B · Launching Effectstream + Local Dev · PRE-WORK

First launch

One command boots two blockchains, a database, the sync node, a batcher, and the frontend. First run downloads the Midnight binaries — give it a few minutes and good Wi-Fi.

One command: bun run dev — 2 EVM chains + Midnight + node + batcher + frontend
Cold start 1–3 min · warm restart ~10 s
Verify: curl localhost:9999/api/erc721 → [] and open http://localhost:10599
Your dev loop: orchestrator status / logs / restart sync

▼ details below

1Start the stack

These ports must be free

The stack binds all of these on localhost — if any is taken, that process fails to start:

5432 database · 8545/8546 EVM chains · 9944/8088/6300 Midnight node/indexer/proof server · 9999 API · 3334 batcher · 8883/9883 MQTT · 10599 frontend · 4747 orchestrator

The usual offender is 5432: if you have a local PostgreSQL running, stop it first (mac: brew services stop postgresql · linux: sudo systemctl stop postgresql). Quick check — this should print nothing:

lsof -i :5432 -i :8545 -i :8546 -i :9944 -i :8088 -i :6300 -i :9999 -i :3334 -i :8883 -i :9883 -i :10599 -i :4747

cd templates/evm-midnight-v2
bun run dev

What the orchestrator launches, in dependency order:

the orchestrator's dependency graph (simplified)

expected log milestones (cold start: 1–3 min; warm restart: ~10 s)

✓ compile-evm-contracts   exited successfully
✓ deploy-evm-contracts    exited successfully
✓ midnight-contract       exited successfully
[sync] [APPLY MIGRATION] Block height: 0 | Migration: 000-init.sql
[sync] Paima Engine HTTP server running on http://127.0.0.1:9999
✓ frontend-build          exited successfully
● frontend-server         running in background

2Poke it

curl -s localhost:9999/api/erc721

expected

[]

Empty array = the sync node is up, the migrations ran, and the API answers.

Then open http://localhost:10599 in your browser — the template's demo dApp should load. If both the curl and the page work, the full stack is alive.

3The orchestrator is your dev loop

During the workshop you'll edit node code and restart just the sync process. Run the stack as a daemon instead:

bunx orchestrator stop        # always stop the foreground run first (frees ports)
bunx orchestrator start --background

bunx orchestrator status      # what's running
bunx orchestrator logs sync   # follow one process's logs
bunx orchestrator restart sync   # <- you'll type this a lot in Section C
bunx orchestrator stop        # tear everything down

Golden rule

Always bunx orchestrator stop before starting again — leftover processes keep ports (8545, 9944, 9999, 10599…) and the next launch fails confusingly.

Port	What
10599	frontend
9999	sync node REST API
3334	batcher
8545 / 8546	Hardhat EVM (main / parallel)
9944 / 8088 / 6300	Midnight node / indexer / proof server
5432	PGLite (yes — the same port a real Postgres uses)
8883 / 9883	MQTT events (TCP / WebSocket)
4747	orchestrator API (when daemonized)

Checkpoint — pre-work done

curl -s localhost:9999/api/erc721 returns [] and bunx orchestrator status shows sync, batcher, and frontend running. Stuck? See Troubleshooting.

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