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.

GET /api/v2/lookupBlock

Lookup block

cURL

curl --request GET \
  --url https://toncenter.com/api/v2/lookupBlock \
  --header 'X-API-Key: <api-key>'

200

{
  "ok": true,
  "result": {
    "@type": "ton.blockIdExt",
    "workchain": 123,
    "shard": "<string>",
    "seqno": 123,
    "root_hash": "<string>",
    "file_hash": "<string>"
  },
  "@extra": "<string>"
}

Authorizations

APIKeyHeaderAPIKeyQuery

X-API-Key · string · header · required

API key header of the form X-API-Key: <token>, where <token> is your API key. Requests without a key are limited to 1 RPS. More info here.

Query Parameters

workchain · integer<int32> · required

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.

shard · string · required

The shard identifier. Masterchain always uses -9223372036854775808. For basechain, shards split and merge dynamically. Use the shards endpoint to discover current shard configuration.

seqno · integer<int32>

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.

lt · string

Logical time of a block

unixtime · integer<int32>

UNIX timestamp of a block

Response

200

application/json

Returns the full block identifier matching the given seqno, logical time, or unix timestamp.

ok · boolean · default: true · required

Returns true if the request succeeded; otherwise false. See the error field for details.

result · object · required

Response data. Present only when ok is true.

Show child attributes

@extra · string

Optional request ID that you can pass in the request and receive back in the response. Useful for matching async responses.