Senderkit Skills MCP Server

SenderKit Skills

Add transactional email, SMS, push, and web-push notifications to any app — straight from your AI coding agent. Portable AI-agent skills for SenderKit, packaged as a plugin for Claude Code, OpenAI Codex, Cursor, and other Agent Skills-compatible coding assistants.

SenderKit sends email, SMS, push, and web-push directly, and can also route through providers like Resend, SendGrid, Postmark, Mailgun, SES, Twilio, FCM, APNs, and Expo — so your app isn't locked into one vendor. These skills let an agent wire SenderKit into your codebase and operate it at runtime over MCP.

This repository contains one senderkit plugin with three related skills:

• senderkit-integration - add SenderKit to an app, or replace/route an existing email, SMS, or push provider through it.
• senderkit-mcp-messaging-operations - send and inspect messages at runtime through the SenderKit MCP connector.
• senderkit-email-deliverability - authenticate a sending domain (SPF/DKIM/DMARC) so email reaches the inbox.

What can I ask?

You don't need to name SenderKit — these skills activate on everyday messaging requests. Examples:

Rule of thumb: integration writes SenderKit into your code; messaging operations sends and inspects messages at runtime via MCP.

Install

This repo ships per-platform metadata — Claude Code (.claude-plugin/), OpenAI Codex (.codex-plugin/), and Cursor (.cursor-plugin/) — and the authored skills under ./skills/. Pick your agent below; each path ends with a quick check so you know it worked.

Claude Code

From the marketplace (recommended):

/plugin marketplace add senderkit/senderkit-skills
/plugin install senderkit@senderkit-skills

From a local checkout (for development):

claude --plugin-dir .

This loads both skills and the SenderKit MCP server from the repo's .mcp.json (OAuth, no key stored). Run /mcp, sign in, and pick a workspace and test/live mode.

Check it works: run /mcp — the senderkit server should be connected — or ask "Use senderkit-integration to add a welcome email."

OpenAI Codex

"ChatGPT" support means Codex, OpenAI's coding agent (CLI / IDE extension / app). The ChatGPT chat app does not load skills.

Codex discovers skills from .agents/skills/ directories. Vendor the skills into your user scope (available in every repo) or a single repo's scope:

git clone https://github.com/senderkit/senderkit-skills.git
mkdir -p ~/.agents/skills
cp -R senderkit-skills/skills/senderkit-integration ~/.agents/skills/
cp -R senderkit-skills/skills/senderkit-mcp-messaging-operations ~/.agents/skills/
# repo-scoped instead? copy into <your-repo>/.agents/skills/

Restart Codex so it picks them up. Connect MCP: set SENDERKIT_API_KEY (the sk_live_/sk_test_ prefix selects mode), then either rely on the bundled .codex-plugin/mcp.json config or run senderkit mcp install --client codex.

Check it works: run /skills (the SenderKit skills should be listed) or invoke one explicitly with $senderkit-integration.

Distributing the full plugin (skills + MCP) to a team? Publish this repo as a Codex marketplace and install via codex → /plugins. See https://developers.openai.com/codex/plugins/build.

Cursor

For an individual install, load this repo as a local plugin:

git clone https://github.com/senderkit/senderkit-skills.git
ln -s "$(pwd)/senderkit-skills" ~/.cursor/plugins/local/senderkit

Reload Cursor (Developer: Reload Window). Skills show up under Settings → Rules & Skills and can be invoked with /senderkit-integration. Connect MCP: set SENDERKIT_API_KEY (the bundled .cursor-plugin/plugin.json expands it into the Authorization: Bearer ${SENDERKIT_API_KEY} header), or run senderkit mcp install --client cursor; toggle the server under Settings → MCP.

For teams, import this GitHub repo as a Team Marketplace (Dashboard → Settings → Plugins; Teams/Enterprise plans). See https://cursor.com/docs/plugins.

Check it works: type /senderkit-integration in chat, or ask "Send a test email and check its status via SenderKit MCP."

Connect the SenderKit MCP server

Installing the plugin/skills gives you the senderkit_* MCP tools. Auth differs per client:

• Claude Code — OAuth via the repo's .mcp.json. Run /mcp, sign in, pick a workspace and test/live mode. No API key is stored in the repo.
• Cursor / Codex — API key. Set SENDERKIT_API_KEY (the sk_live_ / sk_test_ prefix selects mode) before launching.

Other clients (Windsurf, VS Code, Zed, Claude Desktop) and manual config: see skills/senderkit-mcp-messaging-operations/README.md and https://docs.senderkit.com/mcp/installation. The SenderKit CLI can also write the config for you: senderkit mcp install --client cursor (or codex, claude-code, vscode, zed, all).

Skills

SenderKit Integration

Use senderkit-integration when an agent needs to modify an application: detect the stack, add SenderKit, migrate provider calls, preserve existing notification behavior, and verify the integration before live traffic.

Suggested prompt:

Use $senderkit-integration to add SenderKit transactional messaging to this project.

Claude Code plugin command:

/senderkit:senderkit-integration

SenderKit MCP Messaging Operations

Use senderkit-mcp-messaging-operations when an agent has access to the SenderKit MCP server and needs to send messages, inspect templates, check message status, or cancel pending sends through MCP tool calls.

Suggested prompt:

Use $senderkit-mcp-messaging-operations to send a test message and verify its status through SenderKit MCP.

Claude Code plugin command:

/senderkit:senderkit-mcp-messaging-operations

SenderKit Email Deliverability

Use senderkit-email-deliverability when transactional email needs to be authenticated to reach the inbox: diagnose current SPF/DKIM/DMARC with dig, generate the exact records to add, point to the SenderKit dashboard for issued values, and verify publication.

Suggested prompt:

Use $senderkit-email-deliverability to diagnose and fix SPF, DKIM, and DMARC for my sending domain.

Claude Code plugin command:

/senderkit:senderkit-email-deliverability

Repository layout

senderkit-skills/
|-- .claude-plugin/
|   |-- marketplace.json
|   `-- plugin.json
|-- .codex-plugin/
|   |-- mcp.json
|   `-- plugin.json
|-- .cursor-plugin/
|   |-- marketplace.json
|   `-- plugin.json
|-- .mcp.json
|-- AGENTS.md
|-- LICENSE
|-- README.md
|-- llms.txt
`-- skills/
    |-- senderkit-email-deliverability/
    |-- senderkit-integration/
    `-- senderkit-mcp-messaging-operations/

Official docs

• SenderKit MCP overview: https://docs.senderkit.com/mcp/overview
• SenderKit MCP tools: https://docs.senderkit.com/mcp/tools
• SenderKit OpenAPI: https://www.senderkit.com/openapi.yaml