feat: add agent cost reporting

hub/src/agent/cost.ts

@@ -0,0 +1,23 @@
+export function formatRunCostLine(costUsd: number | undefined): string {
+  return costUsd === undefined
+    ? "本次成本: 未记录"
+    : `本次成本: ${formatUsd(costUsd)}`;
+}
+
+export function formatInteger(value: number): string {
+  return new Intl.NumberFormat("en-US").format(value);
+}
+
+export function formatUsd(value: number): string {
+  const digits = value > 0 && value < 0.01 ? 4 : 2;
+  return `$${value.toFixed(digits)}`;
+}
+
+export function decimalToNumberOrNull(value: unknown): number | null {
+  if (value === null || value === undefined) return null;
+  const numberValue = typeof value === "number" ? value : Number(value);
+  if (!Number.isFinite(numberValue)) {
+    throw new Error("invalid cost value");
+  }
+  return numberValue;
+}

hub/src/agent/runner.ts

@@ -73,6 +73,8 @@ export interface RunResult {
   readonly status: RunStatus;
   readonly text: string;
   readonly usage: { inputTokens: number; outputTokens: number };
+  /** Provider- or gateway-reported cost for this run, in USD. */
+  readonly costUsd?: number | undefined;
   readonly numTurns: number;
   readonly sdkSessionId?: string | undefined;
   readonly error?: string;
@@ -123,6 +125,7 @@ export async function runAgent(req: RunRequest): Promise<RunResult> {
 
   let fullText = "";
   let usage = { inputTokens: 0, outputTokens: 0 };
+  let costUsd: number | undefined;
   let numTurns = 0;
   let sdkSessionId: string | undefined;
   let error: string | undefined;
@@ -248,6 +251,7 @@ export async function runAgent(req: RunRequest): Promise<RunResult> {
         case "result": {
           const result = message as SDKResultMessage;
           sdkSessionId = result.session_id;
+          costUsd = Number.isFinite(result.total_cost_usd) ? result.total_cost_usd : undefined;
           if (result.subtype !== "success") {
             error = `result_${result.subtype}`;
           }
@@ -261,6 +265,7 @@ export async function runAgent(req: RunRequest): Promise<RunResult> {
       status: error !== undefined ? "failed" : "completed",
       text: fullText,
       usage,
+      ...(costUsd !== undefined ? { costUsd } : {}),
       numTurns,
       sdkSessionId,
       ...(error !== undefined ? { error } : {}),
@@ -271,6 +276,7 @@ export async function runAgent(req: RunRequest): Promise<RunResult> {
       status: aborted ? "interrupted" : "failed",
       text: fullText,
       usage,
+      ...(costUsd !== undefined ? { costUsd } : {}),
       numTurns,
       sdkSessionId,
       ...(aborted ? {} : { error: e instanceof Error ? e.message : String(e) }),