Reads an account's runtime bytecode from live RPC state, the exact state identified by a pinned CLIENT, or retained execution state. Without a CLIENT, it builds a reusable READ and does not access state.
Live RPC
-- Runtime bytecode of WETH
SELECT code_at(
$client,
'0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2'::address -- Ethereum mainnet WETH
) AS code;code_at(CLIENT, ADDRESS) # Immediate Read · RPC required Reads the CLIENT's current state context. For live clients that means latest; pinned and execution clients retain their own exact state identity.
| Name | Type |
|---|---|
code | BYTES |
Deployed bytecode. Returns runtime bytecode as BYTES. A live RPC no-code response is NULL; pinned and execution state represent known no-code as empty BYTES. NULL or empty client, NULL address and NULL height return NULL; live RPC and decoding failures raise. Historical live reads and pinned-state hydration may require archive access.
code_at(CLIENT, ADDRESS, BIGINT) # Immediate Read · RPC required Reads runtime bytecode at an exact block height through a live CLIENT. Pinned and execution CLIENTs reject an explicit height because their state identity is already fixed.
| Name | Type | Use |
|---|---|---|
client | CLIENT Readable EVM state represented by a live, pinned, or retained execution CLIENT. | required positional |
address | ADDRESS Account address whose runtime bytecode should be read. | required positional |
block_number | BIGINT Optional historical height for a live CLIENT. NULL gives NULL without a read. | required positional |
| Name | Type |
|---|---|
code | BYTES |
Deployed bytecode. Returns runtime bytecode as BYTES. A live RPC no-code response is NULL; pinned and execution state represent known no-code as empty BYTES. NULL or empty client, NULL address and NULL height return NULL; live RPC and decoding failures raise. Historical live reads and pinned-state hydration may require archive access.
Live RPC
-- Runtime bytecode of WETH at Ethereum block 21000000
SELECT code_at(
$client,
'0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2'::address, -- Ethereum mainnet WETH
21000000
) AS code;code_at(CLIENT, ADDRESS, BIGINT, JSON) # Immediate Read · RPC required Reads runtime bytecode at an exact block height through a live CLIENT; with on_error null_on_failure, a failed live read is NULL instead of an error.
| Name | Type | Use |
|---|---|---|
client | CLIENT Readable EVM state represented by a live, pinned, or retained execution CLIENT. | required positional |
address | ADDRESS Account address whose runtime bytecode should be read. | required positional |
block_number | BIGINT Optional historical height for a live CLIENT. NULL gives NULL without a read. | required positional |
options | JSON Constant JSON object. on_error is raise (the default) or null_on_failure: a live read the node could not answer is NULL and no code is empty BYTES, for a caller that records a failed read as unread. Any other key raises. | required positional |
| Name | Type |
|---|---|
code | BYTES |
Deployed bytecode. Returns runtime bytecode as BYTES. A live RPC no-code response is NULL; pinned and execution state represent known no-code as empty BYTES. NULL or empty client, NULL address and NULL height return NULL; live RPC and decoding failures raise. Historical live reads and pinned-state hydration may require archive access.
Live RPC
-- Runtime bytecode of WETH at Ethereum block 21000000, NULL if the node cannot answer
SELECT code_at(
$client,
'0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2'::address, -- Ethereum mainnet WETH
21000000,
'{"on_error":"null_on_failure"}'
) AS code;code_at(ADDRESS) # Read Builder Records one address for a later account-code lookup; construction does not access state.
| Name | Type | Use |
|---|---|---|
address | ADDRESS Contract or account address whose deployed code should be observed. | required positional |
| Name | Type |
|---|---|
read | READ |
Account-code READ. Returns a READ whose successful EVM_VALUE contains the account's runtime bytecode.
Runs locally
SELECT code_at('0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2'::ADDRESS); -- Ethereum mainnet WETHThe two-argument overload reads latest from a live CLIENT, so its result can change between runs.
Use block_number for reproducible bytecode evidence. Older heights may require an archive-capable provider.
Relation-sized attached pinned reads may share one hash-pinned JSON-RPC batch; each request retains the CLIENT's block hash and canonicality requirement.
An explicit block number is valid only for a live CLIENT. Supplying one for pinned or execution state raises STATE_SOURCE_INCONSISTENT.
Pinned reads use the CLIENT's block hash and canonicality requirement. An inconsistent identity or provider result raises STATE_SOURCE_INCONSISTENT.
A detached pinned CLIENT can use retained state only; a cache miss raises HYDRATION_UNAVAILABLE. Attached pinned hydration can also raise HYDRATION_UNAVAILABLE when its provider cannot be reached.
Pinned hydration reports HISTORICAL_STATE_UNAVAILABLE when the provider does not retain the required state.
Execution reads use retained execution state and raise CHECKPOINT_UNAVAILABLE when that state cannot be resolved.
Only overloads returning READ defer state access until an OBSERVATION consumes the READ during PROGRAM execution.