@logtura/destination-slack

Logtura destination driver for Slack incoming-webhooks. Emits a Vector pipeline that coerces each matched event into Slack's expected { "text": "..." } body shape and POSTs it to the configured webhook URL.

npm install @logtura/destination-slack @logtura/core

Config

interface SlackConfig {
  webhookUrl: string;       // https://hooks.slack.com/services/T.../B.../...
  teamName: string | null;  // optional, label only
  channel: string | null;   // optional, label only
}

webhookUrl is a Slack Incoming Webhook URL. Get one at api.slack.com/messaging/webhooks: create or pick a Slack app in your workspace, enable Incoming Webhooks, click "Add New Webhook to Workspace", pick a channel. Slack returns a URL of the shape https://hooks.slack.com/services/T.../B.../....

teamName and channel are optional labels. The driver does not use them at runtime. They are useful if you want to display "which Slack workspace and channel does this sink post to?" in your own UI.

Usage

import { slackDriver } from "@logtura/destination-slack";

// Pass to generateBundle({ destinations: [slackDriver], ... }).
// In the sink, set destinationConfig to a SlackConfig.

What it emits

A pre-sink remap plus an http sink:

sink_<id>_format:
  type: remap
  inputs: [<upstream>]
  source: |-
    msg = string(.message) ?? ""
    if msg == "" { msg = "(empty .message) " + encode_json(.) }
    . = { "text": msg }

sink_<id>:
  type: http
  inputs: ["sink_<id>_format"]
  uri: "${SLACK_WEBHOOK_URL_<id>}"
  method: post
  encoding: { codec: json }
  framing: { method: newline_delimited }
  batch: { max_events: 1, timeout_secs: 5 }

The framing: newline_delimited plus max_events: 1 combo is load-bearing. Slack's incoming-webhook endpoint expects a top-level JSON OBJECT per request and 400s on a JSON ARRAY. Vector's codec: json defaults to wrapping a batch as an array, so each event has to be its own request.

The fallback if msg == "" { msg = "(empty .message) " + encode_json(.) } exists because Slack rejects { "text": "" } with no_text 400. Upstream normalizers should produce non-empty messages. This is the last line of defense.

License

Apache 2.0.