Notification providers | Anjana Data Documentación

Hermes supports sending notifications to 4 external providers. Each notification has configured in the database which providers should receive it. The platform dispatches asynchronously and independently to each enabled provider.

Provider	Type	Mechanism
Email	Email	JavaMailSender (SMTP)
Google Chat	Corporate messaging	Webhook HTTP
Slack	Team messaging	Webhook HTTP
Microsoft Teams	Corporate messaging	Power Automate Webhook

1. Configuration in application.yaml

1.1 Google Chat

YAML

anjana:
  messaging:
    google-chat:
      webhook-url: https://chat.googleapis.com/v1/spaces/XXXXXXXXX/messages?key=YYYYYYY&token=ZZZZZZZ

How to obtain the Webhook URL:

Open the target Google Chat Space
Click on the Space name → Apps & integrations
Add webhooks → Assign a name → Save
Copy the generated URL (includes key and token as query parameters)

1.2 Slack

YAML

anjana:
  messaging:
    slack:
      webhook-url: https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXX

How to obtain the Webhook URL:

Go to api.slack.com/apps → Create New App
Incoming Webhooks → Enable → Add New Webhook to Workspace
Select the target channel → Allow
Copy the generated Webhook URL

1.3 Microsoft Teams

YAML

anjana:
  messaging:
    teams:
      webhook-url: https://TENANT.webhook.office.com/webhookb2/XXXXXXXX@YYYYYYYY/IncomingWebhook/ZZZZZZZZ/WWWWWWWW

Important note: Teams has deprecated Office 365 Connectors. It is mandatory to use Power Automate with the "Post to a channel when a webhook request is received" connector.

How to configure with Power Automate:

In Teams, go to the target channel → ... → Workflows
Search for "Post to a channel when a webhook request is received" → Add workflow
Name the flow → Next → copy the generated webhook URL

1.4 Email (SMTP)

YAML

spring:
  mail:
    host: smtp.example.com
    port: 587
    username: notifications@example.com
    password: ${MAIL_PASSWORD}
    properties:
      mail.smtp.auth: true
      mail.smtp.starttls.enable: true
    from: notifications@anjanadata.com

1.5 HTTP Timeouts (all webhook providers)

YAML

anjana:
  messaging:
    connectTimeoutSeconds: 10   # Maximum time to establish connection
    readTimeoutSeconds: 30      # Maximum time waiting for response
    writeTimeoutSeconds: 10     # Maximum time sending the request

1.6 Full configuration example

YAML

anjana:
  messaging:
    connectTimeoutSeconds: 10
    readTimeoutSeconds: 30
    writeTimeoutSeconds: 10
    google-chat:
      webhook-url: https://chat.googleapis.com/v1/spaces/XXXXXXXXX/messages?key=YYYYYYY&token=ZZZZZZZ
    slack:
      webhook-url: https://hooks.slack.com/services/T00000000/B00000000/XXXXXXXXXXXX
    teams:
      webhook-url: https://TENANT.webhook.office.com/webhookb2/XXXXXXXX/IncomingWebhook/ZZZZZZZZ
  

spring:
  mail:
    host: smtp.gmail.com
    port: 587
    username: notifications@anjanadata.com
    password: ${MAIL_PASSWORD}
    properties:
      mail.smtp.auth: true
      mail.smtp.starttls.enable: true
    mail:
    from: notifications@anjanadata.com

2. Database Configuration

The external_sending field of the hermes.notification table controls which providers receive each type of notification. It is a comma-separated list of values.

2.1 Possible values

Value	Provider
`EMAIL`	Email
`SLACK`	Slack
`MICROSOFT_TEAMS`	Microsoft Teams
`GOOGLE_CHAT`	Google Chat

2.2 Query current configuration

SQL

SELECT
    notification_code,
    subject,
    severity,
    external_sending
FROM hermes.notification
ORDER BY notification_code;

3. Format of sent messages

Each provider receives the message in a specific format automatically generated by Hermes. The subject and body are resolved via the translation keys (translation_key) configured in each notification, in all languages active on the platform.

3.1 Google Chat

JSON

{
  "text": "Notification subject
Full notification body"
}

3.2 Slack

JSON

{
  "text": "**Notification subject**
Full notification body"
}

3.3 Microsoft Teams (Adaptive Card)

JSON

{
  "type": "message",
  "attachments": [{
    "contentType": "application/vnd.microsoft.card.adaptive",
    "content": {
      "$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
      "type": "AdaptiveCard",
      "version": "1.2",
      "body": [
        { "type": "TextBlock", "text": "Notification subject", "weight": "Bolder" },
        { "type": "TextBlock", "text": "Notification body", "wrap": true }
      ]
    }
  }]
}

3.4 Email

HTML email sent to the recipients configured in the notification, with the body built in all languages active in the installation.

4. Asynchronous execution pools

Each provider uses its own thread pool so as not to block the main thread. They are configurable in application.yaml:

YAML

anjana:
  hermes:
    mail-pool:
      pool-size: 5
      core-pool-size: 2
      queue-capacity: 100
    slack-pool:
      pool-size: 3
      core-pool-size: 1
      queue-capacity: 50
    teams-pool:
      pool-size: 3
      core-pool-size: 1
      queue-capacity: 50
    google-chat-pool:
      pool-size: 3
      core-pool-size: 1
      queue-capacity: 50

Parameter	Description
`pool-size`	Maximum number of concurrent threads for that provider
`core-pool-size`	Threads always active (even if there are no messages)
`queue-capacity`	Messages queued before starting to reject

5. Sending flow

Workflow event (task created, assigned, completed...)
       ↓
NotificationService.dispatchToProviders()
       ↓
   For each provider configured in external_sending:
       ├── EMAIL           → EmailService        (mailPoolTaskExecutor)
       ├── SLACK           → SlackService        (slackPoolTaskExecutor)
       ├── MICROSOFT_TEAMS → TeamsService        (teamsPoolTaskExecutor)
       └── GOOGLE_CHAT     → GoogleChatService   (googleChatPoolTaskExecutor)
                                  ↓
                        POST webhook / SMTP send

The providers are invoked in parallel and asynchronously, so a failure in one provider does not block or affect the others.

6. Verification and troubleshooting

6.1 Verify connectivity with curl

Bash

# Google Chat
curl -X POST \
  "https://chat.googleapis.com/v1/spaces/XXXXXXXXX/messages?key=YYYYYYY&token=ZZZZZZZ" \
  -H "Content-Type: application/json" \
  -d '{"text": "Connectivity test from Anjana Data"}'

# Slack
curl -X POST https://hooks.slack.com/services/T00000000/B00000000/XXXX \
  -H "Content-Type: application/json" \
  -d '{"text": "Connectivity test from Anjana Data"}'

6.2 Relevant logs in Hermes

The services log errors at ERROR level when sending fails:

ERROR c.a.h.googlechat.service.GoogleChatService - Error sending message to Google Chat
ERROR c.a.h.slack.service.SlackService          - Error sending message to Slack
ERROR c.a.h.teams.service.TeamsService          - Error sending message to Teams
ERROR c.a.h.email.service.EmailService          - Error sending email notification

6.3 Common issues

Symptom	Probable cause	Solution
Messages are not arriving in Google Chat	Webhook URL expired or incorrect	Regenerate the webhook in the Google Chat Space
401 error in Slack	Token revoked	Recreate the app/webhook in Slack
Teams is not receiving messages	Office 365 Connectors connector deprecated	Migrate to Power Automate
Timeout on send	`readTimeoutSeconds` too low	Increase the value (recommended: 30s)
Field `external_sending` is NULL	Notification with no providers configured	Update it in the Administration Panel with the desired providers
Duplicate messages	Pool misconfigured with multiple workers	Check `core-pool-size` and `queue-capacity`

Product Team · Anjana Data