Everything you need to run production AI
One OpenAI-compatible gateway for routing, reliability, cost control, observability, evaluations, and governance, across 160+ models and every major provider.
No credit card required · Free to start
Route smarter across every model
Send each request to the right model and provider, then keep it fast, cheap, and resilient through one OpenAI-compatible API.
Automatic Model Selection
Let fastrouter/auto pick the best model per request, weighing complexity, domain, and cost.
ExploreProvider Routing
Choose which provider serves each model with strategies for lowest price, latency, and throughput.
ExploreFallback Models
Automatically retry the next candidate when a model or provider fails, so requests don't drop.
ExploreVirtual Model Aliases
Map one stable alias to many models and providers, and swap them without changing code.
ExploreFlex Pricing
Append :flex to eligible models for significantly lower token costs on non-urgent workloads.
ExploreResponse Caching
Cache responses across providers to cut latency and cost on repeated requests.
ExploreBYOK
Route through your own provider keys to keep billing, quotas, and negotiated discounts.
ExploreMCP Gateway
Register MCP tool servers once and expose their tools to any model you route.
ExploreSee and improve every request
Trace what your models actually did, get alerted when metrics drift, and measure quality on your own data.
Tracing
Inspect every request with span-level latency, token usage, cost, and full payloads.
ExploreAlerts
Set Warning and Critical thresholds on latency, errors, usage, and spend, then route them anywhere.
ExploreEvaluations
Benchmark and compare models on your data with LLM-as-a-judge scoring and custom criteria.
ExplorePrompt Optimization
Evolve stronger prompts automatically with GEPA reflection-driven optimization.
ExplorePrompt Management
Version every prompt with visual diffs, side-by-side compare, and one-click rollback.
ExploreDynamic Tags
Tag requests on the fly to slice usage and cost by feature, customer, environment, or team.
ExploreControl access and keep AI safe
Give every teammate the right permissions, automate key lifecycles, and enforce safety on every prompt and response.
Role-Based Access Control
Organization and project roles with permission-aware API keys, budgets, and model scopes.
ExploreProvisioning Keys
Programmatically create, rotate, and revoke API keys across teams and environments.
ExploreGuardrails
Run input and output checks for PII, topic adherence, toxicity, and regex patterns.
ExploreStart routing in minutes
Point your existing OpenAI-compatible code at FastRouter and get routing, failover, observability, and governance out of the box.