> For the complete documentation index, see [llms.txt](https://docs.coda.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.coda.co/https-coda-payments.gitbook.io-zhong-wen-coda-private-technical-documentation/codapay/hou-duan-api-ji-cheng/direct-card-api-ji-cheng/ru-men-zhi-nan/ru-he-sheng-cheng-x-qian-ming.md).

# 如何生成 x 签名

对于每一笔费用请求通知，Coda 系统都会执行验证流程以确保其完整性。Coda 会将请求中的***x-signature***标头与请求正文的签名进行比较。如果签名不匹配，系统将拒绝该请求并返回错误。此流程旨在确保费用请求的完整性和安全性，降低有效载荷被篡改的风险。


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# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.coda.co/https-coda-payments.gitbook.io-zhong-wen-coda-private-technical-documentation/codapay/hou-duan-api-ji-cheng/direct-card-api-ji-cheng/ru-men-zhi-nan/ru-he-sheng-cheng-x-qian-ming.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.