在 Live API 中，会话是指通过同一连接持续流式传输输入和输出的持久连接（详细了解运作方式）。这种独特的会话设计可实现低延迟并支持独特功能，但也可能会带来会话时限和提前终止等挑战。本指南介绍了克服使用 Live API 时可能会出现的会话管理难题的策略。
会话生命周期
不压缩时，仅音频会话的时长限制为 15 分钟，音频和视频会话的时长限制为 2 分钟。如果超出这些限制，系统会终止会话（以及连接），但您可以使用上下文窗口压缩将会话延长到无限时间。
连接的生命周期也受到限制，大约为 10 分钟。连接终止后，会话也会终止。在这种情况下，您可以使用会话恢复功能配置单个会话，使其在多个连接中保持活跃状态。在连接结束之前，您还会收到一条 GoAway 消息，以便您执行进一步操作。
上下文窗口压缩
如需延长会话时长并避免突然断开连接，您可以在会话配置中设置 contextWindowCompression 字段，以启用上下文窗口压缩。
在 ContextWindowCompressionConfig 中，您可以配置滑动窗口机制以及触发压缩的令牌数量。
Python
from google.genai import types
config = types.LiveConnectConfig(
response_modalities=["AUDIO"],
context_window_compression=(
# Configures compression with default parameters.
types.ContextWindowCompressionConfig(
sliding_window=types.SlidingWindow(),
)
),
)
JavaScript
const config = {
responseModalities: [Modality.AUDIO],
contextWindowCompression: { slidingWindow: {} }
};
会话恢复
如需防止在服务器定期重置 WebSocket 连接时会话终止，请在设置配置中配置 sessionResumption 字段。
传递此配置会导致服务器发送 SessionResumptionUpdate 消息，这些消息可用于通过将上次恢复令牌作为后续连接的 SessionResumptionConfig.handle 传递来恢复会话。
Python
import asyncio
from google import genai
from google.genai import types
client = genai.Client()
model = "gemini-live-2.5-flash-preview"
async def main():
print(f"Connecting to the service with handle {previous_session_handle}...")
async with client.aio.live.connect(
model=model,
config=types.LiveConnectConfig(
response_modalities=["AUDIO"],
session_resumption=types.SessionResumptionConfig(
# The handle of the session to resume is passed here,
# or else None to start a new session.
handle=previous_session_handle
),
),
) as session:
while True:
await session.send_client_content(
turns=types.Content(
role="user", parts=[types.Part(text="Hello world!")]
)
)
async for message in session.receive():
# Periodically, the server will send update messages that may
# contain a handle for the current state of the session.
if message.session_resumption_update:
update = message.session_resumption_update
if update.resumable and update.new_handle:
# The handle should be retained and linked to the session.
return update.new_handle
# For the purposes of this example, placeholder input is continually fed
# to the model. In non-sample code, the model inputs would come from
# the user.
if message.server_content and message.server_content.turn_complete:
break
if __name__ == "__main__":
asyncio.run(main())
JavaScript
import { GoogleGenAI, Modality } from '@google/genai';
const ai = new GoogleGenAI({});
const model = 'gemini-live-2.5-flash-preview';
async function live() {
const responseQueue = [];
async function waitMessage() {
let done = false;
let message = undefined;
while (!done) {
message = responseQueue.shift();
if (message) {
done = true;
} else {
await new Promise((resolve) => setTimeout(resolve, 100));
}
}
return message;
}
async function handleTurn() {
const turns = [];
let done = false;
while (!done) {
const message = await waitMessage();
turns.push(message);
if (message.serverContent && message.serverContent.turnComplete) {
done = true;
}
}
return turns;
}
console.debug('Connecting to the service with handle %s...', previousSessionHandle)
const session = await ai.live.connect({
model: model,
callbacks: {
onopen: function () {
console.debug('Opened');
},
onmessage: function (message) {
responseQueue.push(message);
},
onerror: function (e) {
console.debug('Error:', e.message);
},
onclose: function (e) {
console.debug('Close:', e.reason);
},
},
config: {
responseModalities: [Modality.TEXT],
sessionResumption: { handle: previousSessionHandle }
// The handle of the session to resume is passed here, or else null to start a new session.
}
});
const inputTurns = 'Hello how are you?';
session.sendClientContent({ turns: inputTurns });
const turns = await handleTurn();
for (const turn of turns) {
if (turn.sessionResumptionUpdate) {
if (turn.sessionResumptionUpdate.resumable && turn.sessionResumptionUpdate.newHandle) {
let newHandle = turn.sessionResumptionUpdate.newHandle
// ...Store newHandle and start new session with this handle here
}
}
}
session.close();
}
async function main() {
await live().catch((e) => console.error('got error', e));
}
main();
在会话断开连接之前接收消息
服务器发送 GoAway 消息，表示当前连接即将终止。此消息包含 timeLeft，表示剩余时间，可让您在连接被终止为“ABORTED”之前采取进一步行动。
Python
async for response in session.receive():
if response.go_away is not None:
# The connection will soon be terminated
print(response.go_away.time_left)
JavaScript
const turns = await handleTurn();
for (const turn of turns) {
if (turn.goAway) {
console.debug('Time left: %s\n', turn.goAway.timeLeft);
}
}
在生成完成后收到消息
服务器发送 generationComplete 消息，表示模型已完成生成回答。
Python
async for response in session.receive():
if response.server_content.generation_complete is True:
# The generation is complete
JavaScript
const turns = await handleTurn();
for (const turn of turns) {
if (turn.serverContent && turn.serverContent.generationComplete) {
// The generation is complete
}
}
后续步骤
如需探索更多使用 Live API 的方法，请参阅完整的功能指南、工具使用页面或 Live API 食谱。