Day 02 / Daily GitHub Discovery / Backend / APIs

LiteLLM

Bring multiple model providers behind one API, with routing, fallbacks, and usage tracking.

~59,700 stars · checked Sep 28, 2026
PythonRustFastAPIRedisPostgreSQLDocker
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What it does

LiteLLM offers a Python SDK and an AI gateway for calling different LLM providers through a common interface. The gateway adds routing, usage tracking, and access controls around those calls.

Why it’s interesting

Provider integrations can spread throughout an application. A shared gateway gives teams a place to manage model access and fallback behavior while keeping client code simpler.

Real-world use case

Route requests from several internal tools through one gateway. Configure a backup model for provider failures and track which tool is consuming the most tokens.

What I can learn

  • 01

    Adapter patterns

    translate provider-specific requests into a shared API.

  • 02

    Resilience

    reason about retries, cooldowns, and fallback routes.

  • 03

    API gateway design

    centralize access and usage policies.

One thing to explore

Model routing and fallbacks

Find the Router class and follow how a request selects a deployment. Identify where a failed call can take a different route.

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10-Minute Challenge

Map a fallback path

Before you start: Git and a text editor, or browse router.py on GitHub. No provider account needed.

  1. Open litellm/router.py and search for fallback-related functions.
  2. Trace the path from a failed request to a backup deployment.
  3. Write down one condition that should trigger a fallback and one that should return an error.
Terminal
git clone --depth=1 https://github.com/BerriAI/litellm.gitcd litellm# Open litellm/router.py in your editor.

Keep exploring

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