gno.land/r/moul/demo/grc20

Step 6 of the r/moul/demo walkthrough: the same ledger as wikicoin, but on the standard p/nt/grc20 token instead of a hand-rolled tree.

1var (
2	Token         *tokens.Token          // exported: anyone may read
3	privateLedger *tokens.PrivateLedger  // unexported: mint, burn, transfer
4)

That split is the whole lesson. NewToken returns two handles onto one token. The Token handle is read-only and safe to export, so other realms can call Token.BalanceOf(...) or Token.GetName() across the realm boundary. The PrivateLedger handle can move anyone's balance, so it stays unexported: gno's export rules become the access control, with no permission check to get wrong.

Exporting the ledger by accident is a total loss of the token. Keep it lowercase and expose deliberate wrappers instead.

init creates "Foo Token" (FOO, 4 decimals) and mints 100000000 units to a test address. MyBalance() shows a read scoped to the caller.

Previous: wikicoin. Next: vault locks tokens up.

Part of moul/gno-contracts — moul's versioned gno.land contracts. See the repository for the full catalog, build/test tooling, and usage.

On mainnet:

Dependency graph:

⚠️ Disclaimer: provided as-is, without warranty; not security-audited. Full disclaimer: DISCLAIMER.