{"type":"session","harness":"my-agent","id":"abc123","name":"what time is it"}
{"type":"message","message":{"role":"user","content":"what time is it?"}}
{"type":"message","message":{"role":"assistant","content":"","toolCalls":[{"id":"t1","function":{"name":"get_time","arguments":"{}"}}]}}
{"type":"message","message":{"role":"tool","toolCallId":"t1","content":"2026-07-01T15:00:00Z"}}
{"type":"message","message":{"role":"assistant","content":"it is 15:00 UTC"}}