11ai Vercel AI Gateway routing and fallbacks

Fallback can change model behavior, provider terms, cost, latency, and duplicate side effects Resolve the exact project, environment, remote target, permission and cost boundary, and acceptance check before acting.

Version baseline: Use current generally available AI Gateway behavior as of July 2026, including AI SDK 7, multimodal and realtime models, routing, budgets, BYOK, regional inference, and data-retention controls.

Inspect first

rg -n 'providerOptions|gateway:|order:|only:|sort:|region:|caching:|fallback|timeout' TARGET
npm test --if-present -- TARGET

Inspect primary and fallback models, allowed providers, cost/TTFT/TPS sorting, regional inference policy, timeout, retryable conditions, request idempotency, and metadata returned.

Confirm before changing:

• Approved provider allowlist.
• Fallback order and equivalence.
• Timeout and total latency budget.
• Prompt caching privacy and billing.

Operate

npm test --if-present -- TARGET
npm run typecheck --if-present

Use explicit allowlists and bounded timeouts, surface actual provider and model, and prevent application retries from multiplying gateway failover.

Never broaden providers, enable system-credential fallback, reorder production routing, or add cross-model fallback without approval Require explicit approval and preview targets, permissions, counts, cost, remote effects, and rollback.

Verify and report

npm run typecheck --if-present
npm test --if-present
npm run build --if-present

Simulate primary timeout and failure, confirm order, total attempts, actual provider metadata, cost, and no duplicated tools. Report scope, target IDs, files, remote actions, permissions, cost, checks, observability, and rollback. Hand configuration failures to 11ai-operator-vercel-ai-gateway-troubleshooting and seams to 11ai-operator-vercel-ai-gateway-integrations.