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Hermes Agent (Nous Research) reads MCP servers from ~/.hermes/config.yaml. Slashy is a remote HTTP server with OAuth, so the entry is two lines - then one login command.

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Prerequisites

  • A Slashy account signed in with Google. Sign up at slashy.com if you haven’t.
  • Hermes Agent installed, with MCP support (bundled with the standard install).
  • A browser available for the one-time OAuth login.

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Setup

1

Open the Hermes config file

In your terminal:
Terminal editing ~/.hermes/config.yaml
2

Add the Slashy server

Add Slashy under the top-level mcp_servers: key (create the key if it isn’t there yet):
Save and exit.
Prefer one command? hermes mcp add slashy --url https://slashy.ctrlcenter.ai/mcp --auth oauth writes the same entry for you.
Hermes config.yaml with the Slashy mcp_servers block
The key is top-level mcp_servers: - not mcp: with a nested servers:. Hermes ignores entries written under the wrong key, and the server simply never appears.
3

Log in from a fresh terminal

Run:
Hermes prints an authorize URL and opens your browser to the Slashy login page. Sign in with Google and click Allow.
hermes mcp login slashy printing the authorize URL and confirming authentication
Run this from a new terminal, not from inside a running Hermes session. Editing config.yaml mid-session triggers an auto-reload with a 30-second timeout - too short to finish an interactive OAuth flow. hermes mcp login waits the full five minutes.
Running Hermes on a remote host or over SSH? The browser redirect can’t reach a loopback port on another machine. Hermes prints an “Or paste the redirect URL here…” prompt - approve in your browser, copy the full URL it lands on (the connection error is expected), and paste it back.
4

Verify the connection

Test the server, then reload it into your session:
Ask Hermes “Tell me which MCP-backed tools are available right now.” - inside the agent the Slashy tools are namespaced as mcp_slashy_<tool_name>, for example mcp_slashy_list_messages and mcp_slashy_draft_email. (hermes mcp test lists them under their bare server-side names.)
hermes mcp test slashy reporting Connected, tools discovered, and the discovered tool list

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What happens after setup

Hermes caches the OAuth token at ~/.hermes/mcp-tokens/slashy.json with 0600 permissions and reuses it silently until a refresh fails. Your config file holds only the URL - never a secret. To re-authenticate later (new Slashy account, revoked access), run hermes mcp login slashy again.

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Limiting which tools Hermes sees

Slashy exposes a large toolset. To narrow it - for example, a read-only setup that can triage but never send - use an allowlist:
Run /reload-mcp after editing. Use exclude: instead if you want everything except a few tools.

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Next steps

Using Slashy MCP

Email prompts for triage, drafting, follow-ups, and scheduling.

Slashy skill setup

Install a skill so Hermes reaches for Slashy without being told.

Troubleshooting

Fixes for OAuth, missing tools, and wrong accounts.

Slashy MCP overview

What Slashy MCP is and how it works.