# blockSubscribe Subscribe to receive notification anytime a new block is `confirmed` or `finalized`. {% hint style="danger" %} **Unstable Method** This subscription is considered **unstable** and is only available if the validator was started with the `--rpc-pubsub-enable-block-subscription` flag. The format of this subscription may change in the future. {% endhint %} #### Parameters required for this RPC call * filter criteria for the logs to receive results by account type; currently supported: * `all` - include all transactions in block * A JSON object with the following field: * `mentionsAccountOrProgram: ` - return only transactions that mention the provided public key (as base-58 encoded string). If no mentions in a given block, then no notification will be sent. * **configuration object**: This contains the following parameters, all are optional fields. * **commitment**: The commitment describes how finalized a block is at that point in time. Commitment levels processed, confirmed and finalized are supported, defaults to finalized. * **encoding**: Encoding format for Account data * `base58` is slow. * `jsonParsed` encoding attempts to use program-specific state parsers to return more human-readable and explicit account state data * If `jsonParsed` is requested but a parser cannot be found, the field falls back to binary encoding, detectable when the `data` field is type `string`. * Supports: `base58` , `base64` , `base64+zstd` , `jsonParsed` * **transactionDetails**: The level of transaction detail to return * If `accounts` are requested, transaction details only include signatures and an annotated list of accounts in each transaction. * Transaction metadata is limited to only: fee, err, pre\_balances, post\_balances, pre\_token\_balances, and post\_token\_balances. * maxSupportedTransactionVersion: Currently, the only valid value for this parameter is `0`. Setting it to `0` allows you to fetch all transactions, including both Versioned and legacy transactions. This parameter determines the maximum transaction version that will be returned in the response. If you request a transaction with a higher version than this value, an error will be returned. If you omit this parameter, only legacy transactions will be returned—any versioned transaction will result in an error. * showRewards: Whether to populate the `rewards` array. If parameter not provided, the default includes rewards. This is a boolean field. {% tabs %} {% tab title="Websocket" %} ```json { "jsonrpc": "2.0", "id": "1", "method": "blockSubscribe", "params": [ { "mentionsAccountOrProgram": "LieKvPRE8XeX3Y2xVNHjKlpAScD12lYySBVQ4HqoJ5op" }, { "commitment": "confirmed", "encoding": "base64", "transactionDetails": "full", "maxSupportedTransactionVersion": 0, "showRewards": true } ] } ``` {% endtab %} {% tab title="Response" %} ```json { "jsonrpc": "2.0", "result": 0, // id required to unsubscribe "id": 1 } ``` {% endtab %} {% endtabs %} **Notification Format:** The notification will be an object with the following fields: * `slot: ` - The corresponding slot. * `err: ` - Error if something went wrong publishing the notification otherwise null. * `block: ` - A block object as seen in the [getBlock](https://solana.com/docs/rpc/http/getblock) RPC HTTP method. {% tabs %} {% tab title="Notification Format" %} ```json { "jsonrpc": "2.0", "method": "blockNotification", "params": { "result": { "context": { "slot": 112301554 }, "value": { "slot": 112301554, "block": { "previousBlockhash": "GJp125YAN4ufCSUvZJVdCyWQJ7RPWMmwxoyUQySydZA", "blockhash": "6ojMHjctdqfB55JDpEpqfHnP96fiaHEcvzEQ2NNcxzHP", "parentSlot": 112301553, "transactions": [ { "transaction": [ "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", "base64" ], "meta": { "err": null, "status": { "Ok": null }, "fee": 5000, "preBalances": [ 1758510880, 2067120, 1566000, 1461600, 2039280, 2039280, 1900080, 1865280, 0, 3680844220, 2039280 ], "postBalances": [ 1758505880, 2067120, 1566000, 1461600, 2039280, 2039280, 1900080, 1865280, 0, 3680844220, 2039280 ], "innerInstructions": [ { "index": 0, "instructions": [ { "programIdIndex": 13, "accounts": [1, 15, 3, 4, 2, 14], "data": "21TeLgZXNbtHXVBzCaiRmH" }, { "programIdIndex": 14, "accounts": [3, 4, 1], "data": "6qfC8ic7Aq99" }, { "programIdIndex": 13, "accounts": [1, 15, 3, 5, 2, 14], "data": "21TeLgZXNbsn4QEpaSEr3q" }, { "programIdIndex": 14, "accounts": [3, 5, 1], "data": "6LC7BYyxhFRh" } ] }, { "index": 1, "instructions": [ { "programIdIndex": 14, "accounts": [4, 3, 0], "data": "7aUiLHFjSVdZ" }, { "programIdIndex": 19, "accounts": [17, 18, 16, 9, 11, 12, 14], "data": "8kvZyjATKQWYxaKR1qD53V" }, { "programIdIndex": 14, "accounts": [9, 11, 18], "data": "6qfC8ic7Aq99" } ] } ], "logMessages": [ "Program QMNeHCGYnLVDn1icRAfQZpjPLBNkfGbSKRB83G5d8KB invoke [1]", "Program QMWoBmAyJLAsA1Lh9ugMTw2gciTihncciphzdNzdZYV invoke [2]" ], "preTokenBalances": [ { "accountIndex": 4, "mint": "iouQcQBAiEXe6cKLS85zmZxUqaCqBdeHFpqKoSz615u", "uiTokenAmount": { "uiAmount": null, "decimals": 6, "amount": "0", "uiAmountString": "0" }, "owner": "LieKvPRE8XeX3Y2xVNHjKlpAScD12lYySBVQ4HqoJ5op", "programId": "TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA" }, { "accountIndex": 5, "mint": "iouQcQBAiEXe6cKLS85zmZxUqaCqBdeHFpqKoSz615u", "uiTokenAmount": { "uiAmount": 11513.0679, "decimals": 6, "amount": "11513067900", "uiAmountString": "11513.0679" }, "owner": "rXhAofQCT7NN9TUqigyEAUzV1uLL4boeD8CRkNBSkYk", "programId": "TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA" }, { "accountIndex": 10, "mint": "Saber2gLauYim4Mvftnrasomsv6NvAuncvMEZwcLpD1", "uiTokenAmount": { "uiAmount": null, "decimals": 6, "amount": "0", "uiAmountString": "0" }, "owner": "CL9wkGFT3SZRRNa9dgaovuRV7jrVVigBUZ6DjcgySsCU", "programId": "TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb" }, { "accountIndex": 11, "mint": "Saber2gLauYim4Mvftnrasomsv6NvAuncvMEZwcLpD1", "uiTokenAmount": { "uiAmount": 15138.514093, "decimals": 6, "amount": "15138514093", "uiAmountString": "15138.514093" }, "owner": "LieKvPRE8XeX3Y2xVNHjKlpAScD12lYySBVQ4HqoJ5op", "programId": "TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb" } ], "postTokenBalances": [ { "accountIndex": 4, "mint": "iouQcQBAiEXe6cKLS85zmZxUqaCqBdeHFpqKoSz615u", "uiTokenAmount": { "uiAmount": null, "decimals": 6, "amount": "0", "uiAmountString": "0" }, "owner": "LieKvPRE8XeX3Y2xVNHjKlpAScD12lYySBVQ4HqoJ5op", "programId": "TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA" }, { "accountIndex": 5, "mint": "iouQcQBAiEXe6cKLS85zmZxUqaCqBdeHFpqKoSz615u", "uiTokenAmount": { "uiAmount": 11513.103028, "decimals": 6, "amount": "11513103028", "uiAmountString": "11513.103028" }, "owner": "rXhAofQCT7NN9TUqigyEAUzV1uLL4boeD8CRkNBSkYk", "programId": "TokenkegQfeZyiNwAJbNbGKPFXCWuBvf9Ss623VQ5DA" }, { "accountIndex": 10, "mint": "Saber2gLauYim4Mvftnrasomsv6NvAuncvMEZwcLpD1", "uiTokenAmount": { "uiAmount": null, "decimals": 6, "amount": "0", "uiAmountString": "0" }, "owner": "CL9wkGFT3SZRRNa9dgaovuRV7jrVVigBUZ6DjcgySsCU", "programId": "TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb" }, { "accountIndex": 11, "mint": "Saber2gLauYim4Mvftnrasomsv6NvAuncvMEZwcLpD1", "uiTokenAmount": { "uiAmount": 15489.767829, "decimals": 6, "amount": "15489767829", "uiAmountString": "15489.767829" }, "owner": "BeiHVPRE8XeX3Y2xVNrSsTpAScH94nYySBVQ4HqgN9at", "programId": "TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb" } ], "rewards": [] } } ], "blockTime": 1639926816, "blockHeight": 101210751 }, "err": null } }, "subscription": 14 } } ``` {% endtab %} {% endtabs %}