Title: What is the best way to implement reliable Stellar RPC integration and transaction simulation in Stellar DevKit?

[Ayinkx01]

Question:

What architecture would you recommend for implementing a robust Stellar RPC client in Stellar DevKit that supports live network interaction, transaction simulation and submission?

I'm particularly interested in:

1. How should the SDK manage connections to different Stellar RPC endpoints?
2. How should it handle network selection, authentication and RPC errors?
3. How can transaction simulation be integrated before transaction submission?
4. How should the SDK handle transaction status polling and failed submissions?
5. What is the best way to make the RPC layer testable without depending entirely on live Stellar networks?

How can we design this so developers get a reliable and consistent experience across Stellar testnet and mainnet?

[Ayinkx]

I would implement the RPC integration as a transport-independent client with a clear separation between network configuration, request handling, transaction simulation and transaction lifecycle management.

1. RPC transport layer

Create a dedicated RPC client responsible for JSON-RPC communication. It should support configurable endpoints, request timeouts, structured errors and controlled retries.

Avoid embedding endpoint URLs directly into contract or transaction logic.

2. Network configuration

Provide explicit network profiles for:

• Stellar Testnet.
• Stellar Mainnet.
• Local development environments.

Each profile should define its RPC endpoint, network passphrase and configuration requirements. Credentials should be handled securely rather than hardcoded.

3. Transaction simulation

Before submission, the SDK should:

• Construct and validate the transaction.
• Request simulation from the RPC endpoint.
• Inspect simulation results and diagnostic information.
• Apply the returned resource information and required authorization data.
• Prepare the transaction for signing and submission.

Simulation should not be treated as a guarantee that a transaction will succeed on-chain because ledger state can change before execution.

4. Submission and status tracking

After signing, submit the transaction through the RPC client. Handle pending, successful and failed states explicitly.

Provide bounded polling with configurable intervals and clear timeout errors. Preserve transaction hashes and diagnostic information for troubleshooting.

5. Error handling

Use structured error types for network failures, invalid requests, simulation failures, rejected transactions and expired polling windows.

Retry only operations that are safe to retry, and avoid blindly resubmitting transactions.

6. Testing strategy

Use mocked RPC responses for deterministic unit tests, local integration environments where available, and a smaller set of live testnet integration tests.

Test network failures, malformed responses, simulation errors, transaction timeouts and successful submissions.

My recommendation: Build the RPC transport and network configuration first, then add simulation, submission and lifecycle tracking as separate modules. This creates a maintainable foundation for the rest of Stellar DevKit.