Finalized and recent data - SQD Documentation

Portal treats finalized and recent blocks differently:

A finalized block has met the finality rule used by the dataset.
A recent block may not have met that rule. A chain reorganization can replace it and any later blocks built on it.

Portal provides two stream operations:

Operation	Data returned	Reorg handling
`POST /datasets/{dataset}/stream`	Finalized history and, when available, recent unfinalized blocks	Send `parentBlockHash` when resuming and handle HTTP 409
`POST /datasets/{dataset}/finalized-stream`	Finalized blocks only	The stream does not include unfinalized blocks

Use /stream when the client needs blocks close to the chain head. Because those blocks can change, clients that continue a standard stream must account for chain reorganizations. Use /finalized-stream when the client does not need the latest unfinalized blocks. It returns less recent data because finalization happens after a block is first produced. The head operations report the latest block visible through each view:

GET /datasets/{dataset}/head
GET /datasets/{dataset}/finalized-head

For the meaning of a reorganization and links to the chain-specific recovery procedures, continue with Blockchain forks. The complete endpoint details are in the EVM API guide and Solana API guide.