Events

Kilo Code emits its activity as EventFormat::Kilo. It is run with kilo run --format json, which writes a line-delimited JSON stream on standard output: each non-empty line is one complete JSON object carrying a top-level type. Kilo Code is built on the same OpenCode-style step stream as OpenCode, so it shares that stream’s shape; the harness layer parses it and maps it onto the normalized harness events. The session id is captured from a sessionID, session_id, or sessionId field.

Raw event stream

Each line is handled by its top-level type:

Kilo event	Handling
`step_start`, `step_finish`	Step boundaries, consumed. `step_finish` carries the usage totals used for metrics. No event.
`reasoning`	Model thinking. Becomes a reasoning event when it carries text, otherwise consumed.
`text`	The assistant’s plain text becomes an agent message. An empty text emits no event.
`tool_use`	A self-contained tool call, classified in place (see Tool mapping).
`error`	Becomes an error event.

A tool_use event is self-contained — it carries the tool name, input, and a terminal status in one event, so no request/response correlation is needed — and its status sets the success field.

Normalized mapping

Raw event	Normalized event
`step_start`, `step_finish`	none (consumed)
`reasoning`	reasoning message when it carries text, otherwise none
`text`	agent message
`tool_use`	the event its tool classifies to (see Tool mapping)
`error`	error
any other type	unknown

A line that fails to parse as JSON, any unrecognized event type, and a tool_use whose tool is not recognized all become unknown events so the stream stays lossless.

Tool mapping

Kilo Code extends the OpenCode tool set with workflow and semantic-search tools; tool names are matched case-insensitively:

Kilo tool	Event
`task`, `agent_manager`	orchestration when the spawned agent/session is identified, otherwise unknown
`codesearch`	search
`todowrite`, `todoread`	consumed — internal task list, no event
`read`	read
`write`, `edit`	write
`apply_patch`	one write per file named by the patch markers
`grep`, `glob`	search
`bash`	command, or a recognized file operation
`skill`	skill
`lsp`	search when it carries a query/symbol, otherwise unknown
any other tool	unknown

A task or agent_manager call only becomes an orchestration event when the spawned agent or session can be identified from the input; otherwise it falls through to an unknown event rather than guessing. Any other tool delegates to the OpenCode tool mapping.

For the normalized event types these map onto, see Harness Events.