Struct Receipt 

pub struct Receipt {
    pub body: ReceiptBody,
    pub signature_b64: String,
}

A complete receipt: body + detached signature over JCS(body).

The wire shape is intentionally flat (13 body fields + signature_b64 at the top level) — the schema at schemas/receipt-v1.schema.json commits to it and downstream verifiers (avctl receipt-verify, external tools) consume it that way.

#[serde(flatten)] normally silently disables deny_unknown_fields on the inner struct, which would let a hostile issuer add extra top-level fields (“claim_extra”: “grant admin”) that the human reviewer sees but verify() accepts (the field never survives the round-trip to ReceiptBody used inside canonicalize). To close that gap without breaking the wire shape, the Deserialize impl is written by hand and rejects any top-level key outside the declared whitelist. See the allowed_receipt_top_level_keys_cover_body_fields_exactly test for the compile-time-ish drift guard.

Fields

body: ReceiptBody

Signed body.

signature_b64: String

Ed25519 signature over the JCS canonicalization of the body, base64.

Implementations

impl Receipt

pub fn from_json_slice(bytes: &[u8]) -> Result<Self, ReceiptError>

Deserialize a receipt from wire bytes, rejecting any duplicate key at ANY nesting level.

The custom Deserialize impl for Receipt (below) already rejects duplicate top-level keys, but nested structs (ai_agent, tool_calls, cost, subject) went through serde’s default derive which relies on serde_json::Map / IndexMap — both silently collapse duplicate keys with last-wins semantics. A hostile issuer could then sign a receipt whose ai_agent.instance_uid appeared twice ("a" then "b"); JCS canonicalisation saw only "b" so the signature verified, but a first-wins auditor tool (jq’s default, some Python configs) displayed "a" — the exact split-brain the top-level guard was written to prevent, one level deeper.

Round-15 F4: pre-scan the JSON with a strict duplicate-key checker (check_no_duplicate_keys) before deserialising into Receipt. Callers verifying a receipt off the wire should prefer this over serde_json::from_slice::<Receipt>.

pub fn from_json_str(s: &str) -> Result<Self, ReceiptError>

Same as Receipt::from_json_slice for owned/borrowed strings.

pub fn issue( body: ReceiptBody, signer: &dyn Signer, ) -> Result<Self, ReceiptError>

Issue (sign) a receipt over body with signer.

The key_id and public_key_b64 fields of the body are overwritten from the signer — a caller can never claim someone else’s key identity.

pub fn verify(&self, ring: &Keyring) -> Result<(), ReceiptError>

Verify offline against a keyring. Checks, in execution order:

1. AtifTrajectory.retroactive == true (round-16 F8 — retroactive: false on an ATIF-promoted receipt is semantically nonsense; the schema pins it to const: true but the Rust type still accepts false; refuse it here so the two agree);
2. the embedded public key matches the ring’s key for key_id (anti-substitution);
3. the signature verifies over JCS(body).

pub fn verify_embedded(&self) -> Result<(), ReceiptError>

Verify self-contained (trusting the embedded public key). Suitable when the verifier obtained the receipt over an authenticated channel or pins key ids separately. Prefer Receipt::verify with a ring.

Trait Implementations

impl Clone for Receipt

fn clone(&self) -> Receipt

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Receipt

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Receipt

fn deserialize<D: Deserializer<'de>>(deserializer: D) -> Result<Self, D::Error>

Deserialize this value from the given Serde deserializer.

impl PartialEq for Receipt

fn eq(&self, other: &Receipt) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Serialize for Receipt

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for Receipt