# Networks

> Test and Live in one account. Each settles on its own network, and the API key decides which one a request uses.

Section: About. Web page: https://docs.katara.com/about/networks/

Every organization has a Test environment and a Live environment. Live settles on Avalanche C-Chain in USDC. Test settles on Avalanche Fuji in test USDC, which has no value. The pairing is fixed: no setting moves an environment to the other network.

| | Test | Live |
|---|---|---|
| Chain | Avalanche Fuji, chain id 43113 | Avalanche C-Chain, chain id 43114 |
| Token | test USDC, no value | USDC |
| API keys | Start with `kat_test_` | Start with `kat_live_` |
| Model calls paid from | test USDC in your wallet, or the environment's test credits | USDC in your wallet, or Account Credits |
| Adding funds | The faucet: 5 test USDC a day; test credits: 5 a day from the portal | A transfer to your wallet, or Account Credits: the signup credit and card purchases |
| Explorer | `https://testnet.snowtrace.io` | `https://snowtrace.io` |

## One address for both

The API is `https://api.katara.com/v1` for Test and Live alike, and the portal at `https://platform.katara.com` holds both environments. The key decides the network: a request made with a Test key is served by providers on Avalanche Fuji and paid in test USDC, and one made with a Live key is served and paid on Avalanche C-Chain. Code that works in Test runs in Live with nothing changed but the key.

Without a key, `GET https://api.katara.com/v1/models` lists Live models and prices; `https://api.katara.com/test/v1/models` lists Test's. Each network has its own providers, so its prices are its own. The fee is the same on both.

The chat app pays from Live: your wallet on Avalanche C-Chain, or your Account Credits.

## What Test pays with

A direct model call with a Test key pays in test USDC, from your wallet's spending approval or prepaid balance on Avalanche Fuji, or with the environment's test credits. Test credits have no value, are never bought, and pay only for that environment's Test keys; Account Credits do not pay for Test calls. A key's payment method is chosen when the key is made.

Test has no managed fallback. When no provider on Avalanche Fuji is free, a request for [Katara Cortex](https://docs.katara.com/concepts/cortex.txt) gets a simulated reply: fixed text that says no model ran, marked `"simulated": true` in the reply's `katara` object and served as `katara/simulated@1`. It is paid and settled in test USDC like any reply, so the payment works end to end while Test has no capacity. A request that names a model answers `503` `no_capacity` instead; try again shortly.

An agent's Test Compute is different. Its budget pays with Account Credits, which are real money, or in test USDC on Avalanche Fuji: from your wallet ([Pay for runs from your wallet](https://docs.katara.com/products/wallet-budgets.txt)) or by x402 for each run ([Pay for an agent run](https://docs.katara.com/developers/x402.txt#pay-for-an-agent-run)). Either way the payer consents and the run's budget limits it. Simulation, the fixed scenarios a Test agent can run, is free. [Define, test and inspect an agent](https://docs.katara.com/products/runs.txt) explains the three.

Paying per request with a wallet signature and no key works on both networks: under `https://api.katara.com/v1` it pays in USDC on Avalanche C-Chain, and under `https://api.katara.com/test/v1` in test USDC on Avalanche Fuji, so you can try [x402](https://docs.katara.com/developers/x402.txt) without spending anything of value. Under `https://api.katara.com/test`, a request with a Live key is refused with `403` `wrong_environment`.

## Your wallet on both networks

Your wallet has the same address on Avalanche Fuji and Avalanche C-Chain. Its balance, its spending approval and its prepaid balance are separate on each, so approve spending once for Test and once for Live. The portal's Test/Live switch shows the selected network's balances, faucet and explorer links.

## Providers

A provider node serves one network. A Live node uses `-gateway https://api.katara.com` and a Test node `-gateway https://api.katara.com/test`, and each registers on its own network. Test jobs pay in test USDC. [Running a node](https://docs.katara.com/providers/node.txt#serve) has the commands.

## Contracts

Settlements and registrations are public. Check one on `https://snowtrace.io` for Live or `https://testnet.snowtrace.io` for Test.

### Live contracts

On Avalanche C-Chain:

| Contract | Address |
|---|---|
| Settlement | `0x7f8d1049519ddcb1cb041fb1b0df7a125e96acf3` |
| Token, USDC | `0xB97EF9Ef8734C71904D8002F8b6Bc66Dd9c48a6E` |
| Provider registry | `0xb7fbbe9ff8acab868a5a83ce149d9e857dfd5a63` |
| Bundle registry | `0xb03bf0eb60fc0d2aca442b195fd35226e3da6b53` |
| Validator registry | `0xdb3133cbf467094106f47de1c68e76d8360f4153` |

### Test contracts

On Avalanche Fuji:

| Contract | Address |
|---|---|
| Settlement | `0xca03fe30b1c3cea94530ca95f21d8a487db065c7` |
| Token, test USDC | `0xfed854555faeeca02acdb3fed90b0cd4048d3f45` |
| Provider registry | `0xeffb3d1ba71850bbd6850439be99201ef0b5458b` |
| Bundle registry | `0x04a985124b659761a5bad431b3161adc882c2a38` |
| Validator registry | `0xb9725cb45d8a9d51733489e54d76dfb262273835` |
| Faucet | `0xe66bcb6d2864d851bb282440fa3da2a82093cbf5` |

A wallet without a Katara account can claim test USDC from the faucet: call `claim()` on `0xe66bcb6d2864d851bb282440fa3da2a82093cbf5` from the wallet. It sends 5 test USDC to the caller once a day. The call needs a little Avalanche Fuji AVAX for gas.