Stable RPC Endpoint
Flat-rate Stable RPC provider and Stable RPC node access: free tier, no KYC, HTTP & WebSocket. Stable mainnet chain ID 988.
https://rpc.swiftnodes.io/rpc/stable?key=YOUR_API_KEYwss://rpc.swiftnodes.io/ws/stable?key=YOUR_API_KEYStable is a Layer 1 for stablecoin payments, backed by Bitfinex and built around Tether's USDT. USDT0 is its native gas token, and the separate STABLE token is used for governance and security.
stableStable on the SwiftNodes fleet, right now
8 of 12 probed RPC methods supported (batch, debug_traceCall, eth_getProof, eth_getBlockReceipts). The gaps are listed per chain in the method support matrix.
Status and latency from our health checks, refreshed about every 5 minutes. Uptime history. Method support probed automatically on 2026-10-11. Network status
Stable developer facts, measured
- Block time:
- ~699 ms (average of the last 1,000 blocks)
- Finality:
- the latest block is already reported as finalized
- eth_getLogs range:
- 10,000-block ranges accepted; the next size we test was refused
- Historical state:
- readable 64 blocks back, not 10,000
Measured 2026-10-11 through this page's endpoint, re-measured weekly. Limits can differ between the upstream nodes behind it. All chains: measured chain facts.
About Stable
Stable mainnet launched in December 2025 together with the STABLE token and the independent Stable Foundation. Consensus is StableBFT, a proof-of-stake protocol built on CometBFT with deterministic single-slot finality. The v1.2.0 upgrade on February 4, 2026 made USDT0 the native gas token, replacing the earlier gUSDT model.
Stable is EVM-compatible, but it has quirks that matter at the RPC layer. USDT0 uses 18 decimals as the native gas balance and 6 decimals as an ERC-20 token, priority fees are ignored, there is no public mempool, trace_* methods are unsupported (use debug_*), and eth_getLogs is capped at 10,000 blocks per query.
Common Use Cases on Stable
- USDT payments and remittances
- Merchant settlement
- Stablecoin payroll and treasury transfers
- Payment apps that need gas paid in USDT
Stable Mainnet RPC URL (HTTP)
https://rpc.swiftnodes.io/rpc/stable?key=YOUR_API_KEYStable WebSocket RPC URL
wss://rpc.swiftnodes.io/ws/stable?key=YOUR_API_KEYQuick Start: Connect to Stable
cURL
curl -X POST https://rpc.swiftnodes.io/rpc/stable?key=YOUR_API_KEY \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_blockNumber","params":[],"id":1}'ethers.js
import { JsonRpcProvider } from "ethers";
const provider = new JsonRpcProvider(
"https://rpc.swiftnodes.io/rpc/stable?key=YOUR_API_KEY"
);
const blockNumber = await provider.getBlockNumber();
console.log("Stable block:", blockNumber);viem
import { createPublicClient, http } from "viem";
const client = createPublicClient({
transport: http("https://rpc.swiftnodes.io/rpc/stable?key=YOUR_API_KEY"),
});
const blockNumber = await client.getBlockNumber();web3.py
from web3 import Web3
w3 = Web3(Web3.HTTPProvider("https://rpc.swiftnodes.io/rpc/stable?key=YOUR_API_KEY"))
print("Stable block:", w3.eth.block_number)Add Stable to MetaMask
https://rpc.swiftnodes.io/rpc/stable?key=YOUR_API_KEYwss://rpc.swiftnodes.io/ws/stable?key=YOUR_API_KEYFeatures of SwiftNodes for Stable
- Load-balanced across multiple upstream nodes wherever a chain has more than one, with automatic failover
- Health-checked every 2 minutes with automatic failover
- Free tier available — no credit card or KYC required
- Flat-rate monthly pricing with no per-request fees
- HTTP and WebSocket support
- One API key works across all 75+ supported chains, including Stable
Rate Limits
| Plan | Price | HTTP req/s | WS msg/s |
|---|---|---|---|
| Free | $0/mo | 2 | 1 |
| Starter | $49/mo | 50 | 25 |
| Growth | $89/mo | 150 | 75 |
| Scale | $149/mo | 300 | 150 |
| Pro | $249/mo | 500 | 250 |
Frequently Asked Questions: Stable
What is the Stable chain ID?
The Stable mainnet chain ID is 988 (hex 0x3dc).
Why do USDT0 balances differ between eth_getBalance and the token contract?
USDT0 is represented with 18 decimals as the native gas balance and 6 decimals as an ERC-20. Normalize decimals before comparing the two.
Does Stable support trace_* RPC methods?
No. trace_* calls return -32601. Use the debug_* namespace for transaction tracing.
Related EVM chains
Explore RPC endpoints for other EVM networks on SwiftNodes:
Ready to start building on Stable? Connect your wallet and get a free API key in 30 seconds. No email or KYC required.