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ARBR

An open-source self-hosted gateway for AI request routing, governance, and observability

free
Last Updated 9/7/2026

About ARBR

ARBR provides a unified OpenAI-compatible endpoint that connects model providers and selects models for requests using rules, cost guardrails, difficulty-aware selection, and fallback mechanisms. In the request path, it supports budgets, rate limits, output guardrails, prompt injection checks, and a kill switch; it also observes spend, performance, and reliability by provider, model, application, workflow, team, and user, with local dashboard queries or export to OpenTelemetry.

Best for

AI application development teams
Platform engineering teams
Organizations requiring self-hosted deployment

Best use cases

Unify access to multiple model providers

Select models by request cost and difficulty

Enforce budget and security rules in the request path

Analyze usage by team and user

Features

Intelligent model selection

Selects a model for each request using rules, cost guardrails, difficulty-aware selection, and fallback mechanisms.

Request-path governance

Enforces budgets, rate limits, output guardrails, prompt injection checks, and a kill switch in the request path.

Usage observability

Observes spend, performance, and reliability by provider, model, application, workflow, team, and user.

Open integrations

Provides an OpenAI-compatible endpoint, embeddings, real-time voice agents, and JavaScript and Python SDKs.

Pros

  • Provides an OpenAI-compatible endpoint and supports self-hosting and provider neutrality.
  • Budgets, rate limits, and security checks can be enforced in the request path.
  • Supports observing spend, performance, and reliability across multiple business dimensions, with export to OpenTelemetry.

Cons

  • The fine-tuning dataset feature has not yet been delivered.

FAQ

It can be integrated through a single OpenAI-compatible endpoint using the JavaScript or Python SDK.
It supports streaming chat completions, OpenAI-compatible embeddings, real-time voice agents, and JavaScript and Python SDKs.

Tool Information

DeveloperARBR
Release Date9/7/2026
Pricingfree