Backward compatibility philosophy

Strata treats backward compatibility as a design choice, not an assumption.

This page explains what Strata does, what it does not do, and why.

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The core stance

Strata does not guarantee backward compatibility across MINOR versions.

This is intentional.

Backward compatibility that is implicit, undocumented, or accidental is a liability in deterministic systems.

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Why backward compatibility is not automatic

In Strata, guarantees are stronger than convenience:

• Bytes are contracts

• Hashes are identities

• Semantics are invariants

If compatibility is assumed without being enforced, correctness degrades silently.

Strata refuses silent compatibility.

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Compatibility vs determinism

Many formats optimize for:

• evolution

• flexibility

• gradual migration

Strata optimizes for:

• exactness

• verifiability

• long-term reproducibility

These goals conflict.

When they do, Strata chooses determinism.

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What backward compatibility WOULD require

Backward compatibility in Strata must be:

• explicit

• documented

• testable

• enforced by vectors and Northstars

If compatibility cannot be proven mechanically, it is not considered compatible.

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Allowed forms of compatibility

Backward compatibility MAY exist when:

• New versions introduce additive layers

• Existing canonical bytes remain valid

• Hashes of existing values remain unchanged

• Old values retain identical semantics

In such cases, compatibility is earned, not assumed.

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Forbidden forms of compatibility

The following are explicitly rejected:

• Silent reinterpretation of bytes

• Auto-upgrading data on decode

• “Best effort” decoding

• Version sniffing that alters semantics

• Accepting malformed data for convenience

If old data behaves differently, compatibility is broken.

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Compatibility boundaries

Compatibility in Strata is defined at these boundaries:

• Canonical .scb bytes

• Hash output

• Decode acceptance and failure modes

• Cross-language equivalence

Anything outside these boundaries is not compatibility-critical.

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Version lines are trust zones

Each MINOR version defines a trust zone:

• v0.3.x is one trust zone

• v0.4.x is another

Within a trust zone:

• behavior is frozen

• guarantees are stable

Across trust zones:

• behavior may change

• guarantees may evolve

Trust does not automatically cross version lines.

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Why this is safer

This philosophy ensures:

• no accidental breakage

• no ambiguous migrations

• no reliance on undocumented behavior

• no long-term entropy in meaning

Systems depending on Strata can reason about data without guesswork.

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Practical implication

If you need:

• long-lived hashes

• content addressing

• cryptographic verification

• distributed consensus

You must pin a Strata version explicitly.

This is not a weakness. It is how correctness is preserved.

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Summary

Strata does not promise backward compatibility by default.

When compatibility exists:

• it is explicit

• it is tested

• it is enforced

Silence is not compatibility. Assumption is not compatibility.

Only proofs count.