# Routheus

> Live DEX token prices and best-route swap quotes across 13 EVM chains (Base, Ethereum, Arbitrum, BSC, Optimism, Polygon and more). Sub-millisecond answers from our own real-time pool-state engine, not a proxy. Executable swap calldata (Permit2), simulation-verified quotes, chained-state arb quoting, token metadata, token search, DEX pools. For AI agents: pay per call in USDC on Base, Polygon, Arbitrum, Avalanche or Solana via x402 — no API keys, no subscription. From $0.001 per call; failed answers are free.

Payment: x402 v1 (X-PAYMENT) or v2 (PAYMENT-SIGNATURE), scheme `exact`, USDC on any of: base, polygon, arbitrum, avalanche, solana.
No API key. Request a paid endpoint, receive HTTP 402 with one payment option per network, sign one, retry. Only successful responses are charged; failed simulations and no-route answers are free.

FREE TIER: single-input `quote` (4/min per IP) and `quote` with `to=` calldata (2/min per IP) are free — no payment needed — but the full route (pool addresses, per-leg amounts) and simulation are hidden. Enough to test and even execute a swap; pay via x402 for full data + higher limits.

Chains ({chain} path segment — canonical slug, chain name or EIP-155 id all work, e.g. eth = ethereum = 1): arb, ava, base, ber, bsc, eth, gno, hem, hyp, opt, pol, rob, son, uni

## Endpoints (GET) — `quote` free tier as above, all else x402-paid

- `https://routheus.xyz/{chain}/api/router/quote` — Live DEX token price and best-route swap quote for any token pair by contract address: output amount and split routing, sub-millisecond from our own pool-state engine — not an aggregator proxy. Batch up to 50 amounts via amounts_in. — 0.005 USDC per input amount (10% off on multi-input batches) — params: token_in, token_out, amount_in (or amounts_in), slippage_bps
- `https://routheus.xyz/{chain}/api/router/quote` — Ready-to-sign DEX swap transaction: best route plus executable calldata (Permit2 supported), expected output and min-out at slippage. Add to=<recipient>; add with_permit2_data=true for a Permit2 template with signature placeholders. — 0.01 USDC per input amount (10% off on multi-input batches) — params: same as quote + to, with_permit2_data
- `https://routheus.xyz/{chain}/api/router/quote` — Simulation-verified swap quote — amount_out IS the onchain eth_call result, not an estimate. For agents that must not overquote. Failed simulations are free. — 0.02 USDC per simulated amount (10% off on multi-input batches) — params: same as quote/calldata + simulate=true
- `https://routheus.xyz/{chain}/api/router/quote` — EXCLUSIVE chained-state quoting for arbitrage sizing and MEV bundles (quote_on_top_of_amounts): final output as if prior in-flight swaps already executed, up to 8 chained amounts. No other x402 API offers this. — 0.03 USDC per request (not combinable with simulate or amounts_in) — params: same as quote/calldata + quote_on_top_of_amounts=a,b,c
- `https://routheus.xyz/{chain}/api/tokens/metadata` — ERC-20 token metadata by contract address: name, symbol, decimals, balance storage slot. Cache-only; unknown tokens return an error (never charged). — 0.003 USDC per request — params: token
- `https://routheus.xyz/{chain}/api/tokens/search` — Search tokens by symbol, name or contract address — resolve a ticker to the right contract before quoting; returns addresses and pool counts (paginated). — 0.003 USDC per request — params: query, page, page_size

## Discovery

- Info: https://routheus.xyz/x402/info
- OpenAPI: https://routheus.xyz/openapi.json
- Resources: https://routheus.xyz/.well-known/x402
- Chains: https://routheus.xyz/chain-peers
- MCP: https://routheus.xyz/mcp (free discovery tools)

## Contact

Higher rate limits, a custom/enterprise plan or a private deployment? Email contact@routheus.xyz.