> ## Documentation Index
> Fetch the complete documentation index at: https://docs.neynar.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Sync Snapchain to Postgres

> Mirror Snapchain data to a Postgres database for convenient access

### Pre-requisites

* Read access to a Snapchain node

See [running a node](/snapchain/guides/running-a-node) for more information on how to set up a node.

While some applications can be written by directly querying Hubble, most serious applications need to access the data
in a more structured way.

[Shuttle](https://github.com/farcasterxyz/hub-monorepo/tree/main/packages/shuttle) is a package
that can be used to mirror Snapchain's data to a Postgres DB for convenient access to the underlying data.

## Quickstart

```bash theme={"system"}
git clone git@github.com:farcasterxyz/hub-monorepo.git

# Ensure you have node 21 installed, use nvm to install it
nvm install 21

# If necessary, build packages/core dependency
( cd packages/core && yarn install && yarn build; )

# If necessary, build packages/hub-nodejs dependency
( cd packages/hub-nodejs && yarn install && yarn build; )

# Do remainder within the packages/shuttle directory
cd packages/shuttle
yarn install && yarn build

# Start the db dependencies
docker compose up postgres redis

# To perform reconciliation/backfill, start the worker (can run multiple processes to speed this up)
POSTGRES_URL=postgres://shuttle:password@0.0.0.0:6541 REDIS_URL=0.0.0.0:16379 HUB_HOST=<host>:<port> HUB_SSL=false yarn start worker

# Kick off the backfill process (configure with MAX_FID=100 or BACKFILL_FIDS=1,2,3)
POSTGRES_URL=postgres://shuttle:password@0.0.0.0:6541 REDIS_URL=0.0.0.0:16379 HUB_HOST=<host>:<port> HUB_SSL=false yarn start backfill

# Start the app and sync messages from the event stream
POSTGRES_URL=postgres://shuttle:password@0.0.0.0:6541 REDIS_URL=0.0.0.0:16379 HUB_HOST=<host>:<port> HUB_SSL=false yarn start start
```

This package is fully re-used from Hubble because the Snapchain APIs are backwards compatible with Hubble.

Check out the [documentation](https://github.com/farcasterxyz/hub-monorepo/blob/main/packages/shuttle/README.md) for more information.