在 Live API 中，会话是指通过同一连接持续传输输入和输出的持久连接（详细了解其工作原理）。这种独特的会话设计可实现低延迟并支持独特的功能，但也可能会带来一些挑战，例如会话时间限制和提前终止。本指南介绍了在使用 Live API 时可能会遇到会话管理方面的挑战，并提供了应对这些挑战的策略。
会话生命周期
如果不进行压缩，纯音频会话的时长上限为 15 分钟，音频-视频会话的时长上限为 2 分钟。超出这些限制会导致会话（以及连接）终止，但您可以使用上下文窗口压缩将会话延长至无限时长。
连接的生命周期也有限制，约为 10 分钟。当连接终止时，会话也会终止。在这种情况下，您可以使用会话恢复功能，将单个会话配置为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，以便您采取进一步的措施。
上下文窗口压缩
如需延长会话时长并避免连接突然终止，您可以在会话配置中设置 contextWindowCompression 字段来启用上下文窗口压缩。
在 ContextWindowCompressionConfig 中，您可以配置滑动窗口机制和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
为防止服务器定期重置 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，该消息可用于通过将上次恢复令牌作为后续连接的 SessionResumptionConfig.handle 来恢复会话。
恢复令牌在上次会话终止后 2 小时内有效。
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收到消息
服务器会发送一条 GoAway 消息，表示当前连接即将终止。此消息包含 timeLeft，用于指示剩余时间，并让您在连接因 ABORTED 而终止之前采取进一步的措施。
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
服务器会发送 generationComplete 消息，表明模型已完成回答生成。
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
如需详细了解如何使用 Live API，请参阅完整的功能指南、工具使用页面或 Live API 食谱。