---
title: "agents.txt"
description: "agents.txt is a proposed discovery file for publishing a site's agent-facing capabilities. It is designed for AI agents that may need to discover supported protocols, payment mechanisms, authorization schemes, MCP endpoints, skills, A2A agent cards, or other machine-readable interaction surfaces."
canonical_url: "https://promptmetheus.com/resources/llm-knowledge-base/agents-txt"
---

> Index of every page on this site: [llms.txt](https://promptmetheus.com/llms.txt)

agents.txt is a proposed discovery file for publishing a site's agent-facing capabilities. It is designed for AI agents that may need to discover supported protocols, payment mechanisms, authorization schemes, MCP endpoints, skills, A2A agent cards, or other machine-readable interaction surfaces.

Where [llms.txt](https://promptmetheus.com/resources/llm-knowledge-base/llms-txt) helps an agent find content to read, agents.txt helps an agent understand what it can do with a site. It is typically paired with a structured `agents.json` file for richer machine parsing.

Examples of capabilities that may be declared include:

- [MCP](https://promptmetheus.com/resources/llm-knowledge-base/model-context-protocol-mcp) server endpoints;
- [Agent2Agent Protocol (A2A)](https://promptmetheus.com/resources/llm-knowledge-base/agent2agent-protocol-a2a) Agent Card URLs;
- skill package URLs;
- authorization discovery such as [Agent Auth Protocol](https://promptmetheus.com/resources/llm-knowledge-base/agent-auth-protocol);
- agent payment support such as [Agent Payments Protocol (AP2)](https://promptmetheus.com/resources/llm-knowledge-base/agent-payments-protocol-ap2); and
- commerce or interaction profiles.

The file is not a trust guarantee. Agents still need to validate endpoints, authenticate properly, enforce [agent policy](https://promptmetheus.com/resources/llm-knowledge-base/agent-policy), and ask for human approval when actions are consequential.

The [agents.txt standard draft](https://github.com/agents-txt/agents-txt/blob/main/app/site/src/content/spec/AGENTS-TXT-STANDARD.md) defines directives for payments, authorization, MCP, skills, A2A, UCP, and WebMCP discovery.

## Sitemap

See the full [sitemap](https://promptmetheus.com/sitemap.md) for all pages.