Struct Witness 

pub struct Witness {
    pub observer: String,
    pub observation: String,
    pub observed_at: Option<String>,
    pub signature: Option<String>,
}

An independent observation of an action’s effect, made by someone other than the actor. A witness is the raw material of effect verification: the actor’s own effect_confidence is a claim it can mint, but a witness whose key is NOT the actor’s, whose signature verifies against a trusted root, and whose observation matches the effect is a signal the actor could not have forged. Multiple independent witnesses are how a Verified confidence earns its evidence beyond a single self-reported readback.

This struct is only the record. It carries NO independent weight on its own: an unsigned witness, or one signed by the actor’s own key, proves nothing. The reconciliation – does observer resolve to a trusted, non-actor key? does signature verify over the canonical tuple? does observation match the effect? – happens in verify, never here. Do not treat the mere presence of a witness as evidence.

Fields

observer: String

URI or key id of the observer, e.g. “agent://auditor”, “key_9f2c”. Verify resolves this to a trust root and requires it to differ from the action’s actor.

observation: String

sha256:<hex> of what the observer independently saw. Verify checks this equals the effect’s own observed post-state (readback / output_hash); a witness that observed something else corroborates nothing.

observed_at: Option<String>

RFC 3339 instant the observation was made.

signature: Option<String>

The observer’s signature over its own (observer, observation, observed_at) tuple, verifiable against observer’s key. Absent means unsigned: verify gives it zero independent weight.

Implementations

impl Witness

pub fn is_signed(&self) -> bool

True when the witness at least carries a signature to check. This is a necessary-not-sufficient precondition: verify still has to confirm the signature verifies, the observer is a trusted non-actor key, and the observation matches. A true here is NOT evidence by itself.

Trait Implementations

impl Clone for Witness

fn clone(&self) -> Witness

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Witness

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

Formats the value using the given formatter.

impl Default for Witness

fn default() -> Witness

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Witness

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for Witness

impl PartialEq for Witness

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for Witness

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 Witness