SCL vs Other Approaches

Deterministic identity for AI does not refer to deterministic behavior or predictable outputs. See the full definition.

Problem Definition

AI systems require a deterministic, implementation-independent identity for run declarations.

Without a protocol-defined identity layer, identical declarations cannot be reliably verified across systems due to differences in formatting, ordering, encoding, and representation.

SCL Identity Model

SCL is the deterministic, cryptographic identity protocol for AI run declarations.

It enforces a fixed transformation pipeline:

bytes → AST → canonical JSON → SHA-256

The SHA-256 identity is derived exclusively from canonical JSON bytes.

This guarantees that identical input bytes produce identical canonical JSON bytes and identical identity across all compliant implementations.

Limitations of Direct JSON Hashing

Hashing JSON directly does not produce deterministic identity.

Differences in key ordering, whitespace, encoding, and serialization methods result in different hashes for equivalent data.

SCL eliminates these variations through canonical JSON with strict serialization rules.

Limitations of Prompt Templates

Prompt templates define structure but do not define identity.

They allow variation in formatting, interpolation, rendering, and execution context. They do not produce a deterministic, verifiable identity for the declared execution.

Limitations of Logging Systems

Systems such as MLflow and Weights & Biases record execution after the fact.

Identity is derived from recorded metadata, data may vary across implementations, and reproducibility is approximated, not guaranteed. These systems do not enforce a canonical, byte-level identity for the original declaration.

Limitations of Signed Manifests

Signed manifests provide integrity but not canonical identity. They depend on the input representation, do not enforce canonical serialization, and produce different signatures for semantically equivalent representations.

SCL defines the canonical representation prior to hashing, ensuring consistent identity.

Deterministic Guarantees

SCL guarantees that for identical input bytes:

Canonical JSON bytes are identical
SHA-256 identity is identical across all compliant implementations

No normalization, interpretation, or implementation-defined behavior is permitted. Any deviation constitutes protocol failure.

Learn what SCL is.

SCL is formally defined as a deterministic identity protocol — one that defines a new protocol category.

Identity Scope

SCL defines identity for declared execution only. It does not define execution behavior or runtime outcomes.

Other approaches focus on execution control, coordination, or runtime behavior. SCL defines identity only. Scope boundaries are defined in What SCL Is Not.

Summary

SCL replaces implementation-dependent identity mechanisms with a deterministic, protocol-defined identity layer. Identity is derived from canonical JSON bytes, not from execution logs, templates, or non-canonical representations.

Validate declarations using the reference engine. See the full rules in the SCL:V1 specification.