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# Stellar Data: RPC + Horizon API access for reading chain state. Stellar RPC is the preferred entry point for new projects; Horizon remains for legacy and historical-query workflows. For deeper history beyond RPC's 7-day window, use Hubble/Galexie. ## When to use this skill - Calling Stellar RPC methods (`getLatestLedger`, `getLedgerEntries`, `getEvents`, `simulateTransaction`, `sendTransaction`) - Querying Horizon endpoints (accounts, transactions, operations, effects, ledgers) - Streaming live events or operations - Pulling historical data beyond RPC's 7-day window (Hubble, Galexie) - Choosing between RPC and Horizon for a given workflow ## Related skills - Building transactions to send → `/.well-known/agent-skills/dapp/skill.md` - Smart contract simulation and event emission → `/.well-known/agent-skills/smart-contracts/skill.md` - Asset balance and trustline lookups → `/.well-known/agent-skills/assets/skill.md` - Standards (SEP-7 deeplinks, SEP-10 auth) → `/.well-known/agent-skills/standards/skill.md` --- ## Overview Stellar provides two API paradigms: | API | Status | Use Case | |-----|--------|----------| | **Stellar RPC** | Preferred | Smart contracts, real-time state, new projects | | **Horizon** | Legacy-focused | Historical data, legacy applications | **Recommendation**: Use Stellar RPC for all new projects. Use Horizon mainly for historical queries and legacy compatibility paths. ## Quick Navigation - RPC methods and usage: [Stellar RPC](#stellar-rpc) - Horizon endpoints and streaming: [Horizon API (Legacy)](#horizon-api-legacy) - Migration strategy: [Migration: Horizon to RPC](#migration-horizon-to-rpc) - Data history/indexing options: [Historical Data Access](#historical-data-access) - Environment setup and endpoints: [Network Configuration](#network-configuration) ## Stellar RPC ### Endpoints > Note: SDF directly provides Futurenet public RPC. For Mainnet RPC, select a provider from the [RPC providers directory](https://developers.stellar.org/docs/data/apis/rpc/providers). | Network | RPC URL | |---------|---------| | Mainnet | Provider-specific endpoint (see [RPC providers directory](https://developers.stellar.org/docs/data/apis/rpc/providers)) | | Testnet | `https://soroban-testnet.stellar.org` | | Futurenet | `https://rpc-futurenet.stellar.org` | | Local | `http://localhost:8000/soroban/rpc` | ### Setup ```typescript import * as StellarSdk from "@stellar/stellar-sdk"; const rpc = new StellarSdk.rpc.Server("https://soroban-testnet.stellar.org"); ``` ### Key Methods #### Get Account ```typescript const account = await rpc.getAccount(publicKey); // Returns account with sequence number for transaction building ``` #### Get Health ```typescript const health = await rpc.getHealth(); // { status: "healthy" } ``` #### Get Latest Ledger ```typescript const ledger = await rpc.getLatestLedger(); // { id: "...", sequence: 123456, protocolVersion: 25 } ``` #### Get Ledger Entries ```typescript // Read contract storage const key = StellarSdk.xdr.LedgerKey.contractData( new StellarSdk.xdr.LedgerKeyContractData({ contract: new StellarSdk.Address(contractId).toScAddress(), key: StellarSdk.xdr.ScVal.scvSymbol("Counter"), durability: StellarSdk.xdr.ContractDataDurability.persistent(), }) ); const entries = await rpc.getLedgerEntries(key); if (entries.entries.length > 0) { const value = StellarSdk.scValToNative( entries.entries[0].val.contractData().val() ); } ``` #### Simulate Transaction ```typescript const simulation = await rpc.simulateTransaction(transaction); if (StellarSdk.rpc.Api.isSimulationError(simulation)) { console.error("Simulation failed:", simulation.error); } else if (StellarSdk.rpc.Api.isSimulationSuccess(simulation)) { console.log("Cost:", simulation.cost); console.log("Result:", simulation.result); } ``` #### Send Transaction ```typescript const response = await rpc.sendTransaction(signedTransaction); if (response.status === "PENDING") { // Poll for result let result = await rpc.getTransaction(response.hash); while (result.status === "NOT_FOUND") { await new Promise(r => setTimeout(r, 1000)); result = await rpc.getTransaction(response.hash); } if (result.status === "SUCCESS") { console.log("Success:", result.returnValue); } else { console.error("Failed:", result.status); } } ``` #### Get Transaction ```typescript const tx = await rpc.getTransaction(txHash); // status: "SUCCESS" | "FAILED" | "NOT_FOUND" // returnValue: ScVal (for contract calls) // ledger: number ``` #### Get Events ```typescript const events = await rpc.getEvents({ startLedger: 1000000, filters: [ { type: "contract", contractIds: [contractId], topics: [ ["*", StellarSdk.xdr.ScVal.scvSymbol("transfer").toXDR("base64")], ], }, ], }); for (const event of events.events) { console.log("Event:", event.topic, event.value); } ``` ### RPC Limitations - **7-day history for most methods**: `getTransaction`, `getEvents`, etc. only cover recent data - **`getLedgers` exception**: "Infinite Scroll" feature queries any ledger back to genesis via the data lake - **No streaming**: Poll for updates (no WebSocket) - **Contract-focused**: Limited classic Stellar data ## Horizon API (Legacy) ### Endpoints | Network | Horizon URL | |---------|-------------| | Mainnet | `https://horizon.stellar.org` | | Testnet | `https://horizon-testnet.stellar.org` | | Local | `http://localhost:8000` | ### Setup ```typescript import * as StellarSdk from "@stellar/stellar-sdk"; const server = new StellarSdk.Horizon.Server("https://horizon-testnet.stellar.org"); ``` ### Common Operations #### Load Account ```typescript const account = await server.loadAccount(publicKey); // Full account details including balances, signers, data ``` #### Get Account Balances ```typescript const account = await server.loadAccount(publicKey); for (const balance of account.balances) { if (balance.asset_type === "native") { console.log("XLM:", balance.balance); } else { console.log(`${balance.asset_code}:`, balance.balance); } } ``` #### Get Transactions ```typescript // Account transactions const transactions = await server .transactions() .forAccount(publicKey) .order("desc") .limit(10) .call(); // Specific transaction const tx = await server .transactions() .transaction(txHash) .call(); ``` #### Get Operations ```typescript const operations = await server .operations() .forAccount(publicKey) .order("desc") .limit(20) .call(); for (const op of operations.records) { console.log(op.type, op.created_at); } ``` #### Get Payments ```typescript const payments = await server .payments() .forAccount(publicKey) .order("desc") .call(); for (const payment of payments.records) { if (payment.type === "payment") { console.log( `${payment.from} -> ${payment.to}: ${payment.amount} ${payment.asset_code || "XLM"}` ); } } ``` #### Get Effects ```typescript const effects = await server .effects() .forAccount(publicKey) .limit(50) .call(); ``` #### Streaming (Server-Sent Events) ```typescript // Stream transactions const closeHandler = server .transactions() .forAccount(publicKey) .cursor("now") .stream({ onmessage: (tx) => { console.log("New transaction:", tx.hash); }, onerror: (error) => { console.error("Stream error:", error); }, }); // Close stream when done closeHandler(); ``` #### Submit Transaction ```typescript try { const result = await server.submitTransaction(signedTransaction); console.log("Success:", result.hash); } catch (error) { if (error.response?.data?.extras?.result_codes) { console.error("Error codes:", error.response.data.extras.result_codes); } } ``` ### Pagination ```typescript // First page let page = await server.transactions().forAccount(publicKey).limit(10).call(); // Next page if (page.records.length > 0) { page = await page.next(); } // Previous page page = await page.prev(); ``` ## Migration: Horizon to RPC ### Account Loading ```typescript // Horizon (old) const account = await horizonServer.loadAccount(publicKey); // RPC (new) const account = await rpc.getAccount(publicKey); // Note: RPC returns less data, just what's needed for transactions ``` ### Transaction Submission ```typescript // Horizon (for classic transactions) const result = await horizonServer.submitTransaction(tx); // RPC (for smart contract transactions) const response = await rpc.sendTransaction(tx); const result = await pollForResult(response.hash); ``` ### Historical Data ```typescript // Horizon - full history const allTxs = await horizonServer .transactions() .forAccount(publicKey) .call(); // RPC - most methods limited to 7 days // Exception: getLedgers can query back to genesis (Infinite Scroll) // For full historical data, use: // 1. Hubble (SDF's BigQuery dataset) // 2. Galexie (data pipeline) // 3. Your own indexer ``` ### Streaming Replacement ```typescript // Horizon - native streaming server.payments().stream({ onmessage: handlePayment }); // RPC - polling (no native streaming) async function pollForUpdates() { const lastLedger = await rpc.getLatestLedger(); // Check for new events/transactions // Repeat on interval } setInterval(pollForUpdates, 5000); ``` ## Historical Data Access For data older than 7 days (not available via most RPC methods; `getLedgers` can reach genesis via Infinite Scroll): ### Hubble (BigQuery) ```sql -- Query Stellar data in BigQuery SELECT * FROM `crypto-stellar.crypto_stellar.history_transactions` WHERE source_account = 'G...' ORDER BY created_at DESC LIMIT 100 ``` ### Galexie Self-hosted data pipeline for processing Stellar ledger data: - https://github.com/stellar/galexie ### Data Lake RPC "Infinite Scroll" is powered by the Stellar data lake — a cloud-based object store (SEP-0054 format): - **Public access**: `s3://aws-public-blockchain/v1.1/stellar/ledgers/pubnet` (AWS Open Data) - **Self-host**: Use Galexie to export to AWS S3 or Google Cloud Storage - **Hosted**: [Quasar (Lightsail Network)](https://quasar.lightsail.network) provides hosted Galexie Data Lake + Archive RPC endpoints - **Size**: ~3.8TB, growing ~0.5TB/year