CrowdRelay

Live · 14-day free trial

Fan growth for artists that runs itself, inside limits you set.

Most music tools give you a dashboard and leave the work to you. CrowdRelay keeps every fan an artist has met in one place, decides what is worth doing next, does it, and keeps a record of what changed. You approve each step, or let it run.

I built it for Virya first. The band is the first artist on it, so every feature meets real fans before anyone else uses it.

Visit crowdrelay.musicLinkedIn
lines of Rust
~100k
crates with strict layering
6
fan sources merged
13+
free trial
14 days
CrowdRelay landing page: “Most tools give you a dashboard. This one does the work.”

What it does

  • One fan graph

    Fans from Spotify, Meta, Reddit, Discord, Bandcamp, live shows, the email list and more become one record per person, with growth metrics and audience overlap.

  • Decides what is worth doing

    A deterministic Rust engine weighs every eligible action, predicts its outcome before acting and learns from what actually happened. Doing nothing is a valid choice, and sometimes the best one.

  • Acts inside limits you set

    Per context it can observe, recommend, ask for permission or act alone. Confidence thresholds, daily quotas and a global kill switch apply to every action.

  • Measures, then argues with itself

    Actions run with randomised holdouts, so it can tell a fan who arrived because of an action from one who would have come anyway. Beliefs that overclaim get weakened.

  • Tickets and QR check-in

    Stripe takes the payment; passes carry an opaque signed reference, never personal data. Check-in is atomic, so the same ticket can’t get two people in.

  • Draws anyone can verify

    Referral-weighted draws for merch and tickets are reproducible from a revealed seed, with a commitment published to the Sigstore Rekor transparency log.

A closer look

CrowdRelay decision stream: actions with confidence, status and time, next to the fan graph total and today’s authority budget
The decision stream: every action with its confidence, its status and the authority it ran under.

How it's built

PostgreSQL is the source of truth. Every public command writes its business rows, its idempotency record and an outbox event in one transaction. Providers are called afterwards, at least once, and consumers deduplicate, so the API never waits on an email or a third-party call.

Language models are workers, not the boss. They gather and draft; the Rust engine owns the strategy, the evidence, the budget and the final decision.

  • Rust
  • Axum
  • PostgreSQL
  • TypeScript
  • Rust workspace: domain (pure policy), application (use cases, no SQL), infra, api, worker and the decision engine
  • Axum and SQLx on PostgreSQL, with a typed TypeScript client and an OpenAPI contract
  • Transactional outbox with signed webhooks, retries with backoff and a dead-letter queue
  • Push via FCM and Web Push; delivery counts only after the device confirms it showed the notification
  • Fan, staff, admin and control-plane surfaces kept apart by path-prefix authorization

Writing about CrowdRelay

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