Pi 官方文档
JSON 事件流模式
JSON 事件流模式
pi --mode json "Your prompt"
将所有会话事件以 JSON Lines 形式输出到 stdout。适合把 pi 集成到其他工具或自定义 UI 中。
事件类型
事件定义见 AgentSessionEvent:
type AgentSessionEvent =
| AgentEvent
| { type: "queue_update"; steering: readonly string[]; followUp: readonly string[] }
| { type: "compaction_start"; reason: "manual" | "threshold" | "overflow" }
| { type: "compaction_end"; reason: "manual" | "threshold" | "overflow"; result: CompactionResult | undefined; aborted: boolean; willRetry: boolean; errorMessage?: string }
| { type: "auto_retry_start"; attempt: number; maxAttempts: number; delayMs: number; errorMessage: string }
| { type: "auto_retry_end"; success: boolean; attempt: number; finalError?: string };
queue_update 会在挂起的 steering 队列和 follow-up 队列发生变化时,发出完整内容。compaction_start 和 compaction_end 覆盖手动和自动的上下文压缩。
来自 AgentEvent 的基础事件:
type AgentEvent =
// Agent lifecycle
| { type: "agent_start" }
| { type: "agent_end"; messages: AgentMessage[] }
// Turn lifecycle
| { type: "turn_start" }
| { type: "turn_end"; message: AgentMessage; toolResults: ToolResultMessage[] }
// Message lifecycle
| { type: "message_start"; message: AgentMessage }
| { type: "message_update"; message: AgentMessage; assistantMessageEvent: AssistantMessageEvent }
| { type: "message_end"; message: AgentMessage }
// Tool execution
| { type: "tool_execution_start"; toolCallId: string; toolName: string; args: any }
| { type: "tool_execution_update"; toolCallId: string; toolName: string; args: any; partialResult: any }
| { type: "tool_execution_end"; toolCallId: string; toolName: string; result: any; isError: boolean };
消息类型
来自 packages/ai/src/types.ts 的基础消息:
UserMessage(第 134 行)AssistantMessage(第 140 行)ToolResultMessage(第 152 行)
来自 packages/coding-agent/src/core/messages.ts 的扩展消息:
BashExecutionMessage(第 29 行)CustomMessage(第 46 行)BranchSummaryMessage(第 55 行)CompactionSummaryMessage(第 62 行)
输出格式
每一行都是一个 JSON 对象。第一行是会话头:
{"type":"session","version":3,"id":"uuid","timestamp":"...","cwd":"/path"}
随后按事件发生的顺序输出:
{"type":"agent_start"}
{"type":"turn_start"}
{"type":"message_start","message":{"role":"assistant","content":[],...}}
{"type":"message_update","message":{...},"assistantMessageEvent":{"type":"text_delta","delta":"Hello",...}}
{"type":"message_end","message":{...}}
{"type":"turn_end","message":{...},"toolResults":[]}
{"type":"agent_end","messages":[...]}
示例
pi --mode json "List files" 2>/dev/null | jq -c 'select(.type == "message_end")'