fix(ai): keep plan per-minute limits transient

packages/ai/src/error/rate-limit.ts

@@ -24,6 +24,13 @@ const INSUFFICIENT_BALANCE_PATTERN = /insufficient.?balance/i;
 const SPEND_LIMIT_PATTERN = /spend.?limit/i;
 const SUBSCRIPTION_CAP_PATTERN =
 	/\b(?:subscription|plan|membership)\b[^\n]{0,80}\b(?:rate.?limits?|quota|cap)\b|\b(?:rate.?limits?|quota|cap)\b[^\n]{0,80}\b(?:subscription|plan|membership)\b/i;
+const TRANSIENT_INTERVAL_RATE_LIMIT_PATTERN = /\bper\s+(?:second|minute)\b/i;
+
+function matchesSubscriptionCapText(errorMessage: string): boolean {
+	return (
+		SUBSCRIPTION_CAP_PATTERN.test(errorMessage) && !TRANSIENT_INTERVAL_RATE_LIMIT_PATTERN.test(errorMessage)
+	);
+}
 const OPENROUTER_DAILY_FREE_LIMIT_PATTERN = /\bfree[-_ ]models[-_ ]per[-_ ]day\b/i;
 // gRPC/Connect end-streams carry the status as its name (`resource_exhausted`),
 // while HTTP bodies use the phrase ("resource exhausted"). Strip either form
@@ -109,7 +116,7 @@ export function parseRateLimitReason(errorMessage: string): RateLimitReason {
 		return "QUOTA_EXHAUSTED";
 	}
 
-	if (SUBSCRIPTION_CAP_PATTERN.test(errorMessage)) {
+	if (matchesSubscriptionCapText(errorMessage)) {
 		return "QUOTA_EXHAUSTED";
 	}
 
@@ -273,7 +280,7 @@ export function matchesUsageLimitText(errorMessage: string): boolean {
 		(CN_QUOTA_EXHAUSTED_PATTERN.test(errorMessage) && !CN_TRANSIENT_CAP_PATTERN.test(errorMessage)) ||
 		SPEND_LIMIT_PATTERN.test(errorMessage) ||
 		ACCOUNT_RATE_LIMIT_PATTERN.test(errorMessage) ||
-		SUBSCRIPTION_CAP_PATTERN.test(errorMessage) ||
+		matchesSubscriptionCapText(errorMessage) ||
 		OPENROUTER_DAILY_FREE_LIMIT_PATTERN.test(errorMessage)
 	);
 }

packages/ai/test/rate-limit-utils.test.ts

@@ -324,6 +324,11 @@ describe("isUsageLimitOutcome", () => {
 		expect(parseRateLimitReason(transient)).toBe("RATE_LIMIT_EXCEEDED");
 		expect(isUsageLimitOutcome(429, transient)).toBe(false);
 		expect(isUsageLimit(Object.assign(new Error(transient), { status: 429 }))).toBe(false);
+
+		const planPerMinuteLimit = "429 Your plan has a rate limit of 60 requests per minute";
+		expect(parseRateLimitReason(planPerMinuteLimit)).toBe("RATE_LIMIT_EXCEEDED");
+		expect(isUsageLimitOutcome(429, planPerMinuteLimit)).toBe(false);
+		expect(isUsageLimit(Object.assign(new Error(planPerMinuteLimit), { status: 429 }))).toBe(false);
 	});
 
 	it("still rotates on 429 with explicit account rate-limit framing", () => {