Struct PostToolUseHookInput 

pub struct PostToolUseHookInput<'a> {
    pub tool_name: &'a str,
    pub tool_args: &'a Value,
    pub session_id: Option<&'a str>,
    pub duration_ms: u64,
    pub tool_output: Option<&'a str>,
    pub tool_error: Option<&'a str>,
    pub agent_id: Option<&'a str>,
    pub agent_type: &'a str,
}

Context serialized to hook stdin for PostToolUse and PostToolUseFailure events.

The tool_output field is present for success events; tool_error is present for failure events. Both are Option with skip_serializing_if so only the relevant field appears in the JSON written to stdin.

Payload consistency contract

Agent context is delivered two ways:

• All hook events: ZEPH_AGENT_TYPE and (when available) ZEPH_AGENT_ID env vars.
• PostToolUse only: agent_id and agent_type fields in this stdin JSON object.

file_changed, cwd_changed, and turn_complete hooks receive agent context via env vars only — no stdin JSON is written for those events.

Fields

tool_name: &'a str

Name of the tool that was invoked.

tool_args: &'a Value

Arguments passed to the tool (the parsed JSON value).

session_id: Option<&'a str>

Conversation / session identifier, if available.

duration_ms: u64

Wall-clock time the tool took to execute, in milliseconds.

tool_output: Option<&'a str>

Tool output text (success path). Absent for failure events.

tool_error: Option<&'a str>

Tool error text (failure path). Absent for success events.

agent_id: Option<&'a str>

The agent’s stable identifier: conversation_id for the main agent, task_id for sub-agents. Absent when no conversation has been bound yet.

agent_type: &'a str

Discriminator for the agent that fired this hook: "main" or "subagent".

Trait Implementations

impl<'a> Debug for PostToolUseHookInput<'a>

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

Formats the value using the given formatter.

impl<'a> Serialize for PostToolUseHookInput<'a>

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

where __S: Serializer,

Serialize this value into the given Serde serializer.