Sui Testnet RPC & gRPC: Endpoint, Faucet & Developer Setup

Sui Testnet gRPC-First Access and Legacy JSON-RPC

OnFinality's Sui testnet access is gRPC-first. The current integration path uses the Sui protobuf services LedgerService, StateService, TransactionExecutionService, and SubscriptionService. They cover checkpoint queries, object and balance reads, transaction simulation and execution, and streaming subscriptions for checkpoints, transactions, and events.

Legacy Full Node JSON-RPC is still present in some existing tooling, but it should be treated as a migration surface. Do not build new testnet workflows around JSON-RPC; instead, map legacy methods to the equivalent gRPC workflow before committing testnet code.

• Use LedgerService, StateService, TransactionExecutionService, and SubscriptionService for new Sui Testnet integration.
• Treat Full Node JSON-RPC as legacy and migration-only, not as the main implementation path.
• Map existing JSON-RPC calls to gRPC methods before expanding testnet code.

Testnet Endpoint and Credential Configuration

OnFinality provides a managed gRPC endpoint for Sui Testnet. You will receive an endpoint URL and an API token or equivalent credential. Store these in environment variables or a secrets manager. Do not hard-code credentials in repositories.

The following grpcurl example uses placeholders. Replace GRPC_ENDPOINT and ONFINALITY_API_TOKEN with your assigned values. The list command is a grpcurl reflection helper; after importing the Sui protobuf definitions, call the relevant method from LedgerService, StateService, TransactionExecutionService, or SubscriptionService.

Using the Official Sui Faucet Safely

The official Sui Testnet faucet is at https://faucet.sui.io. Always verify the current faucet policy, per-address limits, and cooldown periods before integrating it into automated tests. Request test SUI to a wallet address you control, and never request tokens for addresses you do not own.

Test SUI has no value and cannot be exchanged for mainnet assets. If you have unused test tokens, return them to the faucet's return address to keep the testnet healthy. Keep testnet and mainnet faucet usage separate.

• Use only https://faucet.sui.io for official test SUI.
• Verify current faucet limits and cooldowns before CI runs.
• Keep test SUI separate from mainnet SUI; do not use test addresses for production.
• Return unused test tokens when possible.

Move Deployment, Object Reads, and Transaction Workflows

Sui is object-centric, so your testnet workflow should center on object reads, transaction simulation, and execution. Use StateService to query objects and balances before building a transaction. Use TransactionExecutionService for SimulateTransaction to dry-run a transaction, then use ExecuteTransaction for the final submission. This two-step pattern helps catch Move type errors, object version conflicts, and gas estimation issues without advancing chain state.

Record the transaction digest after execution and query the resulting object changes to verify state transitions.

• Query owned objects and balances with StateService before building a transaction.
• Call SimulateTransaction from TransactionExecutionService to validate gas, object versioning, and Move logic.
• Use ExecuteTransaction from TransactionExecutionService for final submission.
• Record the transaction digest and query the resulting object changes.

Checkpoints and Real-Time Subscriptions

Checkpoints provide a stable chain boundary for indexing and syncing. Query checkpoint sequence numbers and checkpoint data through LedgerService. For streaming updates, use SubscriptionService with SubscribeCheckpoints, SubscribeTransactions, or SubscribeEvents.

Design your client to handle reconnects and backpressure. Testnet resets can interrupt streams, and subscription clients should be able to re-establish sessions automatically.

• SubscribeCheckpoints for checkpoint boundaries.
• SubscribeTransactions for transaction-level streaming.
• SubscribeEvents for event filtering and structured updates.
• Handle reconnects and resets in subscription clients.

Wallet, SDK, and CI Configuration

Wallets and SDKs should be pointed at the managed gRPC endpoint you were assigned. In CI, inject the endpoint and credential via environment variables, and never commit secrets. Use a stage or test job that targets Sui Testnet with a test-only account. Keep mainnet configuration in a separate profile.

The following environment example uses placeholders for CI. Replace the values with your secure store references.

Testnet Limits, Resets, and Operational Checks

Sui Testnet is not permanent and may reset. Endpoints and data can be wiped or changed. Do not treat testnet objects, transaction digests, or faucet balances as durable. Verify current faucet policy before relying on it. Monitor your request usage, handle rate limit responses gracefully, and keep testnet credentials isolated from production.

Migration Path to Sui Mainnet

After your Sui Testnet workflow passes, plan a separate mainnet rollout. Use the mainnet gRPC endpoint and credentials from OnFinality; never reuse testnet tokens, addresses, or object digests. Re-run the same simulation and execution checks with mainnet gas costs.

Review the Sui network pages at /networks/sui-testnet and /networks/sui for current endpoint details and provider guidance. For provider evaluation criteria, see /rpc-assistant/sui-rpc-providers.

Next steps: Sui gRPC Guide.

• Provision separate mainnet credentials and endpoints.
• Re-validate Move packages and transaction flows against mainnet state.
• Use the same gRPC workflow but with mainnet-specific limits and monitoring.
• Do not carry testnet assumptions into production.

Frequently Asked Questions