> ## Documentation Index > Fetch the complete documentation index at: https://docs.whitebit.com/llms.txt > Use this file to discover all available pages before exploring further. # Crypto Lending Quickstart > Walk through the four Flex endpoints — fetch plans, invest, check status, withdraw — in under 5 minutes. export const RegionBaseUrl = ({className = "", showBaseUrl = true}) => { const [region, setRegionState] = useState(() => { if (typeof window !== 'undefined') { return localStorage.getItem("api-region-preference") || "com"; } return "com"; }); const [mounted, setMounted] = useState(false); const observerRef = useRef(null); const isSyncingRef = useRef(false); const updateAllContentOnPage = targetRegion => { try { const domainFrom = targetRegion === "eu" ? "whitebit.com" : "whitebit.eu"; const domainTo = targetRegion === "eu" ? "whitebit.eu" : "whitebit.com"; const links = document.querySelectorAll('a'); links.forEach(link => { let href = link.getAttribute('href'); if (href && href.includes(domainFrom)) { link.setAttribute('href', href.replace(domainFrom, domainTo)); } }); const walker = document.createTreeWalker(document.body, NodeFilter.SHOW_TEXT, { acceptNode: node => { if (node.parentElement?.closest('.region-toggle-component')) { return NodeFilter.FILTER_REJECT; } return node.textContent.includes(domainFrom) ? NodeFilter.FILTER_ACCEPT : NodeFilter.FILTER_REJECT; } }); let currentNode; while (currentNode = walker.nextNode()) { currentNode.textContent = currentNode.textContent.replace(new RegExp(domainFrom, 'g'), domainTo); } console.log(`[RegionSync] Global content updated to ${domainTo}`); } catch (e) { console.error("[RegionSync] Error updating content:", e); } }; const updateRegion = (newRegion, source) => { if (region === newRegion) return; console.log(`[RegionBaseUrl] Updating to "${newRegion}" (Source: ${source})`); if (source === 'observer') { isSyncingRef.current = true; setTimeout(() => isSyncingRef.current = false, 1000); } setRegionState(newRegion); localStorage.setItem("api-region-preference", newRegion); updateAllContentOnPage(newRegion); if (source === 'user-click') { window.dispatchEvent(new CustomEvent("regionChange", { detail: newRegion })); attemptToUpdateNativeDropdown(newRegion, 0); setTimeout(() => attemptToUpdateNativeDropdown(newRegion, 1), 500); setTimeout(() => attemptToUpdateNativeDropdown(newRegion, 2), 1500); } }; const attemptToUpdateNativeDropdown = (targetRegion, attempt) => { if (isSyncingRef.current) return; try { const targetUrl = targetRegion === "eu" ? "https://whitebit.eu" : "https://whitebit.com"; const targetDesc = targetRegion === "eu" ? "EU Server" : "Production Server"; const selects = document.querySelectorAll('select'); for (const select of selects) { if (select.innerHTML.includes('whitebit.com') || select.innerHTML.includes('whitebit.eu')) { select.value = targetUrl; select.dispatchEvent(new Event('change', { bubbles: true })); return; } } const buttons = Array.from(document.querySelectorAll('button, [role="combobox"]')); const serverSelector = buttons.find(btn => { if (btn.closest('a') || btn.closest('[class*="card"]') || btn.closest('nav')) { return false; } const txt = btn.textContent || ""; const isServerDropdown = (txt.includes('Production Server') || txt.includes('EU Server') || txt.includes('WhiteBIT Global Server') || txt.includes('WhiteBIT EU Server')) && !txt.includes('Run') && !txt.includes('Send') || btn.getAttribute('role') === 'combobox'; return isServerDropdown; }); if (serverSelector) { const currentText = serverSelector.textContent || ""; if (currentText.includes(targetDesc)) return; serverSelector.click(); setTimeout(() => { const options = document.querySelectorAll('[role="option"], li, button'); for (const opt of options) { const optText = opt.textContent || ""; if (optText.includes(targetDesc) || optText.includes(targetUrl)) { opt.click(); return; } } }, 100); } } catch (e) { console.error("[Sync] Error:", e); } }; useEffect(() => { setMounted(true); updateAllContentOnPage(region); const handleStorageChange = e => { if (e.key === "api-region-preference" && e.newValue) { updateRegion(e.newValue, 'storage'); } }; const handleRegionChange = e => { if (e.detail !== region) { updateRegion(e.detail, 'event'); } }; window.addEventListener("storage", handleStorageChange); window.addEventListener("regionChange", handleRegionChange); observerRef.current = new MutationObserver(mutations => { if (isSyncingRef.current) return; updateAllContentOnPage(region); for (const mutation of mutations) { if (mutation.type !== 'childList' && mutation.type !== 'characterData') continue; const target = mutation.target; const el = target.nodeType === Node.TEXT_NODE ? target.parentElement : target; if (el && (el.getAttribute('role') === 'option' || el.closest('[role="listbox"]'))) continue; const text = target.textContent || ""; if (text.includes('WhiteBIT EU Server') || text.includes('https://whitebit.eu') && text.includes('Server')) { if (el && el.tagName !== 'A' && !el.closest('.region-toggle-component')) { if (region !== 'eu') updateRegion('eu', 'observer'); } } else if (text.includes('WhiteBIT Global Server') || text.includes('https://whitebit.com') && text.includes('Server')) { if (el && el.tagName !== 'A' && !el.closest('.region-toggle-component')) { if (region !== 'com') updateRegion('com', 'observer'); } } } }); observerRef.current.observe(document.body, { childList: true, subtree: true, characterData: true }); if (typeof window !== 'undefined') { const current = localStorage.getItem("api-region-preference"); if (current) attemptToUpdateNativeDropdown(current, 'init'); } return () => { window.removeEventListener("storage", handleStorageChange); window.removeEventListener("regionChange", handleRegionChange); if (observerRef.current) observerRef.current.disconnect(); }; }, [region]); const apiBaseUrl = region === "eu" ? "https://whitebit.eu" : "https://whitebit.com"; if (!mounted) return null; return
Base URL (
) {showBaseUrl && <> : {apiBaseUrl} }
; }; The four endpoints below cover the full Flex lifecycle — fetch plans, invest, check status, withdraw — operating against Main balance and authenticated with a key that has the Trade permission. ## Prerequisites * A WhiteBIT account with completed KYC ([register](https://whitebit.com/auth/register)) * An API key with **Trade** permission ([create key](https://whitebit.com/settings/api)) * Funds in [Main balance](/concepts/balances) (the lending API operates on Main balance, not Trade balance) * HMAC-SHA512 signing configured ([authentication guide](/api-reference/authentication)) * `curl` and `jq` installed (for command-line examples) The quickstart uses **Flex plan** endpoints, which are available to all authenticated users. Fixed plan endpoints require B2B partner permissions -- see the [overview](/products/lending/overview) for details. Retrieve the list of available Flex plans to find a plan ID for investment. ```bash theme={"theme":{"light":"github-light","dark":"github-dark"}} curl -X POST https://whitebit.com/api/v4/main-account/smart-flex/plans \ -H "Content-Type: application/json" \ -H "X-TXC-APIKEY: YOUR_API_KEY" \ -H "X-TXC-PAYLOAD: YOUR_PAYLOAD" \ -H "X-TXC-SIGNATURE: YOUR_SIGNATURE" \ -d '{"request": "/api/v4/main-account/smart-flex/plans", "nonce": 1709340000000}' ``` ```python theme={"theme":{"light":"github-light","dark":"github-dark"}} import requests, json, hmac, hashlib, base64, time API_KEY = "YOUR_API_KEY" API_SECRET = "YOUR_SECRET" BASE_URL = "https://whitebit.com" def make_request(endpoint, body): nonce = int(time.time() * 1000) body["request"] = endpoint body["nonce"] = nonce data_json = json.dumps(body) payload = base64.b64encode(data_json.encode()) signature = hmac.new( API_SECRET.encode(), payload, hashlib.sha512 ).hexdigest() headers = { "Content-Type": "application/json", "X-TXC-APIKEY": API_KEY, "X-TXC-PAYLOAD": payload.decode(), "X-TXC-SIGNATURE": signature, } return requests.post(f"{BASE_URL}{endpoint}", headers=headers, data=data_json) # Fetch available Flex plans response = make_request("/api/v4/main-account/smart-flex/plans", {}) plans = response.json() print(json.dumps(plans, indent=2)) ``` For Go and PHP examples, see [SDKs](/sdks). **Expected response:** ```json theme={"theme":{"light":"github-light","dark":"github-dark"}} [ { "id": "8f2e9d3c-1a4b-4c2d-9e5f-6a7b8c9d0e1f", "ticker": "USDT", "minInvestment": "10.0", "maxInvestment": "100000.0", "maxRate": "0.15" }, "..." ] ``` Save the `id` value from a plan to use in the next step. Invest into the selected Flex plan using the plan ID from Step 1. ```bash theme={"theme":{"light":"github-light","dark":"github-dark"}} curl -X POST https://whitebit.com/api/v4/main-account/smart-flex/investments/invest \ -H "Content-Type: application/json" \ -H "X-TXC-APIKEY: YOUR_API_KEY" \ -H "X-TXC-PAYLOAD: YOUR_PAYLOAD" \ -H "X-TXC-SIGNATURE: YOUR_SIGNATURE" \ -d '{ "plan": "8f2e9d3c-1a4b-4c2d-9e5f-6a7b8c9d0e1f", "amount": "100.00", "withReinvest": true, "request": "/api/v4/main-account/smart-flex/investments/invest", "nonce": 1709340000001 }' ``` ```python theme={"theme":{"light":"github-light","dark":"github-dark"}} # Create a Flex investment (use plan ID from Step 1) response = make_request("/api/v4/main-account/smart-flex/investments/invest", { "plan": "8f2e9d3c-1a4b-4c2d-9e5f-6a7b8c9d0e1f", "amount": "100.00", "withReinvest": True, }) print(response.json()) ``` **Required fields:** `plan` (UUID from Step 1), `amount` (string). **Optional:** `withReinvest` (boolean, enables auto-reinvestment). **Expected response:** ```json theme={"theme":{"light":"github-light","dark":"github-dark"}} { "data": { "transaction_id": "tx_9f3e0d4c-2b5c-4d3e-8f6g-7a8b9c0d1e2f" } } ``` Verify the investment was created and check the current investment status. ```bash theme={"theme":{"light":"github-light","dark":"github-dark"}} curl -X POST https://whitebit.com/api/v4/main-account/smart-flex/investments \ -H "Content-Type: application/json" \ -H "X-TXC-APIKEY: YOUR_API_KEY" \ -H "X-TXC-PAYLOAD: YOUR_PAYLOAD" \ -H "X-TXC-SIGNATURE: YOUR_SIGNATURE" \ -d '{"request": "/api/v4/main-account/smart-flex/investments", "nonce": 1709340000002}' ``` ```python theme={"theme":{"light":"github-light","dark":"github-dark"}} # Check active investments response = make_request("/api/v4/main-account/smart-flex/investments", {}) investments = response.json() print(json.dumps(investments, indent=2)) ``` **Expected response:** ```json theme={"theme":{"light":"github-light","dark":"github-dark"}} { "data": [ { "id": "inv_7e2d9c3b-1a4b-4c2d-9e5f-6a7b8c9d0e1f", "planId": "8f2e9d3c-1a4b-4c2d-9e5f-6a7b8c9d0e1f", "currency": "USDT", "invested": "100.00", "withAutoReinvest": true, "status": 1, "..." } ], "..." } ``` Withdraw funds from the Flex investment back to Main balance. ```bash theme={"theme":{"light":"github-light","dark":"github-dark"}} curl -X POST https://whitebit.com/api/v4/main-account/smart-flex/investments/withdraw \ -H "Content-Type: application/json" \ -H "X-TXC-APIKEY: YOUR_API_KEY" \ -H "X-TXC-PAYLOAD: YOUR_PAYLOAD" \ -H "X-TXC-SIGNATURE: YOUR_SIGNATURE" \ -d '{ "plan": "8f2e9d3c-1a4b-4c2d-9e5f-6a7b8c9d0e1f", "amount": "50.00", "request": "/api/v4/main-account/smart-flex/investments/withdraw", "nonce": 1709340000003 }' ``` ```python theme={"theme":{"light":"github-light","dark":"github-dark"}} # Withdraw from Flex investment (partial withdrawal) response = make_request("/api/v4/main-account/smart-flex/investments/withdraw", { "plan": "8f2e9d3c-1a4b-4c2d-9e5f-6a7b8c9d0e1f", "amount": "50.00", }) print(response.json()) ``` **Required fields:** `plan` (UUID), `amount` (string). Partial withdrawals are supported. To withdraw everything, use the full invested amount. **Expected response:** ```json theme={"theme":{"light":"github-light","dark":"github-dark"}} { "data": { "transaction_id": "tx_9f3e0d4c-2b5c-4d3e-8f6g-7a8b9c0d1e2f" } } ``` After completing Step 4, the withdrawn amount returns to the [Main balance](/concepts/balances). Verify by checking the [Main balance endpoint](/api-reference/account-wallet/overview). ## What's Next Fixed vs Flex plan mechanics, B2B partner permissions for Fixed endpoints, \~90 supported assets, and auto-invest behavior. Full endpoint documentation for all 13 lending endpoints. For Go and PHP examples, see [SDKs](/sdks).