32();
+          continue;
+        }
+        case 18: {
+          if (tag !== 146) {
+            break;
+          }
+
+          message.outputCacheTag = reader.string();
+          continue;
+        }
+        case 19: {
+          if (tag !== 154) {
+            break;
+          }
+
+          message.outputCacheExpr = reader.string();
+          continue;
+        }
         case 15: {
           if (tag !== 122) {
             break;
@@ -983,6 +1036,18 @@ export const AITokenUsage: MessageFns<AITokenUsage> = {
       inputCacheExpr: isSet(object.inputCacheExpr)
         ? globalThis.String(object.inputCacheExpr)
         : undefined,
+      outputCacheTokens: isSet(object.outputCacheTokens)
+        ? globalThis.Number(object.outputCacheTokens)
+        : 0,
+      outputCacheAmount: isSet(object.outputCacheAmount)
+        ? globalThis.Number(object.outputCacheAmount)
+        : undefined,
+      outputCacheTag: isSet(object.outputCacheTag)
+        ? globalThis.String(object.outputCacheTag)
+        : undefined,
+      outputCacheExpr: isSet(object.outputCacheExpr)
+        ? globalThis.String(object.outputCacheExpr)
+        : undefined,
       metadata: isSet(object.metadata)
         ? globalThis.String(object.metadata)
         : undefined,
@@ -1033,6 +1098,18 @@ export const AITokenUsage: MessageFns<AITokenUsage> = {
     if (message.inputCacheExpr !== undefined) {
       obj.inputCacheExpr = message.inputCacheExpr;
     }
+    if (message.outputCacheTokens !== 0) {
+      obj.outputCacheTokens = Math.round(message.outputCacheTokens);
+    }
+    if (message.outputCacheAmount !== undefined) {
+      obj.outputCacheAmount = Math.round(message.outputCacheAmount);
+    }
+    if (message.outputCacheTag !== undefined) {
+      obj.outputCacheTag = message.outputCacheTag;
+    }
+    if (message.outputCacheExpr !== undefined) {
+      obj.outputCacheExpr = message.outputCacheExpr;
+    }
     if (message.metadata !== undefined) {
       obj.metadata = message.metadata;
     }
@@ -1062,6 +1139,10 @@ export const AITokenUsage: MessageFns<AITokenUsage> = {
     message.inputCacheAmount = object.inputCacheAmount ?? undefined;
     message.inputCacheTag = object.inputCacheTag ?? undefined;
     message.inputCacheExpr = object.inputCacheExpr ?? undefined;
+    message.outputCacheTokens = object.outputCacheTokens ?? 0;
+    message.outputCacheAmount = object.outputCacheAmount ?? undefined;
+    message.outputCacheTag = object.outputCacheTag ?? undefined;
+    message.outputCacheExpr = object.outputCacheExpr ?? undefined;
     message.metadata = object.metadata ?? undefined;
     return message;
   },