Framing

Framing in Strata is explicit, optional, and non-semantic.

Framing exists to move bytes safely. It does not change meaning. It does not participate in canonical encoding. It does not affect hashing.

Canonical truth always lives inside the payload.

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What framing is (and is not)

Framing is a transport convenience layer.

It exists to:

• Define message boundaries

• Enable streaming transports

• Support multiplexed or chunked delivery

Framing does not:

• Interpret data

• Normalize payloads

• Modify bytes

• Affect hashes

• Participate in canonical rules

If framing changes bytes, it is broken.

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Core principle

Framing must be lossless.

Removing framing must yield the exact original .scb bytes.

If this is not true, framing has violated Strata guarantees.

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Framing vs canonical encoding

Canonical encoding answers:

• What bytes represent this value?

Framing answers:

• Where does one payload start and end?

They are intentionally orthogonal.

Canonical encoding is frozen. Framing is replaceable.

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Reference framing format (Rust)

The Rust implementation provides a reference framing format for testing and tooling.

It is not mandatory. It is not special. It is just a concrete example.

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Framed encoding layout

The reference framing layout is:

STRATA_MAGIC (7 bytes) = "STRATA1" VERSION (1 byte) PAYLOAD (canonical .scb bytes)

The payload is identical to unframed .scb.

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Framing encoder

Framed encoding is implemented as a thin wrapper.

pub fn encode_framed(value: &Value) -> Vec

Internally:

• Canonical .scb bytes are produced first

• Framing bytes are prepended

• No transformation occurs

Encoding failures inside framing are canonical failures, not framing failures.

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Why framing is separate

Bundling framing into canonical encoding would:

• Couple transport with meaning

• Make hashing ambiguous

• Break content addressing

• Prevent raw-wire usage

Strata explicitly rejects this.

Canonical bytes must be usable:

• In files

• Over HTTP

• In streams

• In memory

• Inside other protocols

Without modification.

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Streaming and chunking

Framing is essential for streaming transports.

Example cases:

• TCP streams

• HTTP chunked transfer

• WebSockets

• Message queues

In these cases, framing defines boundaries. Payload bytes remain untouched.

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Northstar enforcement

Framing behavior is enforced by Northstar T3.

T3 guarantees:

• Payloads can be split arbitrarily

• Frames can arrive fragmented

• Boundaries do not affect hashes

• Re-encoded payloads remain identical

If framed transport breaks determinism, the implementation fails T3.

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Multiple framing layers

Multiple framing layers are allowed.

For example:

• Length-prefix framing

• Magic-header framing

• Application-level envelopes

Rules:

• Each layer must be removable

• Inner canonical bytes must remain identical

• Hashing must operate only on canonical bytes

If layers interfere, they are invalid.

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When to use framing

Use framing when:

• Transport is streaming

• Message boundaries are required

• Payloads are multiplexed

• Backpressure matters

Do not use framing when:

• Writing canonical .scb to disk

• Hashing content

• Comparing values

• Performing verification

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Framing and hashing

Hashing always operates on canonical payload bytes.

Never hash:

• Framing headers

• Length prefixes

• Transport metadata

Hashing framed bytes is a protocol bug.

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Cross-language expectations

Other language implementations may:

• Use different framing formats

• Use no framing at all

This is allowed.

What is not allowed:

• Framing that changes payload bytes

• Framing that alters decoding behavior

• Framing that affects hash output

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Summary

Framing in Strata is:

• Optional

• Explicit

• Transport-only

• Canonical-neutral

Canonical bytes are sacred.

Everything else is scaffolding.