Struct ContextBreakdown 

pub struct ContextBreakdown {
    pub system_prompt: u32,
    pub rules: u32,
    pub skills: u32,
    pub subagents: u32,
    pub tools: u32,
    pub mcp_dynamic: u32,
    pub conversation: u32,
    pub overhead: u32,
}

Locally-estimated per-component token breakdown of the prompt sent to the provider.

Distinct from TokenUsage (which is the provider’s reported truth): these are local chars/4 estimates, one bucket per logical segment of the assembled prompt. The overhead bucket absorbs the difference between the sum of the other buckets and the provider’s reported prompt_tokens (chat-template wrapping, tool JSON envelope, message separators) so the breakdown is honest about its estimation error rather than pretending to be exact.

Recomputed every step: the static buckets (system_prompt, rules, skills, subagents, tools, mcp_dynamic) change only on a /model hot-swap or tool-registry change, while conversation grows with every transcript mutation and overhead is derived from the provider’s reported prompt_tokens after each step.

Fields

system_prompt: u32

default_system_prompt + the six memory layers + any channel append_system_prompt suffix.

rules: u32

# Project context block: AGENTS.md + CLAUDE.md from prepend_project_context.

skills: u32

skill_index() output.

subagents: u32

## Coordinator workflow + sub_agent usage note (only when sub_agent_enabled).

tools: u32

Eager tool specs that are NOT from MCP and NOT deferred.

mcp_dynamic: u32

Tool specs that ARE MCP-sourced or deferred (the dynamic / discovered-tools bucket).

conversation: u32

self.messages text content (transcript body).

overhead: u32

Provider total - local sum (saturating to 0). Absorbs chat-template wrapping, tool JSON envelope, and message separators that the local estimate can’t reproduce.

Implementations

impl ContextBreakdown

pub fn local_sum(&self) -> u32

Sum of the seven non-overhead buckets.

pub fn total(&self) -> u32

Total of every bucket including overhead.

Trait Implementations

impl Clone for ContextBreakdown

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ContextBreakdown

impl Debug for ContextBreakdown

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

Formats the value using the given formatter.

impl Default for ContextBreakdown

fn default() -> Self

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for ContextBreakdown

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

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for ContextBreakdown

impl PartialEq for ContextBreakdown

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

Equality operator ==.

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

Inequality operator !=.

impl Serialize for ContextBreakdown

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 ContextBreakdown