> For the complete documentation index, see [llms.txt](https://docs.usexpay.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.usexpay.xyz/learn-more/mcp-servers.md).

# MCP Servers

Each creator gets an MCP server at `https://api.usexpay.xyz/mcp/:username`. xPay turns your registered endpoints into MCP tools agents can call directly.

#### How it works

* On initialize, xPay creates (or resumes) a per-user MCP server session
* Tools are generated from endpoints; descriptions include method and cost
* Input schemas are derived from your `sampleBody` and `httpMethod`
* Payment is bypassed for protocol list/initialize methods, enforced for tool calls

#### Session management

* `POST /mcp/:username` with MCP payloads
* `GET /mcp/:username` and `DELETE /mcp/:username` for session operations
* Use `mcp-session-id` header to persist and reuse sessions

#### Best practices

* Provide realistic `sampleBody` and `sampleResponse`
* Keep names clear and descriptive for agent discovery
* Use fair, simple pricing to encourage agent adoption

#### Learn more about the MCP protocol

Read the [official MCP protocol documentation](https://modelcontextprotocol.io/)


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# Agent Instructions
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## 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.usexpay.xyz/learn-more/mcp-servers.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.

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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.