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Oracle is a way of implementing a Smart Contract. Instead of running the contract code directly on the blockchain, the code is executed on some special off-chain entities called oracles which then send the result of the code to the blockchain network with a signature.

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How do we deploy a smart contract with Oraclize to Rinkeby Network?

I have created a smart contract with Oraclize logic which I tested locally using Truffle. Now I want to test it on Rinkeby network along with my front end, what it the process to do so ? How do we ...
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1answer
27 views

question about gas limit when using oraclize

I'm using oraclize to fetch some data from the outside world. Oraclize calls the __callback method of my smart contract. For this call oraclize have to pay gas and there is a function to set the gas ...
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2answers
20 views

Detecting oraclize completion for front-end update using Web3.js

I am using oraclize-api to fetch and store twitter posts into a smart contract. Posts are placed into a mapping using the twitter id as the key (i.e. <username>/status/<id>), and the tweet ...
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17 views

Dapp design to handle delay in callback response from Oraclize

In my dapp design I am receiving few user inputs via a form and passing them to a smart contract. Inside the smart contract I am using Oraclize service to timestamp the user inputs. Its a known fact ...
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1answer
17 views

How to pass parameters to a function that is invoked from inside of Oraclize Callback function

In the design of my dapp I am using Oraclize to get current time. Now from its __Callback function I want to call another function to which I need to pass other parameters as well along with current ...
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1answer
41 views

How to get oraclize to work?

I tried to run the code in http://dapps.oraclize.it/browser-solidity/#version=soljson-v0.4.24+commit.e67f0147.js but I get the error VM: out of gas when I try to run the updatePrice function. I set ...
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16 views

Use JSON Path to get top level object and nested object in single oraclize query

0 down vote favorite I have the below JSON Response which I need the value of id and the value of result.random.data What would be the query using JSON Path in a single Oraclize query? similar to: ...
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1answer
22 views

Capturing an event fired from a contract that was called from another contract

I'm trying calculate tax on arbitrary items/values. To do this I have a single contract is used as an 'Oracle' to get the tax from an external system. This contract defines functions to be called from ...
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14 views

How to process a request with oraclize on the server?

First of all, it's the first time I use Oraclize. I have a contract makes a request to a remote server (Python) that I have, my question is, how to process that request? If I understand correctly, the ...
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3answers
44 views

Ways to Decentralize Oraclize

Based on my understanding, Oraclize is a centralized solution. What are some ways to decentralize Oraclize?
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1answer
39 views

Unable to deploy contract that uses Oraclize. Out of gas

I'm trying to deploy a smart contract that uses Oraclize on the Ropsten TestNet using truffle. It seems that deploy the Oraclize api contract (imported by my contract) it's too costly and causes the ...
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1answer
27 views

Quorum Smart Contract Avoid State Changes External Calls (Oraclize) - Deterministic

One of the Solidity best practices relating to external calls is to avoid state changes after an external call. However, does this principle still apply if one is using a private blockchain such as ...
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13 views

deploying an oracle using web3j

I want to use web3j in order to deploy an oracle (smart contract using OraclizeApi) and I don't know how to do it. normally for a simple smart contract we compile the .sol using solc and then generate ...
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1answer
64 views

oraclize calling a REST API

I am trying to call a third party REST API that I developed using spring boot, and I want to call a function(param1,param2) in the API from the oracle using the oraclize_query() (POST request), but I ...
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1answer
32 views

Solidity: chaining multiple functions

I have a contract that uses Oraclize to query some bits of data. Basically, I have the following three functions: getData() - calls Oraclize contract to query data, __callback() - called ...
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0answers
34 views

Solidity: construct JSON query for Oraclize

I have a Flask webapp, that, when called, returns the following JSON: { "id":"stringID", "struct":["1","2","3","4","5","6"] } I need to construct an Oraclize query, so that it returns the Id string, ...
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1answer
36 views

Solidity Oraclize error

I am learning to use oracles in solidity and I have taken this code to see how it works. But I get the following error: "VM error: revert. revert The transaction has been reverted to the initial state....
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1answer
64 views

Oraclize: callback contain no result Error

I have the following contract to get a random number from 1 to 6 from random.org: pragma solidity ^0.4.0; import "github.com/oraclize/ethereum-api/oraclizeAPI.sol"; contract RandomOrg is ...
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1answer
47 views

How are encrypted Oraclize queries protected against replay attacks, precisely?

The Oraclize API allows users to encrypt a query or part of a query using their public key "to protect data from public scrutiny," to quote their documentation. The documentation has this to say ...
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0answers
25 views

Retrieving ID value from CMC using Oraclize oracle

CoinMarketCap are pushing people to switch to v2 of their API, but unfortunately it doesn't quite work the same as v1 so it's causing some issues. I'm trying to retrieve the ID value of a crypto ...
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2answers
47 views

Does running a Geth RPC server locally also require having a full Ethereum node?

I've been trying to learn about smart contracts and attempting to work through a few examples. Specifically, I found this one about creating an Oracle -- https://github.com/axic/tinyoracle. The ...
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0answers
28 views

Confirm Oraclize is not working on Ropsten? (No callback returned)

I have a contract on Ropsten testnet that was working fine up until 2 hours and 30 minutes ago. I don't believe it is an error on my side because the code hasn't been changed or redeployed. You can ...
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0answers
15 views

What's the best realized dapps for fair betting without oracles? [duplicate]

Pretty much self-explanatory. I accept all kind of suggestions.
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0answers
45 views

Oraclize: oraclize_newRandomDSQuery always reverted

I'm using oraclize for generating random number for my smart contract. I have tested successfully with 2 methods: Using WolframAlpha Using random.org service But when I try oraclize_newRandomDSQuery....
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1answer
70 views

Oraclize: Difference between random methods

I write a smart contract and want to use oraclize for getting random number. Are there any differences between those methods: Using WolframAlpha: oraclize_query("WolframAlpha", "random number ...
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0answers
56 views

Oraclize and IPFS integration through Nucypher

I am trying to build a blockchain which will store the data in IPFS, but it will be private (and encrypted) but the user can share this data by using Nucypher. But I need my smart contracts to access ...
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0answers
30 views

pull multiple properties from a JSON file using Oraclize

I need to pull multiple properties from a JSON file (URL) using oraclize_query in solidity, can someone help? I have seen multiple examples to pull just one property in the result
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1answer
26 views

Im using Oraclize to get a random number but the N of bytes confuses me

It seems like when I give the Oraclize query a N of 4, it always returns a 19 digit number, this might be a coincidence but I think not. What if I actually want a number between lets say 0 and 10 * 10^...
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1answer
67 views

What is the most efficient way to parse a string of integers to an array?

I perform an Oraclize query on an XML file, and receive this string in return: ["31", "25", "24"] What would be the most efficient way to parse through this string and store the numbers into a uint8 ...
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1answer
24 views

How does Ethereum handle undeterministic results from oracles?

Since when a transaction is done, every node in the blockchain runs the smart contract in their machines, what if the smart contract is calling an oracle to get a random value? Shouldn't it return ...
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2answers
64 views

Oraclize doesn't return an answer

I have a problem when I call the function selectWinner(), send some ether with it to pay for Oraclize. I am using Rinkeby with Infura and metamask for the test accounts. I get an error in the meta ...
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0answers
22 views

It seems like oraclized takes way more than $0.05 [closed]

When a TX for a random number like such: https://ropsten.etherscan.io/tx/0x54fa389796fea546ac6562bec7cfe4b0daca1b744920a38a0e85036b07a1e0ee It says that 0.004 ehter was send to oraclized and it is ...
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1answer
20 views

Oraclize random number only works once, then doesn't trigger events and requires a lot of ETH

So I am using the following code contract Damble is usingOraclize{ function Damble() { getRandomNumber(); } function __callback(bytes32 _queryId, string _result, bytes _proof) { if (...
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1answer
42 views

Is there any way to only encrypt the api key in a GET oraclize query

I am building a contract that uses oraclize to query an API. The API only accepts GET requests (no POST) and also has authentication that requires an API key to be sent as an argument(query_token) in ...
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1answer
50 views

No response in fetching ETH to USD current rate?

I'm trying to fetch the current ethereum to usd rate from following link: https://api.infura.io/v1/ticker/ethusd This is my code snippet pragma solidity ^0.4.11; import "github.com/oraclize/...
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51 views

How to get multiple values in single Oraclize query? without JSON Parsing

I am developing a smart contract. I already made my own Token. so I wanna transfer my Tokens to my friends. But I wanna handle it easily, so I made XML what can be loaded on Internet to use ...
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2answers
56 views

Solidity import Tensor Flow Libraries?

Like how we import oraclize in Solidity (as follows), is there some way to import tensorflow libraries for machine learning purpose? import "github.com/oraclize/ethereum-api/oraclizeAPI.sol";
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1answer
21 views

Guarantee of good's delivery via Smart contract

Assume Client A wants to sell a package to client B. How should I write down a smart contract that prevents from B to receive the package while being refuse to pay in a claim that he isn't receive ...
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1answer
54 views

Testing ethereum smart-contracts that work with oraclize

I'm new in Ethereum and I have a smart-contract that receive exchange rate from API through oraclize. But I have problems with testing my smart-contract. For testing I use truffle + ganache. Could ...
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1answer
22 views

Should I include API Key in query to avoid rate limiting?

I'm writing an oraclize query that contacts an endpoint that has a limit of 50 requests per day. Does oraclize only have one server and as a result will it get rate limited and start returning errors? ...
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1answer
84 views

Truffle install oraclize

I am trying to install oraclize with truffle. When i run 'truffle install oraclize', I get an error: Could not find suitable configuration file. I am using truffle v4.1.7 Thanks in advance..
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1answer
54 views

Implementation of Oraclize API connector

Can someone explain to me how, where, and when is the https://github.com/oraclize/ethereum-api/blob/master/connectors/oraclizeConnector.sol deployed to ethereum blockchain ? This is the implementation ...
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0answers
38 views

oraclize_newRandomDSQuery delay bigger than 120 seconds

I'm building an application where timing is very important. oraclize_newRandomDSQuery works perfect for me, however, one can only get 120 seconds of delay on it and my specific application needs ...
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1answer
26 views

Apparent mismatch between Oraclize CBOR and python3 CBOR encodings

I encoded a value using the Oraclize CBOR library like so: Buffer.buffer memory cborArgs; Buffer.init(cborArgs, 64); cborArgs.startArray(); cborArgs.encodeUInt(10); cborArgs....
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0answers
33 views

Oraclize + CBOR Bug?

I'm making a computation query to Oraclize: import "https://github.com/oraclize/ethereum-api/blob/master/oraclizeAPI_0.4.sol" bytes scriptMultihash = "QmVJyXAmxdfuVgazi2PtnwXJdSiYPpkcvv6EydccQKkiZW";...
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1answer
64 views

Concatenating a variable value to a bytes32

I am using Oraclize for randomness. The range of random numbers I want depends on a variable maxNumber, and will be 0 - maxNumber. If you scroll to the right of my code snippet below, you'll see ...
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0answers
134 views

Oraclize : Ethereum-bridge on my local private chain

I can work with oraclize only using a private chain created with testrpc. If I try to use the ethereum-bridge over my locally created private chain it doesn't answer, nether I get message in the ...
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1answer
31 views

Unable to mine smart contract using Oraclize - Invalid JSON RPC response,error code : -32603

I am trying to use Oraclize to make a REST call. Please find below my contract code - pragma solidity ^0.4.16; import "./usingOraclize.sol"; //Importing Oraclize(verion 0.4) contract TestOraclizeCall ...
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1answer
39 views

Orcalize query multi value callback

So I know JSONPATH can be used to select multiple values from a json response with an orcalize query like in the below example http://app.oraclize.it/home/test_query#VVJMKEdFVCk=:...
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1answer
60 views

Do Solidity functions time out?

I have a design where contract A is calling contract B, which then calls Oraclize a few times, and then sends the results back to contract A. The Oraclize calls could end up taking upwards of 30 ...