Polkadot — Methods supported

API reference for Polkadot. All methods ->

Methods supported

• chain_getBlock — retrieves the header and body of a relay chain block.
• chain_getBlockHash — retrieves the block hash for a specific block.
• chain_getHeader — retrieves the header for a specific block.
• chain_getFinalizedHead — retrieves the hash of the last finalized block in the canon chain.
• state_getStorage — retrieves the storage for a key.
• state_getStorageHash — retrieves the storage hash.
• state_getStorageSize — retrieves the storage size.
• grandpa_proveFinality — proves finality for the given block number, returning the Justification for the last block in the set.
• grandpa_roundState — returns the state of the current best round state as well as the ongoing background rounds.
• system_chain — retrieves the chain.
• system_chainType — retrieves the chain type.

---

chain_getBlock

Retrieves the header and body of a relay chain 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):

  • <BlockHash> (data; 32 byte; optional): a hash of the block to retrieve; if omitted, retrieves the latest finalized block.

Returns

• SignedBlock: the header and body data of a relay chain block.

Request example

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

Response example

{
    "jsonrpc": "2.0",
    "result": {
        "block": {
            "header": {
                "parentHash": "0xe121a7c43cbe19eab2601d422df9173a84553cda9f0cd59e0656227696f46d30",
                "number": "0xedaaed",
                "stateRoot": "0x4f4dd4f1bc408dfd01222a8d1401a96c9abb8be86ab60c0e01f10b4a54834b6f",
                "extrinsicsRoot": "0xf310b41030a9bbf5788176a0a187a7fe84833729fb763883329bcc2f9a308a03",
                "digest": {
                    "logs": [
                        "0x0642414245b50103fc000000f4aebb1000000000440c17d240df02d42ddab5c961fe2649e30f69aea189e5bc95487ae5f889a74bc516a159ccc7db48e5253dae8f1168be0c66597b18ab1e2248ecd3862eae9e0a8c74b856d20d6916ab8cbe3cd4955f183c231bde98ca24dbb3f201468cc23b0f",
                        "0x054241424501015a6148654f94084ca0373a6d708704ce54ae704e159d51eb00d7de032b2b3824a91a4509f94f90fda82a3ff372b0003c0440475b9218e6469d883eeba276ac8a"
                    ]
                }
            },
            "extrinsics": [
                "0x280403000bc076d42e8801",
                "0xdd02040c00ecaaed009c98002408011220c9b7d94c0c8dc84ca9034c1a6926bfb2e0b1e31c0c9fbaee8126874d32d122840878742f6970342f3134312e39382e3231392e3139392f7463702f33303333336c682f6970342f3130302e36342e332e31322f7463702f333033333379190000f600000029010000903755c7655994b2ca1f457d26c947041f9e6970e6b3cf578ee8459d061cc20d3d7e65d5c166fcca21059ad60b89d21f8a2b5574da4414adb72941c0c2e44d8c"
            ]
        },
        "justifications": null
    },
    "id": 1
}

---

chain_getBlockHash

Retrieves the block hash for 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):

  <BlockNumber> (string; hex; optional): the number of a block to retrieve the hash for; if omitted, retrieves the latest finalized block.

Returns

• <BlockHash>: the block hash of the block specified.

Request example

curl -X POST https://rpc.ankr.com/polkadot/YOUR_ANKR_API_KEY \
-H 'Content-Type: application/json' \
-d '{
      "jsonrpc": "2.0",
      "id": 1,
      "method": "chain_getBlockHash",
      "params": ["0xb48f90"]
}'

Response example

{
    "jsonrpc": "2.0",
    "result": "0x92f387735d1d4459c8e6d5931bc350712a1697866ed708fb241ee97a1bd0da94",
    "id": 1
}

---

chain_getHeader

Retrieves the header for 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):

  • <BlockHash> (data; 32 byte; optional): a hash of the block to retrieve the header for; if omitted, shows the result for the latest finalized block.

Returns

• <Header>: the header of the block specified.

Request example

curl -X POST https://rpc.ankr.com/polkadot/YOUR_ANKR_API_KEY \
-H 'Content-Type: application/json' \
-d '{
      "jsonrpc": "2.0",
      "id": 1,
      "method": "chain_getHeader",
      "params": ["0x56547256415c6ca5d7e43e32f0664ede1aa78aae59e07cdc64f2037beba31e9e"]
}'

Response example

{
    "jsonrpc": "2.0",
    "result": {
        "parentHash": "0x88ac4b5bc7ea4e0cb1b8d8e1d2dce838e37d1a4480c4bde37bdfdcc9c8fffb64",
        "number": "0xb48f75",
        "stateRoot": "0xa2baf709447aa9055b4ca5046fc76a0ca05ace90758fcf3bc3bc004612173bfa",
        "extrinsicsRoot": "0xe94f82eae3aba9331e0370f1c3b7d72da3bd9a82dd36711448d6197b6659e308",
        "digest": {
            "logs": [
                "0x0642414245b50103c0000000076382100000000084c21f756e3473b8717c13d27c85a94466cbd0f64fe8bbd37cbf23dd46c70e5a49626481005b811dfcff67dda4b12ee502cb3589c6b2ff6450c6537f18298c08fd2942aaa2f0ee1591522fe4dc0482949c920a046201cf39f7ba766af4907509",
                "0x05424142450101340de0372f172ba4d9c12d767ddd42e2f1844691c93f74773e7839ccba29b96f400a6b8bbea109e807033696c182f08c8c02918c3521968612cd20ed82af0b89"
            ]
        }
    },
    "id": 1
}

---

chain_getFinalizedHead

Retrieves the hash of the last finalized block in the canon 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

• <BlockHash>: the hash of the last finalized block in the canon chain.

Request example

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

Response example

{
    "jsonrpc": "2.0",
    "result": "0xc487e58e468240ea30fa17a2d982fb47d0213dd64e6b980e4a0cb4fb6bcc3ca6",
    "id": 1
}

---

state_getStorage

Retrieves the storage for a key.

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):

  • <StorageKey> (string; hex ; required): the key to retrieve the storage for.
  • <BlockHash> (data; 32 byte; optional): a hash of the block.

Returns

• <StorageData>: the storage data.

Request example

curl -X POST https://rpc.ankr.com/polkadot/YOUR_ANKR_API_KEY \
-H 'Content-Type: application/json' \
-d '{
      "jsonrpc": "2.0",
      "id": 1,
      "method": "state_getStorage",
      "params": ["0xf0c365c3cf59d671eb72da0e7a4113c49f1f0515f462cdcf84e0f1d6045dfcbb"]
}'

Response example

{
    "jsonrpc": "2.0",
    "result": "0xf08af92e88010000",
    "id": 1
}

---

state_getStorageHash

Retrieves the storage 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):

  • <StorageKey> (string; hex; required): a storage key.
  • <BlockHash> (data; 32 byte; optional): a hash of the block.

Returns

• <Hash>: the storage hash.

Request example

curl -X POST https://rpc.ankr.com/polkadot/YOUR_ANKR_API_KEY \
-H 'Content-Type: application/json' \
-d '{
      "jsonrpc": "2.0",
      "id": 1,
      "method": "state_getStorageHash",
      "params": ["0xf0c365c3cf59d671eb72da0e7a4113c49f1f0515f462cdcf84e0f1d6045dfcbb"]
}'

Response example

{
    "jsonrpc": "2.0",
    "result": "0xcadcddea7fce8dd4169f521f2c043b3637bca8b07870994491d3b3d9bdfb4102",
    "id": 1
}

---

state_getStorageSize

Retrieves the storage size.

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):

  • <StorageKey> (string; hex; required): the storage key.
  • <BlockHash> (data; 32 byte; optional): a hash of the block.

Returns

• <u64>: the storage size.

Request example

curl -X POST https://rpc.ankr.com/polkadot/YOUR_ANKR_API_KEY \
-H 'Content-Type: application/json' \
-d '{
      "jsonrpc": "2.0",
      "id": 1,
      "method": "state_getStorageSize",
      "params": ["0xf0c365c3cf59d671eb72da0e7a4113c49f1f0515f462cdcf84e0f1d6045dfcbb"]
}'

Response example

{
    "jsonrpc": "2.0",
    "result": 8,
    "id": 1
}

---

grandpa_proveFinality

Proves finality for the given block number, returning the Justification for the last block in the set.

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):

  • <BlockNumber> (integer; required): the number of a block to prove finality for.

Returns

• Option<EncodedFinalityProofs>: the Justification for the last block in the set.

Request example

curl -X POST https://rpc.ankr.com/polkadot/YOUR_ANKR_API_KEY \
-H 'Content-Type: application/json' \
-d '{
      "jsonrpc": "2.0",
      "id": 1,
      "method": "grandpa_proveFinality",
      "params": [11833440]
}'

---

grandpa_roundState

Returns the state of the current best round state as well as the ongoing background rounds.

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

• <ReportedRoundStates>: the states of reported rounds.

Request example

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

Response example

{
    "jsonrpc": "2.0",
    "result": {
        "setId": 1446,
        "best": {
            "round": 14118,
            "totalWeight": 297,
            "thresholdWeight": 199,
            "prevotes": {
                "currentWeight": 297,
                "missing": []
            },
            "precommits": {
                "currentWeight": 0,
                "missing": [
                    "12cCLNxo2WqvqizuMrgHtpjUz2s5xmomTM7y3FWESbvjcwq",
                    "14ZryeDT1MmSSX29QaJ2pbNjJDv8hoLTfwFmDwe6mDMh3Vj",
                    "15E5zYJhV2iqZXmL1FKe8MdFocj9n1phEaJob4izAaXA9bw"
                ]
            }
        },
        "background": []
    },
    "id": 1
}

---

system_chain

Retrieves 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

• <Text>: a chain name.

Request example

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

Response example

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

---

system_chainType

Retrieves the chain type.

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

• <ChainType>: a chain type.

Request example

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

Response example

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