> For the complete documentation index, see [llms.txt](https://docs.nulth.xyz/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.nulth.xyz/reference/contracts.md).

# Deployed contracts

Nulth runs on **Stellar testnet (Protocol 26)**. Mainnet is intentionally held pending external review (see [Security model](/trust-and-security/security-model.md)).

## Shared infrastructure

Everyone's accounts share one verifier and one account program — you don't redeploy them, you instantiate an account against them.

| Component                           | ID / hash                                                                                  |
| ----------------------------------- | ------------------------------------------------------------------------------------------ |
| BN254 Groth16 **verifier** (shared) | `CCKBPVP7MZJOQYU44RK5MG4PA2YKV4UQ7CJMPK3OIHNFHLG5PEMNDREG`                                 |
| Account **wasm hash** (shared)      | `7170207590fce2398ba94ffdbc96282444e02897112f05c73c63af93ba847411`                         |
| Payment asset — **USDC SAC**        | `CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA` (canonical Circle testnet USDC) |
| Reference account (the hosted demo) | `CANA5QYVHNON7AV752ZRATFW2T5BMS3MU5DDPJMU5UGSR3KSH45LOGZE`                                 |

## How a new account is created

Creating a Nulth account is a single `createContractV2` (a.k.a. `createCustomContract`) that instantiates the shared wasm with a constructor:

```
__constructor(vk, policy_commitment, allowlist_root, token, admin)
```

* `vk` — the shared verification key.
* `policy_commitment`, `allowlist_root` — *your* private policy's public commitments (computed in your browser).
* `token` — the USDC SAC above.
* `admin` — your wallet (governance).

The resulting contract ID is your account. The verifier is untouched; you're adding an account, not new infrastructure.

## Costs (decoded on-chain)

|                                     |                                                                                    |
| ----------------------------------- | ---------------------------------------------------------------------------------- |
| Payment proof verify                | **34,149,591 instr · 8.537%** of the 400M budget (constant, allowlist-independent) |
| Disclosure proof verify             | ≈ **28.5M instr**                                                                  |
| One-time prover artifacts (browser) | ≈ 6.3 MB (zkey + wasm), cached                                                     |

## Verify a claim yourself

Every ID above is live — open it on [stellar.expert](https://stellar.expert/explorer/testnet). The repo's `README.md` and `ADVERSARIAL_TESTING.md` link the specific proof-authorized payment and the on-chain FAILED attack transactions.


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