Batch Ethereum JSON-RPC Requests Safely
Batch Ethereum JSON-RPC reads while matching responses by ID, handling individual errors and avoiding the assumption of one shared block snapshot.
Overview
When translating these concepts into an integration, keep the scope described by the wallet history api with the result. The examples in wallet transaction history and smart contract event logs show how the same distinction affects neighbouring data questions.
A JSON-RPC batch packages several requests into one transport message. It can reduce transport overhead, but it does not automatically make the calls atomic or guarantee that each method observes the same chain state.
Match IDs rather than positions
Responses can arrive in an order different from the request array. Use unique request IDs and associate each result or error with its original method and parameters. An HTTP success status does not mean every member succeeded. Bound batch size and response bytes so that one large request cannot exhaust application memory.
Worked example: two balances and an error
A batch asks for balances of A and B plus contract code for C. The response lists B first, an error for C second and A last. Positional parsing swaps wallet balances. An ID-based map produces two valid results and one explicit error. If consistency matters, all supported reads should use the same selected block reference.
Measure the actual trade-off
Test reordered responses, missing IDs, duplicate IDs and mixed method errors. Limit concurrent batches as well as calls per batch. Retry only eligible failed members under a bounded policy, preserving their original block context. Compare latency and payload size with ordinary requests; a batch is a transport option, not evidence that the underlying work is cheaper or faster.
A practical acceptance test
Return a batch response in reverse order with one method error and one missing ID. Verify that valid results map to their original parameters and that incomplete members remain explicit. Duplicate response IDs should be rejected or quarantined under a defined policy. A batch-wide HTTP success must not turn the missing member into an empty successful result.
Questions about the topic
Frequently asked questions
Does batch ordering determine response ordering?
No. Associate responses with request IDs.
Does one batch create an atomic state snapshot?
No. Pin supported reads to a shared block reference when required.
Standards & technical documentation
