You can handle version mismatches in Sui by always fetching the latest version of an object right before signing and submitting your transaction. Since each object has a version number that changes with every update, your transaction will fail if it references an outdated version. To avoid this, make sure your app or backend checks the current state using getObject or similar methods before building the transaction. If a conflict still occurs, you can retry the operation after refreshing the object’s version. For more complex workflows, you might consider redesigning your flow to reduce contention—like using separate objects per user or sharding state across multiple objects.

You're absolutely right to focus on version mismatches—in Sui, every object has a version that strictly increments, and mismatches are a common source of conflicts, especially when multiple users try to update the same object. Here's a breakdown of how conflicts arise and how you can design your system to handle them gracefully:

Why Version Mismatches Happen

• When a transaction is built, it references specific object versions. If another transaction modifies that object first, your transaction becomes stale and fails — typically with a ConflictTransaction or version mismatch error (sui.peera.ai, Sui Documentation).
• This is especially common with shared objects, where concurrent access is expected. Though Sui doesn't use explicit locks, it serializes updates via consensus, and conflicting transactions are rejected (sui.peera.ai, Sui Documentation).

Best Practices for Handling Version Conflicts

1. Always Fetch the Latest Version Before Submission

Make sure your client logic calls something like getObject() right before building and signing the transaction to avoid stale inputs (sui.peera.ai).

2. Implement Retry Logic (Optimistic Concurrency)

If your transaction fails due to a conflict, catch the error, re-fetch the object state, rebuild, and retry. You can even combine this with exponential backoff to manage retries gracefully (sui.peera.ai).

3. Minimize Contention with State Partitioning

Instead of putting all mutable fields in a single object, split the object into smaller sub‑objects—like per-user or per-feature children. This way, updates target independent objects, reducing the likelihood of conflict (sui.peera.ai).

4. Use Shared Objects Strategically

Shared objects support multiple writers, but high-contention writes still lead to failures. Use them only when necessary and design updates so they mostly target smaller child objects or use batching (sui.peera.ai).

5. Adopt Batching for Atomic Multi‑Object Operations

Sui’s TransactionBlock lets you bundle multiple operations or objects into a single atomic execution. This reduces the number of transactions that can conflict and ensures consistency (sui.peera.ai).

6. Avoid Equivocation with Owned Objects

If you build multiple parallel transactions using the same object version, each transaction may only reach partial consensus—resulting in equivocation, locking the object until the next epoch and causing persistent failures (docs.shinami.com, Sui Documentation).

Mitigation strategies:

• Use Sui’s ParallelTransactionExecutor from the SDK, which coordinates owned objects and avoids equivocation (Sui Documentation).
• Alternatively, pool owned objects or assign them per-thread to avoid reuse conflicts (Sui Developer Forum).

Summary Table

Example Workflow

Imagine a DAO voting scenario where multiple users cast votes concurrently:

1. Structure your vote data so that each proposal is its own shared object (or multiple smaller objects).
2. Fetch the current version of the proposal object before the user casts a vote.
3. Wrap the vote into a TransactionBlock that appends the user’s vote.
4. Submit the transaction.
5. If you encounter a ConflictTransaction, retry: re-fetch the object and re-submit.
6. Use backoff or queueing in heavy contention scenarios, or shift to an off-chain commit-reveal flow if perfect real-time accuracy isn't required.

Final Take

To gracefully handle version mismatches in Sui:

• Fetch fresh object versions right before submission.
• Use optimistic retries for conflict resolution.
• Partition state to reduce hotspots.
• Batch related operations into atomic transactions.
• Prevent equivocation by isolating owned object usage or leveraging SDK tools like ParallelTransactionExecutor.

This combination of client-side logic, data modeling, and built-in Sui tooling helps build smooth UX even under high concurrency and version churn.

Let me know your specific use case—I’d be happy to help you architect a tailored strategy!

In Sui, object versioning ensures concurrent updates don’t silently overwrite each other, so you need a strategy for handling conflicts. You can implement optimistic concurrency by catching version mismatches and prompting the client to retry with the latest object state. For high-contention objects, consider splitting state into multiple secondary objects or redesigning flows to reduce simultaneous writes. Another approach is queuing updates off-chain and applying them sequentially on-chain to avoid conflicts. Monitoring object versions and using transaction simulation via dev_inspect helps anticipate failures. You can read more here: Sui Object Versioning.

try {
    await provider.executeTransaction(tx, { gasBudget });
} catch (e) {
    if (e.code === 'VERSION_MISMATCH') {
        const latestObject = await provider.getObject(objId);
        // Update transaction with latest object version and retry
    }
}