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Hermes Agent is Nous Research’s open-source, self-improving agent. It runs in the terminal, on messaging platforms and as a desktop app, and it connects to remote MCP servers such as Danube from one config file.

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Prerequisites

Install Hermes Agent (Linux, macOS, WSL2, Termux):
Windows (PowerShell):
Verify the installation:

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Setup

1

Add the Danube MCP Server

hermes mcp add registers a remote server, prompts for its credential and probes it for tools:
Answer yes when asked whether the server requires authentication, then paste your Danube API key at the API key / Bearer token prompt. Hermes writes the key to ~/.hermes/.env as MCP_DANUBE_API_KEY and sends it as Authorization: Bearer, which Danube accepts in place of the danube-api-key header.Hermes then connects, lists Danube’s tools and asks which to enable. Choose Enable all unless you want a smaller surface (see Fewer tools per session).
2

Verify Connection

The test connects and prints the tools it found. hermes mcp list shows every configured server and whether it is enabled.
3

Use it

Start a session and ask for something Danube can do:
Hermes registers MCP tools with a server prefix, so Danube’s appear as mcp__danube__search_tools, mcp__danube__execute_tool and so on. You never need to type those names; Hermes picks them during normal reasoning.

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Edit the config directly

Hermes reads MCP servers from ~/.hermes/config.yaml (%LOCALAPPDATA%\hermes\config.yaml on Windows) under mcp_servers. This block is equivalent to the CLI setup above, using Danube’s own header instead of a bearer token:
To keep the key out of the config file, reference an environment variable instead. Hermes resolves ${VAR} in headers at connect time from ~/.hermes/.env (falling back to the process environment):
If a Hermes session is already running, type /reload-mcp to reconnect with the new config. Otherwise the next hermes chat picks it up.

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OAuth instead of a pasted key

Danube’s MCP server also supports the MCP OAuth 2.1 flow with PKCE and dynamic client registration, which Hermes handles automatically:
On first connect Hermes opens your browser to Danube’s authorization page, where you enter your API key once. Tokens are cached at ~/.hermes/mcp-tokens/danube.json and refreshed automatically. On a headless host, run hermes mcp login danube and follow the printed URL, or paste the redirect URL back at the prompt.

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Coming from Claude Code?

hermes import-agent claude-code migrates the mcpServers block from ~/.claude.json (along with skills and instructions) into mcp_servers in Hermes’ config. If Danube is already connected in Claude Code, the import carries it over; credentials are never imported, so re-add the key as shown above.

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Fewer tools per session

Danube exposes 31 MCP tools and Hermes registers every enabled one at session start, which costs context. Two ways to trim the list:
  • Ask Danube for a tool group on the connection URL. ?tools=core keeps search, execute, describe, fetch_result, store_credential, report_tool and set_parameter_defaults; a comma list such as ?tools=core,workflows adds a group (skills, workflows, wallet, feedback):
  • Or filter on the Hermes side with tools.include / tools.exclude. hermes mcp configure danube reopens the interactive checklist you saw at install time.

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Troubleshooting

The installer links hermes into ~/.local/bin (/usr/local/bin when run as root). Open a new shell, or add it to your PATH:
  • Verify your API key is correct
  • For the header form, ensure the header name is exactly danube-api-key (lowercase)
  • For the hermes mcp add form, check MCP_DANUBE_API_KEY in ~/.hermes/.env holds the bare key (Hermes strips a leading Bearer on save, but a wrapped or truncated paste still fails)
  • Generate a new API key from danubeai.com/dashboard/api-keys
  • Check your internet connection
  • Verify the URL is correct: https://mcp.danubeai.com/mcp
  • Test the health check: curl https://mcp.danubeai.com/health
  • Raise connect_timeout (default 60 s) on the server entry in config.yaml
  • Run hermes mcp test danube to confirm the server connects and lists tools
  • Run hermes mcp list and check the server is not enabled: false (a failed hermes mcp add offers to save the entry disabled)
  • Type /reload-mcp in a running session after editing config.yaml
  • If you filtered tools, check tools.include in config.yaml or re-run hermes mcp configure danube
Both work. hermes mcp add always writes Authorization: Bearer ${MCP_DANUBE_API_KEY}; replace the headers block in config.yaml with danube-api-key: "${MCP_DANUBE_API_KEY}" if you prefer Danube’s native header. The key in ~/.hermes/.env stays the same.