Struct Observation 

pub struct Observation {
    pub source: String,
    pub content: String,
    pub is_error: bool,
    pub call_id: Option<String>,
    pub metadata: HashMap<String, String>,
}

An observation that feeds into the reasoning step.

Observations come from tool results, environment state, policy feedback, or external events. The loop collects them before each reasoning step.

Fields

source: String

Source of the observation (e.g., tool name, “policy_gate”, “environment”).

content: String

The observation content.

is_error: bool

Whether this observation indicates an error.

call_id: Option<String>

The tool call ID that produced this observation. When present, used as the tool_use_id in conversation messages to correlate tool results with the originating tool_use block.

metadata: HashMap<String, String>

Metadata for logging and auditing.

Implementations

impl Observation

pub fn tool_result( tool_name: impl Into<String>, content: impl Into<String>, ) -> Self

Create a tool result observation.

pub fn tool_error( tool_name: impl Into<String>, error: impl Into<String>, ) -> Self

Create a tool error observation.

pub fn policy_denial(reason: impl Into<String>) -> Self

Create a policy denial observation.

pub fn with_call_id(self, call_id: impl Into<String>) -> Self

Attach a tool call ID to this observation.

Trait Implementations

impl Clone for Observation

fn clone(&self) -> Observation

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Observation

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Observation

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Observation

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

where __S: Serializer,

Serialize this value into the given Serde serializer.