alto-follower 2026.3.0

Run a follower node for alto.
alto-follower-2026.3.0 is not a library.

alto-follower

Crates.io Docs.rs

Run a follower node for alto.

Status

alto-follower is ALPHA software and is not yet recommended for production use. Developers should expect breaking changes and occasional instability.

Installation

Local

cargo install --path . --force

Crates.io

cargo install alto-follower

Usage

follower --config config.yaml

To deploy your own instance of alto, read the guide in deploy.

Configuration

Field Description
source URL of the indexer to fetch blocks and stream certificates from
identity Hex-encoded BLS12-381 threshold public key used to verify consensus signatures
directory Path to store finalized blocks and state
worker_threads Number of runtime worker threads
signature_threads Number of threads for signature verification
log_level Log verbosity (trace, debug, info, warn, error)
metrics_port Port for the Prometheus metrics endpoint
mailbox_size Capacity of internal actor mailboxes
max_repair Maximum concurrent block fetches during backfill
fetch_retry_timeout_ms Milliseconds between follower resolver retries for failed backfill requests
tip Start from the tip of the finalized chain instead of backfilling from genesis
pruning_depth Number of finalized blocks to retain before pruning (null to keep all)

See examples/ for sample configuration files.

Certificate Validation Policy

alto-follower considers invalid consensus certificates a fatal error and may panic if the source provides one. If you observe this behavior, switch to a new source and/or ensure your configuration is correct for the network you are following.