Indigo is Bluesky's Go toolkit for building services on the AT Protocol, and operators reach for it when they need to follow the whole network: run a relay that subscribes to many personal data servers and republishes one combined firehose, split that firehose for many subscribers, or filter it down to the accounts and record types a single application actually cares about. The relay holds upstream host and account state in PostgreSQL, verifies repository integrity and identity signatures, exposes an admin web interface for configuring limits and adding upstream hosts, and emits Prometheus metrics and tracing for production monitoring. Rainbow consumes a relay or PDS firehose and fans events out to large numbers of subscribers, buffering recent history on local disk so late joiners receive the events they missed. Tap handles verification, automatic backfilling of repository history, and filtered delivery by account list or record collection, sending simple JSON events to applications over WebSocket or webhook instead of requiring each developer to parse cryptographic repository formats. Hepa consumes the relay firehose and applies moderation rules to accounts and records, pushing labels into an existing moderation service for teams that operate their own trust and safety pipeline. Each service ships as a single Go binary with Docker packaging, and shared packages provide the client, identity, lexicon, and repository data structures the services are built from. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT and Apache-2.0 licensed.