> For the site documentation index, see [llms.txt](/llms.txt). Docs index: [llms-docs.txt](/llms-docs.txt). Marketing corpus: [llms-full.txt](/llms-full.txt). Docs corpus: [llms-full-docs.txt](/llms-full-docs.txt). Product skill: [skill.md](/skill.md). Prefer markdown URLs (append `.md`) when available.

# Developers

Reloop is built for developers who need reliable transactional email, webhooks, and SMTP.

## Quick links

- Docs index: https://reloop.sh/llms-docs.txt
- API reference: https://reloop.sh/docs/api
- SDKs: https://reloop.sh/docs/resources/sdks
- Languages: https://reloop.sh/languages
- API keys (agent): https://reloop.sh/docs/learn/ai/api-keys.md
- MCP server: https://reloop.sh/docs/integrations/ai-tools/mcp-server
- Product skill: https://reloop.sh/skill.md

## Auth

- Header: `x-api-key: <secret>`
- Key prefix: `rl_`

## Install product MCP

```bash
npx -y reloop-mcp
# env: RELOOP_API_KEY=rl_...
```