getBlocks

getBlocks returns the list of slots that actually produced a confirmed block between a startSlot and an endSlot on Solana, the high-throughput Proof-of-Stake chain whose native token is SOL. Because Solana advances at roughly 400 ms per slot and not every slot yields a block, this method is how indexers find the real, non-empty slots to fetch rather than guessing slot numbers. The result is a plain array of u64 slot numbers; any slot in the range that is missing from the array was skipped. If you omit endSlot, it defaults to the latest slot. Call it against https://solana.therpc.io/YOUR_API_KEY as a JSON-RPC 2.0 POST, then feed each returned slot into getBlock.

Use cases

• List exactly which slots in a range produced blocks, skipping the empty slots, so you never call getBlock on a slot that has no data.
• Drive a block-by-block indexer that walks confirmed Solana slots in order, fetching each one's transactions for an explorer or analytics store.
• Detect skipped slots by diffing the contiguous range against the returned set — the missing slots are the skips, useful for validator-health monitoring.

Parameters

Response

Example request

1curl https://solana.therpc.io/YOUR_API_KEY \
2  -X POST \
3  -H "Content-Type: application/json" \
4  -d '{
5  "jsonrpc": "2.0",
6  "id": 1,
7  "method": "getBlocks",
8  "params": [
9    250000000,
10    250000010,
11    {}
12  ]
13}'

Errors & troubleshooting

Common pitfalls

• The span between startSlot and endSlot is capped (around 500,000 slots). For wider history, chunk the request into successive ranges instead of asking for the whole span at once.
• The array contains only confirmed slots. Gaps relative to the requested range are skipped slots — expected behavior on Solana, not errors to retry.

Supported networks

• Mainnet
• Devnet

See also

• getBlocksWithLimit
• getBlock
• getFirstAvailableBlock