Discover the Available Ledger Range and Backfill Blocks
A 5-step recipe with Solana. We can help you get access.
Recipe · 5 steps
Discover the Available Ledger Range and Backfill Blocks
with Solana
Establish the retained ledger window and page confirmed slots from its floor.
- Find the lowest slot for which the node can still serve a confirmed block. This is the true floor for any backfill against this endpoint.
- Read the lowest slot the node still retains in its ledger. This can differ from the first available block, and the higher of the two is the safe starting point.
- List a bounded page of confirmed slots starting at the floor. Using a limit rather than an open-ended range is what keeps a backfill from requesting more than the node will return.
- List the confirmed slots between an explicit start and end slot. Skipped slots simply do not appear, which is how an indexer learns which slots produced no block.
- Fetch the block at the first paged slot with signatures only, the cheapest form that still proves the block is retrievable before a full backfill is launched against it.
What you'll need to have ready
- pageLimit: How many confirmed slots to return when paging from the floor.
- rangeSpan: How many slots past the floor to bound the explicit start/end slot listing with.
For your developer
Arazzo workflow solana:ledger-backfill-range, 5 operations: getFirstAvailableBlock → minimumLedgerSlot → getBlocksWithLimit → getBlocks → getBlock. Specs on APIs.io.