Vercel AI Gateway Appears to Block BYOK Requests When Account Balance Reaches $0

Description When AI Gateway credits are depleted (zero balance), all requests are blocked - including those that should use BYOK (Bring Your Own Key) credentials. This happens regardless of whether BYOK is configured via: - Dashboard integrations (with working "Test Key" verification) - Programmatic providerOptions.byok in code ## Expected Behavior When BYOK credentials are configured (either via dashboard or providerOptions.byok), requests should be routed directly to the provider using those credentials, without requiring AI Gateway credits. The documentation states: > "Using your own credentials with an external AI provider allows AI Gateway to authenticate requests on your behalf with no added markup." This implies BYOK should bypass the credit system entirely. ## Actual Behavior All requests fail with: `` Insufficient funds. Please add credits to your account to continue using AI services. ` Even when: 1. BYOK integrations are configured in dashboard AND "Test Key" passes 2. providerOptions.byok is explicitly set in the request ## Reproduction Steps 1. Configure BYOK integration in Vercel Dashboard (AI Gateway → Integrations) 2. Verify the key works using "Test Key" feature ✓ 3. Deplete AI Gateway credits to $0 4. Make a request using createGateway(): `typescript import { createGateway, generateText } from "ai"; const gateway = createGateway(); // Method 1: Relying on dashboard BYOK config const response1 = await generateText({ model: gateway("anthropic/claude-3-5-haiku-latest"), prompt: "Hello", }); // Method 2: Explicit BYOK via providerOptions const response2 = await generateText({ model: gateway("anthropic/claude-3-5-haiku-latest"), prompt: "Hello", providerOptions: { gateway: { byok: { anthropic: [{ apiKey: process.env.ANTHROPIC_API_KEY }], }, }, }, }); ` Both fail with "Insufficient funds" error. ## Verification The API keys are valid - direct provider calls work: `typescript import { anthropic } from "@ai-sdk/anthropic"; import { generateText } from "ai"; // This works perfectly const response = await generateText({ model: anthropic("claude-3-5-haiku-latest"), prompt: "Hello", }); ` ## Environment - ai package version: 6.0.0-beta.128 - @ai-sdk/gateway: latest - Node.js: v25.2.1 ## Impact Users who: - Set up BYOK to avoid Vercel credit costs - Have valid provider API keys with available quota - Run out of AI Gateway credits (even accidentally) ...are completely blocked from using AI Gateway, defeating the purpose of BYOK. ## Suggested Fix The credit check should be bypassed when: 1. Valid BYOK credentials are configured in dashboard for the requested provider 2. providerOptions.byok` contains valid credentials for the requested provider The gateway should only require credits when using Vercel's system credentials.