QueryProof wire format

Reference for the serialized shape of bbg::QueryProof — the proof object a BBG read returns and a light client verifies. This is the schema seed for the soft3 SDK's query wire protocol.

Serialization is behind the serde cargo feature in both bbg and cyber-lens (bbg = { features = ["serde"] } enables the whole chain: bbg → lens → hemera). The format is pinned by golden-fixture tests: bbg/rs/tests/serde_wire.rs and lens/core/tests/serde_roundtrip.rs. A format change breaks those tests; it cannot drift silently.

shape

QueryProof serializes as a struct of four fields (JSON shown; any serde format works):

{
  "commitment": [ /* 32 bytes, u8 each — hemera Hash of the dimension poly */ ],
  "opening":    { /* one Opening variant, externally tagged — see below */ },
  "value_bytes": [ /* 8 bytes, little-endian u64: the opened Goldilocks value */ ],
  "point":      [ /* canonical u64 per element, in [0, p), p = 2^64 - 2^32 + 1 */ ]
}

• commitment — lens::Commitment, a newtype over hemera::Hash; serializes as a fixed 32-tuple of bytes.
• opening — lens::Opening, externally tagged enum (standard serde): {"Tensor": {...}}, {"Folding": {...}}, or {"Witness": {...}}. BBG opens cells via Brakedown, so bbg-produced proofs always carry Tensor.
• value_bytes — little-endian u64 encoding of the opened cell value.
• point — the hypercube corner (LSB-first) of the opened cell. Canonical encoding: deserialization rejects any element ≥ p, so each point has exactly one valid wire form.

Opening variants

{"Tensor": {
  "round_commitments": [ /* Commitment... */ ],
  "final_poly":        [ /* bytes */ ],
  "query_responses":   [ [ /* index */, [ /* bytes */ ] ] /* ... */ ]
}}

{"Folding": {
  "round_commitments": [ /* Commitment... */ ],
  "merkle_paths":      [ [ /* Hash (32-tuple of bytes)... */ ] ],
  "final_value":       [ /* bytes */ ]
}}

{"Witness": {
  "witness_commitment": /* Commitment */,
  "witness_opening":    { /* nested Opening */ },
  "certificate":        [ /* bytes */ ]
}}

Tensor = Brakedown / Ikat / Porphyry, Folding = Binius, Witness = Assayer.

root binding

QueryProof.commitment is the dimension commitment — one of the 14 leaves of BBG_root (BbgState::root_leaves()). A verifier that also holds the root checks root_from_leaves(leaves) == BBG_root and that leaves.dims[dim] matches commitment; the proof then binds the opened value all the way to the state root. BBG_root itself is a Particle ([u8; 32]) — four Goldilocks limbs, little-endian — and needs no special serde.