For AI agents: The documentation index is at https://docs.digitalocean.com/llms.txt. Markdown versions of pages use the same URL with index.html.md in place of the HTML page (for example, append index.html.md to the directory path instead of opening the HTML document).

Managed Agents supports Hermes as an agent kind. Unlike the coding adapters, the Hermes gateway is a long-lived process that the sandbox template starts once and supervises there. The harness connects to that process rather than spawning an agent per turn.

You use Hermes when you want the gateway experience (long-lived, dashboard, session-per-attach) rather than a coding-agent adapter.

Hermes ships a web admin UI that starts by default, bound to loopback inside the sandbox on port 9119. doctl harness-runtime port-forward is the access path to the dashboard.

Write the Environment Spec

Create hermes-agent.yaml:

name: my-hermes-agent
agent: hermes
size: mars-2vcpu-4gb
env:
  HARNESS_INFERENCE_MODEL: "<model-name>"
secrets:
  HARNESS_INFERENCE_API_KEY: ${HARNESS_INFERENCE_API_KEY}
permissions:
  default: ask

Export the inference API key so doctl can use it in ${HARNESS_INFERENCE_API_KEY} before upload:

export HARNESS_INFERENCE_API_KEY=<your-inference-api-key>

The spec has the following fields and environment variables:

• agent (required): Must be hermes.
• HARNESS_INFERENCE_API_KEY (required): API key for the inference endpoint. Declare it under secrets, never under env. Without it, the gateway logs a warning at boot and the first turn fails.
• HARNESS_INFERENCE_MODEL (required): Model name to request from that endpoint. Non-secret.
• template (optional): Leave unset. The platform derives coding-hermes automatically.
• size, name, permissions, repos, tools, egress (optional): Same as the other coding adapters.

At boot, Harness Runtime renders the resolved model, base URL, and API key into the gateway configuration file before the gateway starts.

Validate and Start the Session

Validate the spec before you run it:

doctl harness-runtime validate --spec ./hermes-agent.yaml

The command warns when no model is configured.

Start the session:

doctl harness-runtime launch ./hermes-agent.yaml

When the session is ready, launch attaches it to your terminal. Similar to the other adapters, tool calls, reasoning output, streamed replies, human-in-the-loop approvals, and cancellation all surface through attach. Answer approval prompts in the terminal with Enter or y, or reject with n. To resolve a pending approval without attaching, run:

doctl harness-runtime approve <session-id-or-name> <request-id> approve

Replace approve with reject or defer as needed. Detach the session with Ctrl+D. The session stays alive until you pause or remove it.

To attach again after you detach, run:

doctl harness-runtime launch <session-id-or-name>

Reach the Hermes Dashboard

The Hermes dashboard is bound to 127.0.0.1:9119 inside the sandbox and is not published to the public internet. Open it with a doctl port forward in a second terminal:

doctl harness-runtime port-forward <session-id-or-name> 9119

The output looks like this:

Forwarding 127.0.0.1:9119 -> port 9119 in session <session-id>
Ready. Press Ctrl-C to stop.

Then, open http://127.0.0.1:9119 in a browser. The dashboard is bound to loopback inside the sandbox, so the tunnel is the only way in and nothing is published to the internet. Keep the port-forward command running while you use the dashboard. Stop it with Ctrl+C.

For remap options, bind address, and commands, see Forward Sandbox Ports.

Troubleshoot Hermes Sessions

Use this table to diagnose common Hermes errors: