Struct CredentialFieldDecl 

pub struct CredentialFieldDecl {
    pub field_path: Vec<String>,
    pub variant_tag: Option<String>,
    pub metadata: CredentialMetadata,
}

One entry per credential-bearing field in a method’s return type.

Pinned by AUTHZ-CRED-S01-output.md §4 and AUTHZ-CRED-CORE-3 §“Required behavior”. Projected onto MethodSchema.credentials at schema-build time from the CredentialFieldMarker registry the #[derive(Credentials)] macro emits per credential-bearing type (AUTHZ-CRED-MACRO-1).

Field path semantics (Tier B Q-IR-1)

field_path is the JSON-object path to the credential field within the method’s return type. v1 always uses object-field paths (one segment per field name walked); array indices and JSON Pointer syntax are intentionally excluded because credentials always live on object fields in v1, never inside array elements.

Example: for a return type struct LoginResult { session: Credential<String> }, the field path is ["session"]. For a nested case struct LoginResult { auth: AuthBundle } where AuthBundle itself declares a #[plexus::credential(..)] field token: Credential<String>, the field path is ["auth", "token"].

Variant tagging

variant_tag is Some(tag) when the method’s return type is an enum and the credential lives on a single variant. The tag matches the variant identifier as the macro registry records it (e.g. "Issued" for the LoginEvent::Issued variant). None means the return type is a struct, or the credential appears on every variant of the enum (rare).

Wire back-compat

Added in AUTHZ-CRED-CORE-3. Pre-existing readers tolerate credentials: [] (the default on MethodSchema when no credentials are declared) and pre-existing IRs that omit the field altogether decode cleanly via #[serde(default)] on the field site.

Fields

field_path: Vec<String>

JSON-object path to the credential field within the method’s return type. One segment per field-name walk; pinned to object paths (no array indices, no JSON Pointer) per Tier B Q-IR-1.

variant_tag: Option<String>

Variant tag when the return type is an enum and the credential lives on a single variant. None for structs.

metadata: CredentialMetadata

The credential’s metadata (kind, attach site, scheme, scopes, expiry, refresh/revoke hints, issuer, sensitivity). Carried verbatim so consumers embed identical storage-and-attach logic to the runtime.

Implementations

impl CredentialFieldDecl

pub fn from_marker( marker: &CredentialFieldMarker, path_prefix: &[&str], issuer: CredentialIssuer, ) -> Self

Construct a CredentialFieldDecl by composing a CredentialFieldMarker from the macro-emitted registry with the runtime-supplied pieces (expires_at known only at mint time; issuer known at schema-build time from the originating method’s (Origin, MethodPath)).

path_prefix is the field-path walk to the marker’s parent type — for a flat struct it is empty; for a nested case where this marker lives inside a field of the method’s return type the prefix is the path to that wrapping field. The marker’s own field and variant are appended.

Trait Implementations

impl Clone for CredentialFieldDecl

fn clone(&self) -> CredentialFieldDecl

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CredentialFieldDecl

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for CredentialFieldDecl

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl JsonSchema for CredentialFieldDecl

fn schema_name() -> Cow<'static, str>

The name of the generated JSON Schema.

fn schema_id() -> Cow<'static, str>

Returns a string that uniquely identifies the schema produced by this type.

fn json_schema(generator: &mut SchemaGenerator) -> Schema

Generates a JSON Schema for this type.

fn inline_schema() -> bool

Whether JSON Schemas generated for this type should be included directly in parent schemas, rather than being re-used where possible using the $ref keyword.

impl PartialEq for CredentialFieldDecl

fn eq(&self, other: &CredentialFieldDecl) -> 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 CredentialFieldDecl

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

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl Eq for CredentialFieldDecl

impl StructuralPartialEq for CredentialFieldDecl