x402-paywall-client

x402-paywall-client is a skill for Claude Code, Codex from moldy93/smard-x402-mcp. It costs 57 tokens per session (335 once invoked), scanned A, original, no licence file.

A skill for sending paid requests to x402-protected web APIs or MCP services. x402 is a payment method that uses an HTTP request header, with Base and USDC supported here.

In plain words
What is it for?
Creating payment headers, testing paywalled APIs, and demonstrating payment flows with Base or USDC.
Why use it?
It handles the payment step needed to test or call services that require payment before responding.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

Good fit Creating payment headers, testing paywalled APIs, and demonstrating payment flows with Base or USDC.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/moldy93/smard-x402-mcp/x402-paywall-client
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add moldy93/smard-x402-mcp --skill x402-paywall-client
Clone the repo
git clone --depth 1 https://github.com/moldy93/smard-x402-mcp

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for x402-paywall-client

README.md
[![agentmods](https://agentmods.dev/badge/skills/moldy93/smard-x402-mcp/x402-paywall-client/github.svg)](https://agentmods.dev/skills/moldy93/smard-x402-mcp/x402-paywall-client)
Your own site
<a href="https://agentmods.dev/skills/moldy93/smard-x402-mcp/x402-paywall-client"><img src="https://agentmods.dev/badge/skills/moldy93/smard-x402-mcp/x402-paywall-client/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for x402-paywall-client

Your own site · 80×15
<a href="https://agentmods.dev/skills/moldy93/smard-x402-mcp/x402-paywall-client"><img src="https://agentmods.dev/badge/skills/moldy93/smard-x402-mcp/x402-paywall-client.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 57 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 335 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00057 $0.00335
Opus 5 $0.00028 $0.00168
Sonnet 5 $0.00011 $0.00067
Haiku 4.5 $0.00006 $0.00034

Measured 11d ago against content hash 04740b374df1, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

x402-paywall-client scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/x402_pay.mjs), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/x402-paywall-client/SKILL.md · 40 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 11d ago First seen · 40 lines · 57 tokens per session scan A 04740b374df1

Subscribe to this mod's changes

x402-paywall-client is a skill published in the GitHub repository moldy93/smard-x402-mcp (0 stars, last pushed 7mo ago), with no licence file. It adds 57 tokens to every session and 335 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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