Schemas (v0.11)

RGB v0.11 line (rgb-cmd 0.11.1)

Schemas are a v0.11 concept. RGB v0.12 replaced them with codexes, issuers and APIs. See Two RGB lines.

A schema is the template that every contract of one kind follows. It lists the global state types, the owned state types and the allowed transitions, and it points to the AluVM scripts that validate genesis and each transition. Every contract records its schema ID in genesis, and wallets validate each operation of the contract against that schema.

Schemas are Rust code. The rgb-schemas crate (0.11.1, 2026-09-16) builds each one as a Schema value, and its rgb-schemas binary compiles them into strict-encoded .rgb kit files. There is no YAML or text format for schemas, no schema compiler CLI and no schema registry.

No interfaces in v0.11

Line B has no RGB20/RGB21 interfaces: the rgb-ops 0.11.1 source has no Iface types. Line B treats the names "RGB20" and "RGB21" as deprecated and uses the schema names below. Code reads a contract through a schema-specific wrapper, using the IssuerWrapper and SchemaWrapper traits (rgb-ops src/contract/schema.rs).

The five standard schemas

Summarised from rgb-schemas 0.11.1 src/*.rs and the official supported schemas page.

Schema	What it is	Global state	Owned state	Transitions	0.11.1 README
NIA, Non-Inflatable Asset	Fixed-supply fungible token	`spec`, `terms`, `issuedSupply`	`assetOwner` (u64)	`transfer`
IFA, Inflatable Fungible Asset	Fungible token with secondary issuance, burn and link	NIA's, plus `maxSupply`, `rejectListUrl`, `linkedFromContract`, `linkedToContract`	`assetOwner`, `inflationAllowance`, `linkRight`	`transfer`, `inflate`, `burn`, `link`	Not production-ready
UDA, Unique Digital Asset	One NFT per contract	`spec`, `terms`, `tokens` (one `TokenData`), `attachmentTypes`	`assetOwner` (token index and fraction, always 1)	`transfer`
CFA, Collectible Fungible Asset	Fungible token with an optional `art` (Article) string	`art`, `name`, `details`, `precision`, `terms`, `issuedSupply`	`assetOwner` (u64)	`transfer`
PFA, Permissioned Fungible Asset	Fixed supply. The issuer signs every transfer	NIA's, plus `pubkey`	`assetOwner` (u64)	`transfer` (signature checked)	Not production-ready

Guides: NIA tokens, IFA secondary issuance, UDA NFTs and CFA.

Inside a schema

This is the NIA schema from rgb-schemas 0.11.1 src/nia.rs, shortened. It is a Rust value, not a configuration file:

Schema {
    ffv: zero!(),
    name: tn!("NonInflatableAsset"),
    meta_types: none!(),
    global_types: tiny_bmap! {
        GS_NOMINAL => GlobalDetails {
            global_state_schema: GlobalStateSchema::once(types.get("RGBContract.AssetSpec")),
            name: fname!("spec"),
        },
        // GS_TERMS => "terms", GS_ISSUED_SUPPLY => "issuedSupply"
    },
    owned_types: tiny_bmap! {
        OS_ASSET => AssignmentDetails {
            owned_state_schema: OwnedStateSchema::Fungible(FungibleType::Unsigned64Bit),
            name: fname!("assetOwner"),
            default_transition: TS_TRANSFER,
        }
    },
    genesis: GenesisSchema { /* each global Once, assetOwner OnceOrMore, validator */ },
    transitions: tiny_bmap! { TS_TRANSFER => TransitionDetails { /* … */ } },
    default_assignment: Some(OS_ASSET),
}

Type numbers are fixed in src/lib.rs. For example, GS_NOMINAL is 2000, GS_TERMS 2001, GS_ISSUED_SUPPLY 2010, OS_ASSET 4000 and TS_TRANSFER 10000.
Global state belongs to one contract and is append-only. Genesis sets it, and a transition can add entries (an IFA inflate adds a new issuedSupply). Nothing overwrites it.
Owned state comes in three kinds in 0.11.1: declarative (no value), fungible (u64) and structured (strict-typed data, such as the UDA allocation). Attachments are not a state type.
Validation scripts are AluVM bytecode. The NIA transfer check is four instructions:
```
put     a8[0],ERRNO_NON_EQUAL_IN_OUT;  // errno 0 if the check fails
svs     OS_ASSET;                       // sum of inputs == sum of outputs
test;
ret;
```
The PFA transfer script also runs vts, an RGB opcode that verifies the transition's signature against the pubkey global set in genesis (rgb-consensus 0.11.1 src/vm/op_contract.rs). That is how PFA requires the issuer's approval of every transfer.

Amounts are plain u64 values, visible to everyone who validates the consignment. Neither RGB line uses Pedersen commitments.
The schema ID is a commitment to the whole Schema value. Change one field and you get a different schema, so schemas can't be upgraded. IFA's link transition exists so that an issuer can point holders to a replacement contract.

Using a schema

A wallet needs the compiled kit before it can issue or accept contracts of that schema. rgb-schemas ships the kits in schemata/. The IDs below are real rgb import output (rgb-cmd 0.11.1, run offline on 2026-10-19):

rgb -n regtest -d data0 import rgb-schemas/schemata/NonInflatableAsset.rgb
rgb -n regtest -d data0 schemata

Schema	Schema ID
NIA	`rgb:sch:RWhwUfTMpuP2Zfx1~j4nswCANGeJrYOqDcKelaMV4zU#remote-digital-pegasus`
IFA	`rgb:sch:IpjJhFLz3oywYKQxO3KmFgR0Aa415nlTNrNyEFqMZCE#shoe-colombo-mango`
UDA	`rgb:sch:~6rjymf3GTE840lb5JoXm2aFwE8eWCk3mCjOf_mUztE#spider-montana-fantasy`
CFA	`rgb:sch:JgqK5hJX9YBT4osCV7VcW_iLTcA5csUCnLzvaKTTrNY#mars-house-friend`
PFA	`rgb:sch:YvvvQ4UsHuPQDT3nIQ9mnpsqMbrs5lYZRbyymHVrkY8#famous-process-eagle`

rgb-lib 0.3.0-beta.7 embeds NIA, UDA, CFA and IFA (its AssetSchema enum), so apps built on it import nothing. It doesn't support PFA.

To issue from Rust, pass a schema to ContractBuilder::with(issuer, schema, types, scripts, chain_net), or call stock.contract_builder(issuer, schema_id, chain_net). The examples/ directory of rgb-schemas has one program per schema. A custom schema is a new Rust module built the same way. Wallets only accept contracts whose schema they have imported, so in practice apps use the five standard schemas.

RGB v0.12 has no schemas

rgb-core 0.12 removed schema verification. In v0.12 (rgb-wallet 0.12.0-rc.3), a contract is issued from an issuer file, which holds a codex (the validation code) and an API, together with a YAML parameter file such as DemoToken.yaml. See Genesis and the Quick Start.

The five standard schemas​

Inside a schema​

Using a schema​

Further reading​

The five standard schemas

Inside a schema

Using a schema

Further reading