App dev

App Development (Protocol + Contract)

In Trac, an “app” is a subnet:

• the subnet is a P2P ordered log

• the contract is executed locally on every node from that ordered log

• MSB settlement is used as the global source of truth for tx finality and fee checks

This repo ships a demo app:

• dev/tuxemonProtocol.js

• dev/tuxemonContract.js

1) Protocol: map user input into { type, value }

Protocols extend src/artifacts/protocol.js and should implement:

• mapTxCommand(commandString)

This is used by the interactive CLI /tx --command "...".

dApps generally skip string parsing and send a structured prepared_command directly.

2) Contract: deterministic state machine

Contracts extend src/artifacts/contract.js.

Important rules:

• contracts must be deterministic (no network IO, no system time)

• all nodes execute the same ordered ops and must reach the same result

The contract uses a key/value state store. App-defined state should live under:

• app/<your-app>/...

3) Exposing “ABI-like” contract schema

Wallets/dApps need to know which tx types exist and what their input shapes are.

trac-peer exposes a discovery document at:

• GET /v1/contract/schema

The base contract supports metadata registration:

• addFunction(type) — declares a tx type exists (untyped inputs)

• addSchema(type, schema) — declares a tx type + a validator schema (preferred)

If you don’t register schemas, clients can still submit txs, but they’ll have to treat value as opaque.

4) Read APIs (Protocol API)

The protocol instance exposes protocol.api, which is intended for read/query methods.

Those methods can be reflected in the RPC schema so dApps can discover them (similar to “read-only RPC calls” in other ecosystems).

5) Where to wire your app

The default runner scripts/run-peer.mjs currently wires the demo app.

For your own app:

1. add your protocol/contract under dev/

2. create a new runner script that imports them

3. run that runner with the same MSB/subnet flags

See intercom in this workspace for a reference project that uses trac-peer as a dependency.