---
title: "Echo"
description: "Smallest composite pack. In-process, sandbox-safe, no binary."
canonical: https://harnesscontextprotocol.io/packs/echo
---

# Echo

> Smallest composite pack. In-process, sandbox-safe, no binary.

Class `public-read` · adapter `composite` · MIT

```bash
hcpx install github:harnesscontextprotocol/hcp//examples/packs/echo
```

## Commands

| Command | Does | Effect |
| --- | --- | --- |
| `echo.ping` | Ping the echo pack (sandbox-safe). | Reads |
| `echo.say` | Echo a message back. | Reads |

JSON: https://harnesscontextprotocol.io/api/v1/packs/echo

## Sitemap

- [Documentation](https://harnesscontextprotocol.io/docs)
- [Packs](https://harnesscontextprotocol.io/packs)
- [Glossary](https://harnesscontextprotocol.io/docs/reference/glossary)
- [llms.txt](https://harnesscontextprotocol.io/llms.txt)
- [llms-full.txt](https://harnesscontextprotocol.io/llms-full.txt)
- [OpenAPI](https://harnesscontextprotocol.io/openapi.json)
- [MCP](https://harnesscontextprotocol.io/mcp)