JustHandled Agent Utility Gateway

io.github.justhandledlabsPublished by GitHub account justhandledlabsv0.11.1Updated Oct 24, 2026

Thirty-two guarded agent utilities and maintained-data lookups over USDC x402.

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Overview

AI-generated overview

A local MCP server exposing 32 guarded agent utilities and maintained-data lookups that are paid per call in USDC on Base.

What you can do
The package runs a local stdio MCP server that exposes a free catalog tool plus one paid tool per gateway utility. Products include preflights, maintained-data lookups, and evidence products, each returning a versioned evidence receipt. Paid calls are made over USDC x402 on Base mainnet, with an unpaid 402 preview performed first. The client fails closed before signing and pins the gateway, chain, asset, price, and merchant receiver.
When to use it
Worth adding when an assistant needs on-demand preflight checks or maintained-data evidence products, such as filename portability, API-response contract drift, webhook replay, or policy-change evidence. It suits users who already hold USDC on Base and want per-call metered access rather than a subscription.
Requirements
Runs locally via npx from the npm package @justhandledlabs/agent-client, so Node.js is required. A dedicated Base mainnet wallet funded with USDC is needed, supplied through the JH_EVM_PRIVATE_KEY environment variable. Network access to the JustHandled gateway and Base mainnet is required. Desktop only; no web executable.
Before you install
JH_EVM_PRIVATE_KEY is a private key that signs irreversible crypto transfers; the documentation says to use a dedicated low-balance wallet and never a primary one. Paid calls spend USDC: 22 products cost $0.05 and ten cost $0.25 per call. The gateway does not persist customer inputs or complete results, but maintained-data products may retain normalized public-source snapshots disclosed in the receipt.

Installation

In SourceWeft

  1. Open JustHandled Agent Utility Gateway in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

JustHandled Agent Client

A guarded CLI, JavaScript client, and local MCP server for the JustHandled Agent Utility Gateway. The package exposes thirty-two preflights, maintained-data lookups, and evidence products. Twenty-two products cost $0.05 USDC; ten evidence-heavy or maintained-data products cost $0.25, including the live Chicago Contract Change Packet. Every paid call returns a versioned evidence receipt.

The client fails closed before signing. It accepts only the pinned JustHandled gateway, Base mainnet, canonical Base USDC, the exact per-product price, and the published merchant receiver. Customer inputs and complete customer results are not persisted by the gateway; maintained public-source snapshots are labeled in the receipt.

Inspect without a wallet

bash
npx --package @justhandledlabs/agent-client justhandled-agent catalognpx --package @justhandledlabs/agent-client justhandled-agent preview filename-portability-preflight --json '{"paths":["CON.txt"]}'npx --package @justhandledlabs/agent-client justhandled-agent preview agent-run-evidence-pack --file agent-run-evidence-pack.sample.jsonnpx --package @justhandledlabs/agent-client justhandled-agent preview agent-distribution-readiness-pack --file agent-distribution-readiness-pack.sample.jsonnpx --package @justhandledlabs/agent-client justhandled-agent preview community-rule-credibility-preflight --file community-rule-credibility-preflight.sample.jsonnpx --package @justhandledlabs/agent-client justhandled-agent preview qualified-demand-ledger --file qualified-demand-ledger.sample.jsonnpx --package @justhandledlabs/agent-client justhandled-agent preview channel-fit-evidence-matrix --file channel-fit-evidence-matrix.sample.jsonnpx --package @justhandledlabs/agent-client justhandled-agent preview proof-to-channel-evidence-packet --file proof-to-channel-evidence-packet.sample.jsonnpx --package @justhandledlabs/agent-client justhandled-agent preview channel-experiment-postmortem --file channel-experiment-postmortem.sample.jsonnpx --package @justhandledlabs/agent-client justhandled-agent preview chicago-contract-change-packet --file chicago-contract-change-packet.sample.json

Preview performs an unpaid request and validates the returned x402 terms. It does not sign or spend.

The catalog includes API-response contract drift, webhook contract and replay, and policy-change evidence products. Packaged example inputs are available in examples/.

Machine-readable products, exact payment terms, and free deterministic fixtures are available from the gateway's product catalog, OpenAPI document, and sandbox index.

Execute one paid utility

Use a dedicated low-balance Base wallet. Never provide a primary wallet key.

bash
export JH_EVM_PRIVATE_KEY=0x...npx --package @justhandledlabs/agent-client justhandled-agent call filename-portability-preflight --json '{"paths":["CON.txt"]}'

PowerShell:

powershell
$env:JH_EVM_PRIVATE_KEY = "0x..."npx.cmd --package @justhandledlabs/agent-client justhandled-agent call filename-portability-preflight --json '{"paths":["CON.txt"]}'

MCP configuration

json
{  "mcpServers": {    "justhandled": {      "command": "npx",      "args": ["-y", "@justhandledlabs/agent-client"],      "env": {        "JH_EVM_PRIVATE_KEY": "0xDEDICATED_LOW_BALANCE_WALLET_KEY"      }    }  }}

The MCP server exposes a free catalog tool plus one paid tool per gateway utility. Missing wallet configuration produces an error instead of a payment attempt.

The package declares the official MCP Registry identity io.github.justhandledlabs/agent-gateway. Registry identity is discovery metadata only: installing or listing the server does not spend funds, and paid execution still requires a dedicated wallet plus the client's exact-term checks.

Security model

  • Price, chain, asset, receiver, and gateway origin are pinned in code.
  • The ten $0.25 products' 250,000-base-unit price is pinned separately from 50,000-base-unit checks.
  • Every execution starts with an unpaid 402 preview.
  • A mismatched term aborts before signing.
  • The package never prints the private key.
  • The gateway does not persist customer inputs or complete customer results. Maintained-data products may retain normalized public-source snapshots and disclose that state in the receipt.
  • Treat all crypto transfers as irreversible and fund only a dedicated wallet.

Development

bash
npm installnpm run check

The gateway implementation is intentionally not included in this client repository.

Source: README.md at commit e86ff30

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

1
  1. v0.11.1LatestSep 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 days25 pts

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

  • Auth declared10 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