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Migrating to snapchain ​

Snapchain is a more scalable implementation of the Farcaster protocol. In order to interact with snapchain, you can operate your own read node.

Running a node ​

bash
mkdir snapchain
wget https://raw.githubusercontent.com/farcasterxyz/snapchain/refs/heads/main/docker-compose.mainnet.yml -O docker-compose.yml
docker compose up # -d to run in the background

Note, the default http port is 3381, the default gossip port is 3382 and the default grpc port is 3383. You may need to open these ports.

Reading from snapchain ​

Read APIs are fully backwards compatible with hubs so no migration is required. Refer to existing docs for reading data via the client library.

Via http once you have a node running

bash
curl http://locaalhost:3381/v1/info

Via grpc

bash
git clone git@github.com:farcasterxyz/snapchain.git
cd snapchain
grpcurl -plaintext -proto src/proto/rpc.proto -import-path src/proto localhost:3383 HubService/GetInfo

If you are using Shuttle, it will work the same as before. Just need to point it to the snapchain node.

Writing to snapchain ​

The write APIs are also backwards compatible with hubs, with some caveats (see below).

In order to write to snapchain, you should run a node and submit directly to it. Refer to existing docs for writing dia via the client library. Note, you MUST use version 0.16 or later of the hub-nodejs library.

Gotchas ​

  • If you're not using the builders from the hub-nodejs library, you should make sure to populate dataBytes instead of data in every message, like so:

    ts
    if (message.dataBytes === undefined) {
    message.dataBytes = protobufs.MessageData.encode(message.data).finish();
    message.data = undefined;
}

  • Some of the error messages returned from submitMessage are different in Snapchain than in Hubs.

  • Snapchain submits are best-effort. It's possible that submitMessage succeeds but the message is not included into a block. Follow this issue on the plan for providing feedback to clients when a message accepted into the mempool is not able to be included in a block.

Testnet ​

There is a testnet for snapchain, you can run a node against it by using this docker compose file:

bash
mkdir snap_test
wget https://raw.githubusercontent.com/farcasterxyz/snapchain/refs/heads/main/docker-compose.testnet.yml -O docker-compose.yml
docker compose up # -d to run in the background

Note, testnet is unstable and will be reset from time to time.