Interacting With Chainlink Contracts

How to Query Chainlink Contracts

This page will provide you with information regarding how to query a Chainlink Aggregator

Included are some examples using bash.

All examples are based on the LINK / USD price feed on Ethereum Mainnet

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Overview

Each Chainlink Aggregator has a wide range of data that you can query.

From historic price data to the timestamp of the most recent completed round, a lot of information is stored on-chain and available for you to query.

This page will be broken out into each major contract type, and then each individual query that can be made, with examples.

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EACAggregatorProxy

LINK / USD EAC AggregatorProxy contract address: 0x2c1d072e956affc0d435cb7ac38ef18d24d9127c

The Access Controlled Aggregator Proxy is a proxy contract that enables the owner to point it to other contracts as needed/desired.

This prevents the users from having to update anything if they wanted to move to a new contract version/release

Read Calls

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accessController

The accessController is a smart contract that acts as a whitelist for which addresses are able to call the contract. For the LINK / USD price feed, the referenced accessController smart contract is a null value set to 0x0000000000000000000000000000000000000000

• Example Query:
  • ACCESS_CONTROLLER=$(curl -s -H "Content-Type: application/json" https://$YOUR_RPC_ENDPOINT -d '{"jsonrpc": "2.0", "id": 123, "method": "eth_call", "params":[{"from":null,"to":"0x2c1d072e956AFFC0D435Cb7AC38EF18d24d9127c","data":"0xbc43cbaf"}, "latest"]}' | jq -r .result) && echo "$ACCESS_CONTROLLER"

• Example Response:
  • 0x0000000000000000000000000000000000000000000000000000000000000000
    • (remove leading 24 0's)

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aggregator

The aggregator is the on-chain contract that each of the Chainlink Nodes responds to. The AggregatorProxy contract points to the configured Aggregator as it's primary source of information

• Example Query:
  • AGGREGATOR=$(curl -s -H "Content-Type: application/json" https://$YOUR_RPC_ENDPOINT -d '{"jsonrpc": "2.0", "id": 123, "method": "eth_call", "params":[{"from":null,"to":"0x2c1d072e956AFFC0D435Cb7AC38EF18d24d9127c","data":"0x245a7bfc"}, "latest"]}' | jq -r .result) && echo "$AGGREGATOR"

• Example Response:
  • 0x000000000000000000000000dfd03bfc3465107ce570a0397b247f546a42d0fa
    • (remove leading 24 0's)

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decimals

The decimals value tells the reader of the contract how many decimal places they need to adjust to get the proper value.

For example, if the LINK / USD price feed has a decimlas value of 8, and the latest round shows a response of 726792272, then we would shift the decimal 8 places to end with a value of 7.26792272.

• Example Query:
  • DECIMALS=$(curl -s -H "Content-Type: application/json" https://$YOUR_RPC_ENDPOINT -d '{"jsonrpc": "2.0", "id": 123, "method": "eth_call", "params":[{"from":null,"to":"0x2c1d072e956AFFC0D435Cb7AC38EF18d24d9127c","data":"0x313ce567"}, "latest"]}' | jq -r .result) && echo "$((DECIMALS))"
• Example Response:
  • 8

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description

The desctiption of the Proxy is just a friendly name, in this case displaying LINK / USD

• Example Query:
  • DESCRIPTION=$(curl -s -H "Content-Type: application/json" https://$YOUR_RPC_ENDPOINT -d '{"jsonrpc": "2.0", "id": 123, "method": "eth_call", "params":[{"from":null,"to":"0x2c1d072e956AFFC0D435Cb7AC38EF18d24d9127c","data":"0x7284e416"}, "latest"]}' | jq -r .result) && echo $DESCRIPTION | xxd -r -p

• Example Response:
  • LINK / USD

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getAnswer

This call will provide you with the data for the round you have specified.

• Example Query:
  • curl
• Example Response
  • asdf

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getRoundData

Similar to the above getAnswer call, this call will get additional information from the round you have specified.

• Example Query:
  • curl
• Example Response
  • asdf

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getTimestamp

This getTimestamp call will provide you with the timestamp of the block containing the data from the round you have specified.

• Example Query:
  • curl
• Example Response
  • asdf

latestAnswer

The latestAnswer call provides you with the value that was written to chain during the most recent completed round

• Example Query:
  • curl
• Example Response
  • asdf

latestRound

This call will provide you with the most recent completed round number.

• Example Query:
  • curl
• Example Response
  • asdf

latestRoundData

This call is similar to getRoundData, but it will automatically get the round data for the most recently completed round.

• Example Query:
  • curl
• Example Response
  • asdf

latestTimestamp

Similar to latestRoundData and getTimestamp, the latestTimestamp call will provide you with the timestamp of the block containing the response from the latest completed round.

• Example Query:
  • curl
• Example Response
  • asdf

owner

The owner query will respond with the address that has ownership of the contract you query.

• Example Query:
  • curl
• Example Response
  • asdf

proposedAggregator

The proposedAggregator query will give you the address of the proposed aggregator, if there is one.

• Example Query:
  • curl
• Example Response
  • asdf

proposedGetRoundData

This call provides you with the round data for the requested round from the proposed aggregator, if there is one.

• Example Query:
  • curl
• Example Response
  • asdf

proposedLatestRoundData

Similar to the above, this call will get you the data from the latest round of the proposed aggregator.

• Example Query:
  • curl
• Example Response
  • asdf

version

This gets you the version of the contract you're querying.

• Example Query:
  • curl
• Example Response
  • asdf