# Pricing

> Pay once for the engines you need, or subscribe to all of them. Pay with PayPal, no account.

## One engine

- £2.99 per paid effect engine, £4.99 per paid synth, once.
- Yours for good, with updates. Ship it in as many of your plugins as you like.
- New engines are separate purchases.

## Subscriptions

- Everything: £14.99 a month, every paid engine and synth, new ones included.
- Everything, yearly: £149.99 a year, every paid engine and synth, new ones included.
- Prices include UK VAT for UK buyers (VAT invoice for every payment).
- New blocks every day: see what is coming at https://sournd.com/upcoming/index.md
- Black Friday: your first year for £49.00 (51% off), then £99.00 a year. Until 5 December 2026.
- Plugin versions you release while subscribed stay licensed if you cancel. New releases, updates and downloads need an active subscription.
- Everything costs less than one-off purchases once you need more than 5 paid engines.

## Free engines

32 free engines:

- 14 effects, Apache-2.0, free for everyone, in commercial plugins and in GPLv3 ones.
- 18 more free closed libraries (11 effects and 7 synths), free to use in your plugins (not in GPL plugins: they are closed). Every free engine downloads with no account or email: https://sournd.com/download/free/macos (macOS), https://sournd.com/download/free/linux (Linux) or https://sournd.com/download/free/windows (Windows).

## For AI agents

Use the MCP server at https://sournd.com/mcp: `get_price` quotes, `create_checkout` and `create_subscription` return a link the human approves. Agents never pay on a user's behalf.

## Questions

**Do I need an account?** No. Your email address is your account. There is no password to forget.

**How do I get the engines I paid for?** After you pay, we email you a link. It opens Your engines, where every engine you own is ready to download. Lost the email? Ask for a new link on the Your engines page at any time; each link works once, for 30 minutes.

**Is there a licence key to type in?** No. Each download is built for you, so there is nothing to activate inside your plugin.

**Can my AI buy or add engines for me?** Your AI can find, compare and add engines to your plugin using llms.txt, the JSON catalogue and our MCP server. It can start a checkout and hand you the PayPal link, but only you can pay. Free engines it can add straight away; for paid ones, download them from Your engines and point it at the folder.

**Which plan?** One-off: £2.99 an effect, £4.99 a synth, yours for good. One plan, Everything, covers every paid engine and every paid synth, new ones included: £14.99 a month or £149.99 a year.

**Do you use cookies to keep me signed in?** Only after you open an access link or pay. Then this browser keeps one signed cookie for 30 days, so engine pages can show what you own and your downloads are a click away. It holds no email and is not used for tracking. Sign out, or Sign out everywhere on Your engines, ends it.

**Do prices include VAT?** Yes. UK buyers pay 20% VAT, included in the price, and get a VAT invoice for every payment on Your engines. Outside the UK there is no UK VAT.

**What happens if I cancel the subscription?** Plugin versions you released while subscribed stay licensed. New releases, updates and downloads need an active subscription. One-off engines are yours for good either way.

**Can I use engines in commercial plugins?** Yes. Free engines are Apache-2.0. Paid engines ship as closed libraries you can put in as many of your own plugins as you like.

**Do I owe anything if I sell my plugin?** No, not for engines made by sOURnd. There is no royalty and nothing to register. Buy the engines you use, or hold a plan when you release, and what you sell is yours. Engines from other companies, when they arrive, are sold and licensed separately.

**What if I stop paying?** Every plugin or game version you released while subscribed stays licensed for good. New releases and engine updates need an active plan, so nobody can subscribe for a month, build everything and leave.

**Can I put the engines in a game?** Yes, through the C ABI: the same library, linked into your game or an audio middleware plugin (FMOD, Wwise, Unity and Unreal adapters are on the way). A game is licensed the same way as a plugin: no per-game fee and no royalty. See sOURnd for games, /games/.

**Do the engines make music?** No. Every engine is an effect on audio you supply or an instrument you play. The playing, the writing and the sound are yours.