block-kit
Slack's own Block Kit skill — and the rare vendor skill that needs no token, because it validates against Slack's public API.
Install
$ /plugin marketplace add slackapi/slack-skills-pluginNo token needed — blocks.validate is an unauthenticated public method. The same plugin adds slack-api, slack-cli, slack-docs and messaging skills.
Best for
Composing Slack messages, modals and Home tabs where hand-written Block Kit JSON is the thing that keeps breaking — it validates output against Slack rather than guessing.
Not ideal for
Actually sending the message. It generates and validates layouts; delivery is the sibling slack-api skill, which does need a token.
About this skill
Help developers build and validate Block Kit layouts for Slack messages, modals, and Home tabs. Provides authoritative block references and validates with the blocks.validate API. Use whenever the developer wants to compose Slack message layouts, build modals, forms or dialogs, design Home tab interfaces, create interactive messages with buttons or menus, modify existing Block Kit JSON, or asks about any Slack UI component. Also trigger on "blocks", "Block Kit Builder", or pasted JSON containing block structures.
Score breakdown
Score breakdown
rubric 1.0Composite 0–100 score derived from 9 verifiable signals. See the rubric →
Related skills
Twilio's official Developer Kit: 55 skills across SMS, WhatsApp, Voice, Verify, SendGrid, and compliance — plus the Twilio MCP. Public beta.
Resend's own API skill: send transactional and batch email, handle inbound webhooks, and manage domains, templates, and keys.
Resend's deliverability playbook: SPF/DKIM/DMARC, spam avoidance, bounce handling, and CAN-SPAM/GDPR/CASL compliance.
