Design Rationale
Key design decisions and technical constraints that shaped the ERC-7730 standard.
Three priorities drove the standard: keeping transaction data human-readable, accounting for signer hardware constraints, and lowering the barrier for developers to adopt the format.
Core principles
Human readability
Developer-friendly format
The specification uses a syntax and structure designed for direct readability:
- Implementation patterns documented alongside the specification
- Clear examples for common use cases
- Intuitive JSON structure
JSON data format
ERC-7730 uses JSON as its primary data format. The choice reflects two sets of criteria:
- • Widespread familiarity
- • Extensive library support
- • Native parsing capabilities
- • Human-readable debugging
Adoption incentives
The standard includes direct incentives for metadata file creation:
- Broad wallet support for compliant implementations
- Improved user experience as a direct result of implementation
Signer constraints
Signer hardware constraints shaped several key decisions in the specification.
Display limitations
| Constraint | Design response |
|---|---|
| Limited screen size | Fields are flattened to a single nesting level to avoid overflow on small screens |
| UI rendering capabilities | Complex constructs such as layouts and grouping are optional, enabling progressive enhancement for more capable wallets |
| Memory constraints | Data structures are optimized to reduce parsing overhead on constrained devices |
Field structure decisions
Complex UI constructs like layouts and grouping are optional. Primary data fields are prioritized for constrained displays, with progressive enhancement for more capable wallets.
Complex nested structures are discouraged. The recommended approach converts nested objects to flattened field lists, improving display compatibility across signer types.
Formatters that require recursive processing (for example, calldata) have documented limitations. Alternative patterns and graceful degradation paths are provided for signer implementations.
See also
- ERC-7730 Specifications — full specification reference
- External Resources — ERC-7730 EIP, JSON schema, and registry links
- Get Started with Clear Signing — implementation guide for dapp developers
- Clear Signing for Wallets — implementation guide for wallet developers
