Midnight — childstate, rpc, chain, state (1/2)

API reference for Midnight. All methods ->

Part 1 of 2: 1 · 2

`childstate_getStorageSize`

Gets the byte size 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) whose value size should be retrieved.
3. <string> (optional; if omitted, uses the latest block): Block hash at which to query storage.

Returns

<number|null>:
- The size of the value stored under the specified key in the given child storage at the provided block hash, expressed in bytes.
- null if the key does not exist 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_getStorageSize",
    "params": [
      "0x1a2b3c4d5e6f",      // child storage key
      "0x7f8e9d0c1b2a",      // storage key to measure
      "0xabc123abc123abc123abc123abc123abc123abc123abc123abc123abc123abc1"  // block hash
    ]
  }'

Response example

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": 16
}

RPC Meta:

`rpc_methods`

Returns a list of all available RPC methods.

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>: Lists all RPC methods supported by the node along with their version numbers.
- methods (array<string>): An array of available method names.
- version (number): The RPC API version of the node.

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

Response example

{
    "jsonrpc": "2.0",
    "id": 1,
    "result": {
        "methods": [
            "account_nextIndex", "archive_unstable_body", "archive_unstable_call", "archive_unstable_finalizedHeight", "archive_unstable_genesisHash", "archive_unstable_hashByHeight", "archive_unstable_header", "archive_unstable_storage", "author_hasKey", "author_hasSessionKeys", "author_insertKey", "author_pendingExtrinsics", "author_removeExtrinsic", "author_rotateKeys", "author_submitAndWatchExtrinsic", "author_submitExtrinsic", "author_unwatchExtrinsic", "chainHead_v1_body", "chainHead_v1_call", "chainHead_v1_continue", "chainHead_v1_follow", "chainHead_v1_header", "chainHead_v1_stopOperation", "chainHead_v1_storage", "chainHead_v1_unfollow", "chainHead_v1_unpin", "chainSpec_v1_chainName", "chainSpec_v1_genesisHash", "chainSpec_v1_properties", "chain_getBlock", "chain_getBlockHash", "chain_getFinalisedHead", "chain_getFinalizedHead", "chain_getHead", "chain_getHeader",    "chain_getRuntimeVersion", "chain_subscribeAllHeads", "chain_subscribeFinalisedHeads", "chain_subscribeFinalizedHeads", "chain_subscribeNewHead", "chain_subscribeNewHeads", "chain_subscribeRuntimeVersion", "chain_unsubscribeAllHeads", "chain_unsubscribeFinalisedHeads", "chain_unsubscribeFinalizedHeads", "chain_unsubscribeNewHead", "chain_unsubscribeNewHeads", "chain_unsubscribeRuntimeVersion", "childstate_getKeys", "childstate_getKeysPaged", "childstate_getKeysPagedAt", "childstate_getStorage", "childstate_getStorageEntries", "childstate_getStorageHash", "childstate_getStorageSize", "grandpa_proveFinality", "grandpa_roundState", "grandpa_subscribeJustifications", "grandpa_unsubscribeJustifications", "midnight_apiVersions", "midnight_contractState", "midnight_decodeEvents", "midnight_jsonBlock", "midnight_jsonContractState", "midnight_ledgerVersion", "midnight_unclaimedAmount", "midnight_zswapChainState", "midnight_zswapStateRoot", "offchain_localStorageGet", "offchain_localStorageSet", "rpc_methods", "sidechain_getAriadneParameters", "sidechain_getEpochCommittee", "sidechain_getParams", "sidechain_getRegistrations", "sidechain_getStatus", "state_call", "state_callAt", "state_getChildReadProof", "state_getKeys", "state_getKeysPaged", "state_getKeysPagedAt", "state_getMetadata", "state_getPairs", "state_getReadProof", "state_getRuntimeVersion", "state_getStorage", "state_getStorageAt", "state_getStorageHash", "state_getStorageHashAt", "state_getStorageSize", "state_getStorageSizeAt", "state_queryStorage", "state_queryStorageAt", "state_subscribeRuntimeVersion", "state_subscribeStorage", "state_traceBlock", "state_unsubscribeRuntimeVersion", "state_unsubscribeStorage", "subscribe_newHead", "system_accountNextIndex", "system_addLogFilter", "system_addReservedPeer", "system_chain", "system_chainType", "system_dryRun", "system_dryRunAt", "system_health", "system_localListenAddresses", "system_localPeerId", "system_name", "system_nodeRoles", "system_peers", "system_properties", "system_removeReservedPeer", "system_reservedPeers", "system_resetLogFilter", "system_syncState", "system_unstable_networkState", "system_version", "transactionWatch_v1_submitAndWatch", "transactionWatch_v1_unwatch", "transaction_v1_broadcast", "transaction_v1_stop", "unsubscribe_newHead"
        ]
    }
}

Chain & Block Data:

`chain_getBlock`

Returns full block data for the specified 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):
- <string> (optional; default = latest block): Block hash (hex-encoded).

Returns

<object|null>: The full block data for the specified (or latest) block.
- block (object):
  - header (object): Standard block header fields:
    - parentHash (string): Hash of the parent block.
    - number (string): Block number (in hex).
    - stateRoot (string): State trie root hash.
    - extrinsicsRoot (string): Extrinsics trie root hash.
    - digest (object): Consensus-specific digest logs.
  - extrinsics (array<string>): Array of hex-encoded extrinsics included in the block.
- justifications (array, optional): Consensus justifications if available.
null: Returned if the block hash is unknown or unavailable.

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

Response example

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": {
        "block": {
            "header": {
                "parentHash": "0x26b043f145df5bc8a79ef3d4b28c4268f00d8dffb3240a5f2e0a9cb9fdf65463",
                "number": "0xfd930",
                "stateRoot": "0x99e9486ce0903d2e6edd3cb956a8d1e494bd62837a3e49522ae4ce132744c1af",
                "extrinsicsRoot": "0xd76623660daae937c6946187f8fd42f73565d8871f558c38691fc66669d41b95",
                "digest": {
                    "logs": [
                        "0x066175726120b6ef6b1100000000",
                        "0x066d637368806ee7f2ab25cdde91cf901ff3fcf2574b03aab5ff415dad4709d0eaaed37ba253",
                        "0x044d4e535610e02e0000",
                        "0x05617572610101d61d4bb831d89528e61ed672666d5365812e9060e4a9abe832bea327fb48d541eba53fe823022f7d2baee8baa61a981a648c87ded75656a2f01e5fd66fb7b782"
                    ]
                }
            },
            "extrinsics": [
                "0x280401000ba039c2519801",
                "0x9c040a00e12e00007f913da0a8f430c261bda1748a29a452785213eeb5c70f27efd0afa74f7a5e2a"
            ]
        },
        "justifications": null
    }
}

`chain_getBlockHash`

Returns the block hash for a given block number.

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):
- <number> (unsigned integer; optional; default = latest block): Block number.

Returns

<string|null>:
- The block hash (hex-encoded) for the specified block number.
- If no block number is provided, returns the hash of the latest block.
- null if the given block number is unknown or unavailable.

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

Response example

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

`chain_getFinalisedHead`

Returns the latest finalized block 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|null>:
- The hash of the latest finalized block (hex-encoded).
- null if no finalized block is available (rare or only in misconfigured nodes).

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

Response example

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": "0xddeff7d6554d5b2e7d28dd2797ec241b7ff45f48d154b34a0b4e8f0cb19065ff"
}

`chain_getFinalizedHead`

Returns the latest finalized block 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|null>:
- The hash of the latest finalized block (hex-encoded).
- null if no finalized block is available (rare or only in misconfigured nodes).

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

Response example

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": "0x2da74d4471a940299d8e7635aa131224fb5df9bddf1250b9c6d5b7c93a0f4faa"
}

`chain_getHead`

Returns the current best block 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|null>:
- The hash of the current best (head) block in the chain (hex-encoded).
- null if the head is not available or the node is not fully synced.

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

Response example

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": "0xdfe4193fb5f00ba7a0c27b74c1350135a1ab4d317352cd653b2dd1955a47bda4"
}

`chain_getHeader`

Fetches the header of a given 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):
- <string> (optional; default = latest block): Block hash (hex-encoded) of the block header to fetch.

Returns

<object|null>: The block header for the specified block hash or the latest block if no hash is provided.
- parentHash (string): Hash of the parent block.
- number (string): Block number (hex-encoded).
- stateRoot (string): State trie root hash.
- extrinsicsRoot (string): Extrinsics trie root hash.
- digest (object): Consensus-specific digest logs.

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

Response example

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": {
        "parentHash": "0x40053cbf0cd5a892d83dd1e571eca18aa26f23b662d73543e4923fd1a423b72d",
        "number": "0xfda2c",
        "stateRoot": "0x60433a64c395298ed61505bc99640a122ccac6cf001c55a437ee7843d9fdd255",
        "extrinsicsRoot": "0xe5e242d6ee488f323663b2361fc35562a753d4144f4f94ee6530d4109685d646",
        "digest": {
            "logs": [
                "0x066175726120bcf06b1100000000",
                "0x066d637368805157cac8b69df7748c7d9705a707a2a6a1f2d0ed9d7f669d1e568b91a02e26fa",
                "0x044d4e535610e02e0000",
                "0x05617572610101bebbfeb2aa9614db5d1b9cb0835c76b7916cd4012e9aa1ea20cdb0817fcb78037ef3eccbc41d3ed1c445a7869410cb5ac5d2c87a9b49d17b58009ae78e82b482"
            ]
        }
    }
}

`chain_getRuntimeVersion`

Returns the current runtime version 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):
- <string> (optional; default = latest block): Block hash (hex-encoded) at which to retrieve the runtime version.

Returns

<object>: Runtime version details for the given block (or the latest if no hash is provided).
- specName (string): Name of the runtime specification.
- implName (string): Name of the runtime implementation.
- authoringVersion (number): Authoring version of the runtime.
- specVersion (number): Version of the runtime specification.
- implVersion (number): Implementation version.
- apis (array<[string, number]>): List of supported API names and their version numbers.
- transactionVersion (number): Transaction format version supported by the runtime.
- stateVersion (number, optional): State format version (if present).

Request example

{
    "id": 1,
    "jsonrpc": "2.0",
    "result": {
        "specName": "midnight",
        "implName": "midnight",
        "authoringVersion": 1,
        "specVersion": 12000,
        "implVersion": 0,
        "apis": [
            [
                "0xfbc577b9d747efd6",
                1
            ],
            [
                "0xdf6acb689907609b",
                5
            ],
            [
                "0x7d699da8a672e867",
                4
            ]
        ],
        "transactionVersion": 2,
        "stateVersion": 1
    }
}

State & Storage:

`state_call`

Executes a runtime call without submitting an extrinsic.

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>: Runtime function name (e.g., Metadata_metadata).
2. <string>: Data (hex-encoded SCALE-encoded arguments for the function).
3. <string> (32-byte, hex; optional; default = latest block): Block hash.

Returns

<string>: A hex-encoded SCALE-encoded result returned by the runtime function call.
null: Returned if the function call fails or the given parameters are 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": "state_call",
    "params": [
      "Metadata_metadata",
      "0x"
    ]
  }'

Response example

{
    "jsonrpc": "2.0",
    "id": 1,
    "result": "0xde0904006d6574610e8103000c1c73705f636f72651863727970746f2c4163636f756e7449643332000004000401205b75383b2033325d0000040000032000000008000800000503000c08306672616d655f73797374656d2c4163636f756e74496e666f08144e6f6e636501102c4163636f756e74446174610114001401146e6f6e63651001144e6f6e6365000124636f6e73756d657273100120526566436f756e7400012470726f7669646572731001205265664..."
}

`state_callAt`

Executes a runtime call at a specific 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>: Runtime function name (for example, Metadata_metadata).
2. <string>: Data — SCALE-encoded arguments for the function, hex-encoded (use 0x if there are no arguments).
3. <string> (32-byte, hex): Block hash at which to execute the runtime function call.

Returns

<string>: A hex-encoded SCALE-encoded result returned by the runtime function call at the specified block.
null: Returned if the call fails or the provided parameters are 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": "state_callAt",
    "params": [
      "Metadata_metadata",
      "0x",
      "0x94f03b64f26069f6995de0e68442a3470801fd6cdb3a0cf7491ed7ca217f23ec"
    ]
  }'

Response example

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

`state_getChildReadProof`

Returns proof of inclusion for 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>>: Keys — an array of hex-encoded storage keys inside the child storage to generate a read proof for.
3. <string> (hex-encoded, 32-byte): Block hash at which to generate the read proof.

Returns

<object>: The read proof object for the requested child storage keys.
- at (string): Block hash at which the proof was generated.
- proof (array<string>): An array of hex-encoded proof nodes required to prove the existence of the keys.

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": "state_getChildReadProof",
    "params": [
      "0x1a2b3c4d5e6f",      // child storage key
      [
        "0x7f8e9d0c1b2a",    // key 1
        "0x1234567890ab"     // key 2
      ],
      "0x498b4b3aa63dc3abaebf559be8e903357c07589532eb931f9097d533c99800a2" // block hash
    ]
  }'

Response example

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "at": "0x498b4b3aa63dc3abaebf559be8e903357c07589532eb931f9097d533c99800a2",
    "proof": [
      "0x1234abcd5678ef90",
      "0x9abcdeffedcba9876543210011223344"
    ]
  }
}

`state_getKeys`

Returns a list of all keys in the 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>: Key prefix (hex-encoded) to filter returned keys. Use 0x to retrieve all keys.
2. <string> (hex-encoded, 32-byte; optional): Block hash.

Returns

<array<string>>: A list of hex-encoded keys in the state that match the specified prefix.
[]: Returned if no keys match the given prefix.
null: Returned if the provided block hash is invalid or unavailable.

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": "state_getKeys",
    "params": [
      "0x"
    ]
  }'

Response example

{
    "jsonrpc": "2.0",
    "id": 1,
    "result": [
        "0x0b20199ace3564d0964e2c4d4a9ba4694e7b9012096b41c4eb3aaf947f6ea429",
        "0x0cfd083eaa944b95833ee029c0bdffe34e7b9012096b41c4eb3aaf947f6ea429",
        "0x0cfd083eaa944b95833ee029c0bdffe388dcde934c658227ee1dfafcd6e16903",
        "0x0cfd083eaa944b95833ee029c0bdffe3e0cdd062e6eaf24295ad4ccfc41d4609",
        "0x26aa394eea5630e07c48ae0c9558cef702a5c1b19ab7a04f536c519aca4983ac",
        "0x26aa394eea5630e07c48ae0c9558cef70a98fdbe9ce6c55837576c60c7af3850",
        "0x26aa394eea5630e07c48ae0c9558cef734abf5cb34d6244378cddbf18e849d96"
    ]
}

childstate_getStorageSize​

Parameters​

Returns​

Request example​

Response example​

rpc_methods​

Parameters​

Returns​

Request example​

Response example​

chain_getBlock​

Parameters​

Returns​

Request example​

Response example​

chain_getBlockHash​

Parameters​

Returns​

Request example​

Response example​

chain_getFinalisedHead​

Parameters​

Returns​

Request example​

Response example​

chain_getFinalizedHead​

Parameters​

Returns​

Request example​

Response example​

chain_getHead​

Parameters​

Returns​

Request example​

Response example​

chain_getHeader​

Parameters​

Returns​

Request example​

Response example​

chain_getRuntimeVersion​

Parameters​

Returns​

Request example​

state_call​

Parameters​

Returns​

Request example​

Response example​

state_callAt​

Parameters​

Returns​

Request example​

Response example​

state_getChildReadProof​

Parameters​

Returns​

Request example​

Response example​

state_getKeys​

Parameters​

Returns​

Request example​

Response example​

`childstate_getStorageSize`

Parameters

Returns

Request example

Response example

`rpc_methods`

Parameters

Returns

Request example

Response example

`chain_getBlock`

Parameters

Returns

Request example

Response example

`chain_getBlockHash`

Parameters

Returns

Request example

Response example

`chain_getFinalisedHead`

Parameters

Returns

Request example

Response example

`chain_getFinalizedHead`

Parameters

Returns

Request example

Response example

`chain_getHead`

Parameters

Returns

Request example

Response example

`chain_getHeader`

Parameters

Returns

Request example

Response example

`chain_getRuntimeVersion`

Parameters

Returns

Request example

`state_call`

Parameters

Returns

Request example

Response example

`state_callAt`

Parameters

Returns

Request example

Response example

`state_getChildReadProof`

Parameters

Returns

Request example

Response example

`state_getKeys`

Parameters

Returns

Request example

Response example