> ## Documentation Index
> Fetch the complete documentation index at: https://docs.sync2books.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Environments & base URLs

> The Sync2Books base URL, and the difference between Development and Production credentials.

## Base URL

All API requests go to a single base URL — there is **no version path prefix**:

```text theme={null}
https://api.sync2books.com
```

Endpoints sit directly under it, for example:

* `POST /companies`
* `POST /expenses/{connectionId}`
* `GET  /sync/batches/{syncBatchId}`
* `POST /companies/{companyId}/integrations/etims/sales`

<Warning>
  Older examples that used `https://api.sync2books.com/v1/...` are **incorrect** —
  the API is not versioned with a `/v1` segment. Drop the `/v1`.
</Warning>

## Development vs Production

Each application is issued **two independent credential sets**. The environment is
encoded in the key prefix, so you can tell them apart at a glance:

| Environment     | API key prefix     | Use for                                                    |
| --------------- | ------------------ | ---------------------------------------------------------- |
| **Development** | `sk_development_…` | Building and testing. eTIMS calls hit the KRA **sandbox**. |
| **Production**  | `sk_production_…`  | Live traffic. eTIMS calls hit live KRA.                    |

Switch environments simply by swapping the API key (and client secret, if you sign
requests). Nothing else in the request changes.

<Note>
  For eTIMS specifically, the **connection** also carries an environment
  (`SANDBOX` / `PRODUCTION`) chosen when the company is provisioned. Use a
  development API key against a sandbox-provisioned company while testing.
</Note>

## Interactive API explorer

The always-current, machine-generated schema is published with the running API:

* Main API (Expenses, sync, eTIMS): `https://api.sync2books.com/api`
* OpenAPI JSON: `https://api.sync2books.com/api-json`

See the [API reference](/etims-api-reference) for the hand-written endpoint guide.