Going to production

What changes between sandbox and production: the host, the key prefix, KYB, which features only exist in sandbox, and the operating hours of each settlement scheme.

Host and key prefix

Surface

Sandbox

Production

API host

https://api-sandbox.nuvante.iohttps://api.nuvante.io

Portal

https://sandbox.nuvante.iohttps://app.nuvante.io

API key prefix

nvt_sandbox_nvt_live_

A sandbox key can't call the production API. The engine rejects any key whose prefix doesn't match the environment.

KYB and access

You get sandbox access as soon as you apply (see Onboarding). Production access needs a completed Know Your Business review on the same application. Your Nuvanté account team starts the KYB review once your sandbox integration has been accepted. There's no self-serve route to production.

When KYB passes, we set up a production organisation and issue your production credentials. The API surface and auth model stay the same, and only the host and key prefix change.

Features that only exist in sandbox

These features only work while the sandbox mock settlement adapter is enabled. In production they return 503 sandbox_unavailable:

Surface

Reason

POST /api/v1/conformance/run

Conformance arming requires the sandbox simulated-issuer mock. Real issuers control their own outcomes.

PUT /api/v1/admin/sandbox/transactions/:id/simulated-issuer-outcome

Nuvanté-ops sandbox override tool.

Sandbox agent endpoints (/api/v1/sandbox/agents/*)

Simulated agent interactions. Production agents use real mandate flows.

Reserve proof endpoints

Reserve proofs run on the sandbox simulated ZK verifier. Production proof implementation is pending (DECISIONS.md D-6).

Mainnet chain details

Chain	Sandbox cluster	Production network	Finality
Stellar	`testnet`	Stellar Public (mainnet)	Deterministic
Polygon	`Amoy (80002)`	Polygon Mainnet (137)	Probabilistic
Solana	`devnet`	mainnet-beta	Probabilistic
Canton	n/a	Talk to Nuvanté	Deterministic

Settlement scheme operating hours

Chains settle around the clock. RTGS settlement only happens while the relevant central-bank scheme is open. If a transaction reaches the RTGS step while the scheme is closed, it waits in EarmarkSubmitted or SettleSubmitted and carries on once the scheme reopens. That's normal behaviour.

Scheme	Currency	Operating hours	Status
Bank of England Synchro	GBP	Mon–Fri, standard BoE hours (exact cut-offs to be confirmed by ops)	Live
Fedwire Funds Service	USD	Mon–Fri 21:00–18:30 ET, with a maintenance gap	Live
ECB TARGET2	EUR	Mon–Fri 07:00–18:00 CET, closed on ECB holidays	Live
HKMA CHATS	HKD	To be confirmed by ops	Design
MAS MEPS+	SGD	To be confirmed by ops	Design
RBA RITS	AUD	To be confirmed by ops	Design

What the sandbox simulated issuer doesn't cover

In sandbox, a configurable simulated adapter (SimulatedIssuerAdapter) stands in for the issuer gateway. Before you go live, make sure you've done the following:

Tested your real custody path, with your wallet, signing and on-chain lock confirmed on the production chain.
Set up your mainnet chain account using the chain guides.
Completed credential exchange with Nuvanté (an mTLS certificate for issuers, a production API key for participants).
For Mode 3 issuers: implemented the refund endpoint and tested the recovery-status resource.