Struct BudgetHint 

pub struct BudgetHint {
    pub remaining_cost_cents: Option<f64>,
    pub total_budget_cents: Option<f64>,
    pub remaining_tool_calls: usize,
    pub max_tool_calls: usize,
}

Budget state injected into the volatile system prompt section.

All fields are optional — omitted when the corresponding data source is unavailable. BudgetHint::format_xml returns None when all fields would be absent.

Callers should construct this from cost-tracker and tool-orchestrator state, then call format_xml and append the result to the system prompt when Some.

Fields

remaining_cost_cents: Option<f64>

Remaining daily budget in US cents, if a daily limit is configured.

total_budget_cents: Option<f64>

Total daily budget in US cents, if a daily limit is configured.

remaining_tool_calls: usize

Remaining tool-call iterations this turn.

max_tool_calls: usize

Maximum allowed tool-call iterations per turn (0 = no limit configured).

Implementations

impl BudgetHint

pub fn format_xml(&self) -> Option<String>

Render the budget hint as an XML fragment for injection into the system prompt.

Returns None when no meaningful budget data is available — callers must skip injection rather than injecting an empty <budget></budget> block.

Examples

use zeph_agent_context::helpers::BudgetHint;

let hint = BudgetHint {
    remaining_cost_cents: Some(50.0),
    total_budget_cents: Some(100.0),
    remaining_tool_calls: 8,
    max_tool_calls: 10,
};
let xml = hint.format_xml().unwrap();
assert!(xml.contains("<remaining_cost_cents>50.00</remaining_cost_cents>"));
assert!(xml.contains("<remaining_tool_calls>8</remaining_tool_calls>"));