Run a devnet

A devnet runs every validator of a committee in one process, each on its own thread with its own copy of the state, exchanging real signed messages over in-memory channels. Everything else is the real protocol: lane certificates, consensus, Pulse execution, header certificates, data availability and the World Proof.

Start one in a terminal:

sion devnet

Siontology devnet: 4 validators, 2 shards, API on http://127.0.0.1:8730
chain identity (pin it: sion verify --chain …): 6345655cfd2a714ed1dab69c0660f2f48f429ce2981e25629d0467d7b7ee97b7
accounts funded at genesis: alice, bob, carol
Pulse 1  certified 1  round 8  executed [0,0,0]  claims 0  objects 22  proven 1
Pulse 2  certified 2  round 15  executed [1,0,0]  claims 0  objects 23  proven 2
Pulse 4  certified 3  round 22  executed [1,0,0]  claims 0  objects 23  proven 4

• The chain identity is the value a light client pins. Write it down; Verify as a light client uses it.
• alice, bob and carol start with 100,000 USD each, in four coins, so each can send several transactions in one Pulse. A faucet account holds the devnet’s supply.
• Every five seconds the devnet prints the latest executed Pulse, the latest certified Pulse, the consensus round, the transactions executed (successful, failed, rejected) since the process started, claims in the knowledge log, objects in the state, and the latest proven Pulse.

How often Pulses close depends on the machine. On the 2-core machine used for this book, shared with other work, an idle devnet closed about 0.3 Pulses a second (17 Pulses in its first minute).

An idle devnet runs its rounds back to back, so it keeps a core busy. With --idle-round-ms 10000, a devnet with nothing to order waits ten seconds between rounds, and starts the next at once when a transaction arrives. The chain sion setup makes runs that way: one validator at rest used 98.8% of a core unpaced and 5.7% paced, measured on two cores (The chain at rest).

The devnet runs until you press Ctrl-C (or for --duration seconds). Without --data-dir it keeps everything in memory and starts from genesis every time; see Running a devnet for persistence, restarts and every flag.

Talk to it

In another terminal:

sion status

{
  "active": true,
  "active_validators": 4,
  "anchors": 2,
  "beacon": "30de983de39a060dc990e95512f3f51adc2c5570006ed775c9dc81fab667921b",
  "certified_pulse": 0,
  "chain": "6345655cfd2a714ed1dab69c0660f2f48f429ce2981e25629d0467d7b7ee97b7",
  "chain_id": "sion-devnet-1",
  "claims": 0,
  "commitment": {
    "config": "2d86efe308c60641d10f022ce94b57596644f923d10c7fbcf7aa3dc029e45592",
    "knowledge_root": "b3950ae788d193123558660817bb152c629460ad232a154ae961493db2ce2542",
    "knowledge_size": 0,
    "pulse": 0,
    "state_root": "a7f345b0d0b0b6cb03d58a264886d44a4501392686d38e0346d3632292e414cd"
  },
  "epoch": 0,
  "epoch_end": 9223372036854775807,
  "executed": [
    0,
    0,
    0
  ],
  "forced_overdue": 0,
  "forced_pending": 0,
  "genesis": "30de983de39a060dc990e95512f3f51adc2c5570006ed775c9dc81fab667921b",
  "insecure_signatures": false,
  "objects": 22,
  "proven_pulse": null,
  "pulse": 0,
  "round": 6,
  "session": 0,
  "shards": 2,
  "validator": "cdc0cc1da885c87ebdb67a8c05e027449f8cc15e4743959f8c0f3fa469b3ab38",
  "validators": 4
}

This was taken right after start: no Pulse has executed yet, so certified_pulse is 0 and proven_pulse is null. The default devnet runs one epoch that never ends, hence the large epoch_end. Every field is described in the HTTP API reference. Note the two names: chain_id is the chain’s configured name, and chain is the chain identity.

The CLI talks to http://127.0.0.1:8730 unless you pass --node or set SION_NODE. The node serves plain JSON over HTTP, so curl works too:

curl -s http://127.0.0.1:8730/v1/status

Next

Your first transfer.