Hermes Devin Auth

Use Devin's SWE coding models in Hermes Agent. Sign in with your Devin account, choose a model, and start working in Hermes.

You get browser sign-in, a picker for available models, streaming responses, and support for Hermes tool calling. You do not need to install the Devin CLI.

Before you start

• Install Hermes Agent with support for hermes plugins install and model-provider plugins.
• Make sure Git is available in your terminal: git --version.
• Have a Devin account and a browser available for sign-in.

Get started

1. Install both plugins

Run both commands in your terminal, using the full paths shown:

hermes plugins install zensi-dev/hermes-devin-auth/plugins/model-providers/devin --enable
hermes plugins install zensi-dev/hermes-devin-auth/plugins/devin --enable

Both are required: devin-provider connects Hermes to Devin's models, and devin adds the sign-in and model-selection commands. Accept any dependency prompts during installation.

If you use multiple Hermes profiles, install and run the plugins in the same profile. Restart any existing Hermes sessions after installation.

2. Sign in and choose a model

hermes devin login

Complete sign-in in your browser, then return to the terminal. In an interactive terminal, the model picker opens automatically. Your selection becomes the default model for Hermes, using Devin as the provider.

If the picker does not open, run hermes devin use to choose your model.

Check that sign-in and API access are working:

hermes devin status

If the browser does not open, follow the manual sign-in steps.

3. Start using Hermes

Start a session with your selected default model:

hermes

Or give Hermes a task directly:

hermes -z "fix the tests"

Inside an existing Hermes session, use /model devin to select a Devin model.

Everyday commands

Run these in your terminal:

Command	What it does
hermes devin login	Sign in through your browser and choose a default model.
hermes devin use	Choose a different default model from the available list.
hermes devin models	List available model IDs.
hermes devin status	Check sign-in, session expiry, and API access.
hermes devin status --no-check	Check sign-in and session expiry without contacting the API.
hermes devin logout	Remove the saved browser sign-in credentials.

Inside a Hermes session, use /devin to check sign-in status or /model devin to switch models.

Sign out or change accounts

To remove your saved browser sign-in:

hermes devin logout

To use another account, sign out, then run hermes devin login and sign in with that account in your browser.

If you previously set DEVIN_API_KEY, it takes priority over your saved browser sign-in. Logout does not remove that environment variable or credentials added with hermes auth add devin; manage those separately if you use them.

Alternative installation: pinned pack

If hermes plugins pack --help is available, you can install both plugins with one command at the exact versions recorded in the pack:

hermes plugins pack install https://raw.githubusercontent.com/zensi-dev/hermes-devin-auth/main/hermes-pack.yaml

Run this in an interactive terminal and confirm the pack review and any per-plugin prompts. Successful entries are enabled. Check that both plugins installed successfully, then continue with sign-in and model selection.

If pack is unrecognized, use the two installation commands above. The pack's recorded versions may differ from the latest repository version.

Troubleshooting

Installation fails with a repository or Git error

Use the full slash-separated paths in the installation commands and check that git --version works.

A plugin already exists

Check what is installed:

hermes plugins list

If both devin-provider and devin are present, enable them:

hermes plugins enable devin-provider
hermes plugins enable devin

To replace an existing plugin, back up any edits you made inside its plugin directory, then repeat its installation command with --force. Plugin directories are normally under ~/.hermes/plugins/.

hermes devin is missing or reports a missing provider

Check that both devin and devin-provider are installed and enabled in your active Hermes profile. If only one installed successfully, fix the failed installation before signing in. Restart existing Hermes sessions afterward.

Installation reports a missing Python dependency

The provider requires httpx>=0.24,<1. Recent Hermes versions manage this dependency during installation. If your version only prints a dependency hint, update Hermes or install the dependency into Hermes' own Python environment, not an unrelated system Python.

The browser does not open or Hermes runs on another machine

Run hermes devin login in a terminal. Open the sign-in URL printed there in your browser and complete sign-in. Copy the full callback URL you are redirected to and paste it into the waiting terminal.

Your session has expired or API access fails

Run hermes devin status to see the error. If the session has expired, run hermes devin login again. If you have set DEVIN_API_KEY, check it too: it overrides the saved browser sign-in.

A pack-installed plugin will not update

Pack-installed plugins are pinned; ordinary hermes plugins update does not move their pins. To reinstall both at the pack's recorded versions, back up any edits inside their plugin directories and repeat the pack installation command with --force. This uses the versions recorded in the pack, which may differ from the latest repository version.

Still stuck?

When reporting a problem, include the command you ran, the error message, and the output of hermes --version. Remove any tokens or sign-in callback URLs before sharing.