---
title: Introduction
description: How turbo uses a remote cache, what this server stores, and who can read it.
---

Turborepo Remote Cache is an open-source server for the [Turborepo Remote Cache API](https://turborepo.dev/docs/core-concepts/remote-caching#remote-cache-api). It stores the artifacts that `turbo` uploads and returns them to any machine that asks with the right token.

## How turbo uses the cache

`turbo` hashes the inputs of every task. Before it runs a task, it asks the cache for an artifact with that hash:

1. On a hit, `turbo` downloads the artifact, restores the task's outputs and logs, and skips the task.
2. On a miss, `turbo` runs the task, packs its outputs into an artifact, and uploads it.

The next machine that runs the task with the same inputs gets a hit, whether it's a teammate's laptop or a CI runner. `turbo` decides what to cache and when. The server only stores and returns artifacts.

## What the server stores

Each artifact is one object with the key `<team>/<hash>`. The team is the `teamId` or `slug` that `turbo` sends, or `team_default_team` when it sends neither. Beside the artifact, the server keeps the headers that `turbo` uploads with it, such as the task's duration and, for a signed artifact, its signature.

The server deletes artifacts older than 30 days by default. [Retention and expiry](/retention) explains how to change that.

## One token opens every team

Every client sends the same bearer token, the server's `TURBO_TOKEN`. Teams keep artifacts apart, but they don't restrict access: anyone with the token can read and write every team's artifacts. Give the token only to people and CI jobs you trust to write to your cache. Run a separate deployment for each group that must stay apart.

## Where it runs

The server is a [Nitro](https://nitro.build) app, and every build serves the same API. The default build targets Cloudflare Workers. It is the only build with built-in R2 and KV storage, and the only one that CI runs end to end against a real `turbo` client. [Deploy to Cloudflare](/get-started) to start there, or see [Platforms](/deploy) for Node.js, Bun, Deno, Vercel, Netlify, and AWS Lambda.