Core Infrastructure

The foundation relies on proven, high-performance components that handle identity, data storage, and network-wide event distribution. Each component is chosen for production stability and operational simplicity.

Tranquil PDS

RUST

The Personal Data Server is the user's home on the network. Tranquil PDS compiles to a single binary without a Node.js runtime, using PostgreSQL for robust data storage. It extends the reference PDS with enterprise-grade authentication and account delegation — essential for humans authorizing AI agents.

Authentication

WebAuthn/FIDO2 passkeys
TOTP two-factor
SSO login & signup
Backup codes & trusted devices

Authorization

Granular OAuth scopes
Consent UI with scope unchecking
App passwords with permissions
Account delegation levels

Identity

did:plc (default)
did:web (PDS-hosted subdomains)
Bring-your-own did:web
Multi-channel verification

Operations

Single binary deployment
PostgreSQL backend
Docker/Podman/Nix/K8s
Built-in admin web UI

# Quick deploy with Docker Compose
$ cp example.toml config.toml
$ openssl rand -base64 48  # generate secrets
$ podman-compose -f docker-compose.prod.yaml up -d

# Configuration precedence:
# env vars → --config file → /etc/tranquil-pds/config.toml → defaults

Indigo Relay

The relay subscribes to multiple PDS hosts and outputs a combined firehose event stream. It verifies repo data structure integrity and identity signatures. The current implementation scales to approximately 100 million accounts and tens of thousands of events per second at peak.

Key Characteristics

Single server (not distributed)

PostgreSQL in production, SQLite for testing

Highly concurrent, not CPU intensive

Single Go binary deployment

Prometheus metrics + OTEL traces

Admin web interface

Sync v1.1 (non-archival mode)

~$34/month for full global network

# Key environment variables
RELAY_ADMIN_PASSWORD=your_admin_key
DATABASE_URL=postgres://relay:CHANGEME@localhost:5432/relay
RELAY_PERSIST_DIR=/data/relay/persist
RELAY_REPLAY_WINDOW=24h
RELAY_TRUSTED_DOMAINS=*.host.bsky.network

# API endpoints
GET /xrpc/com.atproto.sync.subscribeRepos  (WebSocket)
GET /xrpc/com.atproto.sync.getRepo         (HTTP redirect)
POST /xrpc/com.atproto.sync.requestCrawl
GET /xrpc/com.atproto.sync.listHosts

Indigo Tap

Tap is the critical bridge between the relay firehose and your Rust AppView. It handles connection management, cryptographic verification, historical backfill, and collection filtering — delivering simple JSON events that your AppView can process without dealing with binary formats or signature validation.

Delivery Modes

WebSocket + acks
Fire-and-forget
Webhook POST

Network Modes

Dynamic (add/remove)
Collection signal
Full network

Guarantees

At-least-once delivery
Per-repo ordering
Backfill before live

Fig 2 — Event delivery pipeline: PDS → Relay → Tap → AppView

# Tap event format (JSON)
{
  "id": 12345,
  "type": "record",
  "record": {
    "live": true,
    "did": "did:plc:abc123",
    "collection": "com.network.agent.task",
    "action": "create",
    "record": { /* your lexicon data */ }
  }
}