# Sumly

> Sumly (https://sumly.dev) shows an indie founder's revenue and the visitors who brought it on one screen: MRR, payments, customers, churn and costs from Stripe, Paddle, Lemon Squeezy, Polar, Creem, RevenueCat, the App Store, Google Play and more, beside a cookie-light visitor count from its own site script, with each payment traced to the source of the buyer's first visit.

Sumly measures the way in and the money, never what users do inside an app. Data is per workspace; a workspace has projects (one per site or app), each with its own keys. Amounts are in euros unless a field says otherwise.

## For AI assistants (MCP)

- [MCP server](https://sumly.dev/mcp): Streamable HTTP, OAuth 2.1 sign-in (no key to copy). Works in ChatGPT, Claude, Cursor and other MCP clients. Read tools answer MRR, revenue in any period, payments, customers, plans, subscriptions, visitors, sources, ROI, funnels, retention, live visitors and setup; write tools add costs, notes, funnels, projects and provider connections. Destructive tools are marked as such and ask first.
- [Connect an assistant](https://sumly.dev/assistant): the page that shows the MCP address, connected apps and the last tool calls.
- [skill.md](https://sumly.dev/skill.md): a short guide for agents on which tool or endpoint answers what.

## HTTP API

- [API docs](https://sumly.dev/docs/api): keys, endpoints and examples.
- [OpenAPI 3.1 spec](https://sumly.dev/openapi.json): the whole API in one file.
- Read a project's numbers: `GET /api/v1/stats/overview`, `/stats/visitors`, `/stats/sources` with its read key (`rk_sumly_…`).
- Send events, costs and payments: `POST /api/v1/events`, `/costs`, `/payments` with its secret key (`sk_sumly_…`); events also take the public site key.

## Setting up

- [Install guides](https://sumly.dev/install): the site script on each framework and host.
- [Integrations](https://sumly.dev/integrations): every payment provider and app store, and what Sumly reads from each.
- [Guides](https://sumly.dev/guides)

## Optional

- [Monthly reports for the accountant](https://sumly.dev/accountant-reports)
- [Several businesses in one workspace](https://sumly.dev/multiple-businesses)
- [Live demo](https://sumly.dev/demo): the real app with made-up numbers.
- [Privacy](https://sumly.dev/privacy), [Terms](https://sumly.dev/terms), [Support](https://sumly.dev/support)