Lumen Works Decoder

io.github.Dansgit2bv1.1.0Updated Oct 10, 2026

Decode/lint x402 payment headers, EIP-712 typed data and EVM calldata. Free tier; x402-paid HTTP.

VerifiedStreamable HTTPWeb executableDeveloper Tools Finance

Overview

AI-generated overview

Decodes and lints x402 payment headers, EIP-712 typed data, and EVM calldata through a remote MCP endpoint.

What it does: Exposes three tools: x402_lint decodes and checks x402 PAYMENT-REQUIRED, SIGNATURE and RESPONSE headers; eip712_decode returns the domain separator, digest and risk notes for typed data; calldata_decode resolves a selector via openchain/4byte lookup and decodes arguments. The same operations are also offered as POST JSON HTTP routes, with free paths under /v1/free/... and paid paths under /v1/... .
When to use it: Useful when debugging x402 payment flows, inspecting EIP-712 signing payloads, or reading raw EVM calldata during wallet, payment or smart-contract work. Worth adding if you want these decoders available to an assistant without running your own tooling.
Requirements: A remote streamable HTTP endpoint; no local runtime, package or declared authentication. The free tier allows 20 tool calls per hour per IP. Paid calls require x402 payment in USDC on Base mainnet; Celo payment options appear only when the server operator sets X402_CELO_API_KEY.

Before you install

Beyond the free hourly limit, tool calls return x402 payment requirements and paid routes cost 0.002 USDC per call on Base mainnet, so spending real funds is possible. The service is described as early-stage and unaudited. Decoded calldata and typed data are sent to a third-party remote server, and calldata decoding performs an external selector lookup.

Installation

In SourceWeft

Open Lumen Works Decoder in the dashboard and add it to a workspace.
Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "lumenworks-decoder": {
      "type": "http",
      "url": "https://lumenworks-x402-decoder.onrender.com/mcp"
    }
  }
}

README

Lumen Works Decoder API (x402)

Pay-per-call decoders, 0.002 USDC per call on Base mainnet via x402 (exact scheme, PayAI public facilitator). Author: Dan (Dansgit2b). Early-stage, unaudited.

Endpoint (POST JSON)	What
`/v1/x402/lint` `{header}`	decode + lint x402 PAYMENT-REQUIRED/SIGNATURE/RESPONSE
`/v1/eip712/decode` `{typedData}`	domain separator, digest, risk notes
`/v1/calldata/decode` `{data, signature?}`	selector, openchain/4byte lookup, decoded args

Free tier: same paths under /v1/free/... (20/hour/IP). Discovery: /, /.well-known/x402, /openapi.json, /llms.txt. payTo: 0xee9790cB3960952F585379F831a89b4e00B4029A.

End-to-end proof (local run, 2026-10-10): paid call settled on Base, tx 0xff4af45df7caeef958b77700e96ba94e5ed37d3bac6e8cf40d6528a9497d77d4.

Deploy: Render (render.yaml, free plan) or any Docker host (Dockerfile). Set PUBLIC_BASE to the public origin. No secrets needed (server only receives payments). License MIT.

MCP server

Remote MCP (streamable HTTP, stateless JSON): https://lumenworks-x402-decoder.onrender.com/mcp, with tools x402_lint, eip712_decode and calldata_decode. Free tier: 20 tool calls/hour/IP. After that the tool returns the x402 payment requirements for the matching paid HTTP endpoint (0.002 USD).

Celo

When X402_CELO_API_KEY (from the x402.celo.org dashboard) is set, every paid route also accepts USA₮ and USDC on Celo (eip155:42220), settled through Celo's hosted facilitator at api.x402.celo.org.

Source: README.md at commit 36f96a6

Tools

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Version history

v1.1.0LatestOct 10, 2026