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Darkfibre Documentation

Buy + Sell

A complete buy/sell round-trip that validates your credentials work end-to-end.

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Setup

Section titled “Setup”
Terminal window
git clone https://github.com/darkfibre-dev/darkfibre-examples.git
cd darkfibre-examples/02-buy-sell
npm install
cp .env.example .env

Edit .env with your credentials:

Terminal window
DARKFIBRE_API_KEY=your-api-key
SOLANA_PRIVATE_KEY=your-base58-private-key

Edit index.ts to set the MINT constant to the token you want to trade.

Run

Section titled “Run”
Terminal window
npm start

Code

Section titled “Code”
import { DarkfibreSDK, APIError, ValidationError, SigningError } from '@darkfibre/sdk';
import 'dotenv/config';


// Configuration
const MINT = 'YOUR_TOKEN_MINT_HERE';  // Token to trade
const SOL_AMOUNT = 0.005;              // SOL to spend on buy
const SLIPPAGE = 0.05;                // 5% slippage tolerance
const PRIORITY = 'fast' as const;     // Transaction priority


// Validate Environment
const { DARKFIBRE_API_KEY, SOLANA_PRIVATE_KEY } = process.env;


if (!DARKFIBRE_API_KEY) {
  console.error('Missing DARKFIBRE_API_KEY in .env');
  process.exit(1);
}


if (!SOLANA_PRIVATE_KEY) {
  console.error('Missing SOLANA_PRIVATE_KEY in .env');
  process.exit(1);
}


// Main
const sdk = new DarkfibreSDK({
  apiKey: DARKFIBRE_API_KEY,
  privateKey: SOLANA_PRIVATE_KEY,
});


try {
  // Buy
  console.log(`\n[BUY] Buying tokens with ${SOL_AMOUNT} SOL...`);


  const buyResult = await sdk.buy({
    mint: MINT,
    solAmount: SOL_AMOUNT,
    slippage: SLIPPAGE,
    priority: PRIORITY,
  });


  console.log(`[BUY] Success!`);
  console.log(`  Tokens received: ${buyResult.tradeResult.outputAmount}`);
  console.log(`  SOL spent: ${buyResult.tradeResult.inputAmount}`);
  console.log(`  Priority fee: ${buyResult.priorityCost} SOL`);
  console.log(`  https://solscan.io/tx/${buyResult.signature}`);


  // Wait
  await new Promise((resolve) => setTimeout(resolve, 1000));


  // Sell
  console.log(`\n[SELL] Selling ${buyResult.tradeResult.outputAmount} tokens...`);


  const sellResult = await sdk.sell({
    mint: MINT,
    tokenAmount: buyResult.tradeResult.outputAmount,
    slippage: SLIPPAGE,
    priority: PRIORITY,
  });


  console.log(`[SELL] Success!`);
  console.log(`  Tokens sold: ${sellResult.tradeResult.inputAmount}`);
  console.log(`  SOL received: ${sellResult.tradeResult.outputAmount}`);
  console.log(`  Priority fee: ${sellResult.priorityCost} SOL`);
  console.log(`  https://solscan.io/tx/${sellResult.signature}`);
} catch (error) {
  if (error instanceof ValidationError) {
    console.error(`\n[ERROR] Validation: ${error.message}`);
    if (error.field) {
      console.error(`  Field: ${error.field}`);
    }
  } else if (error instanceof SigningError) {
    console.error(`\n[ERROR] Signing: ${error.message}`);
    console.error('  Check that your private key is valid and in base58 format.');
  } else if (error instanceof APIError) {
    console.error(`\n[ERROR] API [${error.code}]: ${error.message}`);
  } else {
    throw error;
  }
  process.exit(1);
}

What It Does

Section titled “What It Does”
  1. Initializes the SDK with your credentials
  2. Buys tokens with SOL
  3. Waits 1 second
  4. Sells all tokens back for SOL
  5. Prints detailed transaction info with Solscan links

Configuration

Section titled “Configuration”

Edit index.ts to change:

VariableDescriptionDefault
MINTToken mint address to trade-
SOL_AMOUNTAmount of SOL to spend on buy0.005
SLIPPAGESlippage tolerance (0.05 = 5%)0.05
PRIORITYTransaction priority'fast'

Error Handling

Section titled “Error Handling”

This example demonstrates handling all SDK error types:

Error TypeDescription
APIErrorAPI failures (auth, validation, insufficient funds)
ValidationErrorTrade limit exceeded (maxPriceImpact, maxPriorityCost)
SigningErrorTransaction signing failures

Expected Output

Section titled “Expected Output”
[BUY] Buying tokens with 0.005 SOL...
[BUY] Success!
  Tokens received: 1234567.89
  SOL spent: 0.005
  Priority fee: 0.0001 SOL
  https://solscan.io/tx/5xK7j...abc123


[SELL] Selling 1234567.89 tokens...
[SELL] Success!
  Tokens sold: 1234567.89
  SOL received: 0.00495
  Priority fee: 0.0001 SOL
  https://solscan.io/tx/3mN8p...def456
Section titled “Related”