Linked Questions

0 votes
2 answers
2k views

How can an Ethereum contract read data from excel [duplicate]

Is there a possibility to read excel from smart contract? If yes how? Do I need some relay or something.
senzacionale's user avatar
1 vote
1 answer
2k views

Calling External Web Service from Smart Contract [duplicate]

Trying to find a way to invoke a external web service to perform any operation based on some action on the smart contract. Request to share details as to how to perform the same.
Susmit's user avatar
  • 1,804
0 votes
1 answer
501 views

Most secure way to get ERC20 token price in Solidity (Polygon network) [duplicate]

I'm building infrastructure for a blockchain game where users can spend ERC20 tokens to buy tickets whose prices are $0.25, $0.5, $1, etc. For that, I need to get ERC20 token current price in ...
MantasFam's user avatar
  • 327
0 votes
0 answers
271 views

HTTP GET/POST request from within a solidity smart contract [duplicate]

I am working on a problem that requires a solidity smart contract to make an HTTP GET/POST request to a website. The scenario is given below -A simple text file 'abc.txt' with a 32-byte string is ...
Nauman Shakir's user avatar
0 votes
1 answer
188 views

Is there any chance to retrieve data on a database(sql) to a smart contract [duplicate]

I want to write a smart contract that gets id numbers as inputs and then retrieve data that are recorded in a database.Is there any specific database for that process.
lasitha431's user avatar
1 vote
0 answers
230 views

Can a ethereum smart contract look up the current dollar/ether exchange rate and then change its behaviour depending on it?? and how? [duplicate]

can a contract on blockchain get outside data like "current dollar/ether exchange rate" using api like call?? If yes, how can it be done? and is there any technique to control the behaviour of the ...
siddesh sangodkar's user avatar
3 votes
1 answer
217 views

What is the intended way for Ethereum contracts to interact with third party software? [duplicate]

Let us assume we have an Ethereum contract to issue software licenses. The contract creates an entry in it's local database to document the availability of the license to the purchaser. In which way ...
Norbert Lotter's user avatar
2 votes
0 answers
169 views

Using External API in a Contract? [duplicate]

Is it possible (and feasible) to have a solidity contract connect to an external api and execute a contract based on what is found? For example betting on sports games by agreeing to a credible API ...
Philip Kirkbride's user avatar
1 vote
0 answers
60 views

Alleged solution for music copyright payment with smart contract [duplicate]

Everywhere on the internet people are blogging/bragging about how smart contract can reinforce payment to musicians/content providers (on each usage (download, listening/clicking) of the content!!), ...
andrew's user avatar
  • 11
0 votes
0 answers
21 views

Live stock value from Google finance [duplicate]

How to link live data from Google finance to a token? Can select LIVE stock values be displayed in the token?
Raj's user avatar
  • 1
0 votes
0 answers
15 views

Smart contract that recognizes Tweets made by each Twitter user [duplicate]

Is there a way for a Solidity smart contract to interface with Twitter accounts or Twitter API to recognize the number of "relevantly tagged" tweets that account made? For example, an ERC-20 ...
user610620's user avatar
  • 1,518
70 votes
3 answers
19k views

Why can't contracts make API calls?

The model that contracts can only accept and process data, instead of also being able to retrieve data from the Internet, seems limiting (even if not, it's less direct). If a concern is that data or ...
eth's user avatar
  • 85.8k
20 votes
3 answers
6k views

How does Oraclize handle the TLSnotary secret?

Oraclize claims to offer a provably honest secure retrieval of a webpage by taking advantage of TLSnotary (a service that allows an auditor to verify if a specific web page was accurately retrieved) ...
Jeff Coleman's user avatar
  • 22.1k
19 votes
2 answers
5k views

How to access external knowledge / data in a smart contract

let’s say a contract wants to execute on knowledge contained outside the blockchain (e.g. whats the price of gold, what was the avg windspeed in NYC, how many people moved to portland in the last ...
dougvk's user avatar
  • 293
12 votes
1 answer
5k views

What is a blockchain oracle?

What is a blockchain oracle for smart contracts? And why is it needed? I've seen a lot of posts about "how do oracles work", and "what is the oracle problem" but I don't understand ...
Keenan Olsen's user avatar

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