> ## Documentation Index
> Fetch the complete documentation index at: https://handbook.polar.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# Developer faq

## Testing taxes locally

To test tax calculation (Stripe-based):

1. Go to your **Stripe Sandbox** and in there go to Tax > Registrations ([https://dashboard.stripe.com/test/tax/registrations](https://dashboard.stripe.com/test/tax/registrations)).
2. Create a registration in Ireland
   1. First select the “I’ve already registered” option
   2. Then the  “Non-Union One-Stop Shop (OSS)” option  – this matches our production setup.
   3. Select “Immediately” (on when to start collecting)
   4. Then click “Close” (no need to set up filing)

You’ll now see VAT applied to EU countries!

* e.g. Ireland itself will have 23%
* Denmark and Sweden have 25%
* Greece has 24%
* Cyprus has 19%

## Speakeasy: How do I run with a local version of the API?

1. Clone the `polar-js` repository
2. In `polar-js/.speakeasy/workflow.yaml` change `https://api.polar.sh/openapi.json` to `http://127.0.1:8000/openapi.json`
3. Instal the Speakeasy CLI: [https://www.speakeasy.com/docs/speakeasy-reference/cli/getting-started](https://www.speakeasy.com/docs/speakeasy-reference/cli/getting-started)
4. Run `speakeasy run --skip-versioning` to generate the SDK locally
5. In the main polar repo, go to `clients/apps/web` and install the local dependency with `pnpm` e.g. `pnpm add "/Users/<user>/Development/polar-js"` (or whatever your local path to the `polar-js` repository is).
6. Do the same for `clients/packages/checkout`