refactor(plugin-sdk): share auth, routing, and stream/account helpers

src/agents/stream-message-shared.ts

@@ -17,10 +17,32 @@ export function buildZeroUsage(): Usage {
   };
 }
 
-export function buildAssistantMessageWithZeroUsage(params: {
+export function buildUsageWithNoCost(params: {
+  input?: number;
+  output?: number;
+  cacheRead?: number;
+  cacheWrite?: number;
+  totalTokens?: number;
+}): Usage {
+  const input = params.input ?? 0;
+  const output = params.output ?? 0;
+  const cacheRead = params.cacheRead ?? 0;
+  const cacheWrite = params.cacheWrite ?? 0;
+  return {
+    input,
+    output,
+    cacheRead,
+    cacheWrite,
+    totalTokens: params.totalTokens ?? input + output,
+    cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+  };
+}
+
+export function buildAssistantMessage(params: {
   model: StreamModelDescriptor;
   content: AssistantMessage["content"];
   stopReason: StopReason;
+  usage: Usage;
   timestamp?: number;
 }): AssistantMessage {
   return {
@@ -30,11 +52,26 @@ export function buildAssistantMessageWithZeroUsage(params: {
     api: params.model.api,
     provider: params.model.provider,
     model: params.model.id,
-    usage: buildZeroUsage(),
+    usage: params.usage,
     timestamp: params.timestamp ?? Date.now(),
   };
 }
 
+export function buildAssistantMessageWithZeroUsage(params: {
+  model: StreamModelDescriptor;
+  content: AssistantMessage["content"];
+  stopReason: StopReason;
+  timestamp?: number;
+}): AssistantMessage {
+  return buildAssistantMessage({
+    model: params.model,
+    content: params.content,
+    stopReason: params.stopReason,
+    usage: buildZeroUsage(),
+    timestamp: params.timestamp,
+  });
+}
+
 export function buildStreamErrorAssistantMessage(params: {
   model: StreamModelDescriptor;
   errorMessage: string;