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Midnight — system, account, grandpa, offchain, archive, midnight, sidechain, childstate (1/3)

API reference for Midnight. All methods ->

Part 1 of 3: 1 · 2 · 3

system_chain​

Returns the name of the chain.

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): none.

Returns​

  • <string>: the name of the blockchain network the node is connected to.

Request example​

curl -X POST https://rpc.ankr.com/midnight_testnet/YOUR_ANKR_API_KEY/ \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "method": "system_chain",
    "params": [],
    "id": 1
  }'

Response example​

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": "testnet-02-1"
}

system_chainType​

Returns chain type (dev, local, live).

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): none.

Returns​

  • <string>: The type of chain the node is connected to. Common values include:
    • Live: A production network.
    • Development: A local development chain.
    • Local: A locally run chain or test instance.

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": "system_chainType",
    "params": []
  }'

Response example​

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": "Live"
}

system_health​

Returns node health and sync status.

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): none.

Returns​

  • <object>: A health status object describing the current state of the node. It contains the following fields:
    • isSyncing (boolean): Indicates whether the node is currently syncing with the network.
    • peers (integer): The number of peers the node is connected to.
    • shouldHavePeers (boolean): Indicates whether the node is expected to have peers (based on its configuration).
    • networkState (object, optional): Additional network diagnostics (included on some node types).

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": "system_health",
    "params": []
  }'

Response example​

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": {
        "peers": 19,
        "isSyncing": false,
        "shouldHavePeers": true
    }
}

system_properties​

Returns chain properties (token decimals, etc).

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): none.

Returns​

  • <object>: A key-value object containing chain-specific properties. Common fields include:
    • ss58Format (integer): The default SS58 address format used by the chain.
    • tokenDecimals (array<integer>): Number of decimal places used by each token on the chain.
    • tokenSymbol (array<string>): The symbols of the tokens used by the chain (e.g., ["DUST"] or ["ADA"]).
    • Additional implementation-specific properties may also be returned depending on the chain configuration.

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": "system_properties",
        "params": []
      }'

Response example​

{
    "jsonrpc": "2.0",
    "id": 1,
    "result": {
        "genesis_tx": "fe6a2c00040500e26a2c00303230343030303030303030303030343030303030303030303033383030303030303031356666353561343934666466653636626535353639393864396262663937313232623537313931386239623230636638313430626565393..."
    }
}

system_syncState​

Returns sync status and highest known 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): none.

Returns​

  • <object>: Synchronization status of the node, containing:
    • startingBlock (string): The block number at which the node started syncing.
    • currentBlock (string): The current block number the node has synced up to.
    • highestBlock (string): The highest known block number that the node is aware of.

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": "system_syncState",
    "params": []
  }'

Response example​

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": {
        "startingBlock": 657521,
        "currentBlock": 967344,
        "highestBlock": 967344
    }
}

system_version​

Returns node implementation version.

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): none.

Returns​

  • <string>: The version of the node implementation, typically including:
    • The client name,
    • Semantic version number, and
    • Build metadata (if applicable).

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": "system_version",
    "params": []
  }'

Response example​

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": "0.12.0-29935d2f"
}

Accounts & Keys:

account_nextIndex​

Returns the next nonce for an account.

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):

    • <string>: The account address (SS58-encoded) for which to retrieve the next usable nonce.

Returns​

  • <string>: The next valid transaction nonce for the given account, returned as a string representing an unsigned integer. This value is used when constructing a new extrinsic to ensure it has the correct transaction order.

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": "account_nextIndex",
    "params": [
      "5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY"  // example Base58 address
    ]
  }'

Response example​

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "5"
}

system_accountNextIndex​

Alias to account_nextIndex.

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):

    • <string>: The account address (SS58-encoded) for which to retrieve the next usable nonce.

Returns​

  • <string>: The next valid transaction nonce for the given account, returned as a string representing an unsigned integer. This value is used when constructing a new extrinsic to ensure it has the correct transaction order.

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": "system_accountNextIndex",
    "params": [
      "5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY"  // example Base58 address
    ]
  }'

Response example​

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "5"
}

Grandpa Finality:

grandpa_proveFinality​

Provides a justification proof for finalized blocks via Grandpa.

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):

    • <string> (block number or hash): The block identifier for which to generate a GRANDPA finality proof. Can be specified as a block number (hex or decimal) or a block hash (hex).

Returns​

  • <object>: A GRANDPA finality proof object, which typically contains:
    • block: (string) The block hash that was proven finalized.
    • justification: (string) A hex-encoded GRANDPA justification, proving the finality of the block.

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": "grandpa_proveFinality",
    "params": [981031]
  }'

Response example​

{
    "jsonrpc": "2.0",
    "id": 1,
    "result": "0x315fed908a6b3ecdba9098b49b3d4e1df77a7c4ba1ed34669cdea91dfa98ad4aa91feb09000000000000315fed908a6b3ecdba9098b49b3d4e1df77a7c4ba1ed34669cdea91dfa98ad4a62f80e003c315fed908a6b3ecdba9098b49b3d4e1df77a7c4ba1ed34669cdea91df..."
}

grandpa_roundState​

Returns the current round state of the Grandpa finality mechanism.

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): none.

Returns​

  • <object>: Information about the current GRANDPA finality round state. Common fields include:
    • setId (string): Identifier of the current GRANDPA authority set.
    • best (object): The best round known to the node, including round number and state.
    • background (array<object>): Other rounds running in the background with their states and details.

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": "grandpa_roundState",
    "params": []
  }'

Response example​

{
    "jsonrpc": "2.0",
    "id": 1,
    "result": {
        "setId": 852,
        "best": {
            "round": 1457,
            "totalWeight": 1200,
            "thresholdWeight": 801,
            "prevotes": {
                "currentWeight": 1149,
                "missing": [
                    "5C9FrTp4JJZZsAVScQVNhFaQTcxLNhmFW9r9mPDFLCbjK9BL",
                    "5CAJk7RPtFHmRefs7dpuid9VHi5nG2so2pS4MsfDYQQ6Z3L5",
                    "5CjZ1FWmxwkrLPysomPbXmKdMiwNqqofQgbxZER2TVMaLX7K",
                    "5DCdVZpFv6uMvXZDgPjvq47crKS5abVFCUfmfgXYZs2Seu8W",
                    "5DDKJxdjrMWL8AJF9xZmpjkseLVJCjTBqxFM15Kjndv2Bojr",
                    "5Dc3F4sUqWn7ntf9tnrNgk6R528o59TsHrstgjohJDXtYN63",
                    "5DrNYsps2JJH4wfrpfnSvmLV2ZoaCY4cCGKRNV36PdTBiFyK",
                    "5DwjEBxvtJCjYVRjcNWiRE93a8Yr6g725iHHmBfUDjwqNef5",
                    "5E2vguriAEWW2VZ8itKPw4LTcbHKA5LYm8TP65Ty7LncYp4K"
                ]
            }
        },
        "background": []
    }
}

Offchain Storage:

offchain_localStorageGet​

Gets data from local offchain 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>: The storage kind, which defines the namespace. Common kinds include:

      • PERSISTENT: Data that persists across restarts.
      • LOCAL: Data stored only in memory.

    2. <string>: The storage key to retrieve, typically hex-encoded or UTF-8 string depending on use case.

Returns​

  • <string|null>:
    • A hex-encoded value stored under the provided key and storage kind, if it exists.
    • null if no value is associated with the given 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": "offchain_localStorageGet",
    "params": [
      "PERSISTENT",                // storage kind
      "0x1234567890abcdef"         // key to retrieve
    ]
  }'

Response example​

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x68656c6c6f"  // hex-encoded value
}

offchain_localStorageSet​

Stores data in local offchain 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>: The storage kind, which defines the namespace. Common kinds include:

      • PERSISTENT: Data that persists across restarts.
      • LOCAL: Data stored only in memory.

    2. <string>: The storage key to set, typically hex-encoded or UTF-8 string depending on use case.

    3. <string>: The storage value to store, hex-encoded.

Returns​

  • <null>:
    • Returns null if the operation is successful.
    • Errors are returned if the node cannot write to offchain storage or if the method is restricted (common on public RPC endpoints).

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": "offchain_localStorageSet",
    "params": [
      "PERSISTENT",                // storage kind
      "0x1234567890abcdef",        // key to set
      "0x68656c6c6f"               // value to store
    ]
  }'

Response example​

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": null
}

Archive & Unstable Chain Access:

archive_unstable_body​

Fetches block body for historical blocks.

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):

    • <string> (block hash): The hash of the block whose body (list of extrinsics) should be retrieved.

Returns​

  • <array<string>>: An array of hex-encoded extrinsics contained in the block body.

    • Each string is a SCALE-encoded extrinsic represented in hexadecimal.
    • If the block has no extrinsics, an empty array is returned.

  • null: Returned if the specified block hash does not exist or cannot be accessed.

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": "archive_unstable_body",
    "params": [
      "0xabc123abc123abc123abc123abc123abc123abc123abc123abc123abc123abc1"
    ]
  }'

Response example​

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": [
    "0x280403000b009cbe..." ,
    "0x1c0200000500d2a4..."
  ]
}

archive_unstable_call​

Executes a runtime call at a specific block height.

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>: The name of the runtime function to call (e.g., Balances_freeBalance).
    2. <string>: A hex-encoded SCALE-encoded parameter payload for the runtime function (can be 0x if no parameters).
    3. <string>: The block hash at which to execute the call.

Returns​

  • <string> (hex): The hex-encoded SCALE-encoded result of the runtime function call executed at the specified block.
  • null: Returned if the block does not exist, the runtime function is unknown, or execution fails.

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": "archive_unstable_call",
    "params": [
      "Balances_freeBalance",                  // runtime function to call
      "0x1cbd2d1b6d8a54b6208b1e5d5ba3f9a3",   // SCALE-encoded params (mock data)
      "0xabc123abc123abc123abc123abc123abc123abc123abc123abc123abc123abc1" // block hash
    ]
  }'

Response example​

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x00000000000000000000000000000064"
}

archive_unstable_finalizedHeight​

Returns the finalized block height.

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): none.

Returns​

  • <string>: The height (block number) of the latest finalized block in the archive, returned as a string representing an unsigned integer.

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": "archive_unstable_finalizedHeight",
    "params": []
  }'

Response example​

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": 995341
}

archive_unstable_genesisHash​

Returns the genesis hash.

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): none.

Returns​

  • <string>: The hash of the genesis block of the chain, returned as a hex-encoded string.

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": "archive_unstable_genesisHash",
    "params": []
  }'

Response example​

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": "0x2757396f0837b1c8f52d6c16887f0d4b39c9bca5462b774a86570fb82701040b"
}

archive_unstable_hashByHeight​

Returns the block hash at a specific height.

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):

    • <integer>: The block height (number) for which to retrieve the block hash.

Returns​

  • <string|null>:
    • A hex-encoded block hash corresponding to the specified block height if it exists.
    • null if no block is found at the given height or the archive does not have that block stored.

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": "archive_unstable_hashByHeight",
    "params": [
      981031
    ]
  }'

Response example​

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": [
        "0x87f5c08ba8334e4ee1642ff9646e94dd46080b71fff03714be8b36f22e481b95"
    ]
}