# Environments

| Environment | Base URL | Use it for |
|---|---|---|
| Test | `https://tmstest.reconex.io` | **Where you start.** Building and testing your integration, and trying changes later |
| Production | `https://tms.reconex.io` | Live shipments, once we've set you up there (see [Going live](/going-live)) |

**Start in test.** Your first invitation is to the test environment, and every request you make while you build goes
there, with the API key you generate at your first sign-in. You get production access when you're ready to go live.

The two environments are completely separate:

- **Sign-in and keys:** you have a TMS user in each, with its own sign-in, and you generate a key in each. A test key
  never works in production, and a production key never works in test.
- **Data:** the test environment has its own customers, accounts, carriers and rates, set up for testing. Ids such as
  account and location ids can differ from production; your Reconex contact gives you the ones to use in each.
- **Shipments:** nothing created in test is tendered to a carrier or billed.

In the [API Reference](/api), the test environment is the default server; pick production only once you're live.