Plugin Installation Flow

OAuth installation flow between TRMNL and your web server.

Third Party plugins use a simplified OAuth2 flow. There is no client_id or client_secret to manage — TRMNL identifies your plugin by the URLs you registered during Plugin Creation, and each installation is authorized by a single-use code.

1. Installation Request

When a user installs your plugin, TRMNL redirects their browser to your installation_url. This is a GET request, so both parameters arrive in the query string (URL-encoded):

• code — a single-use installation code, unique to this user + plugin

• installation_callback_url — the TRMNL URL you send the user back to once installation is complete (see Step 4)

GET 'https://your-server.com/your-installation-url?code=abc123&installation_callback_url=https%3A%2F%2Ftrmnl.com%2Fplugin_settings%2Fnew%3Fkeyname%3Dyour_plugin%26code%3Dabc123'

1. Fetch Access Token

Exchange the code from Step 1 for an access_token by sending a POST request to TRMNL's token endpoint. The code is the only parameter required, sent as a form-encoded body:

curl -XPOST 'https://trmnl.com/oauth/token' \
-H 'Content-Type: application/x-www-form-urlencoded' \
-d 'code=abc123'

1. Access Token

TRMNL responds with a JSON body containing the access_token. Persist this token — you'll use it as the Bearer token to authenticate the screen generation requests TRMNL sends to your server.

{ "access_token": "a1b2c3d4e5f6..." }

If the code is missing or invalid, TRMNL responds with an error body instead (note: the HTTP status is still 200):

{ "error": true, "message": "invalid code" }

1. Installation Callback

Redirect the user's browser to the installation_callback_url you received in Step 1. This GET redirect returns them to TRMNL to finish connecting the plugin.

GET '<installation_callback_url>'

1. Success Webhook

Once the user has finished installing the plugin, TRMNL sends a POST request to your installation_success_webhook_url. The request is authenticated with the user's access_token and the body is JSON.

HTTP Headers:

Authorization: Bearer <access_token>
Content-Type: application/json

Body:

{
  "user": {
    "id":5678,
    "name":"Ronak J",
    "email":"[e-mail]",
    "first_name":"Ronak",
    "last_name":"J",
    "locale":"en",
    "time_zone":"Pacific Time (US & Canada)",
    "time_zone_iana":"America/Los_Angeles",
    "utc_offset":-28800,
    "plugin_setting_id":1234,
    "uuid": "674c9d99-cea1-4e52-9025-9efbe0e30901"
  }
}

Time zone mappings are available here under "Constants:" https://api.rubyonrails.org/classes/ActiveSupport/TimeZone.html

The plugin_setting_idis useful for building a redirect URI in your own application, for example to send a user back to trmnl.com/plugin_settings/:plugin_setting_id/edit.