> ## Documentation Index
> Fetch the complete documentation index at: https://docs.senderkit.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Add SenderKit from your coding agent
> Install the SenderKit skills plugin so Claude Code, Codex, or Cursor can wire SenderKit into your app and operate it over MCP.
[SenderKit Skills](https://github.com/senderkit/senderkit-skills) is an open-source
plugin that teaches an AI coding agent how to work with SenderKit. Install it once and
your agent can add transactional email, SMS, push, and web-push to your codebase — and
send, inspect, and manage messages at runtime — without you spelling out the API every
time.
It's portable: the same plugin runs in [Claude Code](https://code.claude.com), OpenAI
[Codex](https://developers.openai.com/codex), [Cursor](https://cursor.com), and other
[Agent Skills](https://code.claude.com/docs/en/skills)-compatible assistants.
This is different from the two other AI integrations in these docs. The
[MCP server](/mcp/overview) is the *connection* an agent calls SenderKit through;
the [AI-agent guide](/guides/ai-agent) gives *your own app's* agent a send tool. The
**skills plugin** is the layer that makes a *coding* agent good at both — it ships the
know-how, and bundles the MCP server so runtime sends work out of the box.
## The two skills
The plugin contains one `senderkit` plugin with two skills. They split along a single
line: **does the agent change your code, or operate SenderKit at runtime?**
**Writes SenderKit into your app.** Detects your stack, adds SenderKit behind a small
local wrapper, migrates an existing provider (Resend, SendGrid, Postmark, Mailgun,
SES, SMTP, Twilio, FCM, APNs, Expo) or routes through it, and verifies in test mode
before live traffic.
**Operates SenderKit at runtime over [MCP](/mcp/overview).** Sends templated or raw
messages, lists and inspects [messages](/concepts/messages), drafts
[templates](/concepts/templates), and cancels pending sends — without touching code.
You don't have to name the skills — they activate on everyday messaging requests.
| You ask | Skill that helps |
| ------------------------------------------------------------- | ------------------------------------ |
| "Add a welcome email when a user signs up" | `senderkit-integration` |
| "Set up SMS OTP / verification codes" | `senderkit-integration` |
| "Add push notifications to this project" | `senderkit-integration` |
| "Switch my email provider to SenderKit (or route through it)" | `senderkit-integration` |
| "Send a test email and check its delivery status" | `senderkit-mcp-messaging-operations` |
| "Why did this message fail? Cancel that scheduled send" | `senderkit-mcp-messaging-operations` |
## Install
Install from the marketplace:
```text theme={null}
/plugin marketplace add senderkit/senderkit-skills
/plugin install senderkit@senderkit-skills
```
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.
Developing against a local checkout instead:
```bash theme={null}
claude --plugin-dir .
```
**Check it works:** run `/mcp` — the `senderkit` server should be connected — or ask
*"Use senderkit-integration to add a welcome email."*
Codex discovers skills from `.agents/skills/` directories. Vendor the skills into your
user scope (every repo) or a single repo's scope:
```bash theme={null}
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 /.agents/skills/
```
Restart Codex so it picks them up. Then connect MCP with an API key — set
`SENDERKIT_API_KEY` (the `sk_live_` / `sk_test_` prefix selects mode), or run
`senderkit mcp install --client codex`.
**Check it works:** run `/skills` (the SenderKit skills should be listed) or invoke
one explicitly with `$senderkit-integration`.
Load the repo as a local plugin:
```bash theme={null}
git clone https://github.com/senderkit/senderkit-skills.git
ln -s "$(pwd)/senderkit-skills" ~/.cursor/plugins/local/senderkit
```
Reload Cursor (**Developer: Reload Window**). Skills appear under **Settings → Rules &
Skills**. Then connect MCP with an API key — set `SENDERKIT_API_KEY` (the `sk_live_` /
`sk_test_` prefix selects mode), or run `senderkit mcp install --client cursor`, and
toggle the server under **Settings → MCP**.
**Check it works:** type `/senderkit-integration` in chat, or ask *"Send a test email
and check its status via SenderKit MCP."*
Installing the plugin gives you the `senderkit_*` MCP tools, but auth differs by client:
**Claude Code** uses OAuth (no key stored); **Codex** and **Cursor** use an API key via
`SENDERKIT_API_KEY`. For every other client, manual config, and self-hosting, see
[MCP installation](/mcp/installation). Start with an `sk_test_` key so a coding agent
can't send to real people until you trust it.
## What's next
The connection the messaging-operations skill rides on — tools and modes.
Connect the MCP server in any client, including manual config.
The other direction — give your app's own agent a send tool.
Every tool the messaging-operations skill can call.