Midnight — system, account, grandpa, offchain, archive, midnight, sidechain, childstate (3/3)

API reference for Midnight. All methods ->

Part 3 of 3: 1 · 2 · 3

childstate_getKeysPagedAt

Returns paged keys from a past block.

Parameters

• id (integer; required): a request ID (example: 1).

• jsonrpc (string; required): a JSON RPC spec used (example: 2.0).

• method (string; required): a method used for the request.

• params (array; required):

  1. <string>: Child storage key (hex-encoded) identifying the child storage.
  2. <string>: Key prefix (hex-encoded) to filter keys. Use "0x" to match all keys.
  3. <number>: Count — the maximum number of keys to return.
  4. <string>: Start key (hex-encoded) for pagination. Use "0x" or omit to start from the beginning.
  5. <string> (required): Block hash at which to query state.

Returns

• <array<string>>: A list of child storage keys (hex-encoded) that match the given prefix, limited by pagination parameters, at the specified block.
• []: Returned if no keys match the prefix at the given block.
• null: Returned if the child storage key or block hash is invalid.

Request example

curl -X POST https://rpc.ankr.com/midnight_testnet/YOUR_ANKR_API_KEY/ \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "childstate_getKeysPagedAt",
    "params": [
      "0x1a2b3c4d5e6f",      // child storage key
      "0x",                  // key prefix (empty = all keys)
      10,                    // maximum number of keys to return
      "0x",                  // start key for pagination (empty = start from first key)
      "0xabc123abc123abc123abc123abc123abc123abc123abc123abc123abc123abc1"  // block hash
    ]
  }'

Response example

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": [
    "0x1a2b3c4d5e6f0011",
    "0x1a2b3c4d5e6f0022",
    "0x1a2b3c4d5e6f0033"
  ]
}

---

childstate_getStorage

Gets a storage entry from child storage.

Parameters

• id (integer; required): a request ID (example: 1).

• jsonrpc (string; required): a JSON RPC spec used (example: 2.0).

• method (string; required): a method used for the request.

• params (array; required):

  1. <string>: Child storage key (hex-encoded) identifying the child storage.
  2. <string>: Storage key (hex-encoded) to fetch the value for.
  3. <string>: Block hash at which to query storage (optional; if omitted, uses the latest block).

Returns

• <string|null>:
  • The hex-encoded SCALE-encoded value stored under the given key in the specified child storage at the given block hash.
  • null if no value exists for the key or if the storage key/block hash is invalid.

Request example

curl -X POST https://rpc.ankr.com/midnight_testnet/YOUR_ANKR_API_KEY/ \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "childstate_getStorage",
    "params": [
      "0x1a2b3c4d5e6f",      // child storage key
      "0x7f8e9d0c1b2a",      // storage key to fetch
      "0xabc123abc123abc123abc123abc123abc123abc123abc123abc123abc123abc1"  // block hash
    ]
  }'

Response example

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x01020304"
}

---

childstate_getStorageEntries

Gets multiple entries from child storage.

Parameters

• id (integer; required): a request ID (example: 1).

• jsonrpc (string; required): a JSON RPC spec used (example: 2.0).

• method (string; required): a method used for the request.

• params (array; required):

  1. <string>: Child storage key (hex-encoded) identifying the child storage.
  2. <array<string>>: Storage keys (hex-encoded) for which values should be fetched.
  3. <string> (optional; if omitted, uses the latest block): Block hash at which to query storage.

Returns

• <array<string|null>>: An array of hex-encoded SCALE-encoded values corresponding to the requested storage keys, in the same order as provided in the request.

Each element is either:

• A hex-encoded value (if the key exists).
• null (if no value exists for that key).

Request example

curl -X POST https://rpc.ankr.com/midnight_testnet/YOUR_ANKR_API_KEY/ \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "childstate_getStorageEntries",
    "params": [
      "0x1a2b3c4d5e6f",                // child storage key
      [
        "0x7f8e9d0c1b2a",              // storage key 1
        "0x1234567890ab"               // storage key 2
      ],
      "0xabc123abc123abc123abc123abc123abc123abc123abc123abc123abc123abc1" // block hash
    ]
  }'

Response example

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": [
    "0x01020304",
    null
  ]
}

---

childstate_getStorageHash

Gets hash of a child storage value.

Parameters

• id (integer; required): a request ID (example: 1).

• jsonrpc (string; required): a JSON RPC spec used (example: 2.0).

• method (string; required): a method used for the request.

• params (array; required):

  1. <string>: Child storage key (hex-encoded) identifying the child storage.
  2. <string>: Storage key (hex-encoded) for which to retrieve the hash.
  3. <string> (optional; if omitted, uses the latest block): Block hash at which to query storage.

Returns

• <string|null>:
  • A hex-encoded hash of the value stored under the specified key in the given child storage at the provided block hash.
  • null if no value exists for the key or if the storage key/block hash is invalid.

Request example

curl -X POST https://rpc.ankr.com/midnight_testnet/YOUR_ANKR_API_KEY/ \
  -H "Content-Type: application/json" \
  -d '{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "childstate_getStorageHash",
    "params": [
      "0x1a2b3c4d5e6f",      // child storage key
      "0x7f8e9d0c1b2a",      // storage key to hash
      "0xabc123abc123abc123abc123abc123abc123abc123abc123abc123abc123abc1"  // block hash
    ]
  }'

Response example

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x7f8e9d0c1b2a4f00112233445566778899aabbccddeeff001122334455667788"
}

---