> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ton.org/llms.txt
> Use this file to discover all available pages before exploring further.
## Submitting Feedback
If you encounter incorrect, outdated, or confusing documentation on this page, submit feedback:
POST https://docs.ton.org/feedback
```json
{
"path": "/ecosystem/api/toncenter/v2/blocks/lookup-block",
"feedback": "Description of the issue"
}
```
Only submit feedback when you have something specific and actionable to report.
# Lookup block
> Finds a block by position or time. Specify workchain and shard, then provide either: `seqno` (exact block number), lt (find block containing this logical time), or unixtime (find block closest to this timestamp). Returns the full block ID including hashes needed for verification.
## OpenAPI
````yaml get /api/v2/lookupBlock
openapi: 3.1.1
info:
title: TON HTTP API C++
description: >
This API enables HTTP access to TON blockchain - getting accounts and
wallets information, looking up blocks and transactions, sending messages to
the blockchain, calling get methods of smart contracts, and more.
In addition to REST API, all methods are available through a JSON-RPC
endpoint with `method` equal to method name and `params` passed as a
dictionary.
The response contains a JSON object, which always has a boolean field `ok`
and either `error` or `result`. If `ok` equals true, the request was
successful and the result of the query can be found in the `result` field.
In case of an unsuccessful request, `ok` equals false and the error is
explained in the `error`.
API Key should be sent either as `api_key` query parameter or `X-API-Key`
header
version: 2.1.1
servers:
- url: https://toncenter.com
description: TON Mainnet
- url: https://testnet.toncenter.com
description: TON Testnet
security: []
tags:
- name: Accounts
description: Information about accounts
- name: Transactions
description: Fetching and locating transactions
- name: Blocks
description: Information about blocks
- name: Run method
description: Run get-method of smart contracts
- name: Send
description: Send data to blockchain
- name: Utils
description: Some useful methods
- name: Configuration
description: Information about blockchain config
- name: RPC
description: JSON-RPC and POST endpoints
paths:
/api/v2/lookupBlock:
get:
tags:
- Blocks
summary: Lookup block
description: >-
Finds a block by position or time. Specify workchain and shard, then
provide either: `seqno` (exact block number), lt (find block containing
this logical time), or unixtime (find block closest to this timestamp).
Returns the full block ID including hashes needed for verification.
operationId: lookupBlock_get
parameters:
- $ref: '#/components/parameters/workchain'
- $ref: '#/components/parameters/shard'
- $ref: '#/components/parameters/seqnoOptional'
- name: lt
in: query
description: Logical time of a block
required: false
schema:
type: string
x-usrv-cpp-format: std::int64_t
- name: unixtime
in: query
description: UNIX timestamp of a block
required: false
schema:
type: integer
format: int32
responses:
'200':
description: >-
Returns the full block identifier matching the given `seqno`,
logical time, or unix timestamp.
content:
application/json:
schema:
$ref: '#/components/schemas/LookupBlockResponse'
'401':
$ref: '#/components/responses/401'
'403':
$ref: '#/components/responses/403'
'422':
$ref: '#/components/responses/422_lookup'
'429':
$ref: '#/components/responses/429'
'504':
$ref: '#/components/responses/504'
security:
- APIKeyHeader: []
- APIKeyQuery: []
components:
parameters:
workchain:
name: workchain
in: query
description: >-
The workchain to query. Use `-1` for masterchain (validators, system
contracts, config) or `0` for basechain (regular accounts and
contracts). Most user transactions happen on workchain `0`.
required: true
schema:
type: integer
format: int32
shard:
name: shard
in: query
description: >-
The shard identifier. Masterchain always uses `-9223372036854775808`.
For basechain, shards split and merge dynamically. Use the `shards`
endpoint to discover current shard configuration.
required: true
schema:
type: string
x-usrv-cpp-type: std::int64_t
seqnoOptional:
name: seqno
in: query
description: >-
Query state at a specific block height. If omitted, returns the current
state. Use this to look up historical data at a specific point in time.
required: false
schema:
type: integer
format: int32
schemas:
LookupBlockResponse:
type: object
additionalProperties: false
required:
- ok
- result
properties:
ok:
type: boolean
default: true
description: >-
Returns `true` if the request succeeded; otherwise `false`. See the
`error` field for details.
result:
$ref: '#/components/schemas/TonBlockIdExt'
description: Response data. Present only when `ok` is `true`.
'@extra':
type: string
description: >-
Optional request ID that can be passed in the request and received
back in the response. Useful for matching async responses.
TonBlockIdExt:
type: object
additionalProperties: false
properties:
'@type':
type: string
enum:
- ton.blockIdExt
default: ton.blockIdExt
description: >-
TonLib type identifier for full block identifiers. Refer to the
[TonLib type reference](/ecosystem/api/toncenter/v2-tonlib-types)
for a full list.
workchain:
type: integer
description: 'Workchain ID: `-1` for masterchain, `0` for basechain.'
shard:
type: string
x-usrv-cpp-type: std::int64_t
description: >-
Shard identifier as a signed 64-bit integer string. Masterchain uses
`-9223372036854775808`.
seqno:
type: integer
description: >-
Block sequence number within its workchain and shard. For the
masterchain (workchain `-1`), this equals the global block height.
For basechain shards (workchain `0`), this is the sequence number
local to that specific shard, not a global height.
root_hash:
$ref: '#/components/schemas/TonHash'
description: Merkle root hash of the block state tree.
file_hash:
$ref: '#/components/schemas/TonHash'
description: >-
Hash of the serialized block file. Together with `root_hash`,
uniquely identifies a block.
required:
- '@type'
- workchain
- shard
- seqno
- root_hash
- file_hash
description: >-
A complete block identifier with cryptographic hashes. Contains
`workchain`, `shard`, `seqno` (position) plus `root_hash` and
`file_hash` (verification).
TonHash:
type: string
x-usrv-cpp-type: ton_http::types::ton_hash
description: >-
A 256-bit hash value. Accepts either hex format (64 characters) or
base64 format (44 characters). Used for block hashes, transaction
hashes, and cryptographic proofs.
responses:
'401':
description: API key does not exist. Check for typos or generate a new key.
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- ok
- code
- error
properties:
ok:
type: boolean
const: false
description: Always `false` for error responses.
code:
type: integer
const: 401
description: HTTP status code `401`.
error:
type: string
enum:
- API key does not exist
'@extra':
type: string
description: Extra data passed through from the request.
example:
ok: false
code: 401
error: API key does not exist
'403':
description: >-
API key is not allowed for this network (e.g. testnet key used on
mainnet).
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- ok
- code
- error
properties:
ok:
type: boolean
const: false
description: Always `false` for error responses.
code:
type: integer
const: 403
description: HTTP status code `403`.
error:
type: string
enum:
- Network not allowed
'@extra':
type: string
description: Extra data passed through from the request.
example:
ok: false
code: 403
error: Network not allowed
'429':
description: >-
Rate limit exceeded. Back off and retry, or use an API key for higher
limits.
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- ok
- code
- error
properties:
ok:
type: boolean
const: false
description: Always `false` for error responses.
code:
type: integer
const: 429
description: HTTP status code `429`.
error:
type: string
enum:
- Ratelimit exceeded
'@extra':
type: string
description: Extra data passed through from the request.
example:
ok: false
code: 429
error: Ratelimit exceeded
'504':
description: Timeout waiting for liteserver response.
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- ok
- code
- error
properties:
ok:
type: boolean
const: false
description: Always `false` for error responses.
code:
type: integer
const: 504
description: HTTP status code `504`.
error:
type: string
enum:
- LITE_SERVER_NETWORK timeout
'@extra':
type: string
description: Extra data passed through from the request.
example:
ok: false
code: 504
error: LITE_SERVER_NETWORK timeout
422_lookup:
description: Invalid block lookup parameters.
content:
application/json:
schema:
type: object
additionalProperties: false
required:
- ok
- code
- error
properties:
ok:
type: boolean
const: false
description: Always `false` for error responses.
code:
type: integer
const: 422
description: HTTP status code `422`.
error:
type: string
enum:
- failed to parse workchain
- failed to parse shard
- exactly one of seqno, lt, unixtime should be specified
- lt should be non-negative
- unixtime should be non-negative
'@extra':
type: string
description: Extra data passed through from the request.
example:
ok: false
code: 422
error: failed to parse workchain
securitySchemes:
APIKeyHeader:
type: apiKey
in: header
name: X-API-Key
description: >-
API key header of the form `X-API-Key: `, where `` is the
API key. Requests without a key are limited to 1 RPS. Refer to the
[authentication guide](/ecosystem/api/toncenter/v2-authentication) for
details.
APIKeyQuery:
type: apiKey
in: query
name: api_key
description: >-
API key query parameter of the form `?api_key=`, where ``
is the API key. Equivalent to the header method. Refer to the
[authentication guide](/ecosystem/api/toncenter/v2-authentication) for
details.
````