Gas Estimator API

io.github.Br0ski777Published by GitHub account Br0ski777v1.1.0Updated Nov 2, 2026

Multi-chain gas estimation — ETH, Base, Polygon, Arbitrum, BSC. x402 micropayment.

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Overview

AI-generated overview

Remote MCP endpoint that returns multi-chain EVM gas price estimates and USD transfer costs, paid per call via x402 USDC micropayments.

What you can do
  • Estimate gas prices across Ethereum, Base, Polygon, Arbitrum and BSC in one call, optionally limited to a single chain
  • Get low, medium and high gwei levels for slow, standard and fast confirmation
  • See the estimated USD cost of a simple transfer on each chain and which chain is currently cheapest
When to use it
Useful when an assistant needs to compare gas costs across EVM chains before a transaction, or when a multi-chain agent wants to pick the cheapest chain to send on. It is not for swap quotes or bridging routes.
Requirements
A remote MCP client pointed at the hosted endpoint; no API key or signup. Each call is paid per use in USDC on Base L2 through the x402 protocol, so an x402-capable client or funded wallet is needed to complete the payment challenge.
Before you install
Every call costs money ($0.005 per estimate) and is settled in USDC on Base, so a wallet with funds is exposed to the service; payment goes through third-party facilitators (Coinbase CDP, PayAI). No credentials are requested, but spending should be capped or monitored.

Installation

In SourceWeft

  1. Open Gas Estimator API in the dashboard and add it to a workspace.
  2. 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%2Fgas-estimator/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.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "gas-estimator-api": {
      "type": "sse",
      "url": "https://gas-estimator.api.klymax402.com/mcp"
    }
  }
}

README

Gas Estimator API

[MCP Server] [x402] [License: MIT]

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.):

json
{  "mcpServers": {    "gas-estimator": {      "url": "https://gas-estimator.api.klymax402.com/mcp"    }  }}

Quickstart -- HTTP (x402)

bash
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

ToolMethodPathPriceDescription
crypto_estimate_gasPOST/api/estimate$0.005Get 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

NameTypeRequiredDescription
chainstringnoChain name: ethereum, base, polygon, arbitrum, bsc. Omit for all chains.

Returns

  • chains -- array of chain gas data with chain name
  • low -- gas price in gwei for slow confirmation
  • medium -- gas price in gwei for standard confirmation
  • high -- gas price in gwei for fast confirmation
  • transferCostUsd -- estimated USD cost for a simple transfer on each chain
  • cheapestChain -- which chain currently has the lowest gas cost

Example response:

json
{"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.

License

MIT

Source: README.md at commit 7e01e61

Tools

0
SourceWeft has not read this server's tools yet.

Version history

1
  1. v1.1.0LatestSep 16, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • 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