Calls a contract function at an explicit block number and returns ABI-decoded SQL values.
Needs RPC · RPC required
-- Chainlink ETH/USD at one block per day
WITH as_of(day) AS (
SELECT day
FROM generate_series('2024-01-01'::DATE, '2024-01-07'::DATE, INTERVAL 1 DAY) AS t(day)
)
SELECT
day,
format_units(
(read_contract_at(
$client,
'0x5f4eC3Df9cbd43714FE2740f5E3616155c5b8419'::ADDRESS,
'[{"type":"function","name":"latestRoundData","inputs":[],"outputs":[{"name":"roundId","type":"uint80"},{"name":"answer","type":"int256"},{"name":"startedAt","type":"uint256"},{"name":"updatedAt","type":"uint256"},{"name":"answeredInRound","type":"uint80"}]}]'::JSON,
'latestRoundData',
block_at($client, day::TIMESTAMPTZ)
)).answer,
8
)::DOUBLE AS eth_usd
FROM as_of;Exact signatures with descriptions, requirements, inputs, returns, and examples.
read_contract_at(CLIENT, ADDRESS, JSON, VARCHAR, BIGINT, ...args) # RPC required The non-negative BIGINT block number may vary by row. ABI and function_name must be literal or foldable. Pinned and retained execution CLIENT values reject the explicit selector.
| Name | Type | Use |
|---|---|---|
client | CLIENT Live, pinned, or retained execution CLIENT. Pinned and execution state require the resolved block selector to be latest and reject other selectors. | requiredpositional |
to | ADDRESS Contract address to call. | requiredpositional |
abi | JSON Literal or foldable JSON ABI used for argument encoding and output types. | requiredpositional |
function_name | VARCHAR Literal or foldable ABI function name. | requiredpositional |
block_number | BIGINT Non-negative BIGINT block number. NULL produces NULL without issuing an RPC call. | requiredpositional |
| Name | Type |
|---|---|
result dynamic | ABI-derived scalar or STRUCT A function with one output returns that value directly. A function with multiple outputs returns a STRUCT with fields named from ABI outputs, or field_0, field_1, and so on for unnamed outputs. |
Use read_contract_at when the block number is already a typed BIGINT value or comes from block_at.
The ABI and function name remain planning-time constants so the exact scalar or STRUCT return type can be inferred.