DEX Swap Quotes API
io.github.Br0ski777Published by GitHub account Br0ski777v1.1.0Updated Nov 2, 2026
Best swap quotes across DEXes (Uniswap, SushiSwap, Aerodrome). Base & Ethereum. x402.
Overview
Remote MCP endpoint that returns the best DEX swap quote across Uniswap, SushiSwap and Aerodrome on Base or Ethereum, paid per call via x402.
- What you can do
- Get the best swap quote for a token pair, with the winning DEX, expected output amount, price impact, minimum received after slippage, route and estimated gas cost in USD.
- Choose the chain (Base by default, or Ethereum) and pass token contract addresses plus a raw-unit amount.
- Same quote available as a GET or POST variant of the single quote tool.
- When to use it
- Useful when an assistant needs a pre-trade price check, route comparison or slippage estimate before swapping tokens on-chain on Base or Ethereum. Not intended for gas-only lookups, yield discovery or wallet balances, which the README points to other services for.
- Requirements
- A remote MCP client pointed at the server's endpoint; nothing to install locally. No API key or signup, but each call is paid in USDC on Base L2 through the x402 protocol, so an x402-aware client or wallet that can answer the 402 payment challenge is needed. Network access to the endpoint and to the payment facilitator.
Installation
In SourceWeft
- Open DEX Swap Quotes API in the dashboard and add it to a workspace.
- Enable the server for the chats that should use its tools.
Web executable via SSE. Remote servers run from the web runtime once configured in a workspace.
Use with an agent
Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.
Read https://sourceweft.com/mcp/io.github.Br0ski777%2Fdex-quotes/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.Other MCP clients
Add this to your client's mcpServers config.
{
"mcpServers": {
"dex-swap-quotes-api": {
"type": "sse",
"url": "https://dex-quotes.api.klymax402.com/mcp"
}
}
}README
DEX Swap Quotes API
[MCP Server] [x402] [License: MIT]
Best swap quotes across Uniswap, SushiSwap, Aerodrome -- price impact, route, slippage. Pre-trade essential. Pay-per-call via x402 (USDC on Base L2) -- no API key, no signup, no rate-limit wall.
Part of the klymax402 marketplace -- 100 x402 micropayment APIs for AI agents, one wallet, USDC on Base.
Quickstart -- MCP
Add to your MCP client config (Claude Desktop, Cursor, ElizaOS, etc.):
Quickstart -- HTTP (x402)
Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.
Tools
dex_get_swap_quote
Use this when you need a swap quote before trading tokens on-chain. Returns the best price across multiple DEXes in JSON.
Parameters
Returns
bestDex-- which DEX offers the best rate (Uniswap, SushiSwap, Aerodrome)amountOut-- expected output token amountpriceImpact-- percentage price impact of the trademinimumReceived-- minimum output after slippage toleranceroute-- swap path (e.g. USDC -> WETH -> TOKEN)gasEstimateUsd-- estimated gas cost in USD
Example response:
When to use: executing any token swap to find the best rate and estimate slippage. Essential for trade sizing and DEX comparison.
Not for: gas estimation only (use gas_get_current_price), yield opportunities (use defi_find_best_yields), wallet balance (use wallet_get_portfolio).
dex_get_swap_quote
Use this when you need a swap quote before trading tokens on-chain. Returns the best price across multiple DEXes in JSON. POST variant of dex_get_swap_quote -- same params passed as JSON body instead of query string.
Parameters
Returns
bestDex-- which DEX offers the best rate (Uniswap, SushiSwap, Aerodrome)amountOut-- expected output token amountpriceImpact-- percentage price impact of the trademinimumReceived-- minimum output after slippage toleranceroute-- swap path (e.g. USDC -> WETH -> TOKEN)gasEstimateUsd-- estimated gas cost in USD
Example response:
When to use: executing any token swap to find the best rate and estimate slippage. Essential for trade sizing and DEX comparison.
Not for: gas estimation only (use gas_get_current_price), yield opportunities (use defi_find_best_yields), wallet balance (use wallet_get_portfolio).
Example agent prompts
- "A swap quote before trading tokens on-chain"
- "A swap quote before trading tokens on-chain"
Payment
- Protocol: x402 -- HTTP-native pay-per-call, no signup, no API key
- Network: Base L2 (
eip155:8453) - Asset: USDC
- Facilitator: Coinbase CDP (primary), PayAI (fallback)
- Also reachable via ATXP (OAuth-wrapped x402, RFC 9728 protected-resource metadata)
Part of klymax402
100 x402 micropayment APIs for AI agents -- one wallet, USDC on Base, zero signup.
- Catalog: https://klymax402.com/llms.txt
- Full API reference: https://klymax402.com/llms-full.txt
- Live stats: https://klymax402.com/stats
License
MIT
Source: README.md at commit 6ada77f
Tools
0Version history
1- v1.1.0LatestSep 16, 2026
Score
50% of the applicable checks met
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- Reached in the last 30 daysRequired25 pts
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- Auth declaredRequired10 pts
Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.
- Tools listed15 pts
Answer tools/list without a credential, or ship a package that starts in a sandbox without one.
- DescriptionRequired15 pts
- Logo10 pts
- Documentation15 pts
- License10 pts