# Address Lookup Tables > Address Lookup Table queries through getProgramAccounts and getProgramAccountsV2, answered from an in-memory index, with plan rates, account layout and filters. Source: https://docs.constant-k.com/rpc/address-lookup-tables/ Address Lookup Tables are found and read in bulk with `getProgramAccounts` or `getProgramAccountsV2` on the Address Lookup Table program. ## Access Queries go through [`getProgramAccounts`](https://docs.constant-k.com/rpc/http/getprogramaccounts/) or [`getProgramAccountsV2`](https://docs.constant-k.com/rpc/http/getprogramaccountsv2/) with `AddressLookupTab1e1111111111111111111111111` as the first parameter. The endpoint and the API key are the same as every other Solana RPC call. There is no separate method, hostname or add-on. | Plan | Availability | | :------------------ | :-------------------------------------------------------------------------------------------------------------------------------------------- | | Blade Runner, Nexus | Served | | Free, Operator | HTTP `403`, code `-32600`, message `getProgramAccounts requires higher tier`. The `getProgramAccountsV2` message names `getProgramAccountsV2` | Answers come from an in-memory index, not a disk scan. No filter is required, and the 256 MB scan-results cap of a disk scan does not apply. Batch requests (a JSON array of calls) are not served: one call per HTTP request. ## Rate limits | Plan | Calls per second per API key | | :------------- | :--------------------------: | | Blade Runner | 25/s | | Nexus | 75/s | | Free, Operator | — | The budget is shared per API key. Address Lookup Table queries count together with every other `getProgramAccounts` and `getProgramAccountsV2` call on that key, whichever program they address. A Nexus key sending 50 calls per second against other programs has 25 calls per second left for table queries. There is no cap on open requests; only the rate is counted. The plan's total requests-per-second limit also applies. See [Plans & Limits](https://docs.constant-k.com/get-started/plans-and-limits/). Over the rate, the response is HTTP `429` with code `-32005` and the message `Rate limit exceeded (gpa: 25/sec)` on Blade Runner or `Rate limit exceeded (gpa: 75/sec)` on Nexus. It carries no `Retry-After` header and no rate-limit headers. The window is one whole second. See [Gateway errors](https://docs.constant-k.com/rpc/errors/#gateway-errors). ## One known table A table whose address is already known is read with [`getAccountInfo`](https://docs.constant-k.com/rpc/http/getaccountinfo/) or [`getMultipleAccounts`](https://docs.constant-k.com/rpc/http/getmultipleaccounts/) with `encoding: "jsonParsed"`. That is a plain account read: it is not an index query and does not count against the `getProgramAccounts` budget. `getProgramAccounts` on the Address Lookup Table program is for finding tables by content (authority, size, addresses, status) or for walking all tables. ## Account layout | Offset | Size | Field | Notes | | :----- | -----: | :--------------------------- | :------------------------------------------------------------------------------------- | | 0 | 4 | `type` | u32 little-endian; `1` = lookup table | | 4 | 8 | `deactivationSlot` | u64 little-endian; `18446744073709551615` (all bytes `0xFF`) while the table is active | | 12 | 8 | `lastExtendedSlot` | u64 little-endian | | 20 | 1 | `lastExtendedSlotStartIndex` | u8 | | 21 | 1 | authority present | `1` = has an authority, `0` = frozen | | 22 | 32 | `authority` | public key | | 54 | 2 | padding | | | 56 | 32 × N | `addresses` | N stored addresses, at most 256 | Account size is `56 + 32 × N` bytes. A table with 4 addresses is 184 bytes. ## Filters | Goal | Filter | | :---------------------------------------- | :-------------------------------------------------------------------------- | | Tables controlled by an authority | `memcmp` at offset 22, `bytes` = the authority public key (base58) | | Tables with an authority set (not frozen) | `memcmp` at offset 21, `bytes: "2"` (base58 of the single byte `0x01`) | | Active tables only | `memcmp` at offset 4, `bytes: "jpXCZedGfVQ"` (base58 of eight `0xFF` bytes) | | Tables holding exactly N addresses | `dataSize: 56 + 32 × N` | | Tables whose address at index i is X | `memcmp` at offset `56 + 32 × i`, `bytes` = X | `memcmp` compares at one fixed offset, so a table that holds an address at an unknown position matches only a filter for that position. There is no "contains" filter. Filters combine with AND. `memcmp` bytes may be base58 (default) or base64 via `memcmp.encoding`. ## Examples `getProgramAccounts` on the tables controlled by one authority, with no account data returned: ```bash curl "https://rpc-newyork.constant-k.com/?api-key=YOUR_API_KEY" \ -X POST -H "Content-Type: application/json" \ -d '{ "jsonrpc": "2.0", "id": 1, "method": "getProgramAccounts", "params": [ "AddressLookupTab1e1111111111111111111111111", { "filters": [ { "memcmp": { "offset": 22, "bytes": "DStdNqtygUnfNwkHNrEhsPWwN7hqXrYrMJ8JMkLvidjT" } } ], "dataSlice": { "offset": 0, "length": 0 } } ] }' ``` `dataSlice` with `length: 0` returns no data, so the answer carries only the table addresses and account metadata. The response is trimmed to one account: ```json [ { "account": { "data": ["", "base64"], "executable": false, "lamports": 2171520, "owner": "AddressLookupTab1e1111111111111111111111111", "rentEpoch": 18446744073709551615, "space": 184 }, "pubkey": "1AjuJovi8byYxtUPyFna86jaRipDgVeX4TCXbkWNZxg" } ] ``` `getProgramAccountsV2` returns one page of tables with the layout decoded: ```bash curl "https://rpc-newyork.constant-k.com/?api-key=YOUR_API_KEY" \ -X POST -H "Content-Type: application/json" \ -d '{ "jsonrpc": "2.0", "id": 1, "method": "getProgramAccountsV2", "params": [ "AddressLookupTab1e1111111111111111111111111", { "encoding": "jsonParsed", "filters": [{ "dataSize": 184 }], "limit": 1, "withContext": true } ] }' ``` ```json { "jsonrpc": "2.0", "id": 1, "result": { "context": { "slot": 457692691 }, "value": { "accounts": [ { "account": { "data": { "parsed": { "info": { "addresses": [ "TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA", "SysvarRent111111111111111111111111111111111", "Ce6TQqeHC9p8KetsN6JsjHK7UTZk7nasjjnr7XxXp9F1", "6EF8rrecthR5Dkzon8Nwu78hRvfCKubJ14M5uBEwF6P" ], "authority": "DStdNqtygUnfNwkHNrEhsPWwN7hqXrYrMJ8JMkLvidjT", "deactivationSlot": "18446744073709551615", "lastExtendedSlot": "306248204", "lastExtendedSlotStartIndex": 0 }, "type": "lookupTable" }, "program": "address-lookup-table", "space": 184 }, "executable": false, "lamports": 2171520, "owner": "AddressLookupTab1e1111111111111111111111111", "rentEpoch": 18446744073709551615, "space": 184 }, "pubkey": "1AjuJovi8byYxtUPyFna86jaRipDgVeX4TCXbkWNZxg" } ], "paginationKey": "1AjuJovi8byYxtUPyFna86jaRipDgVeX4TCXbkWNZxg" } } } ``` `paginationKey` is the cursor for the next page. It is passed back as `paginationKey` on the next call, and is `null` on the last page. ## Parameters | Parameter | Values | Notes | | :----------------- | :-------------------------------------------------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `encoding` | `base64` (default), `base64+zstd`, `base58`, `jsonParsed` | `base58` covers data up to 128 bytes after `dataSlice`; larger data returns `-32602` with `base58 encoding is only supported for data under 129 bytes; use base64` | | `dataSlice` | `{ offset, length }` | `length: 0` returns no data, only addresses and account metadata | | `filters` | `dataSize`, `memcmp` | Optional; every filter must match | | `withContext` | `true`, `false` | Adds `context.slot` | | `minContextSlot` | slot number | If the index has not reached it, `-32016` with `Minimum context slot has not been reached` | | `commitment` | any level | Accepted, no effect. See the note below | | `limit` | 1 to 10,000, default 1,000 | `getProgramAccountsV2` only. Outside the range: `-32602` with `limit must be between 1 and 10000` | | `paginationKey` | account address | `getProgramAccountsV2` only; the cursor from the previous page | | `changedSinceSlot` | slot number | `getProgramAccountsV2` only; returns only tables changed since that slot, for incremental sync | > **commitment is accepted and ignored:** Answers are at confirmed commitment. A finalized request gets confirmed data. ## Result size and freshness `getProgramAccounts` answers up to 1 GB of matched account data. Above that it returns `-32012` with `scan aborted: The accumulated scan results exceeded the limit`. `getProgramAccountsV2` pages through any size, so walking every table uses it with `limit` up to 10,000 and `paginationKey`. Results are narrowed with `filters` and `dataSlice`. If the index falls behind the chain, a `getProgramAccountsV2` call with `changedSinceSlot` returns `-32005` with `data.numSlotsBehind` until the index catches up. ## Errors | HTTP | Code | Message | Cause | | :---- | :------: | :------------------------------------------------------------------------------------------------------------ | :------------------------------------------------------------------------------------- | | `403` | `-32600` | `getProgramAccounts requires higher tier` | Free or Operator plan. The `getProgramAccountsV2` message names `getProgramAccountsV2` | | `429` | `-32005` | `Rate limit exceeded (gpa: 25/sec)`, `Rate limit exceeded (gpa: 75/sec)` | Over the plan's calls per second | | `200` | `-32602` | `base58 encoding is only supported for data under 129 bytes; use base64`, `limit must be between 1 and 10000` | An invalid parameter | | `200` | `-32012` | `scan aborted: The accumulated scan results exceeded the limit` | Matched account data over 1 GB. `getProgramAccounts` only | | `200` | `-32016` | `Minimum context slot has not been reached` | `minContextSlot` is above the slot the index has reached | | `200` | `-32005` | Error `data` carries `numSlotsBehind` | The index is behind the chain. Only with `changedSinceSlot` | See [Errors](https://docs.constant-k.com/rpc/errors/) for every code and its fix.