Summary
Provides real-time gas price estimates across Ethereum, Base, Polygon, Arbitrum, and BSC through a single interface. Built on the x402 micropayment protocol, so you pay per query rather than dealing with API keys or subscriptions. The server exposes these estimates via SSE transport at a hosted endpoint, making it straightforward to integrate gas cost calculations into workflows where you need cross-chain fee data. Reach for this when you're building multi-chain tools, need to optimize transaction timing, or want to surface gas costs to users without maintaining your own node infrastructure or juggling multiple chain-specific APIs.
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Public tool metadata for what this MCP can expose to an agent.
1 tools
crypto_estimate_gasUse this when you need to compare gas prices across multiple EVM chains at once. Returns multi-chain gas estimates in JSON. 1. chains: array of chain gas data with chain name 2. low: gas price in gwe1 params
Use this when you need to compare gas prices across multiple EVM chains at once. Returns multi-chain gas estimates in JSON. 1. chains: array of chain gas data with chain name 2. low: gas price in gwe
Parameters* required
chainstringChain name: ethereum, base, polygon, arbitrum, bsc. Omit for all chains.
Gas Estimator API
Multi-chain gas prices in one call -- ETH, Base, Polygon, Arbitrum, BSC. Compare chains to find cheapest. 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.):
{
"mcpServers": {
"gas-estimator": {
"url": "https://gas-estimator.api.klymax402.com/mcp"
}
}
}
Quickstart -- HTTP (x402)
curl -X POST "https://gas-estimator.api.klymax402.com/api/estimate" \
-H "Content-Type: application/json" \
-d '{}'
# -> 402 Payment Required, with an x402 payment challenge in the response body
Any x402-aware client (@x402/fetch, x402-agent-tools, ATXP) handles the 402 -> sign -> retry cycle automatically.
Tools
| Tool | Method | Path | Price | Description |
|---|---|---|---|---|
crypto_estimate_gas | POST | /api/estimate | $0.005 | Get gas price estimates across multiple EVM chains with USD cost |
crypto_estimate_gas
Use this when you need to compare gas prices across multiple EVM chains at once. Returns multi-chain gas estimates in JSON.
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
chain | string | no | Chain name: ethereum, base, polygon, arbitrum, bsc. Omit for all chains. |
Returns
chains-- array of chain gas data with chain namelow-- gas price in gwei for slow confirmationmedium-- gas price in gwei for standard confirmationhigh-- gas price in gwei for fast confirmationtransferCostUsd-- estimated USD cost for a simple transfer on each chaincheapestChain-- which chain currently has the lowest gas cost
Example response:
{"chains":[{"chain":"base","low":0.005,"medium":0.008,"high":0.012,"transferCostUsd":0.01},{"chain":"ethereum","low":12.5,"medium":18.0,"high":25.0,"transferCostUsd":0.85}],"cheapestChain":"base"}
When to use: choosing the cheapest chain before a cross-chain transaction. Essential for multi-chain agents that need to optimize gas costs.
Not for: swap quotes (use dex_get_swap_quote), bridging (use bridge_find_best_route).
Example agent prompts
- "Compare gas prices across multiple EVM chains at once"
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
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Plug Mailtrap into your AI workflow and let it handle the email.
Connect Mailtrap MCP →Agent, run crypto. Access onchain data & trade routes via 1inch.
Install now →Make coding agent sessions - Searchable, Shareable, Vendor-neutral & Scored.
Try For Free →Your agent targets a perfect 10 Code Health score. Deterministic. Every commit.
Try For Free →Integrate web data into your AI product. One API to scrape website & brand data.
Get API Key Now →belt cli automatically finds the best tools and skills for your agent. image, video, music, tts...
one prompt install →