FastRouter

FastRouter is a unified API gateway for large language models, operated by AI.tech Ltd. It gives engineering teams one OpenAI-compatible endpoint that reaches more than 200 models from providers including OpenAI, Anthropic, Google, xAI, and others, covering text, image, video, embeddings, and speech. Rather than integrating every vendor separately, a team points its existing SDK at the FastRouter base URL and changes the model identifier when it wants a different model.

Routing is the center of the product. An auto router inspects each request and sends it to a model chosen for cost, latency, or output quality, depending on the policy a team configures. Virtual model aliases group several providers and models behind one name, so an application calls a single alias while FastRouter selects a healthy backend. Fallback lists, automatic retries, and load balancing across providers keep requests moving when one provider degrades, and aggregated capacity across providers can raise the effective rate limits a workload sees.

Cost control sits alongside routing. Every plan passes model usage through at the provider's list price with no markup, and a pricing calculator estimates monthly spend before a team commits. Budget caps, per-project API keys, rate limits, member roles, and role-based access control let platform owners contain spend without blocking developers. Response caching, provider-native prompt caching, and batch processing reduce repeated token spend, while guardrails validate inputs and outputs in observe or block mode.

Observability is built in rather than added later. One dashboard tracks usage, latency, errors, and cost across models and providers, with filters and a per-request activity log. Distributed tracing follows a request through the gateway, alert rules fire on spend anomalies and error spikes, and the Insights feature reviews traffic that is already routed and returns a ranked list of model or routing changes, each with the sampled requests and savings math behind it.

Beyond the gateway, FastRouter includes a model playground and a Model Council for side-by-side comparison and multi-model cross-checking, custom and video evaluations, prompt management and prompt optimization, an MCP gateway, bring-your-own-key routing through a team's existing provider accounts, and setup guides for Claude Code, Codex, and agent frameworks. Starter is free forever with 200,000 logs a month, Pro and Business add tracing, more organizations, and higher limits, and Enterprise can self-host the gateway inside a customer's own cloud so prompts, responses, logs, and provider keys stay inside the network.