One round of random inspection visits

GET /v1/spot-checks/{day}

https://verify.tanba-ooh.kz/v1/spot-checks/{day}

The round of one Asia/Almaty working day (YYYY-MM-DD). Right after the draw it gives only commitment, the SHA-256 of the secret, and where that hash sits in the public ledger. From reveal_after it also gives the secret, the candidates with their weights and the sample with the visit windows. The sample is a weighted draw without replacement (key u^(1/w), u from the first 8 bytes of HMAC-SHA256(secret, structure code)) of the first day_size structures by descending key, and the visit window inside operating hours is also derived from the secret. To check: SHA-256 of the secret equals commitment, and the draw over the candidates gives the same codes in the same order. Photos and inspector names are not published.

Authentication

None. This call is public.

Parameters

Name	In	Type	Required	Description	Example
`day`	path	string	yes	The Asia/Almaty working day of the round.	`2026-10-15`

Responses

200 The round.

`application/json`

SpotRound

Name	Type	Required	Description	Example
`day`	string (date)	yes	The Asia/Almaty working day of the round.	`"2026-10-15"`
`commitment`	string	yes	Hex SHA-256 of the secret of the round.	`"6f1ed002ab5595859014ebf0951522d9a1f6a7a9e8b6dbd2d4f1d43fb3ac4a43"`
`revealed`	boolean	yes	True once the secret and the sample are public.	`true`
`reveal_after`	string (date)	yes	The first day on which the secret and the sample are public.	`"2026-10-22"`
`ledger`	object		Where the seal sits in the public ledger.
`ledger.day`	string (date)	yes	The ledger day that holds the seal: the day the seal was made.	`"2026-10-14"`
`ledger.status`	string	yes	State of that ledger day's Bitcoin timestamp, as in the ledger days list. pending, pending_check, anchored
`ledger.block_height`	integer		Bitcoin block of the attestation, present only when anchored.	`905123`
`ledger.digest`	string	yes	The ledger day's digest, the value that is timestamped.	`"fb1877ee8cb63b394ddd8a47987bb9c384f5d8ca97353e2248df2ca663db6dd3"`
`ledger.proof`	object	yes	Inclusion proof of the seal's leaf in that ledger day's tree.
`ledger.proof.v`	const	yes	Version of the proof format.	`1`
`ledger.proof.day`	string (date)	yes	The Asia/Almaty day of the tree.	`"2026-10-05"`
`ledger.proof.leaf`	oneOf	yes	One entry of a ledger day. The kind says what the entry is about.
`ledger.proof.leaf_sha256`	string	yes	Hex SHA-256 of the leaf.	`"3a6e9c0cc1490e884c3b4a9c6bfd39e19d928a0838407cd48b6317ebcc2ed825"`
`ledger.proof.index`	integer	yes	Position of the leaf in the tree, counting from 0.	`3`
`ledger.proof.leaf_count`	integer	yes	Number of leaves in the tree.	`14`
`ledger.proof.path`	array of object	yes	Siblings from the leaf up to the root; a node is SHA-256(0x01, left, right).
`ledger.proof.path[].side`	string	yes	Where the sibling sits. left, right
`ledger.proof.path[].hash`	string	yes	Hex SHA-256 of the sibling node.	`"e6e9ae1d34d7966232cd03927b9cf18c6d1e1c9532cde816ca929ed482e27326"`
`ledger.proof.merkle_root`	string	yes	Hex SHA-256 root of the tree.	`"53f8fe42a83fc01075e856d385cea164e06b7124d4c76b3a498e39de98d7168b"`
`ledger.proof.anchor_sha256`	string	yes	Hex SHA-256 of the anchor body of the day.	`"e9f1bb3a2238f73741a8245a599da12c813c8c84ccee623aa5c68c71845db4c4"`
`ledger.proof.digest`	string	yes	Hex SHA-256 of the anchor body hash followed by the Merkle root.	`"44eeee2dfc054adad906be43d8d227a8052c19e5080b0ed64dc572fad9ee8f46"`
`secret`	string		Hex of the 32 secret bytes; present once revealed.	`"5d0c2e4a9b7f3318a6c4e1f09d2b7a58c3e6f1049b8d27a5e0c3b6f9124d87ae"`
`weekly_size`	integer		Structures to visit in the week of the round: 2 % of the active structures, at least 5; present once revealed.	`6`
`day_size`	integer		Structures drawn for this day, the weekly size spread over the five working days; present once revealed.	`1`
`candidates`	array of SpotCandidate		The structures that could be drawn, those already drawn earlier in the week left out; present once revealed.
`candidates[].code`	string	yes	Public code of the structure.	`"ALM-0042"`
`candidates[].weight`	integer	yes	Weight in the draw: 1, 2, 4 or 8 for the compliance band green, yellow, orange or red, doubled while the structure has an open high or critical event.	`1`
`selected`	array of SpotSelected		The sample, by descending key, with the visit windows; present once revealed.
`selected[].code`	string	yes	Public code of the structure to visit.	`"ALM-0042"`
`selected[].from`	string	yes	Start of the visit window, Asia/Almaty time.	`"2026-10-15T10:35:00+05:00"`
`selected[].to`	string	yes	End of the visit window: one hour after the start.	`"2026-10-15T11:35:00+05:00"`

Example

{
  "day": "2026-10-15",
  "commitment": "6f1ed002ab5595859014ebf0951522d9a1f6a7a9e8b6dbd2d4f1d43fb3ac4a43",
  "revealed": true,
  "reveal_after": "2026-10-22",
  "ledger": {
    "day": "2026-10-14",
    "status": "pending",
    "block_height": 905123,
    "digest": "fb1877ee8cb63b394ddd8a47987bb9c384f5d8ca97353e2248df2ca663db6dd3",
    "proof": {
      "v": 1,
      "day": "2026-10-05",
      "leaf": {
        "kind": "issued",
        "approval_number": "TNB-2026-000123",
        "manifest_sha256": "878a9b0a8452700baaab5574e39716d67a93a07597baab30823639c69bf1e889",
        "signed_at": "2026-10-05T06:20:31.482913Z",
        "revoked_at": "2026-10-05T09:02:44.100200Z"
      },
      "leaf_sha256": "3a6e9c0cc1490e884c3b4a9c6bfd39e19d928a0838407cd48b6317ebcc2ed825",
      "index": 3,
      "leaf_count": 14,
      "path": [
        {
          "side": "left",
          "hash": "e6e9ae1d34d7966232cd03927b9cf18c6d1e1c9532cde816ca929ed482e27326"
        }
      ],
      "merkle_root": "53f8fe42a83fc01075e856d385cea164e06b7124d4c76b3a498e39de98d7168b",
      "anchor_sha256": "e9f1bb3a2238f73741a8245a599da12c813c8c84ccee623aa5c68c71845db4c4",
      "digest": "44eeee2dfc054adad906be43d8d227a8052c19e5080b0ed64dc572fad9ee8f46"
    }
  },
  "secret": "5d0c2e4a9b7f3318a6c4e1f09d2b7a58c3e6f1049b8d27a5e0c3b6f9124d87ae",
  "weekly_size": 6,
  "day_size": 1,
  "candidates": [
    {
      "code": "ALM-0042",
      "weight": 1
    }
  ],
  "selected": [
    {
      "code": "ALM-0042",
      "from": "2026-10-15T10:35:00+05:00",
      "to": "2026-10-15T11:35:00+05:00"
    }
  ]
}

Errors

Errors are problem documents (application/problem+json) with a stable code.

Status	Meaning
404	Nothing there, or not visible to the caller.
429	Rate limit; see `Retry-After`.

Code samples

curl

curl 'https://verify.tanba-ooh.kz/v1/spot-checks/2026-10-15'

Python

import requests

response = requests.get(
    "https://verify.tanba-ooh.kz/v1/spot-checks/2026-10-15",
)
print(response.status_code, response.text)

package main

import (
	"fmt"
	"io"
	"net/http"
)

func main() {
	req, err := http.NewRequest("GET", "https://verify.tanba-ooh.kz/v1/spot-checks/2026-10-15", nil)
	if err != nil {
		panic(err)
	}
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer resp.Body.Close()
	data, _ := io.ReadAll(resp.Body)
	fmt.Println(resp.Status, string(data))
}