# Authentication for agents

Agents do not need credentials to use Xearch.

## Discover

Read https://xearch.pcstyle.tech/llms.txt or https://xearch.pcstyle.tech/.well-known/ard.json to find the agent surfaces. Each one below is public.

## Pick a method

- **MCP**: https://xearch.pcstyle.tech/mcp (search) and https://xearch.pcstyle.tech/docs/mcp (docs). Anonymous: send no Authorization header.
- **REST API**: https://xearch.pcstyle.tech/api/v1 (described at https://xearch.pcstyle.tech/openapi.json), NLWeb at https://xearch.pcstyle.tech/ask and A2A at https://xearch.pcstyle.tech/a2a. Anonymous.
- **WebMCP**: tools registered in the page at https://xearch.pcstyle.tech/. They run with the visitor's own anonymous guest session.
- **Website**: https://xearch.pcstyle.tech/?q=... works without signing in.

## Register

Nothing to register. There are no API keys or client registrations.

## Use

Call `initialize`, then `tools/list` and `tools/call` on the MCP endpoint with plain JSON-RPC over HTTP POST, or send a plain `GET https://xearch.pcstyle.tech/api/v1/search?q=...`.

## Errors

Malformed requests get a JSON-RPC error (MCP, A2A) or an RFC 9457 problem document (REST) with a code and a message. A tool that fails (for example, when the search service is briefly unavailable) returns a result with `isError: true` and a message explaining what happened.

## Revocation

There is nothing to revoke: Xearch issues no agent credentials.

Signing in on the website (email codes for operators who run imports) is for people only and is not offered to agents.