@jennifer/slack

Posts messages to a Slack channel through an Incoming Webhook from a Jennifer program, as plain text or as Block Kit blocks. Replaces the slack module of Jennifer's standard library (shipped since 0.18.0, deprecated from 0.26.0, removed in 0.28.0); the API is unchanged, only the import differs.

Documentation

Install

jvc add @jennifer/slack

This vendors the deck to vendor/jennifer/slack/. Without jvc, unpack the src/ subtree of a release archive (jennifer-slack-<version>.tar.gz) there.

Usage

import "@jennifer/slack/" as slack;
import "http.j" as http;

def url as string init os.getEnv("SLACK_WEBHOOK_URL");
def r as http.Response init slack.send($url, "deploy finished");
io.printf("%d\n", $r.status);   # 200 with body "ok"; a bad webhook is 4xx, not an error

examples/post.j posts a plain and a Block Kit message.

Requirements

Jennifer 0.25.0 or newer and network access to hooks.slack.com. Posts need the default jennifer binary; the stock jennifer-tiny has no network driver.

Development

tools/check-all.sh                   # the full gate, as CI runs it
jennifer test src/slack_test.j       # the test overlay
tools/check-docs.sh                  # docs against the code
tools/pack.sh dist                   # build the release archive

Licence

LGPL-3.0-only, see LICENSE. Copyright (C) 2026 mplx <[email protected]>.

tools/check-headers.sh checks every source file's SPDX header against deck.toml.