ProxAI is a transparent reverse proxy designed to enforce hard hourly and daily spending caps per LLM API client. With a simple change of just one base_url and no SDK required, developers can seamlessly protect their budgets against runaway LLM costs.

The tool works out-of-the-box with major providers including OpenAI, Anthropic, Mistral, Groq, DeepSeek, and 5 others. If a client goes over its set cap, ProxAI immediately responds with a 429 status code before the upstream provider is ever called, ensuring that the worst-case scenario is your predefined cap rather than an unexpected credit card bill.

ProxAI is fully open-source (licensed under AGPL-3.0) and highly portable. It can be self-hosted as a single Go binary or a lightweight ~10 MB Docker image supporting both amd64 and arm64 architectures with zero telemetry. Alternatively, users can take advantage of the hosted beta version available at proxai.eu, which is free and requires no credit card.

Pros of ProxAI

Enforces hard hourly and daily spending caps per LLM API client
Requires only a single base_url change with no SDK needed
Supports OpenAI, Anthropic, Mistral, Groq, DeepSeek, and 5 additional providers
Blocks requests exceeding the cap (returning 429) before calling upstream
Highly self-hostable as a single Go binary or lightweight ~10 MB Docker image with zero telemetry

Cons of ProxAI

Hosted version is currently in beta
Open-source license is AGPL-3.0, which may have specific compliance requirements for commercial adaptations
Limited to the specific providers and features outlined in the current tool scope

Frequently Asked Questions

How does ProxAI enforce spending caps?

ProxAI acts as a transparent reverse proxy. When a client makes a request, it checks the hourly or daily spending limits. If the cap is exceeded, it immediately returns a 429 status code before the upstream API is ever called.

Do I need to install a special SDK to use ProxAI?

No SDK is required. You only need to change a single base_url in your existing configuration to route your requests through ProxAI.

Which LLM providers are supported?

ProxAI supports OpenAI, Anthropic, Mistral, Groq, DeepSeek, and 5 additional providers.

Can I self-host ProxAI?

Yes, ProxAI is fully self-hostable. It is available as a single Go binary or a lightweight ~10 MB Docker image (supporting amd64 and arm64) with zero telemetry, licensed under AGPL-3.0.