> ## Documentation Index > Fetch the complete documentation index at: https://docs.chainstack.com/llms.txt > Use this file to discover all available pages before exploring further. # getBlockHeader | TON v2 > The getBlockHeader method retrieves the header of a specific block in the TON blockchain. getBlockHeader on TON v2 via Chainstack. The `getBlockHeader` method retrieves the header of a specific block in the TON blockchain. This method provides detailed metadata about a block, including its identifiers, state flags, and timing information. **TON billing: full or archive by block age** This method is billed as archive (2 RUs) when the requested block is 128 or more seqno behind the tip, and full (1 RU) otherwise. See [Request units — TON method scope](/docs/request-units#ton-method-scope). ## Parameters * `workchain` (integer, required) — The ID of the workchain. Example: `-1` for the masterchain. * `shard` (string, required) — The ID of the shard. Example: `"-9223372036854775808"` for the masterchain. * `seqno` (integer, required) — The sequence number of the block. Example: `39064874`. ## JSON-RPC example ```shell Shell theme={"system"} curl -X POST \ 'https://ton-mainnet.core.chainstack.com/f2a2411bce1e54a2658f2710cd7969c3/api/v2/jsonRPC' \ -H 'Content-Type: application/json' \ -d '{ "jsonrpc": "2.0", "id": 1, "method": "getBlockHeader", "params": { "workchain": -1, "shard": "-9223372036854775808", "seqno": 39064874 } }' ``` ## Response * `id` (object) — The identifier of the block, containing: * `workchain` (integer) — The workchain ID of the block. * `shard` (string) — The shard ID of the block. * `seqno` (integer) — The sequence number of the block. * `root_hash` (string) — The root hash of the block. * `file_hash` (string) — The file hash of the block. * `global_id` (integer) — The global ID of the block. * `version` (integer) — The version of the block. * `after_merge` (boolean) — Whether the block was created after a merge. * `before_split` (boolean) — Whether the block was created before a split. * `after_split` (boolean) — Whether the block was created after a split. * `want_merge` (boolean) — Whether the block wants to merge. * `want_split` (boolean) — Whether the block wants to split. * `validator_list_hash_short` (integer) — The short hash of the validator list. * `catchain_seqno` (integer) — The sequence number in the catchain. * `min_ref_mc_seqno` (integer) — The minimum referenced masterchain sequence number. * `is_key_block` (boolean) — Whether the block is a key block. * `prev_key_block_seqno` (integer) — The sequence number of the previous key block. * `start_lt` (string) — The start logical time of the block. * `end_lt` (string) — The end logical time of the block. * `gen_utime` (integer) — The generation time of the block. * `vert_seqno` (integer) — The vertical sequence number of the block. ## Use case A possible use case for the `getBlockHeader` method in TON is for blockchain explorers, validators, or any application that needs detailed metadata about specific blocks. This method can be used to: 1. Display comprehensive block information in a block explorer. 2. Analyze the structure and evolution of the blockchain, including shard splits and merges. 3. Verify the integrity and sequence of blocks in a custom validation process. 4. Track key blocks and their relationships in the blockchain. ## OpenAPI ````yaml openapi/ton_node_api/v2/getBlockHeader.json GET /getBlockHeader openapi: 3.0.0 info: title: getBlockHeader example version: 1.0.0 description: >- This is an API example for getBlockHeader, a method to retrieve the header of a specific block in the TON blockchain. servers: - url: >- https://ton-mainnet.core.chainstack.com/f2a2411bce1e54a2658f2710cd7969c3/api/v2 security: [] paths: /getBlockHeader: get: tags: - TON Operations summary: getBlockHeader operationId: getBlockHeader parameters: - name: workchain in: query required: true description: The workchain ID schema: type: integer default: -1 example: -1 - name: shard in: query required: true description: The shard ID schema: type: string default: '-9223372036854775808' example: '-9223372036854775808' - name: seqno in: query required: true description: The sequence number of the block schema: type: integer default: 39064874 example: 39064874 responses: '200': description: The header of the specified block content: application/json: schema: type: object properties: id: type: object properties: workchain: type: integer description: The workchain ID of the block shard: type: string description: The shard ID of the block seqno: type: integer description: The sequence number of the block root_hash: type: string description: The root hash of the block file_hash: type: string description: The file hash of the block global_id: type: integer description: The global ID of the block version: type: integer description: The version of the block after_merge: type: boolean description: Whether the block was created after a merge before_split: type: boolean description: Whether the block was created before a split after_split: type: boolean description: Whether the block was created after a split want_merge: type: boolean description: Whether the block wants to merge want_split: type: boolean description: Whether the block wants to split validator_list_hash_short: type: integer description: The short hash of the validator list catchain_seqno: type: integer description: The sequence number in the catchain min_ref_mc_seqno: type: integer description: The minimum referenced masterchain sequence number is_key_block: type: boolean description: Whether the block is a key block prev_key_block_seqno: type: integer description: The sequence number of the previous key block start_lt: type: string description: The start logical time of the block end_lt: type: string description: The end logical time of the block gen_utime: type: integer description: The generation time of the block vert_seqno: type: integer description: The vertical sequence number of the block ````