配置提示词装饰器
在使用大型语言模型 (LLM) 进行专业内容生成时，通常会预先设计并配置提示词（Prompt），将其作为后续交互中的“行为规则”，以约束模型在既定指南和安全标准下运行。
本文将介绍如何在 APISIX 中使用 ai-prompt-decorator 插件配置提示词装饰器，在用户自定义消息前（prepend）和后（append）追加额外内容。本文以 OpenAI 作为示例上游服务，但同样适用于其他 LLM 服务提供商。
前置条件
获取 OpenAI API Key
在继续之前，请创建一个 OpenAI 账户 并生成一个 API Key。你也可以将其保存为环境变量，例如：
export OPENAI_API_KEY=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 # replace with your API key
创建路由
在本示例中，你将：
创建一个指向 Chat Completion 接口的路由，并预配置提示词模板：
curl "http://127.0.0.1:9180/apisix/admin/routes" -X PUT \
-H "X-API-KEY: ${ADMIN_API_KEY}" \
-d '{
"id": "ai-prompt-decorator-route",
"uri": "/anything",
"plugins": {
"ai-proxy": {
"provider": "openai",
"auth": {
"header": {
"Authorization": "Bearer '"$OPENAI_API_KEY"'"
}
},
"options": {
"model": "gpt-4"
}
},
"ai-prompt-decorator": {
"prepend":[
{
"role": "system",
"content": "Answer briefly and conceptually."
}
],
"append":[
{
"role": "user",
"content": "End the answer with a simple analogy."
}
]
}
}
}'
❶ 在用户消息之前追加 system 消息，用于设置助手行为。
❷ 在用户自定义提示之后追加额外的 user 消息。
验证
向该路由发送一个包含示例消息的 POST 请求：
curl "http://127.0.0.1:9080/anything" -X POST \
-H "Content-Type: application/json" \
-d '{
"messages": [{ "role": "user", "content": "What is mTLS authentication?" }]
}'
可以看到，模型的回答既遵循了“简洁且概念化”的要求，也在结尾使用了一个简单类比。
{
"choices": [
{
"finish_reason": "stop",
"index": 0,
"message": {
"content": "Mutual TLS (mTLS) authentication is a security protocol that ensures both the client and server authenticate each other's identity before establishing a connection. This mutual authentication is achieved through the exchange and verification of digital certificates, which are cryptographically signed credentials proving each party's identity. In contrast to standard TLS, where only the server is authenticated, mTLS adds an additional layer of trust by verifying the client as well, providing enhanced security for sensitive communications.\n\nThink of mTLS as a secret handshake between two friends meeting at a club. Both must know the handshake to get in, ensuring they recognize and trust each other before entering.",
"role": "assistant"
}
}
],
"created": 1723193502,
"id": "chatcmpl-9uFdWDlwKif6biCt9DpG0xgedEamg",
"model": "gpt-4o-2024-05-13",
"object": "chat.completion",
"system_fingerprint": "fp_abc28019ad",
"usage": {
"completion_tokens": 124,
"prompt_tokens": 31,
"total_tokens": 155
}
}
下一步
你现在已经学会了在 APISIX 与 LLM 服务集成时如何配置提示词装饰器。
如果你希望对接 OpenAI 的流式 API，可以使用 proxy-buffering 插件禁用 NGINX 的 proxy_buffering 指令，以避免服务器发送事件（SSE）被缓冲。