# RedStone oracle (https://docs-i0yym09dy-ton-core-docs.vercel.app/llms/ecosystem/oracles/redstone/content.md)



## How to use real-time data in TON contracts [#how-to-use-real-time-data-in-ton-contracts]

RedStone is a pull oracle that uses an alternative design for providing oracle data to smart contracts. Instead of constantly persisting data on the contract's storage, the information is brought on-chain only when needed by end users. Until that moment, data remains in the decentralized cache layer, powered by RedStone light cache gateways and a stream-based data broadcasting protocol.

Data is transferred to the contract by end users, who attach signed data packages to their function invocations. The information integrity is verified on-chain through signature checking.

## Install the RedStone SDK [#install-the-redstone-sdk]

Install the RedStone TON connector and other necessary dependencies:

```bash
npm install @redstone-finance/ton-connector @redstone-finance/sdk
```

## Write code to interact with oracle [#write-code-to-interact-with-oracle]

### Off-chain data fetch and update [#off-chain-data-fetch-and-update]

The following code snippet demonstrates how to fetch price updates and interact with RedStone contracts on TON:

```ts
import { TonPricesContractConnector } from "@redstone-finance/ton-connector";
import { ContractParamsProvider, getSignersForDataServiceId } from "@redstone-finance/sdk";

async function main() {
  // Configure API endpoint
  const apiV2Config = {
    apiEndpoint: "https://testnet.toncenter.com/api/v2/jsonRPC",
    apiKey: "your-api-key-here", // Get your TON Center API key
  };

  // Initialize the connector
  const contractAddress = "EQCMxfukwpP3BI_6Pn3lmOXgxlp3dPabVGOM0UvJCjsDhkdD";
  const prices = new TonPricesContractConnector(network, contractAddress);

  // Configure RedStone data service parameters
  const paramsProvider = new ContractParamsProvider({
    dataServiceId: "redstone-main-demo",
    uniqueSignersCount: 1,
    dataPackagesIds: ["ETH", "BTC"],
    authorizedSigners: getSignersForDataServiceId("redstone-main-demo"),
  });

  // Get prices using on-the-fly processing (doesn't modify contract state)
  const pricesFromPayload = await (await prices.getAdapter()).getPricesFromPayload(paramsProvider);
  console.log("ETH and BTC prices from payload:", pricesFromPayload);

  // Write prices to contract storage (modifies contract state)
  await (await prices.getAdapter()).writePricesFromPayloadToContract(paramsProvider);
  console.log("Prices written to contract storage successfully.");

  // Read prices from contract storage
  const storedPrices = await (await prices.getAdapter()).readPricesFromContract(paramsProvider);
  console.log("Stored prices:", storedPrices);

  // Get timestamp of last update
  const lastUpdateTimestamp = await (await prices.getAdapter()).readTimestampFromContract();
  console.log("Last update timestamp:", lastUpdateTimestamp);
}

main().catch(console.error);
```

This code snippet does the following:

1. Imports the `TonPricesContractConnector` and sets up the RedStone SDK.
2. Configures the API endpoint and creates a connector to your deployed contract.
3. Sets up a `ContractParamsProvider` with the data service ID and feed identifiers.
4. Fetches price data using on-the-fly processing (no gas cost).
5. Writes price data to the contract's storage (requires gas).
6. Reads stored prices and the last update timestamp from the contract.

## Contract types [#contract-types]

RedStone provides several contract types for different use cases:

### Price Manager [#price-manager]

Manages multiple price feeds with signature verification and supports both on-the-fly processing and storage persistence.

### Single Feed Manager [#single-feed-manager]

Simplified version for handling a single price feed, reducing gas costs for single-feed applications.

### Price Feed [#price-feed]

An individual feed contract that stores price data for a specific asset.

### Sample Consumer [#sample-consumer]

Example consumer contract that demonstrates how to read data from price feeds.

## Error handling [#error-handling]

Common error codes you might encounter:

* **300+**: Insufficient valid signers (less than `signer_count_threshold`)
* **200+**: Timestamp validation failed (data too old or in the future)
* **Other codes**: See [RedStone constants](https://github.com/redstone-finance/redstone-oracles-monorepo/blob/main/packages/ton-connector/src/config/constants.ts)

## Additional resources [#additional-resources]

You may find these additional resources helpful for developing your TON application:

* [RedStone documentation](https://docs.redstone.finance/docs/introduction)
* [RedStone TON connector](https://github.com/redstone-finance/redstone-oracles-monorepo/tree/main/packages/ton-connector)
* [RedStone smart contracts](https://github.com/redstone-finance/redstone-oracles-monorepo/tree/main/packages/ton-connector/contracts)
* [RedStone showroom](https://ton-showroom.redstone.finance/)