Mattermost — CyberCLI notification channel

Self-hosted Slack alternative. Incoming webhook to your own server.

Where to get it

Your self-hosted Mattermost server + an incoming webhook URL.

Install / what you need

No install here — you need an incoming webhook from your Mattermost server.

How to connect

1 Create an incoming webhook in your Mattermost server.
2 Dashboard → Notifications → Add destination → mattermost, paste the webhook URL.
3 Send test.

When you'd use it

SOC ops in a self-hosted team chat.

Slack-shaped workflow without the cloud.

MSP shared server.

What Herald sends through this channel

2 setup fields

Herald hands every alert to the MattermostAdapter as a DispatchPlan. The fields below are what the dashboard form asks for; the sample is the plan the adapter receives. The adapter renders it into the channel-native shape (Discord embeds, Teams MessageCards, PagerDuty Events-API payloads, TwiML, JSON POST bodies) on the way out — that wire transcript varies per channel.

Setup form fields

field	type	required	description / default
webhook_url	string	required	Mattermost incoming webhook URL (Integrations → Incoming Webhooks)
timeout_seconds	number	optional	no description · default: 10

Sample DispatchPlan (input to the adapter)

{
  "decision_id": "tdc-2026-06-20-abc12",
  "channel": "<channel-type>",
  "recipient": {
    "recipient_id": "soc-oncall",
    "display_name": "SOC on-call",
    "addresses": [
      {
        "channel": "<channel-type>",
        "address": "<destination>",
        "min_defcon": 5
      }
    ]
  },
  "urgency": "high",
  "retry_policy": {
    "max_attempts": 3,
    "initial_backoff_seconds": 5
  },
  "subject": "Suspicious login on CEO-LAPTOP",
  "body": "Warden flagged a PowerShell child of WINWORD.EXE. The encoded command resolved to a base64-wrapped Invoke-WebRequest to a newly-registered domain. Trust ladder: L3.",
  "approval_link": "https://app.cybercli.local/approve/abc12",
  "incident_ref": "case-2026-0142",
  "signal_id": "sig-2026-06-20-9f3"
}

Sovereignty: byo_external · Min tier (BYO): free · Self-hosted Slack alternative; Slack-compatible incoming webhook.

Sovereignty

Posts go to your Mattermost server; nothing routes through us.

Who notifies through it

Herald — the Guild's voice role — routes alerts, daily digests, and AI verdicts here, on a per-CYCON-state matrix you control. CYCON 1/2 alerts repeat until an operator acks.

The Guild →

Other Chat channels

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