For AI coding agents
Let your coding agent add email the right way
One command teaches Claude Code, Codex, Cursor, Copilot and other agents how Sendpository works - so the code they write keeps your key on the server, sends from a verified domain, retries without duplicates and verifies webhooks.
In short
Runnpx sendpository@latest agents in your project, or paste the prompt below into your agent. It installs the Sendpository skill - plain Markdown instructions your agent reads before it writes email code.Using an AI coding agent?
Paste this in and it sets up Sendpository the right way.
Show the promptHide the prompt
Add Sendpository email to this project. First run `npx sendpository@latest init` - it opens my browser for me to approve, saves the API key to the env file and installs the Sendpository skill - then follow the skill. If you can't run commands, read https://www.sendpository.com/agents/sendpository/SKILL.md instead.
Starting from scratch? One command
npx sendpository@latest init
It opens your browser - approve, or sign up first - and then saves your API key to .env.local or .env, makes sure git ignores it, installs the SDK and this skill, and sends you a test email where your account allows. Your agent can run it too; you just click Approve.
Only the skill
npx sendpository@latest agents
It looks at your project and writes the instructions where your agents look for them:
| Agent | Where it goes |
|---|---|
| Claude Code | .claude/skills/sendpository/ |
| Codex, Copilot, Gemini CLI and others | AGENTS.md |
| Cursor (when the project uses it) | .cursor/rules/sendpository.mdc |
Add --global to install the Claude Code skill for every project on your machine, or --dry-run to see what it would write.
What the skill teaches
- Keep SENDPOSITORY_API_KEY on the server - never in the browser, a NEXT_PUBLIC_ variable or a mobile app.
- Send from a verified domain, and what to tell you when a domain isn't verified yet.
- Use idempotency keys derived from the event, so a retried request never sends twice.
- Verify webhook signatures on the raw body, and handle bounces, complaints and opens.
- Every error type, what it means and whether to retry.
- Ready-made patterns for Next.js, Express, background jobs, serverless, Python and plain HTTP.
- Switching from Resend, SendGrid, Postmark, Mailgun, Amazon SES or Nodemailer: find every send, map the fields and webhook events, bring the suppression list over, and cut over behind a flag.
Read the files directly
For agents that fetch a URL instead of running commands:
- /agents/sendpository/SKILL.md
- /agents/sendpository/references/api.md
- /agents/sendpository/references/webhooks.md
- /agents/sendpository/references/frameworks.md
- /agents/sendpository/references/receiving.md
- /agents/sendpository/references/migrate.md
Questions
Which coding agents does the Sendpository skill work with?
Claude Code reads it as a skill from .claude/skills/sendpository. Codex, Cursor, GitHub Copilot, Gemini CLI and other agents that read AGENTS.md get a short section there pointing at the same files. Any agent that can fetch a URL can read the raw SKILL.md directly.
Does installing it change my code?
No. It only adds instruction files for your agent: .claude/skills/sendpository/, a marked section in AGENTS.md, and a Cursor rule if the project uses Cursor. Run it again to update them; nothing else in the project is touched.
Does npm install sendpository add the skill automatically?
The files ship inside the package at node_modules/sendpository/agents, but nothing is written into your project during install - install scripts that edit files are a security risk. Run npx sendpository agents once to set it up.
Can my agent move my app from another email provider?
Yes. Ask it to switch the project's email to Sendpository. The skill has a step-by-step migration guide for Resend, SendGrid, Postmark, Mailgun, Amazon SES and Nodemailer: it finds every place the app sends email, maps the fields and webhook events, and switches over behind a flag so you can move back. You add the domain and import the old provider's suppression list in the dashboard.
Is my API key sent anywhere?
No. The skill contains instructions only. It tells the agent to read your key from the SENDPOSITORY_API_KEY environment variable and never to put it in client-side code.
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