# MCP: connect external tool servers

> Expose selected tools from a local or remote MCP server to Hermes without building a native tool first.

Canonical: https://hermeswatcher.com/tools/mcp  
Kind: Integration · Development & operations  
Last reviewed: Oct 19, 2026  
Basis: Explained from the official Hermes Agent docs and repository (Nous Research). Steps follow the linked official sources.

## What it is for

MCP is a connection method for capabilities that live outside Hermes, such as repository tools, databases, or internal APIs. The official integration supports local stdio servers, remote HTTP servers, tool discovery, and per-server filtering. Start from a concrete task and expose only the relevant operations. A successful connection should be judged by an actual tool result, not by the presence of a saved server entry.

## What you need

- A reachable server with documentation for its transport, authentication, runtime, and permissions.
- An appropriate Hermes profile and any local server runtime required by the chosen deployment.

## Setting it up

1. Prefer a documented or catalogued route and inspect the server's source and permission scope before connecting.
2. Configure the transport and credentials using the supported Hermes connection flow. Filter unnecessary tools, then begin with a read-only query against a known object.

## How to check it works

- Confirm authorization and tool discovery separately; an authorized account can still have unavailable tools.
- Compare the retrieved record against the original service and confirm that errors identify account, access, or connectivity gaps.

## Limits

- MCP does not remove the underlying service's access restrictions, costs, or usage limits.
- A listed tool may write data. Connection approval should not be treated as blanket permission to send, delete, purchase, or publish.

## Related workflows

- [Build a useful GitHub issue review](https://hermeswatcher.com/workflows/github-issue-review.md)
- [Turn a crowded inbox into a review queue](https://hermeswatcher.com/workflows/inbox-triage.md)
- [Carry project knowledge into the next session](https://hermeswatcher.com/workflows/project-knowledge.md)

## Sources

- [Official MCP integration](https://hermes-agent.nousresearch.com/docs/user-guide/features/mcp)

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HermesWatcher is an independent guide. It is not affiliated with or endorsed by Nous Research. The [official Hermes Agent documentation](https://hermes-agent.nousresearch.com/docs) and [repository](https://github.com/NousResearch/hermes-agent) from Nous Research are the authority; each page here lists the official sources it was written from. If this site and the official docs disagree, trust the official docs. Index for agents: https://hermeswatcher.com/llms.txt