Sanity import transaction size limits?

Based on the documentation I've reviewed, here's what you need to know about transaction size limits for @sanity/import:

Transaction Size Limits for @sanity/import

While the @sanity/import package doesn't have explicitly documented transaction size limits in its own documentation, there are important API-level limits you need to be aware of:

Key Limits:

1. Maximum mutation request body size: 4 MB - This is the critical limit for transactions. When importing data, the @sanity/import tool batches mutations into transactions, and each transaction request cannot exceed 4 MB.

2. Maximum request body size: 100 MB - This applies to the overall HTTP request, but mutation requests specifically are limited to 4 MB.

3. Maximum mutation rate: 25 requests/second - Rate limiting per IP address.

4. Maximum concurrent mutations: 100 - Per dataset concurrency limit.

How @sanity/import Handles This:

According to the importing data documentation, when using client libraries (which @sanity/import uses under the hood):

• Multiple mutations per transaction: It's recommended to batch multiple mutations within a single transaction, but you must ensure the request size stays within the 4 MB limit.
• Automatic batching: The CLI import tool has built-in abstractions that automatically batch mutations into transactions to avoid rate limits.
• Visibility mode: Using deferred visibility (instead of sync) makes imports faster, as it doesn't wait for documents to be searchable before returning.

Best Practices:

1. Keep individual transaction payloads well under 4 MB
2. Use the official CLI tool (sanity dataset import) which handles batching automatically
3. If writing custom import scripts, implement proper batching and concurrency control (the docs recommend using libraries like p-queue with a concurrency of 1 request per 40ms, or 25 req/s)
4. Monitor your request sizes, especially when importing documents with large content or many references

The 4 MB mutation request limit is the main constraint you'll encounter with @sanity/import transactions. The tool handles this automatically by batching your imports appropriately, but if you're building custom import logic, you'll need to manage this yourself.