# Architecture principles whose scope is message

> 7 records

This index as JSON: https://banes-lab.com/json/api/facets/architecture/scope/message

## Entries

- [Data Contract](https://banes-lab.com/records/architecture/data-contract.md): A rule or precondition that data exchanged between parties has declared fields, types, nullability and meaning.
- [Schema Contract](https://banes-lab.com/records/architecture/schema-contract.md): A rule or precondition that every payload is validated against a machine-readable schema at the boundary it crosses.
- [Protocol Compatibility](https://banes-lab.com/records/architecture/protocol-compatibility.md): A rule or precondition that both ends of a connection speak a declared protocol version they both support.
- [Correlation ID](https://banes-lab.com/records/architecture/correlation-id.md): A mechanism that attaches one identifier to a request and carries it through every call, message and log line the request causes.
- [Causation ID](https://banes-lab.com/records/architecture/causation-id.md): A mechanism that stamps each event with the identifier of the event that caused it.
- [Schema Validation](https://banes-lab.com/records/architecture/schema-validation.md): A mechanism that parses incoming data against a schema at the boundary and rejects any payload that does not conform.
- [Canonical Schema](https://banes-lab.com/records/architecture/canonical-schema.md): A formal definition of one concept's shape, published once and used by every API, message and store that carries the concept.