state_getStorageSize - Bittensor RPC Method
Get the byte length of a storage value for a given key on Bittensor.
Returns the size in bytes of the SCALE-encoded storage value for a given key at the best block (or at a specified block hash). This is useful for checking whether a key exists and estimating the bandwidth needed to fetch its full value without actually downloading it.
Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
key | string | Yes | Hex-encoded storage key. |
blockHash | string | No | Hex-encoded block hash. Defaults to the best block if omitted. |
Response
| Field | Type | Description |
|---|---|---|
result | number or null | Size in bytes of the storage value, or null if the key does not exist. |
Code Examples
Use Cases
- Existence check -- Determine if a storage key exists without fetching the value (returns
nullfor non-existent keys). - Bandwidth estimation -- Estimate how much data will be transferred when reading a storage value, useful for planning batch reads.
- Runtime code size -- Check the size of the Wasm runtime blob stored under
:codewithout downloading it. - Storage monitoring -- Track the size of specific storage entries over time to monitor chain growth.
Notes
- Returns the size of the raw SCALE-encoded value, not the decoded value.
- Returns
nullfor non-existent keys rather than 0. - Requires an archive node for historical block hashes.
Related Methods
state_getStorage-- Read the full storage valuestate_getStorageHash-- Get the hash of a storage valuestate_getStorageAt-- Read storage at a specific block hashchildstate_getStorageSize-- Get size of child trie storage values